Laboratory reference values for healthy adults from southern Tanzania

Determine Complete Blood Count Reference Values Among Healthy Adult Populations

Background

Complete blood counts (CBC) are commonly used in diagnostic medicine to evaluate normal and abnormal hematological status. Furthermore, reference values (RVs) of CBC supplied by researchers are the most reliable means of the judgment-making stage and can aid interpretation and accurate diagnosis of diseases. Reference values vary between peoples because of differences in lifestyle, dietary habits, ethnicity and environment. Moreover, the Clinical and International Standards Institute (CISI) advises determining the RVs for each area. There are no RVs for CBC in Yemen. Therefore, this study aimed to determine the common RVs of CBC for healthy adults in Ibb City in the middle of Yemen.

Methods

A cross-sectional study was conducted from April 1, to November 30, 2023. Of the 623 adults who participated in this study, 433 (aged 18-80 years) were included in the final analysis after applying exclusion criteria. The mean, median, and 95th percentile RVs (2.5th-97.5th percentiles) were calculated for gender, age, and residence by the GraphPad Prism 8.0.1.

Results

The RVs of hemoglobin (Hb) 11.16-17.54g/dl, red blood cells (RBC) 3.890-6.340×1012/l, hematocrit (HCT) 33.03-49.30%), mean corpuscular volume (MCV) 72.83-94.55fl), mean corpuscular hemoglobin (MCH) 23.95-33.55pg, mean corpuscular hemoglobin concentration (MCHC) 32.97-36.7354g/dl, platelet (PLT) count 140.0-418.6×109/l, total white blood cells (WBC) 2.810-8.797 ×109/l and WBC differential count (basophils 0.000-1.000%, neutrophils 30.10-69.17%, eosinophils 1.500-5.000%, lymphocytes 23.86-63.45% and monocytes1.873-5.600%). Significantly higher median values were observed in males compared to females for Hb (P<0.0001), RBC (P<0.0001), HCT (P<0.0001), lymphocyte (P=0.0197) and monocytes (P=0.0009). Contrariwise, females demonstrated significantly higher neutrophils (P=0.0009), eosinophils (P=0.0020), basophils (P<0.0001) and platelets (P=0.0324) than males. This study showed differences in the RVs of CBC compared to those reported in other countries in the Middle East, Asia, Africa, and Europe.

Conclusion

In this study, the reference values of CBC are considered as a benchmark that may assist in accurately judging laboratory results and enhancing medical and clinical services for adults in Ibb City, Yemen.

Establishment of Reference Intervals for Common Renal and Liver Function Parameters in Healthy Adults in Mogadishu, Somalia: A Cross-Sectional Study

Introduction

Reference intervals (RIs) are crucial for the accurate interpretating of laboratory test results in clinical settings, serving as benchmarks for evaluating individual health status. This study investigates the influence of sex and age on common liver function tests (LFTs) and renal function tests (RFTs) in healthy adults in Mogadishu, Somalia.

Methods

A community-based cross-sectional study was carried out from October 2022 to January 2023 on a randomly selected sample of 255 healthy participants from Mogadishu, Somalia. Approximately 5 mL of whole blood was collected from each participant and processed screening of hepatitis B and C, and human immunodeficiency virus, and then biochemical analyses were conducted for common liver and kidney parameters.

Results

The study found significant sex and age-related differences in the measured LFTs and RFTs parameters. For LFTs, males had higher levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) compared to females (ALT: 11.5 vs 7.5 U/L; AST: 25.5 vs 19.1 U/L; both p < 0.001). Age-related differences were also observed, with individuals aged 30 and above had higher levels of ALT and AST compared to those aged 18-29 (ALT: 10.9 vs 8.5 U/L; AST: 24.3 U/L vs 21.0 U/L, both p < 0.001). For RFTs, males had higher levels of creatinine (0.9 vs 0.7 mg/dL), urea (23.1 vs 16.1 mg/dL), and uric acid (5.2 vs 4.2 mg/dL) than females, all with p < 0.001.

Conclusion

The study established population specific RIs for common liver and renal function parameters and revealed significant variations across sex and age groups. These findings underscore the importance of developing and using local RIs to ensure accurate clinical interpretation and effective patient management. Further research with larger sample sizes and in diverse regions of Somalia is highly recommended.

Reference intervals of complete blood count parameters in the adult western Sudanese population

BACKGROUND

A complete blood count (CBC) analysis is one of the most common conventional blood tests that physicians frequently prescribe.

THE OBJECTIVE

of this study was to determine the reference intervals (RIs) of CBC parameters in the population of healthy adults living in the western Sudan region.

METHODS

A cross-sectional study of healthy people residing in the western area of Sudan was carried out. We assessed the CBC RIs in samples taken from 153 individuals using an automated haematology analyser (Sysmex KX-21) and a modified Box-Cox transformation procedure to transform the data into a Gaussian distribution after eliminating outliers using the Dixon method. IBM SPSS Statistics version 25 was used to analyse the data, and t tests were employed to examine variations in the mean CBC parameters according to sex and age. P was considered significant at ≤ 0.05.

RESULTS

Beyond all the other measured values, the only CBC parameters that significantly differed between the sexes were haemoglobin (HGB) and white blood cell (WBC) counts. Women were found to experience more WBC counts than men did. However, they have less HGB RIs.The male participants in our study exhibited lower WBC count RIs, a significantly lower limit, and a greater upper limit of platelet RIs than did the individuals from other nations.

CONCLUSIONS

Compared with males, females had higher platelet and WBC counts and lower HGB.

Reference intervals of biochemical parameters in Chilean adults

Background

Establishing reference intervals (RIs) in clinical laboratories is essential, as these can vary due to inter-individual variability as well as the analytical methods used. The purpose of this study was to determine RIs for markers and ratios biochemical in apparently healthy Chilean adults.

Methods

A sample of 1,143 data was selected from the Universidad Católica de Temuco, Clinical Laboratory database, La Araucanía Region, Chile, which were analysed by sex. The Tukey's Fences was used to detect outliers and the RIs were established using the non-parametric method.

Reference Intervals of Haematological Parameters for Apparently Healthy Adults in Northeast Ethiopia

Background

Clinical laboratory reference intervals play a vital role in evaluating overall well-being, tracking the progression of diseases, and detecting potential harmful effects and complications. Despite evidence revealing disparities, many African nations currently rely on reference intervals for blood analysis obtained mainly from Western populations. This practice increases the risk of misidentifying and misdiagnosing healthy individuals. The aim of this study was to establish common hematological parameters reference intervals for healthy adults in Northeast Ethiopia.

Methods

This community-based cross-sectional study consisted of 328 individuals who were presumed to be in good health. To assess their blood-related characteristics, blood samples were collected and analyzed using the advanced Dirui BF-6500 analyzer, along with serological testing. In accordance with guidelines provided by the Clinical and Laboratory Standards Institute, the study employed a non-parametric approach to calculate the medians and 95% confidence intervals. To explore potential variations between males and females, a statistical test known as the Mann-Whitney U-test was used to compare the reference intervals.

Results

The established reference intervals were: white blood cells 3.5-11.3×109/L; red blood cells 4.0-6.1×1012/L; hemoglobin 11.2-17.5g/dL; hematocrit 35.4-52.0%; MCV 77.9-93.8fl; MCH 24.7-32.0pg; MCHC 306-349g/L; RDW-CV 12.1-13.8% and platelet 131-391×109/L. The reference values of monocytes, eosinophils, red blood cells, hemoglobin, hematocrit and RDW-CV in males were higher than females, while females had significantly higher platelet counts compared to males. The reference intervals discovered differed from the reference intervals now in use, those mentioned in earlier research in Ethiopia or other African nations, as well as those conducted on Western populations.

Conclusion

In the adult demographic of Northeast Ethiopia, specific reference intervals for commonly observed hematological parameters were established, tailored to the local community. Consequently, these reference intervals hold the potential to enhance informed decision-making within this population, by providing valuable guidance when interpreting laboratory test outcomes.

Assessment of immune cell profiles among post-menopausal women in the Women's Health Initiative using DNA methylation-based methods

BACKGROUND

Over the past decade, DNA methylation (DNAm)-based deconvolution methods that leverage cell-specific DNAm markers of immune cell types have been developed to provide accurate estimates of the proportions of leukocytes in peripheral blood. Immune cell phenotyping using DNAm markers, termed immunomethylomics or methylation cytometry, offers a solution for determining the body's immune cell landscape that does not require fresh blood and is scalable to large sample sizes. Despite significant advances in DNAm-based deconvolution, references at the population level are needed for clinical and research interpretation of these additional immune layers. Here we aim to provide some references for immune populations in a group of multi-ethnic post-menopausal American women.

RESULTS

We applied DNAm-based deconvolution to a large sample of post-menopausal women enrolled in the Women's Health Initiative (baseline, N = 58) or the ancillary Long Life Study (WHI-LLS, N = 1237) to determine the reference ranges of 58 immune parameters, including proportions and absolute counts for 19 leukocyte subsets and 20 derived cell ratios. Participants were 50-94 years old at the time of blood draw, and N = 898 (69.3%) self-identified as White. Using linear regression models, we observed significant associations between age at blood draw and absolute counts and proportions of naïve B, memory CD4+, naïve CD4+, naïve CD8+, memory CD8+ memory, neutrophils, and natural killer cells. We also assessed the same immune profiles in a subset of paired longitudinal samples collected 14-18 years apart across N = 52 participants. Our results demonstrate high inter-individual variability in rates of change of leukocyte subsets over this time. And, when conducting paired t tests to test the difference in counts and proportions between the baseline visit and LLS visit, there were significant changes in naïve B, memory CD4+, naïve CD4+, naïve CD8+, memory CD8+ cells and neutrophils, similar to the results seen when analyzing the association with age in the entire cohort.

CONCLUSIONS

Here, we show that derived cell counts largely reflect the immune profile associated with proportions and that these novel methods replicate the known immune profiles associated with age. Further, we demonstrate the value this methylation cytometry approach can add as a potential application in epidemiological studies.

Reference intervals for common clinical chemistry parameters in healthy adults of Northeast Ethiopia

BACKGROUND

Clinical chemistry reference intervals are important tools for health evaluation, diagnosis, prognosis and monitoring adverse events. Currently used reference intervals in most African countries including Ethiopia are mainly derived from Western populations, despite studies reporting differences that could lead to incorrect clinical decisions. The aim of this study was to establish reference intervals for commonly used clinical chemistry parameters for healthy adults in Northeast Ethiopia.

METHODS

A community based cross-sectional study was conducted among 328 apparently healthy adults between the ages of 18 and 57 years. Blood samples were collected for clinical chemistry analysis using Dirui CS-T240 auto-analyzer and serological testing to screen the population. Medians and 95% reference intervals were computed using non-parametric method according to the Clinical and Laboratory Standards Institute guideline. The Mann-Whitney U test was used to compare reference values between males and females.

RESULTS

Reference intervals established were: ALT 11.2-48.0 U/L, AST 16-60 U/L, ALP 53-342.3 U/L, total protein 5.4-8.9 mg/dL, total bilirubin 0.1-1.23 mg/dL, glucose 65-125 mg/dL, total cholesterol 69-213 mg/dL, triglycerides 46-207 mg/dL, creatinine 0.3-1.2 mg/dL and urea 9.5-46.3 mg/dL. Significant sex-differences were observed for ALT, AST, ALP, total cholesterol, triglycerides, creatinine and urea. We found that the established reference intervals substantially differ from the reference ranges currently in use. Up to 43.1% of apparently healthy adults are considered as having abnormal test values on the bases of the currently in use reference ranges. If the reference values from the United States based intervals were applied to the study population, 81.8% would have been classified as having abnormal laboratory test results.

CONCLUSIONS

Local population-specific reference intervals were established for commonly used clinical chemistry parameters in adult population of Northeast Ethiopia. Although further study is needed, these reference intervals may have the potential to facility the decision-making process based on laboratory test results in this population.

Hematological indices in the adult saudi population: Reference intervals by gender, age, and region

Introduction

Hematological parameters are critical in disease diagnosis, management, and monitoring; however, complete blood count (CBC) reference intervals vary across populations. The aim of the current study was to provide the reference ranges of hematological parameters/indices in the healthy adult Saudi population.

Methods

A multicenter retrospective cross-sectional study was conducted with a sample of employees who were screened pre-employment from January 2015 to December 2019, at tertiary care hospitals in three regions. Demographic and CBC data were extracted from the electronic health system. The 2.5^th and 97.5^th percentiles were used to determine the reference intervals.

Results

Of a total of 1,388 participants, 53.82% were male. The majority 96% was less than 40 years old, and 85% were from the Central region. Gender-related differences were observed for the RBC count, Hb, HCT, MCV, MCH, MCHC, and the platelet count. Age-related differences were observed for the RBC, Hb, HCT, and eosinophils. The WBC parameters did not differ by gender or age categories. Region-related differences were observed for the RBC, hemoglobin, HCT, MCV, WBC, and basophils. The platelet count was higher in the female group, the age group 40 years and above, and in the Western region. The prevalence of anemia was high in the female group and the Eastern region. The overall neutropenia rate was 12.8%.

Conclusion

The data from this study provide hematological parameter reference ranges for the adult Saudi population by gender, age, and region. Gender and age-related differences were observed for the hematological parameters. Anemia was more frequent in the female group and the Eastern region. Caution must be taken when comparing or interpreting results from different age groups, gender, region of origin, and ethnicity.

Reference Intervals for Common Renal and Liver Function Clinical Chemistry Parameters Among Apparently Healthy Pregnant and Non-pregnant Women in South Wollo Zone, Amhara National Regional State, Northeast Ethiopia

Background

Physiological changes during pregnancy cause alterations in concentration of biochemical analytes. Thus, locally established pregnancy-specific reference intervals are important for accurate diagnosis, treatment, and prognosis of diseases. The objective of the study was to establish reference interval for the common renal and liver function clinical chemistry parameters among pregnant and non-pregnant women of South Wollo zone, Ethiopia.

Methods

A community-based cross-sectional study was conducted on a total of 323 apparently healthy study participants randomly selected from South Wollo zone, Ethiopia, from April to June 2019. Medical history, physical examination and sociodemography were collected by using questionnaire. Liver and renal function clinical chemistry tests were done using A25 Biosystems, clinical chemistry analyzer. After the exclusion of outliers, Kolmogorov–Smirnov test was used to check its normality. The 95% RI with 95% confidence interval was established using the nonparametric method. The significance of differences was evaluated using Mann–Whitney U test.

Result

There was statistically significant variation between pregnant and non-pregnant women in values of albumin, T. protein, ALP, urea and creatinine, but not for AST, ALT, bilirubin (direct) and bilirubin (total). Reference intervals established for pregnant women includes albumin 26.14–42.87g/L, total protein 48.52–74.71 g/L, AST 2.4–43.6 U/L, ALT 0.94–28.35 U/L, ALP 21.2–337 U/L, bilirubin (direct) 0.03–0.32 mg/dL, bilirubin (total) 0.26–0.94 mg/dL, creatinine 0.29–0.87 mg/dL, urea 7.17–20.82 mg/dL. Albumin: 32.81–47.87, total protein: 56.71–83.9 U/L, AST: 4.2–37.1 U/L, ALT: 2.69–41.18 U/L, ALP: 3.22–278.7 U/L, bilirubin (direct) 0.1–0.51 mg/dL, bilirubin (total) 0.24–1.06 mg/dL, creatinine 0.44–1.00 mg/dL, urea 8.07–27.87 mg/dL for non-pregnant women.

Conclusion

The study showed marked difference in albumin, total protein, alkaline phosphatase, urea and creatinine. Therefore, physiological adaptations of pregnancy should be considered when interpreting liver and renal function tests in a pregnant woman.

Reference range of serum uric acid and prevalence of hyperuricemia: a cross-sectional study from baseline data of ELSA-Brasil cohort

Background

Most of the few studies that have established reference ranges for serum uric acid (SUA) have not taken into account factors which may interfere with its levels and followed rigorous laboratory quality standards. The aim of this study was to establish reference ranges for SUA and determine the prevalence of hyperuricemia.

Method

Cross-sectional study including 15,100 participants (all sample) aged 35 to 74 years from baseline data of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicentric cohort of volunteer civil servants from five universities and one research institute located in different regions of Brazil. It was established a reference sample excluding participants with factors that directly influence SUA levels: glomerular filtration rate lower than 60 ml/min, excessive alcohol intake, use of diuretics, aspirin, estrogen or urate-lowering therapy. SUA was measured using the uricase method and following rigorous international quality standards. Reference ranges were defined as values between percentiles 2.5 (P2.5) and 97.5 (P97.5) of SUA distribution in the reference sample, stratified by sex. Hyperuricemia was defined as SUA ≥ 7 mg/100 ml in the all sample.

Results

The reference sample was composed of 10,340 individuals (55.3% women, median age 50 years). Reference ranges (P2.5 to P97.5) for SUA were: 4.0 to 9.2 mg/100 ml for men and 2.8 to 6.9 mg/100 ml for women. Sex was a major determinant for SUA levels (median [IQR], mg/100 ml: 6.1 [5.3–7.0] for men versus 4.5 [3.9–5.3] for women, p < 0.001). Higher levels of SUA were found in patients with higher BMI. Higher age had (a modest) influence only for women. The prevalence of hyperuricemia for all sample (N = 15,100) was 31.9% (95% confidence interval [CI] 30.8–33.0%) in men and 4.8% (95% CI 4.3–5.3%) in women.

Conclusion

SUA reference ranges were 4.0 to 9.2 mg/100 ml for men and 2.8 to 6.9 mg/100 ml for women. Prevalence of hyperuricemia was 31.9% in men and 4.8% in women. Updated SUA reference ranges and prevalence of hyperuricemia are higher nowadays and might be used to guide laboratories and the screening for diseases related to SUA.

Hematologic reference intervals for healthy adult Saudis in Riyadh

BACKGROUND

Laboratory hematological tests are widely used in clinical practice to assess health and disease conditions. Reference ranges provided by laboratory reports are considered the most authoritative medical tools to assist in the decision-making phase. International standards institutes recommend that reference ranges be established for each region.

OBJECTIVES

Provide reference values of routine hematological parameters in Saudi adults according to age and gender.

DESIGN

Cross-sectional SETTING: Central province of Saudi Arabia.

PATIENTS AND METHODS

Apparently healthy Saudi adults were subjected to laboratory testing of routine hematological parameters (full blood count, hemostatic profile, and serum hematinics), after completing a detailed health medical questionnaire.

MAIN OUTCOME MEASURES

Hematological reference values based on the local population.

SAMPLE SIZE AND CHARACTERISTICS

637 after screening 827 potentially healthy Saudi adults with ages ranging from 15 to 65 years.

RESULTS

The reference values of routine hematological parameters for the full population and by gender are presented with 90% CI as the lower and upper limits. Reference ranges mostly differed from universal established ranges shown in textbooks.

CONCLUSION

The reference ranges of routine hematologic parameters for accurate assessment and appropriate management will help improve the routine clinical care of the adult Saudi population.

LIMITATIONS

Difficulty in assessing health status of participants, who could have subclinical illnesses not reflected in the evaluated blood measurement. Lack of ability to eliminate individuals who might be carriers for haemoglobinopathies. Studies with larger sample sizes from different areas of the country are required to achieve a more accurate representation of the whole Saudi population.

CONFLICT OF INTEREST

None.

Establishment of dry chemistry based reference intervals of renal function test parameters for the adult population of Kaski District, Nepal

Background

Reference intervals (RIs) for clinical chemistry test parameters are specific to the method of measurement and population under service. However, there has been no locally available dry chemistry based RIs for the Nepalese population. Thus, the present study aimed to establish dry chemistry based RIs for sodium, potassium, urea, and creatinine specific to adult populations of Kaski districts, Nepal

Methods

This was a cross-sectional study conducted at the Manipal Teaching Hospital, Pokhara, Kaski, Nepal on 360 healthy adult participants aged 18–65 years. The test parameters under study were analyzed using a fully automated OCD Vitros 350 dry chemistry analyzer following the protocols provided by the reagent kit manufacturer. The RIs were estimated using reference limits at 2.5th and 97.5th percentiles. The normal distribution of the data was tested by Kolmogorov–Smirnov, and Shapiro–Wilk tests. The differences between males and females RIs were compared by the Mann-Whitney test while age-specific RIs for each sex was compared by One-Way-ANOVA and Dunnett’s Multiple Comparisons Tests. All the data were managed and analyzed using MS Excel and SPSS version 20.

Results

The RIs of urea, creatinine, sodium, and potassium specific to the adult population of Kaski district, Nepal are as follows: urea: 4.20–13.70 mmol/L (males: 4.70–13.99; females: 4.20–13.23); creatinine: 44.20–106.10 μmol/L (males: 48.82–106.10; females: 35.40–83.78); sodium 135–146 mmol/L (males: 135–146; females: 135–146) and potassium 3.60–5.10 mmol/L (males: 3.54–5.0; females: 3.60–5.10). These RIs were found to be different from currently used RIs provided by the reagent manufacturer. RIs of all the test parameters were significantly influenced by the age of the study participants. However, only the RIs of urea, creatinine, and potassium were significantly influenced by sex.

Conclusions

The present study has for the first time established dry chemistry based RIs for selected renal function test parameters specific to the adult population of Kaski district, Nepal. This result will aid the clinician in minimizing the errors in result interpretation and making a precise clinical decision.

Clinical laboratory reference values in adults in Kisumu County, Western Kenya; hematology, chemistry and CD4

BACKGROUND

Clinical laboratory reference intervals (RIs) are essential for diagnosing and managing patients in routine clinical care as well as establishing eligibility criteria and defining adverse events in clinical trials, but may vary by age, gender, genetics, nutrition and geographic location. It is, therefore, critical to establish region-specific reference values in order to inform clinical decision-making.

METHODS

We analyzed data from a prospective observational HIV incidence cohort study in Kombewa, Kenya. Study participants were healthy males and females, aged 18-35 years, without HIV. Median and 95% reference values (2.5th percentile to 97.5th percentile) were calculated for laboratory parameters including hematology, chemistry studies, and CD4 T cell count. Standard Deviation Ratios (SDR) and Bias Ratios (BR) are presented as measures of effect magnitude. Findings were compared with those from the United States and other Kenyan studies.

RESULTS

A total of 299 participants were analyzed with a median age of 24 years (interquartile range: 21-28). Ratio of males to females was 0.9:1. Hemoglobin range (2.5th-97.5th percentiles) was 12.0-17.9 g/dL and 9.5-15.3 g/dL in men and women respectively. In the cohort, MCV range was 59-95fL, WBC 3.7-9.2×103/μL, and platelet 154-401×103/μL. Chemistry values were higher in males; the creatinine RI was 59-103 μmol/L in males vs. 46-76 μmol/L in females (BRUL>.3); and the alanine transferase range was 8.8-45.3 U/L in males vs. 7.5-36.8 U/L in females (SDR>.3). The overall CD4 T cell count RI was 491-1381 cells/μL. Some parameters including hemoglobin, neutrophil, creatinine and ALT varied with that from prior studies in Kenya and the US.

CONCLUSION

This study not only provides clinical reference intervals for a population in Kisumu County but also highlights the variations in comparable settings, accentuating the requirement for region-specific reference values to improve patient care, scientific validity, and quality of clinical trials in Africa.

Clinical laboratory hematology reference values among infants aged 1month to 17 months in Kombewa Sub-County, Kisumu: A cross sectional study of rural population in Western Kenya

There is an urgent need for reliable region-specific hematological reference values for clinical monitoring. Laboratory reference ranges are important for assessing study participant eligibility, toxicity grading and management of adverse events in clinical trials and clinical diagnosis. Most clinical laboratories in Kenya rely on hematological reference values provided by instrument manufacturers and/or textbooks, which are based on population from Europe or North America. The use of such values in medical practice could result in improper patient management, selection bias in selection of appropriate participants for clinical trials and flawed classification of the clinical adverse events when applied to African populations. The aim of this study was to establish local laboratory hematological reference values in infants aged 1 month to 17 months from Kombewa Sub-county that could be true representative of the existing rural population. The study participants in the current study were those who had previously been recruited from GSK-sponsored study. This study was a phase III, Double Blind, Randomized, GSK-sponsored, Malaria Vaccine Clinical Trial that was conducted in infants aged 1month to 17months. 1,509 participants were included in the study analysis. Data were partitioned into 3 different age groups (1-6 months[m], 6-12 m and 12-17 m) and differences between gender were compared within each group. Data were analyzed using Graphpad prism V5 to generate 95% reference ranges (2.5th-97.5th percentile). There was evidence of gender differences in hemoglobin values (p = 0.0189) and platelet counts (p = 0.0005) in the 1 to 6m group. For the 12-17m group, there were differences in MCV (p<0.0001) and MCH (p = 0.0003). Comparing gender differences for all age groups, differences were noted in percent lymphocytes (p = 0.0396), percent monocytes (p = 0.0479), percent granulocytes (p = 0.0044), hemoglobin (p = 0.0204), hematocrit (p = 0.0448), MCV (p = 0.0092), MCH (p = 0.0089), MCHC (p = 0.0336) and absolute granulocytes (p = 0.0237). In 1 to 6m age group and all age groups assessed, for WBCs, hemoglobin, hematocrit, MCV and lymphocytes absolute counts, both 2.5th and 97.5th percentiles for Kisumu infants were higher than those from Kilifi. Platelet ranges for Kisumu children were narrower compared to Kilifi ranges. Kisumu hematology reference ranges were observed to be higher than the ranges of Tanzanian children for the WBCs, absolute lymphocyte and monocyte counts, hemoglobin, hematocrit and MCV. Higher ranges of WBCs, absolute lymphocyte and monocyte counts were observed compared to the values in US/Europe. Wider ranges were observed in hemoglobin, hematocrit, and MCV. Wider ranges were observed in platelet counts in Kisumu infants compared to the US/Europe ranges. Compared to Harriet Lane Handbook reference values that are used in the area, higher counts were observed in WBC counts, both absolute and percent lymphocyte counts, as well as monocyte counts for current study. Wider ranges were observed in RBC, platelets and RDW, while lower ranges noted in the current study for hemoglobin, hematocrit and granulocyte counts. This study underscores the importance of using locally established hematology reference ranges of different age groups in support of proper patient management and for clinical trials.

Adult and paediatric haematology and clinical chemistry laboratory reference limits for Liberia

Background

As more research is conducted in Liberia, there is a need for laboratory reference limits for common chemistry and haematology values based on a healthy population. Reference limits from the United States may not be applicable.

Objective

The aim of this study was to present laboratory reference ranges from a Liberian population and compare them to United States ranges.

Methods

Serum chemistry and haematology values from 2529 adults and 694 children and adolescents obtained from two studies conducted in Liberia between 2015 to 2017 were used to determine reference limits. After removing outliers, the reference limits defined by the 2.5th and 97.5th percentiles were determined by sex in three age groups (6–11, 12–17, and 18+ years).

Results

The median (interquartile range) of adults was 29 (23, 37) years; 44% were female. The median (interquartile range) for children and adolescents was 12 (9, 15) years; 53% were female. Several reference ranges determined using Liberian participants differed from those in the US. For chemistries, a high percentage of both adults and children/adolescents had high serum chloride levels based on United States ranges. For haematology, a high percentage of Liberian participants had haemoglobin and related assays below the lower limit of United States ranges.

Conclusion

Chemistry and haematology reference intervals determined for a Liberian population of healthy individuals should be considered for establishing eligibility criteria and monitoring of laboratory adverse events for clinical trials as well as for use in clinical settings in Liberia and perhaps for other countries in Western Africa.

Establishing Ghanaian adult reference intervals for hematological parameters controlling for latent anemia and inflammation

Background

In Ghana, diagnostic laboratories rely on reference intervals (RIs) provided by manufacturers of laboratory analyzers which may not be appropriate. This study aimed to establish RIs for hematological parameters in adult Ghanaian population.

Methods

This cross‐sectional study recruited 501 apparently healthy adults from two major urban areas in Ghana based on the protocol by IFCC Committee for Reference Intervals and Decision Limits. Whole blood was tested for complete blood count (CBC) by Sysmex XN‐1000 analyzer, sera were tested for iron and ferritin by Beckman‐Coulter/AU480, for transferrin, vitamin‐B12, and folate was measured by Centaur‐XP/Siemen. Partitioning of reference values by sex and age was guided by “effect size” of between‐subgroup differences defined as standard deviation ratio (SDR) based on ANOVA. RIs were derived using parametric method with application of latent abnormal values exclusion method (LAVE), a multifaceted method of detecting subjects with abnormal results in related parameters.

Results

Using SDR ≥ 0.4 as a threshold, RIs were partitioned by sex for platelet, erythrocyte parameters except mean corpuscular constants, and iron markers. Application of LAVE had prominent effect on RIs for majority of erythrocyte and iron parameters. Global comparison of Ghanaian RIs revealed lower‐side shift of RIs for leukocyte and neutrophil counts, female hemoglobin and male platelet count, especially compared to non‐African countries.

Conclusion

The LAVE effect on many hematological RIs indicates the need for deliberate secondary exclusion for proper derivation of RIs. Obvious differences in Ghanaian RIs compared to other countries underscore the importance of country‐specific RIs for improved clinical decision‐making.

Haematological and Biochemical Reference Values for Healthy Population of Maferinyah Rural Community in Guinea

Guinea's reference ranges for biological parameters rely on those of Caucasian values. Variability in reference ranges according to the context is well-documented. We conducted this study for the purpose of future malaria clinical trials that assess the efficacy and safety of malaria drugs. A repeated cross-sectional study was carried out, in an apparently healthy cohort population. Surveys took place in Maferinyah rural community, which is located at 75 km from the capital. The 2.5^th and 97.5^th percentiles were determined nonparametrically and stood for reference intervals. Reference values were determined separately for males and females according to ranges of age (6-10 years of age; 11-15 years of age; 16-45 years of age). Differences between genders were tested using the Mann-Whitney test, while the Friedman test was performed to test differences within each gender group according to the seasons. A total of 450 volunteers were enrolled. The median age was 13. Males 16-45 years of age had significantly higher hematologic and biochemical values compared to a female of the same age (for hematological parameters: Mean Cell Hemoglobin Concentration MCHC p ≤ 0.001, Platelets p ≤ 0.001, monocytes p = 0.0305, eosinophils p = 0.0225; for biochemical parameters: Aspartate aminotransferase AST p ≤ 0.001, Alanine Aminotransferase ALT p ≤ 0.001, creatinine p ≤ 0.001). We noticed significant seasonal variations for all the biochemical parameters and some hematologic parameters (Mean Corpuscular Hemoglobin MCH, MCHC, Mean Cell volume). This is the first study establishing hematologic and biochemical parameters in Guinea. These findings provide a useful guide for the clinical researchers and care providers. Studies on large scale and in different settings would be also desirable.

Determining hematological, biochemical and immunological reference values in healthy adults with high-risk for HIV acquisition in Mozambique

Introduction

In many African countries, laboratory reference values are not established for the local healthy adult population. In Mozambique, reference values are known for young adults (18-24yo) but not yet established for a wider age range. Our study aimed to establish hematological, biochemical and immunological reference values for vaccine trials in Mozambican healthy adults with high-risk for HIV acquisition.

Methods

A longitudinal cohort and site development study in Mozambique between November 2013 and 2014 enrolled 505 participants between 18 to 35 years old. Samples from these healthy participants, were analyzed to determine reference values. All volunteers included in the analysis were clinically healthy and human immunodeficiency virus (HIV), hepatitis B and C virus, and syphilis negative. Median and reference ranges were calculated for the hematological, biochemical and immunological parameters. Ranges were compared with other African countries, the USA and the US National Institute of Health (NIH) Division of AIDS (DAIDS) toxicity tables.

Results

A total of 505 participant samples were analyzed. Of these, 419 participants were HIV, hepatitis B and C virus and syphilis negative including 203 (48.5%) females and 216 (51.5%) males, with a mean age of 21 years. In the hematological parameters, we found significant differences between sex for erythrocytes, hemoglobin, hematocrit, MCV, MCH and MCHC as well as white blood cells, neutrophils and platelets: males had higher values than females. There were also significant differences in CD4⁺T cell values, 803 cells/μL in men versus 926 cells/μL in women. In biochemical parameters, men presented higher values than women for the metabolic, enzymatic and renal parameters: total and direct bilirubin, ALT and creatinine.

Conclusion

This study has established reference values for healthy adults with high-risk for HIV acquisition in Mozambique. These data are helpful in the context of future clinical research and patient care and treatment for the general adult population in the Mozambique and underline the importance of region-specific clinical reference ranges.

Comparison of Lymphocyte Subset Populations in Children From South Africa, US and Europe

Background: Typically, African healthcare providers use immunological reference intervals adopted from Europe and the United States (US). This may be inappropriate in a setting with many differences including exposure to different environmental stimuli and pathogens. We compared immunological reference intervals for children from Europe and the US with South African children to explore whether healthy children living in settings with high rates of infectious diseases have different baseline immunological parameters. Methodology: Blood was taken from 381 HIV-uninfected children aged between 2 weeks and 13 years of age from a Child Wellness Clinic in an informal settlement in Cape Town to establish local hematological and lymphocyte reference intervals for South African children. Flow-cytometry quantified percentage and absolute counts of the B-cells, NK-cells, and T-cells including activated, naïve, and memory subsets. These parameters were compared to three separate studies of healthy children in Europe and the US. Results: Increased activated T-cells, and natural killer cells were seen in the younger age-groups. The main finding across all age-groups was that the ratio of naïve/memory CD4 and CD8 T-cells reached a 1:1 ratio around the first decade of life in healthy South African children, far earlier than in resource-rich countries, where it occurs around the fourth decade of life. Conclusions: This is the largest data set to date describing healthy children from an African environment. These data have been used to create local reference intervals for South African children. The dramatic decline in the naïve/memory ratio of both CD4 and CD8 T-cells alongside increased activation markers may indicate that South African children are exposed to a wider range of environmental pathogens in early life than in resource-rich countries. These marked differences illustrate that reference intervals should be relevant to the population they serve. The implications for the developing pediatric immune system requires further investigation.

Assessment of the AQUIOS flow cytometer - An automated sample preparation system for CD4 lymphocyte PanLeucogating enumeration

Background

Flow cytometry has been the approach of choice for enumerating and documenting CD4-cell decline in HIV monitoring. Beckman Coulter has developed a single platform test for CD4+ T-cell lymphocyte count and percentage using PanLeucogating (PLG) technology on the automated AQUIOS flow cytometer (AQUIOS PLG).

Objectives

This study compared the performance of AQUIOS PLG with the Flowcare PLG method and performed a reference interval for comparison with those previously published.

Methods

The study was conducted between November 2014 and March 2015 at 5 different centres located in Canada; Paris, France; Lyon, France; the United States; and South Africa. Two-hundred and forty samples from HIV-positive adult and paediatric patients were used to compare the performances of AQUIOS PLG and Flowcare PLG on a FC500 flow cytometer (Flowcare PLG) in determining CD4+ absolute count and percentage. A reference interval was determined using 155 samples from healthy, non-HIV adults. Workflow was investigated testing 440 samples over 5 days.

Results

Mean absolute and relative count bias between AQUIOS PLG and Flowcare PLG was −41 cells/µL and −7.8%. Upward and downward misclassification at various CD4 thresholds was ≤ 2.4% and ≤ 11.1%. The 95% reference interval (2.5th – 97.5th) for the CD4+ count was 453–1534 cells/µL and the percentage was 30.5% – 63.4%. The workflow showed an average number of HIV samples tested as 17.5 per hour or 122.5 per 8-hour shift for one technician, including passing quality controls.

Conclusion

The AQUIOS PLG merges desirable aspects from conventional flow cytometer systems (high throughput, precision and accuracy, external quality assessment compatibility) with low technical operating skill requirements for automated, single platform systems.

Hypertensive disorders of pregnancy are associated with an inflammatory state: evidence from hematological findings and cytokine levels

Background

Abnormalities of blood cell counts and of cytokine profiles in women with hypertensive disorders of pregnancy (HDP) have been reported in several studies. Although their cause-effect relationships to HDP are not yet clear, detecting and monitoring these alterations can be of use for prognosis and management of HDP. This study aimed to determine hematological, coagulation and cytokine profiles in hypertensive as compared to normotensive pregnancy and to identify correlations between these profiles.

Methods

This was a hospital-based comparative cross-sectional study conducted from September 2017 to February 2018. There were two groups: the comparison group consisted of 77 normotensive pregnant women attending the antenatal clinic of Muhimbili National Hospital (MNH); the index group consisted of 76 hypertensive pregnant women admitted to the maternity block of the same hospital. Hematological and cytokine parameters were compared between the hypertensive and the normotensive group. We analyzed the data using Student’s independent t-test when the data were normally distributed; and the Mann–Whitney U-test when the data were not normally distributed. Kruskal Wallis with Dunn’s multiple comparison tests was run for subgroup analysis and correlation studies were done using Spearman ranking.

Results

Hemoglobin levels were slightly but significantly lower, (P < 0.01) in women with HDP compared to normotensive (N) women; the same was true for platelet counts (P < 0.001). The red cell distribution width (RDW) was slightly but significantly higher in HDP than in N. Neutrophil counts and Interleukin 6 (IL-6) levels were significantly (P < 0.001) higher in HDP than in N; and within HDP IL-6 levels increased with increasing severity of HDP. A novel remarkable finding was that eosinophil counts, normal in N, were lower and lower with increasing severity of HDP, to the point that they were nearly absent in women with eclampsia.

Conclusion

There are significant changes in hematological, cytokine and coagulation parameters in pregnant women with hypertensive disorders compared to normotensive pregnant women. The picture that emerges is that of an inflammatory state associated with hypertensive disorders of pregnancy.

The increase in hemoglobin concentration with altitude varies among human populations

Decreased oxygen availability at high altitude requires physiological adjustments allowing for adequate tissue oxygenation. One such mechanism is a slow increase in the hemoglobin concentration ([Hb]) resulting in elevated [Hb] in high-altitude residents. Diagnosis of anemia at different altitudes requires reference values for [Hb]. Our aim was to establish such values based on published data of residents living at different altitudes by applying meta-analysis and multiple regressions. Results show that [Hb] is increased in all high-altitude residents. However, the magnitude of increase varies among the regions analyzed and among ethnic groups within a region. The highest increase was found in residents of the Andes (1 g/dL/1000 m), but this increment was smaller in all other regions of the world (0.6 g/dL/1000 m). While sufficient data exist for adult males and females showing that sex differences in [Hb] persist with altitude, data for infants, children, and pregnant women are incomplete preventing such analyses. Because WHO reference values were originally based on [Hb] of South American people, we conclude that individual reference values have to be defined for ethnic groups to reliably diagnose anemia and erythrocytosis in high-altitude residents. Future studies need to test their applicability for children of different ages and pregnant women.

Establishment of reference values for selected haematological parameters in young adult Nigerians

BACKGROUND

Haematological reference values are necessary for accurate diagnosis of diseases, clinical decision-making, treatment monitoring and clinical research. Due to unavailability of pan-Nigerian reference values, local results interpretation is based on the use of Western values.

OBJECTIVE

This study aims to establish national reference values for some haematological parameters in apparently healthy young adult Nigerians.

METHODS

Seven Thousand, Seven Hundred and Ninety-Seven (7,797) volunteers aged 18 to 26 years participated in the study. Participants' interviewer-administered questionnaires and blood samples were collected, analyzed and those with confounding factors (HIV infection, Hepatitis B sero-positivity, Malaria and Pregnancy) were excluded from statistical analysis. The 95-percentile reference range was determined for each haematological parameter using SPSS Version 16®. The result obtained was reviewed with reference to already established reference values in two West African and Western countries.

RESULTS

Blood specimens from 6153 (78.9%) participants [comprising 5915 (96.1%) males and 238 (3.9%) females] were analyzed after exclusion of 1,644 (21.1%) participants with confounding variables. Reference ranges among males and females varied and these were consistent with findings from two other West African countries. The median platelets count in this study was 218 x 109/l while commonly used Western value is 280 x 109/l. Other haematological parameters in the study were similar to Western values.

CONCLUSION

The findings of this study will improve clinical and research decision-making. Considering that this study is limited to young adult participants, there is a need to conduct future pan-Nigerian studies that will include all age groups.

Determination of Haematological Reference Ranges in Healthy Adults in Three Regions in Ghana

Laboratory results interpretation for diagnostic accuracy and clinical decision-making in this period of evidence-based medicine requires cut-off values or reference ranges that are reflective of the geographical area where the individual resides. Several studies have shown significant differences between and within populations, emphasizing the need for population-specific reference ranges. This cross-sectional experimental study sought to establish the haematological reference values in apparently healthy individuals in three regions in Ghana. Study sites included Nkenkaasu, Winneba, and Nadowli in the Ashanti, Central, and Upper West regions of Ghana, respectively. A total of 488 healthy participants were recruited using the Clinical and Laboratory Standards Institute (United States National Consensus Committee on Laboratory Standards, NCCLS) Guidance Document C28A2. Medians for haematological parameters were calculated and reference values determined at 2.5th and 97.5th percentiles and compared with Caucasian values adopted by our laboratory as reference ranges and values from other African and Western countries. RBC count, haemoglobin, and haematocrit (HCT) were significantly higher in males compared to females. There were significant intraregional and interregional as well as international variations of haematological reference ranges in the populations studied. We conclude that, for each geographical area, there is a need to establish geography-specific reference ranges if accurate diagnosis and concise clinical decisions are to be made.

Variations in biochemical values for common laboratory tests: a comparison among multi-ethnic Israeli women cohort

BACKGROUND

Biochemical laboratory values are an essential tool in medical diagnosis, treatment, and follow-up; however, they are known to vary between populations. Establishment of ethnicity-adjusted reference values is recommended by health organizations.

AIM

To investigate the ethnicity element in biochemical lab values studying women of different ethnic groups.

METHODS

Biochemical lab values (n = 27) of 503 adult Israeli women of three ethnicities (Jewish Ashkenazi, Jewish Sephardic, and Bedouin Arab) attending a single medical center were analyzed. Biochemical data were extracted from medical center records. Ethnic differences of laboratory biochemicals were studied using ANCOVA to analyze the center of the distribution as well as quartile regression analysis to analyze the upper and lower limits, both done with an adjustment for age.

RESULTS

Significant ethnic differences were found in almost half (n = 12) of the biochemical laboratory tests. Ashkenazi Jews exhibited significantly higher mean values compared to Bedouins in most of the biochemical tests, including albumin, alkaline phosphatase, calcium, cholesterol, cholesterol LDL and HDL, cholesterol LDL calc., folic acid, globulin, and iron saturation, while the Bedouins exhibited the highest mean values in the creatinine and triglycerides. For most of these tests, Sephardic Jews exhibited biochemical mean levels in between the two other groups. Compared to Ashkenazi Jews, Sephardic Jews had a significant shift to lower values in cholesterol LDL.

CONCLUSIONS

Ethnic subpopulations have distinct distributions in biochemical laboratory test values, which should be taken into consideration in medical practice enabling precision medicine.

Baseline haematological and biochemical reference values for healthy male adults from Mali

INTRODUCTION

Haematological reference values are very important for diagnostic orientation and treatment decision. The aim of this study was to establish haematological reference values for Malian healthy adults.

METHODS

A cross-sectional study including 161 male Malians aged between 19 and 54 years old was performed. Median and reference ranges were calculated for haematological and biochemical parameters. Parametric student's t-test was used to determine any statistically significant differences by age, smoker status, body mass index (BMI) and occupation. Ranges were further compared with those reported for other African, Afro-American and Caucasian populations.

RESULTS

Increased levels of MCV, MCH, PLT and EOS were found in younger Malians who had abnormal BMI and altered platelets parameters. Notably, significantly lower eosinophil and monocyte counts were observed in Malians compared to Europeans The smoking status did not seem to directly affect RIs.

CONCLUSION

This is the first study to determine normal laboratory parameters in Malian adult males. Our results underscore the necessity of establishing region-specific clinical reference ranges that would allow clinicians and practitioners to manage laboratory tests, diagnosis and therapies. These data are useful not only for the management of patients in Mali, but also to support European and American clinicians in the health management of asylum seekers and migrants from Mali.

Effect of schistosomiasis on the outcome of patients infected with HIV-1 starting antiretroviral therapy in rural Tanzania

Background

It has been hypothesized that schistosomiasis negatively influences immune reconstitution in people living with HIV starting antiretroviral therapy (ART). In this study, we investigated the effect of schistosomiasis on the course of HIV infection in patients starting ART in a rural part of Tanzania.

Methodology

Retrospective study including patients prospectively enrolled in a HIV cohort in Ifakara, south-central Tanzania between January 1, 2013 and April 1, 2015. Schistosomal circulating anodic antigen (CAA) was assessed in pre-ART cryopreserved plasma. Regression models were utilized to estimate the effect of CAA positivity on virological and immunological failure and a composite outcome of death/loss to follow-up (LFU).

Principal findings

At ART-initiation 19.1% (88/461) of patients were CAA-positive. A tendency of higher CD4 increases was seen in CAA-positive patients (+182 cells/μl, interquartile range (IQR), 87–285 cells/μl) compared to CAA-negative patients (+147 cells/μl, IQR, 55–234 cells/μl, p = 0.09) after 10 months of follow-up. After adjustment for baseline risk factors, CAA-positivity showed no association with virological or immunological failure. In CAA-positive patients, 22.7% (20/88) died or were LFU, compared to 29.5% (110/373) of CAA-negative patients (hazard ratio (HR): 0.76, 95% confidence interval (CI), 0.47–1.22, p = 0.25). After adjustment for age, sex, body mass index, educational attainment, WHO-stage, tuberculosis status, and year of ART initiation, CAA-positivity showed a trend of a decreased hazard of death/LFU (HR: 0.58, 95% CI: 0.32–1.05, p = 0.07), while CD4 count at baseline (HR: 0.86, 95% CI: 0.76–1.00, p = 0.02) and MXD (sum of eosinophils, basophils, and monocytes counts) >1,100 cells/μl (HR: 0.56, 95% CI: 0.34–0.93, p = 0.03) were identified as independently protective factors.

Conclusions/Significance

Schistosomiasis is prevalent in this HIV cohort and may be beneficial for immunological reconstitution, while no effect on virological failure was apparent. A positive effect of schistosomiasis-induced immunomodulation on survival and retention in care needs confirmation in future studies.

Infections with HIV and blood flukes (Schistosoma) both exert chronic modulatory effects on the host’s immune system. Coinfections, meaning the host is simultaneously infected with both pathogens, are common in sub-Saharan Africa. In this situation the induced immune modulation of one pathogen may affect the course of the disease induced by the other pathogen. One study showed that coinfection with Schistosoma in people living with HIV who begin antiretroviral therapy (ART) may have deleterious effects on the reconstitution of the HIV-induced immunosuppression. In the current study, we investigated the effect of Schistosoma coinfection on the recovery of the patient’s immune system, on the efficacy of ART to suppress HIV replication, and on a combined endpoint of lost to follow-up or death. We found that schistosomiasis may have beneficial effects on immune reconstitution, while no deleterious effect was detected on HIV-suppressive efficacy of ART. Surprisingly, our data suggest that schistosomiasis-induced immunomodulatory effects might be beneficial for survival and retention in care. Future studies are warranted to confirm these findings. In the era of increasing access to ART in sub-Saharan Africa, the issue of schistosomiasis-HIV coinfection may have major consequences on the outcome of HIV treatment programs.

Reference intervals of routine clinical chemistry parameters among apparently healthy young adults in Amhara National Regional State, Ethiopia

Background

Clinical laboratory reference intervals (RIs) are essential for clinical diagnosis, treatment and therapeutic monitoring. Locally established RIs are required to correctly interpret clinical laboratory results. In Ethiopia, clinical laboratory test results are interpreted based on RIs derived from a western population.

Methods

A multicenter cross-sectional study was conducted among blood donors in Amhara National Regional State, Ethiopia from March 2016 to May 2017. A total of 1,175 apparently healthy study participants were included in the study from four blood banks in the region. All clinical chemistry parameters were analyzed using Mindray BS-200E full automated clinical chemistry analyzer. The 95% RIs were estimated using reference limits at 2.5th percentile for the lower reference limit and 97.5th percentile for the upper reference limit. Kolmogorov–Sminorv and Wilcoxon rank-sum tests were used to check data distribution normality and whether partitions were needed between variables, respectively.

Results

RIs established include: ALT 5.13–42.88 U/L for males and 4.3–37 U/L for females; AST 12.13–46.88 for males and 10–43.8 U/L for females; ALP 77.2–475.8 U/L for males and 89–381 U/L for females; amylase 29–309.8 U/L for males and 29–287.9 U/L for females; GGT 7–69.8 U/L for males and 6–39.1 U/L for females; total bilirubin 0.11–1.18 mg/dl for males and 0.08–0.91 mg/dl for females; creatinine 0.48–1.13 mg/dl for males and 0.47–1.09 mg/dl for females; total cholesterol 78.13–211.75 mg/dl for males and 83.6–202.7 mg/dl for females; total protein 5.7–9.7 g/dl for males and 5.6–9.47 for females; triglycerides 36–221.9 mg/dl for males and 35.3–201.5 mg/dl for females; urea 12–43 mg/dl for males and 10–38.7 mg/dl for females; and uric acid 2.7–6.9 mg/dl for males and 2.1–5.9 mg/dl for females.

Conclusion

This study has established RIs for routine clinical chemistry parameters. These RIs are important as they support the interpretation of clinical laboratory results for medical decision making and other health-related activities.

Complete blood count reference intervals from a healthy adult urban population in Kenya

BACKGROUND

There are racial, ethnic and geographical differences in complete blood count (CBC) reference intervals (RIs) and therefore it is necessary to establish RIs that are population specific. Several studies have been carried out in Africa to derive CBC RIs but many were not conducted with the rigor recommended for RI studies hence limiting the adoption and generalizability of the results.

METHOD

By use of a Beckman Coulter ACT 5 DIFF CP analyser, we measured CBC parameters in samples collected from 528 healthy black African volunteers in a largely urban population. The latent abnormal values exclusion (LAVE) method was used for secondary exclusion of individuals who may have had sub-clinical diseases. The RIs were derived by both parametric and non-parametric methods with and without LAVE for comparative purposes.

RESULTS

Haemoglobin (Hb) levels were lower while platelet counts were higher in females across the 4 age stratifications. The lower limits for Hb and red blood cell parameters significantly increased after applying the LAVE method which eliminated individuals with latent anemia and inflammation. We adopted RIs by parametric method because 90% confidence intervals of the RI limits were invariably narrower than those by the non-parametric method. The male and female RIs for Hb after applying the LAVE method were 14.5-18.7 g/dL and 12.0-16.5 g/dL respectively while the platelet count RIs were 133-356 and 152-443 x10(3) per μL respectively.

CONCLUSION

Consistent with other studies from Sub-Saharan Africa, Hb and neutrophil counts were lower than Caucasian values. Our finding of higher Hb and lower eosinophil counts compared to other studies conducted in rural Kenya most likely reflects the strict recruitment criteria and healthier reference population after secondary exclusion of individuals with possible sub-clinical diseases.

Haematological and immunological reference intervals for adult population in the state of Amhara, Ethiopia

OBJECTIVE

Reference intervals (RIs) currently being used in Ethiopia are derived from western populations. Thus, this study aimed to establish locally derived haematological and immunological RIs.

METHOD

The study was conducted in Amhara State, Ethiopia with a total of 967 (55.2% males) participants. 56.9% of males and 43.1% of females were eligible for haematological and immunological RI determination. A non-parametric test was used for the determination of upper (97.5th percentile) and lower (2.5th percentile) reference interval limits with 95% CI. The Harris and Boyd Rule was used to determine the need of partitioning of reference intervals based on gender.

RESULT

The established 95% reference intervals (2.5th-97.5th percentile) were: for WBC: 3-11.2 × 10⁹ /l; for platelet: 90-399 × 10⁹ /l; for RBC: 4-6 × 10¹² /l for males and 3.5-5.6 × 10¹² /l for females; for haemoglobin: (Hgb) 12-18.9 g/dl for males and 10.7-17.5 g/dl for females; for PCV: 35.7-55.3% for males and 32.2-50.1% for females; for CD4: 400-1430 × 10⁹ /l for males and 466-1523 × 10⁹ /l for females; for CD4 percentage: 18-49.1% for males and 21.3-52.9% for females; for MCV: 81-100 fl; for MCH: 25.3-34.6 pg; MCHC: 28.8-36.9%; for RDW: 11.6-15.4% and for MPV: 8-12.3 fl. Males had significantly higher RBC, Hgb and PCV than females. CD4 counts and CD4 percentage were significantly higher in females.

CONCLUSION

The reference intervals established in this study differ from others and thus should be used for the interpretation of laboratory results in diagnosis and safety monitoring in clinical trials in Amhara.

Blood Pressure and Haematological Indices in Twelve Communities in Ashanti, Ghana

Hypertension is the most important risk factor for cardiovascular mortality and morbidity in Sub-Saharan Africa. In western populations, high haemoglobin levels are associated with raised BP unlike in Sub-Saharan Africa where there is a paucity of data. Our study examines the association between haematological indices with BP variables. Weight, height, BP, and whole blood indices of viscosity (Hb, haematocrit, RBC count, and MCV) were measured in 921 adults (340 men, 581 women; aged 40-75) in 12 communities in Ghana. Mean values for Hb (12.3 g/dl ± 1.7 SD), haematocrit (36.7% ± 5.2), RBC (4.10 million/μL ± 0.64), and MCV were lower than reference values used in Sub-Saharan Africa. Mean BMI was 21.1 ± 4.1 indicating a lean population. Systolic BP increased by 1.0 mmHg (95% CI 0.5-1.5), p < 0.001, for women and 0.5 (0.1-1.0), p = 0.027, for men per unit increase in haematocrit. Similar relationships were found for Hb and RBC but not for MCV or platelets. The relationships were weaker when adjusted for BMI, 0.7 mmHg (0.2-1.2) in women and 0.5 (0.0-1.0) in men. Findings for diastolic BP were similar. Overall haematological indices were low. We have found a significant, positive relationship between BP, Hb, Haematocrit, and RBC count in our population.

Establishment of the hematology reference intervals in a healthy population of adults in the Northwest of Morocco (Tangier-Tetouan region)

Introduction

Among the most useful biological examinations in common medical practice, blood count is the most prescribed. The reference intervals of the hematological parameters of this examination are of major importance for clinical orientations and therapeutic decisions. In Morocco, the reference values used by the laboratories of medical biology and used by doctors are ones collected from Caucasian and European individuals. These values could be different in the Moroccan population. Besides, reference intervals of the blood count specific to the various Moroccan regions are missing. We decided to determine the reference intervals from a population of healthy adults of the Tangier-Tetouan region by following the procedures recommended by the IFCC-CLSI guidelines in 2008 and comparing them to those of the literature.

Methods

Blood samples were taken from 15840 adult volunteers (8402 men from 18 to 55 years old and 7438 women from 18 to 50 years old) from the regional transfusion center of Tangier and Tetouan during a period between November 2014 and May 2016. The complete blood count was measured by the Sysmex KX21N^® analyzer. For each sample a systematic blood smear was done to determine the leukocyte differential. The data analysis was made by the software SPSS 20.0 by using percentiles 2.5^th and 97.5^th.

Results

A significant difference between both sexes was noted (p<0,001) for all the hematological parameters (red blood cells, hematocrit, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, leukocytes, neutrophils, basophils, eosinophils, monocytes, platelets and mean platelet volume) except for the numeration of lymphocytes (p = 0.552). The values of this study were compared with those reported in Arabic, Caucasian and African populations. Said comparisons showed the existence of significant differences.

Conclusion

This study tries to accentuate the necessity of proceeding with the establishment of reference intervals specific to the blood count of the Moroccan population to avoid errors of diagnosis, allow clinicians to interpret with greater specificity the hematological examinations and to improve the quality of medical care distributed to patients.

Establishment of hematological reference intervals for healthy adults in Asmara

Objectives

Clinical laboratory reference intervals used in a specific area should be derived from the local population as they are influenced by many factors. The purpose of this quantitative cross sectional study was to establish hematological reference intervals for healthy adults in Asmara and to determine whether the currently used reference interval do represent the adult population in the city. In addition, the established reference intervals were compared to findings from similar studies conducted in selected countries in Africa.

Results

There was a significant difference between males and females in the reference intervals for erythrocyte count, hemoglobin, hematocrit, mean cell volume, mean cell hemoglobin, mean cell hemoglobin concentration and differential white blood cell count. All the evaluated hematological analytes were found to be higher in males than in females except for platelet count. The out of range percentage for the parameters extends from 3.5 to 46.7%; with red blood cell count having the lowest while mean cell volume having the highest out of range percentage. The results indicated that the currently used reference interval does not represent the population in Asmara and are different from those obtained elsewhere in Africa.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3142-y) contains supplementary material, which is available to authorized users.

Biochemistry reference intervals for healthy elderly population in Asmara, Eritrea

OBJECTIVE

There is a scarcity of reference interval studies on the elderly in Africa. This study establishes reference interval for the elderly for some commonly used biochemical parameters. In this study, 255 conveniently sampled, healthy elderly, participants meeting Clinical and Laboratory Standards Institute (CLSI C28-A3) guidelines were enrolled. The results obtained may have utility in clinical diagnosis, patient management and research.

RESULTS

In general, the consensus reference interval established in this study tended to be higher than reference interval from Caucasian populations; but lower than those obtained from reference interval studies in several African countries. This pattern was observed in a number of analytes including Alanine aminotransferase; aspartate aminotransferase; alkaline phosphatase; sodium; potassium among others. Significant sex-related variations were also observed in total bilirubin; direct bilirubin; indirect bilirubin; albumin; sodium; chloride; plasma carbon dioxide, creatinine and anion gap. The results demonstrate that reference interval for Eritrean urban population differs from those derived from other African or North American populations. In this regard, the use of reference interval values obtained from Caucasian populations may result in misdiagnosis.

Verification of chemistry reference ranges using a simple method in sub-Saharan Africa

Background

Chemistry safety assessments are interpreted by using chemistry reference ranges (CRRs). Verification of CRRs is time consuming and often requires a statistical background.

Objectives

We report on an easy and cost-saving method to verify CRRs.

Methods

Using a former method introduced by Sigma Diagnostics, three study sites in sub-Saharan Africa, Bondo, Kenya, and Pretoria and Bloemfontein, South Africa, verified the CRRs for hepatic and renal biochemistry assays performed during a clinical trial of HIV antiretroviral pre-exposure prophylaxis. The aspartate aminotransferase/alanine aminotransferase, creatinine and phosphorus results from 10 clinically-healthy participants at the screening visit were used. In the event the CRRs did not pass the verification, new CRRs had to be calculated based on 40 clinically-healthy participants.

Results

Within a few weeks, the study sites accomplished verification of the CRRs without additional costs. The aspartate aminotransferase reference ranges for the Bondo, Kenya site and the alanine aminotransferase reference ranges for the Pretoria, South Africa site required adjustment. The phosphorus CRR passed verification and the creatinine CRR required adjustment at every site. The newly-established CRR intervals were narrower than the CRRs used previously at these study sites due to decreases in the upper limits of the reference ranges. As a result, more toxicities were detected.

Conclusion

To ensure the safety of clinical trial participants, verification of CRRs should be standard practice in clinical trials conducted in settings where the CRR has not been validated for the local population. This verification method is simple, inexpensive, and can be performed by any medical laboratory.

Clinical chemistry reference intervals of healthy adult populations in Gojjam Zones of Amhara National Regional State, Northwest Ethiopia

Background

Reference interval is crucial for disease screening, diagnosis, monitoring, progression and treatment efficacy. Due to lack of locally derived reference values for the parameters, clinicians use reference intervals derived from western population. But, studies conducted in different African countries have indicated differences between locally and western derived reference values. Different studies also indicated considerable variation in clinical chemistry reference intervals by several variables such as age, sex, geographical location, environment, lifestyle and genetic variation.

Objective

This study aimed to determine the reference intervals of common clinical chemistry parameters of the community of Gojjam Zones, Northwest Ethiopia.

Method

Population based cross-sectional study was conducted from November 2015 to December 2016 in healthy adult populations of Gojjam zone. Data such as, medical history, physical examination and socio-demographic data were collected. In addition, laboratory investigations were undertaken to screen the population. Clinical chemistry parameters were measured using Mindray BS 200 clinical chemistry autoanalyzer as per the manufacturer’s instructions. Descriptive statistics was used to calculate mean, median and 95^th percentiles. Independent sample T-test and one way ANOVA were used to see association between variables.

Results

After careful screening of a total of 799 apparently healthy adults who were consented for this study, complete data from 446 (224 females and 222 males) were included for the analysis. The mean age of both the study participants was 28.8 years. Males had high (P<0.05) mean and 2.5^th-97.5^th percentile ranges of ALT, AST, ALP, creatinine and direct bilirubin. The reference intervals of amylase, LDH, total protein and total bilirubin were not significantly different between the two sex groups (P>0.05). Mean, median, 95% percentile values of AST, ALP, amylase, LDH, creatinine, total protein, total bilirubin, and direct bilirubin across all age groups of participants were similar (P>0.05). But, there was a significant difference in the value of ALT (P<0.05). The reference intervals of ALT, total protein and creatinine were significantly (P<0.05) high in people having monthly income >1500 ETB compared to those with low monthly income. Significant (P<0.05) higher values of the ALT, ALP and total protein were observed in people living in high land compared to low land residences.

Conclusion

The study showed that some of the common clinical chemistry parameters reference intervals of healthy adults in Gojjam zones were higher than the reference intervals generated from developed countries. Therefore, strict adherence to the reference values generated in developed countries could lead to inappropriate diagnosis and treatment of patients. There was also variation of reference interval values based on climate, gender, age, monthly income and geographical locations. Therefore, further study is required to establish reference intervals for Ethiopian population.

Haematological and CD4+ T cells reference ranges in healthy adult populations in Gojjam zones in Amhara region, Ethiopia

Introduction

Establishing national population haematological and immunological reference ranges are essential for clinical management of patients. However, there is scarcity of information on community based haematological reference ranges established from Ethiopian population. Therefore, this study aimed at determining haematological and CD4⁺ T cells reference ranges in healthy adults from East and West Gojjam zones, Ethiopia.

Methods

Community based cross-sectional study was conducted from May 2015 to December 2015 in healthy adult residents of Gojjam zone. A total of 481(246 females and 235 males) healthy adults enrolled in the study. Healthy adults were defined by medical history, physical examination and laboratory screening for HIV, HBV, HCV and intestinal parasitosis. Haematological parameters were measured using haematology analyzer MindrayBC320 (Mindray Biomedical electronic Corporation, China). CD4⁺Tcells were enumerated using FACS count (Becton Dickinson).

Results

The median age of the participants was 25 years. The overall median and 95^th percentile of CD4⁺ T cells count were 869 cells/mm³ and396–1598 cells/mm³, respectively. Females had a significantly higher CD4⁺ T cell counts compared to males (P = 0.002). The 95^th percentile range for red blood cells (RBCs) was 3.93–6.1 x 10⁶cells/mm³and for hematocrit (Hct) was 40–58% while for hemoglobin (Hb) was 15.69–17.84g/dl. Males had significantly higher values of RBC and Hct than females (P < 0.001). Females (120–379 x 10⁶ cells/mm³) had significantly higher platelet counts than males (106–352 x10⁶ cells/mm³) (P < 0.001). The overall median of WBC was6.78 x10³/mm³and its95^thpercentile range was3.5–11.5 x10³/mm³. The overall 95^th percentile range of MCV, MCH and MCHC were 89.5–107.5 fl, 28–34 pg and 30–33.2g/dl, respectively. The higher mean absolute count of RBCs was found in the youngest age groups (P = 0.03). The mean count of RBCs and Hct were significantly higher in highschool completed and above than other participants (P < 0.001). The lower and upper limit of platelet counts was significantly higher in highland (118 -383x10⁶ cells/mm3) compared to lowland residents (107–352 x10⁶ cells/mm3) (P < 0.001). Moreover, it was significantly higher in residents with better monthly income (124–383 x10⁶ cells/mm3) compared to the counters (115–368 x10⁶ cells/mm³) (P = 0.02).

Conclusions

Some of the haematological and CD4⁺ T cells reference ranges of the healthy adults in this study showed variations with the reference ranges used and reported so far in Ethiopia, Africa and Western countries. We recommend further study considering gender, altitude, and residency in other parts of Ethiopia to establish national reference ranges for Ethiopian population.

Reference Value Profile for Healthy Individuals From the Aljouf region of Saudi Arabia

Background

Many factors influence hematological values such as sex, age, ethnic origin, geographic location, season, and genetic disease. The aim of this study was to detect the hematological reference value profile for healthy adults from the Aljouf region of Saudi Arabia.

Methods

The project was carried out on 2,040 healthy individuals, 1,152 males and 888 females, with ages ranging from 17 to 28 years. A group of participants were recruited from the higher secondary schools, university students and premarital centers of Aljouf cities. Hematological reference value profile, hemoglobin (Hb) concentration, red blood cell (RBC) count, RBC indices, white blood cell (WBC) count, differential WBC and platelet (Plt) count were measured. Moreover, a peripheral blood film was prepared in order to detect abnormalities of RBC and all samples were examined for liver function tests (LFTs) and renal function test (RFT) performed, along with a lipid profile.

Results

Hb concentration, hematocrit (Hct) and RBCs were found to be significantly higher in males than in females (P < 0.01). On the contrary, Plt ranges were significantly lower in male as compared to female (P < 0.01). No significant differences in the study population were determined in the other hematological parameters (P > 0.05).

Conclusion

Our findings reflect that healthy adults from the Aljouf region have some hematological parameters differing quantitatively from Caucasians. The hematological reference value profile reported here can be used as normal reference values for Saudi people of the Aljouf region to help in diagnosis and consequently treatment of individuals with hematological disorders.

Establishing Reference Ranges of Hematological Parameters from Malian Healthy Adults

INTRODUCTION

Measurement of immuno-hematological parameters has been historically helpful in the diagnosis and treatment monitoring of many infectious diseases and cancers. However, these parameters have not yet been established in many developing countries where patient care strongly relies on such low-cost tests. This study describes the immuno-hematological parameter ranges for Malian healthy adults.

METHODS

A cross sectional study was conducted from August 2004 to May 2013. We included 213 healthy volunteers (173 male and 40 female), aged between 18-59 years. Median, 2.5 and 97.5 percentile ranges for each immuno-hematological parameter are presented.

RESULTS

In our study population, the hematological parameters' ranges were mostly different to the universal established ranges. We found in our population a Median white blood cell (WBC) count of 5200 cells/μL [3237.5-11900], Red Blood Cell (RBC) count of 4.94 10^6 [3.56-6.17], hemoglobin (Hb) of 14.2 g/dL [12.2-17.38], platelet count (Plt) of 275 10^3/μL [145.4-614.4], lymphocytes 2050/μL [1200-3800], neutrophils 2200/μL [1040-6220]; monocytes 200/μL [100-660]; eosinophils 131/μL [0-1026]; CD4 902 cells/μL [444-1669] and CD8 485 cells/μL [0-1272]. We found significant gender differences in RBC, Hb level and MPV. However, RBC and Hb were higher in males median values compared to females (median values) (p<0.001), whereas the Mean platelet volume lower values (MPV) in males than females (P<0.047). The hemoglobin level for some West African countries (Mali, Burkina Faso, Togo, and Nigeria) ranged from 13.5 to 15.1 g/dL for males and 12 to 13 g/dL for females. However in East and Southern Africa, the values were anywhere from 14.1 to 16.1 for males and 11.2 to 14.4 for females.

CONCLUSION

Our data may help physicians to better define hematological abnormalities in patients. They may also be used to define new "normal hematological values" in Malian population or in the whole West African population.

Adult Hematology and Clinical Chemistry Laboratory Reference Ranges in a Zimbabwean Population

Background

Laboratory reference ranges used for clinical care and clinical trials in various laboratories in Zimbabwe were derived from textbooks and research studies conducted more than ten years ago. Periodic verification of these ranges is essential to track changes over time. The purpose of this study was to establish hematology and chemistry laboratory reference ranges using more rigorous methods.

Methods

A community-based cross-sectional study was carried out in Harare, Chitungwiza, and Mutoko. A multistage sampling technique was used. Samples were transported from the field for analysis at the ISO15189 certified University of Zimbabwe-University of California San Francisco Central Research Laboratory. Hematology and clinical chemistry reference ranges lower and upper reference limits were estimated at the 2.5^th and 97.5^th percentiles respectively.

Results

A total of 769 adults (54% males) aged 18 to 55 years were included in the analysis. Median age was 28 [IQR: 23–35] years. Males had significantly higher red cell counts, hemoglobin, hematocrit, and mean corpuscular hemoglobin compared to females. Females had higher white cell counts, platelets, absolute neutrophil counts, and absolute lymphocyte counts compared to males. There were no gender differences in eosinophils, monocytes, and absolute basophil count. Males had significantly higher levels of urea, sodium, potassium, calcium, creatinine, amylase, total protein, albumin and liver enzymes levels compared to females. Females had higher cholesterol and lipase compared with males. There are notable differences in the white cell counts, neutrophils, cholesterol, and creatinine kinase when compared with the currently used reference ranges.

Conclusion

Data from this study provides new country specific reference ranges which should be immediately adopted for routine clinical care and accurate monitoring of adverse events in research studies.

Boosting with Subtype C CN54rgp140 Protein Adjuvanted with Glucopyranosyl Lipid Adjuvant after Priming with HIV-DNA and HIV-MVA Is Safe and Enhances Immune Responses: A Phase I Trial

Background

A vaccine against HIV is widely considered the most effective and sustainable way of reducing new infections. We evaluated the safety and impact of boosting with subtype C CN54rgp140 envelope protein adjuvanted in glucopyranosyl lipid adjuvant (GLA-AF) in Tanzanian volunteers previously given three immunizations with HIV-DNA followed by two immunizations with recombinant modified vaccinia virus Ankara (HIV-MVA).

Methods

Forty volunteers (35 vaccinees and five placebo recipients) were given two CN54rgp140/GLA-AF immunizations 30–71 weeks after the last HIV-MVA vaccination. These immunizations were delivered intramuscularly four weeks apart.

Results

The vaccine was safe and well tolerated except for one episode of asymptomatic hypoglycaemia that was classified as severe adverse event. Two weeks after the second HIV-MVA vaccination 34 (97%) of the 35 previously vaccinated developed Env-specific binding antibodies, and 79% and 84% displayed IFN-γ ELISpot responses to Gag and Env, respectively. Binding antibodies to subtype C Env (included in HIV-DNA and protein boost), subtype B Env (included only in HIV-DNA) and CRF01_AE Env (included only in HIV-MVA) were significantly boosted by the CN54rgp140/GLA-AF immunizations. Functional antibodies detected using an infectious molecular clone virus/peripheral blood mononuclear cell neutralization assay, a pseudovirus/TZM-bl neutralization assay or by assays for antibody-dependent cellular cytotoxicity (ADCC) were not significantly boosted. In contrast, T-cell proliferative responses to subtype B MN antigen and IFN-γ ELISpot responses to Env peptides were significantly enhanced. Four volunteers not primed with HIV-DNA and HIV-MVA before the CN54rgp140/GLA-AF immunizations mounted an antibody response, while cell-mediated responses were rare. After the two Env subtype C protein immunizations, a trend towards higher median subtype C Env binding antibody titers was found in vaccinees who had received HIV-DNA and HIV-MVA prior to the two Env protein immunizations as compared to unprimed vaccinees (p = 0.07).

Conclusion

We report excellent tolerability, enhanced binding antibody responses and Env-specific cell-mediated immune responses but no ADCC antibody increase after two immunizations with a subtype C rgp140 protein adjuvanted in GLA-AF in healthy volunteers previously immunized with HIV-DNA and HIV-MVA.

Trial Registration

International Clinical Trials Registry PACTR2010050002122368

A pilot study to determine the normal haematological indices for young Malawian adults in Blantyre, Malawi

BACKGROUND

Reference ranges for haematological and other laboratory tests in most African countries are based on populations in Europe and America and, because of environmental and genetic factors, these may not accurately reflect the normal reference ranges in African populations.

AIM

To determine the distribution of haematological parameters in healthy individuals residing in Blantyre, Malawi. We also examined the effect of sociodemographic and nutritional factors on the haematological variables.

METHODS

We conducted a proof-of-concept cross-sectional study, involving 105 healthy blood donors at Malawi Blood Transfusion Service in Blantyre. Eligible participants were HIV-negative males and females, aged 19 to 35 years, who did not have any evidence of acute or chronic illness, or blood-borne infection. We performed the haematological tests at the Malawi-Liverpool Wellcome Trust laboratory in Blantyre, and the screening tests at Malawi Blood Transfusion Service laboratories.

RESULTS

Out of 170 consenting healthy volunteers, haematological results were available for 105 participants. The proportions of results which were below the lower limit of the manufacturer's reference ranges were 35.2% (37/105) for haemoglobin, 15.2% (16/105) for neutrophils, 23.8% (25/105) for eosinophils, and 88.6 % (93/105) for basophils. The proportions of results that were above the upper limit of the manufacturer's reference ranges were 9.5% (10/105) for platelets and 12.4% (13/105) for monocytes. We also observed that the mean leucocyte and basophil counts were significantly higher in males than females (p = 0.042 and p = 0.015, respectively). There were no statistically significant differences in haematological results observed among different ethnic, age, and body mass index groups.

CONCLUSIONS

Over half of otherwise healthy study participants had at least one abnormal haematological result, using previously established foreign standards. More detailed studies are needed to establish locally relevant normal ranges for different age groups and other demographic characteristics of the Malawian population. This will lead to accurate interpretation of laboratory results.

Sex and Urbanicity Contribute to Variation in Lymphocyte Distribution across Ugandan Populations

Management of patient care and interpretation of research data require evaluation of laboratory results in the context of reference data from populations with known health status to adequately diagnose disease or make a physiological assessment. Few studies have addressed the diversity of lymphocyte subsets in rural and urban Ugandan populations. Here, 663 healthy blood bank donors from semi-urban centers of Kampala consented to participate in a study to define lymphocyte reference ranges. Whole blood immunophenotyping was performed to determine the frequency and absolute counts of T, B, and NK cells using clinical flow cytometry. Results from blood bank donors were compared to a rural cohort from the district of Kayunga and more urban clinical trial participants from the capital city, Kampala. Relationships between hematological and lymphocyte parameters were also explored. In the semi-urban blood donors, females were significantly different from males in all parameters except the frequency of CD8 T and B cells. Females had higher absolute counts of CD4 T, CD8 T and B cells, whereas males had higher NK cell counts. NK cell frequency and counts were significantly higher in semi-urban blood donors, regardless of sex, compared to more urban study participants. CD8 T cell frequency and counts were significantly higher in the blood donors compared to the rural participants, irrespective of sex. Interestingly, basophil counts were positively associated with overall T cell counts. These findings suggest that both sex and level of cohort urbanicity may influence lymphocyte subset distributions in Ugandans.

Evaluation of locally established reference intervals for hematology and biochemistry parameters in Western Kenya

Background

Important differences have been demonstrated in laboratory parameters from healthy persons in different geographical regions and populations, mostly driven by a combination of genetic, demographic, nutritional, and environmental factors. Despite this, European and North American derived laboratory reference intervals are used in African countries for patient management, clinical trial eligibility, and toxicity determination; which can result in misclassification of healthy persons as having laboratory abnormalities.

Methods

An observational prospective cohort study known as the Kisumu Incidence Cohort Study (KICoS) was conducted to estimate the incidence of HIV seroconversion and identify determinants of successful recruitment and retention in preparation for an HIV vaccine/prevention trial among young adults and adolescents in western Kenya. Laboratory values generated from the KICoS were compared to published region-specific reference intervals and the 2004 NIH DAIDS toxicity tables used for the trial.

Results

About 1106 participants were screened for the KICoS between January 2007 and June 2010. Nine hundred and fifty-three participants aged 16 to 34 years, HIV-seronegative, clinically healthy, and non-pregnant were selected for this analysis. Median and 95% reference intervals were calculated for hematological and biochemistry parameters. When compared with both published region-specific reference values and the 2004 NIH DAIDS toxicity table, it was shown that the use of locally established reference intervals would have resulted in fewer participants classified as having abnormal hematological or biochemistry values compared to US derived reference intervals from DAIDS (10% classified as abnormal by local parameters vs. >40% by US DAIDS). Blood urea nitrogen was most often out of range if US based intervals were used: <10% abnormal by local intervals compared to >83% by US based reference intervals.

Conclusion

Differences in reference intervals for hematological and biochemical parameters between western and African populations highlight importance of developing local reference intervals for clinical care and trials in Africa.

Reference values for peripheral blood lymphocyte subsets in a healthy korean population

Flow cytometric immunophenotyping of peripheral blood lymphocyte subsets is a powerful tool for evaluating cellular immunity and monitoring immune-mediated diseases. The numbers and proportions of blood lymphocyte subsets are influenced by factors such as gender, age, ethnicity, and lifestyle. This study aimed to establish reference ranges for peripheral blood lymphocyte subsets in a healthy Korean population. Blood samples from 294 healthy adults were collected. Lymphocyte subsets were analyzed using a single-platform method with a flow cytometer; white blood cells and lymphocytes were analyzed using an automated hematology analyzer. The mean value of the white blood cell count was 5,665 cells/µl, and the mean values of the subtype counts (percentages) were as follows: lymphocytes, 1,928 cells/µl (35.08%); CD3⁺ cells, 1,305 cells/µl (67.53%); CD3⁺CD4⁺ cells, 787 cells/µl (40.55%); CD3⁺CD8⁺ cells, 479 cells/µl (25.23%); CD3^-CD19⁺ cells, 203 cells/µl (10.43%); and CD3^-CD56⁺ cells, 300 cells/µl (15.63%). Additionally, the CD4⁺/CD8⁺ ratio was 1.81. In this study, gender and age significantly influenced blood lymphocyte subsets. Our results demonstrate that, as with other populations, a healthy Korean population has its own, region-specific, lymphocyte subset reference ranges.

Reference intervals for total bilirubin, ALT, AST and creatinine in healthy Chinese elderly

BACKGROUND

The aim of this study was to establish the reference intervals (RIs) of total bilirubin (TBIL), alanine aminotransferase (ALT), aspartate transaminase (AST), and creatinine (CREA) for apparently healthy elderly (Han ethnicity) in Shuyang, China.

MATERIAL AND METHODS

A total of 54 912 blood specimens from elderly residents age 65-104 years were collected by standard procedures in Shuyang county of Jiangsu province. TBIL, ALT, AST, and CREA for each participant were determined by automatic biochemical analyzer. Distribution and differences of TBIL, ALT, AST, and CREA were analyzed and compared between the elderly of the same age of different sexes and different ages of the same sex. RIs of TBIL, ALT, AST, and CREA were compared with the current RIs. The RIs and 95% confidence intervals were calculated using nonparametric method (2.5th-97.5th percentiles) according to the guideline of the Clinical and Laboratory Standards Institute.

RESULTS

RIs established for the healthy elderly include: TBIL 7.8~30.6 µmol/L for males and 7.3~26.1 µmol/L for females; ALT 8.7~47.3 U/L for males and 8.4~45.2 U/L for females; AST 15.7~46.9 U/L for males and 15.1~46.2 U/L for females; and CREA 45.1~100.9 µmol/L for males and 38.7~85.0 µmol/L for females. Reference intervals of TBIL, ALT, AST, and CREA for male elderly were higher than those of females, and values of CREA increased with increasing age.

CONCLUSIONS

We have established a panel of locally relevant RIs. It is necessary to establish scientific and reasonable RIs of TBIL, ALT, AST, and CREA for the healthy elderly in our region, which will provide a reference for clinicians and inspection officers.

Hyperuricaemia in the Pacific: why the elevated serum urate levels?

Pacific Island populations, particularly those of Polynesian descent, have a high prevalence of hyperuricaemia and gout. This is due to an inherently higher urate level among these populations with a demonstrated genetic predisposition. While an excess of urate can cause pathology, urate is also important for human health. It has been implicated as an antioxidant, has a neuroprotective role and is involved in innate immune responses. This paper provides a brief review of urate levels worldwide, with a particular focus on island Southeast Asia and the Pacific. We then present possible evolutionary explanations for the elevated serum urate levels among Pacific populations in the context of the physiological importance of urate and of the settlement history of the region. Finally, we propose that ancestry may play a significant role in hyperuricaemia in these populations and that exposure to malaria prior to population expansion into the wider Pacific may have driven genetic selection for variants contributing to high serum urate.

Comprehensive reference ranges for hematology and clinical chemistry laboratory parameters derived from normal Nigerian adults

BACKGROUND

Interpretation of laboratory test results with appropriate diagnostic accuracy requires reference or cutoff values. This study is a comprehensive determination of reference values for hematology and clinical chemistry in apparently healthy voluntary non-remunerated blood donors and pregnant women.

METHODS AND FINDINGS

Consented clients were clinically screened and counseled before testing for HIV, Hepatitis B, Hepatitis C and Syphilis. Standard national blood donors' questionnaire was administered to consented blood donors. Blood from qualified volunteers was used for measurement of complete hematology and chemistry parameters. Blood samples were analyzed from a total of 383 participants, 124 (32.4%) males, 125 (32.6%) non-pregnant females and 134 pregnant females (35.2%) with a mean age of 31 years. Our results showed that the red blood cells count (RBC), Hemoglobin (HB) and Hematocrit (HCT) had significant gender difference (p = 0.000) but not for total white blood count (p>0.05) which was only significantly higher in pregnant verses non-pregnant women (p = 0.000). Hemoglobin and Hematocrit values were lower in pregnancy (P = 0.000). Platelets were significantly higher in females than men (p = 0.001) but lower in pregnant women (p =  .001) with marked difference in gestational period. For clinical chemistry parameters, there was no significant difference for sodium, potassium and chloride (p>0.05) but gender difference exists for Bicarbonate (HCO3), Urea nitrogen, Creatinine as well as the lipids (p<0.05). Total bilirubin was significantly higher in males than females (p = 0.000). Significant differences exist for all chemistry parameters between pregnant and non-pregnant women in this study (p<0.05), except Amylase and total cholesterol (p>0.05).

CONCLUSIONS

Hematological and Clinical Chemistry reference ranges established in this study showed significant gender differences. Pregnant women also differed from non-pregnant females and during pregnancy. This is the first of such comprehensive study to establish reference values among adult Nigerians and difference observed underscore the need to establish reference values for different populations.