Methods and analyzers for hemoglobin measurement in clinical laboratories and field settings

Assessing Accuracy and Precision of Hemoglobin Determination in Venous, Capillary Pool, and Single-Drop Capillary Blood Specimens Using three Different HemoCue® Hb Models: The Multicountry Hemoglobin Measurement (HEME) Study

BACKGROUND

Anemia prevalence estimates reported in population surveys can vary based on the blood specimen source (capillary or venous) and analytic device (hematology autoanalyzers or portable hemoglobinometers) used for hemoglobin (Hb) determination.

OBJECTIVES

This study aimed to compare accuracy and precision of Hb measurement in three blood specimen types on three models of hemoglobinometers against the results from venous blood from the same individuals measured on automated analyzers (AAs).

METHODS

This multisite (Cambodia, Ethiopia, Guatemala, Lebanon, Nigeria, and Tanzania) study assessed Hb measurements in paired venous and capillary blood specimens from apparently healthy women (aged 15-49 y) and children (aged 12-59 mo) using three HemoCue® Hb models (201+, 301, and 801). Measurements were compared against reference values: venous blood in hematology AA and adjusted via regression calibration or mean difference in HemoCue® Hb. Venous, capillary pool, and single-drop capillary blood specimens were assessed for accuracy and precision.

RESULTS

Venous blood measured using HemoCue® Hb 301 exhibited a positive mean error, whereas responses in HemoCue® Hb 201+ and 801 were nondirectional compared with the reference. Adjustment with the reference harmonized mean errors for all devices across study sites to <1.0 g/L using venous blood. Precision was highest for venous blood (±5-16 g/L) in all sites, lowest for single-drop capillary (±9-37 g/L), and intermediate (±9-28 g/L) for capillary pool blood specimen. Imprecision differed across sites, especially with both capillary blood specimens, suggesting different levels of personnel skills.

CONCLUSIONS

Findings suggest that venous blood is needed for accurate and precise Hb determination. Single-drop capillary blood use should be discouraged owing to high measurement variability. Further research should evaluate the viability and reliability of capillary pool blood for this purpose. Accuracy of HemoCue® Hb devices can be improved via standardization against results from venous blood assessed using AA.

The prevalence of anemia during pregnancy and its correlates vary by trimester and hemoglobin assessment method in Eastern Maharashtra, India

Approximately half of pregnant women in India are anemic, representing over 7.5 million women. Few studies have assessed the relationship between multiple micronutrient deficiencies and anemia during pregnancy or the trajectory of hemoglobin (Hb) during pregnancy in low-resource settings. We enrolled 200 pregnant women from the Maternal and Newborn Health (MNH) registry, a population-based pregnancy and birth registry in Eastern Maharashtra, India to address these gaps. The women provided capillary (finger-prick) and venous blood specimens at enrollment (<15 weeks), and a second capillary specimen in the 3rd trimester (>27 weeks). Capillary specimens were analyzed at the time of collection with a HemoCue Hb 201+; venous specimens were shipped on dry ice to a laboratory for cyanmethemoglobin assessment. In the 1st trimester, mean Hb concentration and anemia (Hb<11.0 g/dL) prevalence using capillary specimens were 10.9 ± 1.5 g/dL and 51.1%; mean Hb concentration using venous blood specimens was estimated to be 11.3 ± 1.3 g/dL and anemia prevalence was 37.5%. The prevalence of iron, vitamin B12 and folate deficiencies were 40%, 30% and 0%, respectively. Among women with anemia in the 1st trimester (venous blood), 56% had concurrent iron deficiency (inflammation-adjusted serum ferritin <15 µg/L) indicating that their anemia may be amenable to iron supplementation. In total, 21% of women had ID and anemia, 19% ID in the absence of anemia, 16.5% anemia in the absence of ID and 43.5% had neither. By the 3rd trimester, mean Hb from capillary specimens had declined to 10.1 ± 1.35 g/dL and anemia prevalence increased to 70.7%, despite 99.4% mothers reporting receipt of iron-folic acid (IFA) supplements during her current pregnancy, and 83.9% reporting IFA consumption the previous day. Significant predictors of anemia in the 1st trimester (both venous and capillary) included the number of weeks gestation at the time of Hb assessment and inflammation-adjusted serum ferritin. For 3rd trimester anemia, significant predictors included 1st trimester height, BMI and IFA consumption during the 3rd trimester (but not 1st trimester micronutrient biomarkers), indicating that IFA supplementation over the course of pregnancy may have influenced micronutrient status and anemia risk. Our findings highlight the severity of the burden of anemia and micronutrient deficiencies in Eastern Maharashtra, but also highlight that in many cases, ID and anemia affect different individuals. Preventing and managing anemia in pregnancy in India will require strengthening both clinical and community-based strategies targeting iron deficiency, as well as other causes of anemia.

Comparison of venous and pooled capillary hemoglobin levels for the detection of anemia among adolescent girls

Introduction

Blood source is a known preanalytical factor affecting hemoglobin (Hb) concentrations, and there is evidence that capillary and venous blood may yield disparate Hb levels and anemia prevalence. However, data from adolescents are scarce.

Objective

To compare Hb and anemia prevalence measured by venous and individual pooled capillary blood among a sample of girls aged 10-19 years from 232 schools in four regions of Ghana in 2022.

Methods

Among girls who had venous blood draws, a random subsample was selected for capillary blood. Hb was measured using HemoCue® Hb-301. We used Lin's concordance correlation coefficient (CCC) to quantify the strength of the bivariate relationship between venous and capillary Hb and a paired t-test for difference in means. We used McNemar's test for discordance in anemia cases by blood source and weighted Kappa to quantify agreement by anemia severity. A multivariate generalized estimating equation was used to quantify adjusted population anemia prevalence and assess the association between blood source and predicted anemia risk.

Results

We found strong concordance between Hb measures (CCC = 0.86). The difference between mean venous Hb (12.8 g/dL, ± 1.1) and capillary Hb (12.9 g/dL, ± 1.2) was not significant (p = 0.26). Crude anemia prevalence by venous and capillary blood was 20.6% and 19.5%, respectively. Adjusted population anemia prevalence was 23.5% for venous blood and 22.5% for capillary (p = 0.45). Blood source was not associated with predicted anemia risk (risk ratio: 0.99, 95% CI: 0.96, 1.02). Discordance in anemia cases by blood source was not significant (McNemar p = 0.46). Weighted Kappa demonstrated moderate agreement by severity (ĸ = 0.67). Among those with anemia by either blood source (n = 111), 59% were identified by both sources.

Conclusion

In Ghanaian adolescent girls, there was no difference in mean Hb, anemia prevalence, or predicted anemia risk by blood source. However, only 59% of girls with anemia by either blood source were identified as having anemia by both sources. These findings suggest that pooled capillary blood may be useful for estimating Hb and anemia at the population level, but that caution is needed when interpreting individual-level data.

Burden of Submicroscopic Plasmodium Infections and Detection of kelch13 Mutant Parasites in Military and Civilian Populations in Papua New Guinea

Malaria remains a major public health problem in Papua New Guinea (PNG) and an important force health protection issue for both PNG and Australian Defence Forces. To investigate the malaria burden in the military and civilians residing on military bases, a cross-sectional survey was conducted in April 2019 at three military bases in Wewak, Manus Island, and Vanimo, PNG. A total of 1,041 participants were enrolled; 235 military personnel from three bases and 806 civilians from Wewak and Vanimo. Polymerase chain reaction (PCR) revealed an overall high prevalence of Plasmodium infection in both the military and civilians. Among the military, the infection prevalence was significantly higher in Wewak (35.5%) and Vanimo (33.3%) bases than on Manus Island (11.8%). Among civilians, children (<16 years old) had significantly higher odds of being PCR positive than adults (≥16 years old). At Wewak and Vanimo, Plasmodium vivax accounted for 85.4%, 78.2%, and 66.2% of infections in military, children, and adult populations. Overall, 87.3%, 41.3%, and 61.3% of Plasmodium infections in the military, children, and adults, respectively, were detected only by PCR, not by microscopy (submicroscopic [SM] infections). Children had a significantly lower proportion of SM infections than adults and Papua New Guinea Defence Force personnel. Infection status was not associated with hemoglobin levels in these populations at the time of the survey. Mutant kelch13 (C580Y) parasites were identified in 5/68 Plasmodium falciparum-infected individuals. The survey results indicate extensive malaria transmission on these bases, especially in Wewak and Vanimo. More intensified interventions are required to reduce malaria transmission on PNG military bases.

Hemoglobin measurement in venous blood compared with pooled and single-drop capillary blood: a method-comparison study in a controlled and survey setting in Uganda among children and women

BACKGROUND

Standard practice for estimating anemia in population-based surveys is to use a point-of-care device to measure hemoglobin (Hb) in a single drop of capillary blood. Emerging evidence points to larger than expected differences in Hb concentration depending on the blood source.

OBJECTIVE

We evaluated use of different blood sources to measure Hb with a HemoCue 201+ analyzer compared with the reference method of venous blood tested with a Sysmex XN-450 hematology analyzer.

METHODS

Hb concentration in venous, pooled capillary, and single-drop capillary blood were collected in controlled (laboratory) and survey (Demographic Health Survey-8 pilot) settings in Uganda among children 6-59 mo and nonpregnant women 15-49 y. Venous and capillary blood collected from the same individual was tested using a HemoCue 201+ analyzer and the venous blood was also measured with a Sysmex XN-450 hematology analyzer. Agreement between measures was estimated using Lin's concordance correlation coefficient, Bland-Altman plots, and Deming regression. Means and prevalences were compared using paired t-tests and McNemar's tests, respectively.

RESULTS

The limits of agreement between Hb measured using a HemoCue 201+ analyzer and the reference method were lowest for venous (1.1-1.96 g/dL), followed by pooled capillary (1.45-2.27 g/dL), and single-drop capillary blood (2.23-3.41 g/dL). Mean differences were <0.5 g/dL across comparators. There were statistically significant differences in Hb concentration from both types of capillary blood. Anemia prevalence was lower in pooled capillary blood compared with the reference method.

CONCLUSIONS

The variability of Hb measured by capillary blood using the HemoCue 201+ analyzer is higher than venous blood but the extent to which this impacts the validity of Hb and anemia estimates requires further exploration. Future research is also needed to evaluate the implications of using venous compared with capillary blood in population-based surveys. This trial was registered at clinicaltrials.gov (NCT05059457).

Overview of Trends in Anemia and Iron Deficiency in the Mexican Population From 1999 to 2018-19

BACKGROUND

Despite the emergence of diverse programs in Mexico to address anemia and micronutrient deficiencies in disadvantaged groups, progress on reducing their prevalence has stagnated. In Mexico, anemia surveillance at the population level is conducted through the National Health and Nutrition Survey ENSANUT (for its acronym in Spanish).

OBJECTIVE

To overview the trends in anemia and iron deficiency (ID) from 1999 to 2018-19 in the Mexican population before COVID-19 pandemic.

METHODS

Data from five nationwide surveys in Mexico were used. Where available, data on anemia, ID, and ID anemia (IDA) were extracted from ENSANUTs 1999, 2006, 2012, 2016, and 2018-19 in participants from 1 to 99 years old. Blood sample collection methods were similar across surveys (1999-2018) where capillary drop blood was used to estimate Hb using a HemoCue and serum blood samples to measure ferritin and C-reactive protein concentration.

RESULTS

The trend in anemia prevalence shows a U-shape from 1999 to 2018-19 in <60 years old. In older adults (≥60 years), an increasing trend was observed. Anemia declined progressively from 1999 to 2012 but increased from 2016 to 2018-19 in comparison with 2012. In contrast, ID declined from 2006 to 2018-19, mainly in children, while IDA did not change over this period. In older adults, ID prevalence remained constant over time.

CONCLUSIONS

The shifting trend in anemia prevalence across ENSANUTs 1999 through 2018-19 did not mimic the decreasing trend of ID over the same period of time. Other noncausal factors seem to play an important role in the variability of hemoglobin measurements.

Ten2Twenty-Ghana: a randomised controlled trial on the efficacy of multiple micronutrient-fortified biscuits on the micronutrient status of adolescent girls

Adolescent girls are an important target group for micronutrient interventions particularly in Sub-Saharan Africa where adolescent pregnancy and micronutrient deficiencies are common. When consumed in sufficient amounts and at levels appropriate for the population, fortified foods may be a useful strategy for this group, but little is known about their effectiveness and timing (regarding menarche), particularly in resource-poor environments. We evaluated the effect of consuming multiple micronutrient-fortified biscuits (MMB), sold in the Ghanaian market, 5 d/week for 26 weeks compared with unfortified biscuits (UB) on the micronutrient status of female adolescents. We also explored to what extent the intervention effect varied before or after menarche. Ten2Twenty-Ghana was a 26-week double-blind, randomised controlled trial among adolescent girls aged 10-17 years (n 621) in the Mion District, Ghana. Biomarkers of micronutrient status included concentrations of Hb, plasma ferritin (PF), soluble transferrin receptor (TfR) and retinol-binding protein (RBP), including body-iron stores. Intention-to-treat analysis was supplemented by protocol-specific analysis. We found no effect of the intervention on PF, TfR and RBP. MMB consumption did not affect anaemia and micronutrient deficiencies at the population level. MMB consumption increased the prevalence of vitamin A deficiency by 6·2 % (95 % CI (0·7, 11·6)) among pre-menarche girls when adjusted for baseline micronutrient status, age and height-for-age Z-score, but it decreased the prevalence of deficient/low vitamin A status by -9·6 % (95 % CI (-18·9, -0·3)) among post-menarche girls. Consuming MMB available in the market did not increase iron status in our study, but reduced the prevalence of deficient/low vitamin A status in post-menarcheal girls.

Determinants of iron deficiency and anemia among Nunavimmiut: results from the Qanuilirpitaa? 2017 Nunavik Health Survey

OBJECTIVE

To estimate the prevalence of iron deficiency (ID) and anemia and study their main distal and proximal protective and risk factors among Nunavimmiut 16 years and older in 2017.

METHODS

In a cross-sectional participatory survey of 831 women and 436 men from the Qanuilirpitaa? 2017 Nunavik Inuit Health Survey, venous blood samples were collected to measure various indicators of iron status and anemia as well as biomarkers of nutritional and inflammatory status and contaminant exposures. Sociodemographic, food security status, anthropometric, lifestyle, dietary, and health data were collected using questionnaires, clinical sessions, and a medical chart review. ID and anemia diagnoses were based on serum ferritin (SF) and hemoglobin (Hb), respectively. Multiple regressions were used to assess correlates of anemia and iron status.

RESULTS

Prevalence of ID was highest among women of childbearing age (16-49 years old, 33%) and anemia among adults aged 50 years and older (31%). These estimates are prone to biases due to the relatively low participation rate (37%). Serum vitamin D, omega-3 polyunsaturated fatty acid content of erythrocyte membranes, blood selenium, inflammation, higher socioeconomic status (SES), obesity, and alcohol consumption were all positively associated with SF, while Helicobacter pylori infection and a recent pregnancy were negatively associated with Hb among women of childbearing age. Among older adults, food insecurity was associated with lower SF.

CONCLUSION

While data reported here provide some indication of an improvement since the previous survey conducted in 2004, additional efforts should be devoted to further increasing the SES and access to country foods and nutritious market foods in this population, the two main protective factors against ID and anemia identified in the present study.

Comparing Non-Invasive Spectrophotometry to Hematology Analysis for Hemoglobin Measurements in Sickle Cell Disease Patients

Patients with sickle cell disease (SCD) require repeated blood sampling for hemoglobin (Hb) concentration measurements. The primary aim of this study was to compare non-invasive spectrophotometric hemoglobin (SpHb, g/dL) measurements to those taken via an automated hematology analyzer (Hb, g/dL) in patients with SCD visiting outpatient clinics and to investigate the correlations and agreements between both measurement techniques. Secondarily, we aimed to identify the SpHb cut-off concentration for the diagnosis of anemia and to monitor the effects of the pleth variability index (PVI, %) and perfusion index (PI) on SpHb measurements. The results gained from the examination of one hundred and fifty-eight patients indicated that the SpHb measurements overestimated the lab Hb concentrations, with a mean (SpHb-Hb) bias of 0.82 g/dL (SD 1.29). The SpHb measurements were positively correlated with the Hb measurements (Kendall's tau correlation (τ), n = 158, τ = 0.68, p < 0.001), with an intra-class correlation (ICC) of 0.67 and a 95% CI from 0.57 to 0.74 (p = 0.000). The SpHb cut-off concentration to diagnose anemia was 11.4 and 11.7 g/dL for males and females, respectively. SpHb sensitivity was low for males and females at 64.4% and 57.1%; however, the specificity was higher at 90.9% and 75%, with positive predictive values (PPVs) of 95.6 and 85.7, respectively. No correlation existed between SpHb measurements and the PVI (%) in contrast with a moderate correlation with the PI (r = 0.049, p = 0.54, and r = 0.36, p < 0.001, respectively). The mean PI was low at 2.52 ± 1.7. In conclusion, the SpHb measurements were consistently higher than the lab Hb concentrations, with a positive correlation. The sensitivity and precision of the SpHb measurements were lower than expected. However, the SpHb specificity and its positive predictive values (PPVs) indicated that it is less likely for a patient with a positive SpHb test result for anemia to be non-anemic. These results will allow SpHb measurement to play a role in excluding the presence of anemia. In light of the low PI values determined, the SpHb measurements were challenging to take and, thus, require further technological improvements.

Accuracy of a portable hemoglobinometer (HemoCue) to measure fetal hemoglobin values during in utero transfusion

OBJECTIVES

The current recommended treatment for severe fetal anemia is in utero transfusion (IUT). During this procedure, the evaluation of the necessary volume of transfused blood is based on regular measurement of fetal hemoglobin (FHb) concentration. The gold standard measurement is performed in the biology laboratory. A rapid medical test such as HemoCue® is an effective way to predict FHb concentration. It would reduce the time to obtain results and therefore the procedure duration. To evaluate the accuracy of HemoCue® to measure FHb during IUT, we compared Hb levels obtained by HemoCue® and by our biology laboratory.

METHODS

This retrospective study involved all pregnant women who had undergone an IUT in the university hospital of Clermont-Ferrand, France, during the period from 1 January 2010 to 6 June 2021. The FHb level was evaluated by two methods, a rapid medical test, HemoCue®, and a standard method in the biology laboratory.

RESULTS

We obtained 244 pairs of results from HemoCue® and our laboratory, of 90 IUT procedures. The correlation between the two sets of results was excellent, with Lin's concordance correlation coefficient of 0.979. However, we established that the measurements were not significantly modified by IUT number, puncture time, cause of fetal anemia, estimated fetal weight, gestational age, and delay between two IUT or middle cerebral artery peak systolic velocity values.

CONCLUSION

Our results allowed to extend the relevance of FHb measurements by HemoCue® during IUT.

Improving Anemia Assessment in Clinical and Public Health Settings

We aim to provide a practical approach to assess anemia and its primary causes, both in clinical settings and in the context of public health programs. Anemia remains a global challenge; thus, to achieve goals for anemia reduction and assess progress, standardized approaches are required for the assessment of anemia and its causes. We first provide a brief review of how to assess anemia, based on hemoglobin concentrations and cutoffs that correspond to age, sex, and physiologic status. Next, we discuss how to assess the likely causes of anemia in different settings. The causes of anemia are classified as non-nutritional (for example, because of infection, inflammation, blood loss, or genetic disorders) or nutrition-specific (for example, because of deficiencies of iron, vitamin A, riboflavin, vitamin B12, or folate). There is an important overlap between these 2 categories, such as the increased likelihood of iron deficiency in the context of inflammation. Given the multifaceted nature of anemia etiology, we introduce a framework for anemia assessment based on the "ecology of anemia," which recognizes its many overlapping causes. This conceptual framework is meant to inform what data on anemia causes may need to be collected in population surveys. The framework has a supporting table with information on the diagnostic tests, biomarkers and proposed cutoffs, characteristics, and feasibility of collecting the myriad information that can help elucidate the anemia etiology. We also provide examples of how this framework can be applied to interpret the anemia risk factor data from population-based surveys that can inform decisions about context-specific interventions. Finally, we present research gaps and priorities related to anemia assessment.

Characteristics of hemoglobin distributions in preschool children and non-pregnant women of reproductive age and their implications for establishing quality control criteria for hemoglobin data in field surveys: evidence from 483 surveys conducted in refugee settings worldwide

BACKGROUND

Currently, there is a lack of clear guidance on hemoglobin (Hb) data quality parameters and plausible flagging ranges for population-representative surveys. There is a need to determine which properties of Hb data indicate lower data quality and increased measurement error and which represent intrinsic statistical properties of Hb distributions rather than quality problems.

METHODS

We explored statistical characteristics of Hb distributions and plausible exclusion ranges in population-representative surveys of non-pregnant women of reproductive age (WRA) (15-49 years, n = 401 surveys) and children (6-59 months, n = 461 surveys) conducted in refugee settings by the United Nations High Commissioner for Refugees (UNHCR). Hb distribution characteristics [standard deviation (SD), skewness and kurtosis] were compared to those from Demographic and Health Surveys (DHS).

RESULTS

Overall, 0.08% of child and 0.14% of WRA Hb values were outside of the previously proposed 4.0-18.0 g/dL plausible range. Surveys conducted in Uganda tended to have unusually high SD compared with surveys from other settings, possibly an indication of problematic measurement quality. We therefore used summary results on SD, skewness and kurtosis excluding surveys from Uganda when comparing with DHS results or proposing plausible ranges. Both WRA and child Hb distributions tended to be left-skewed and had excess positive kurtosis. Mean survey-level SD was greater, mean skewness more negative, and mean kurtosis more positive in WRA surveys compared to child surveys. All these findings were broadly similar to those from DHS surveys. Mean SD in DHS surveys was higher than that in our data for both children (1.48 vs. 1.34) and WRA (1.58 vs. 1.43).

CONCLUSIONS

We observed several statistical characteristics of Hb distributions that may not necessarily be indicative of data quality problems and bear strong similarities with the characteristics found in DHS surveys. Hb distributions tended to be negatively skewed and positively kurtotic, and SD in many surveys exceeded 1.5 (previously proposed upper plausible range). Based on our empirical evidence, surveys with skewness above + 0.2 and kurtosis below -0.5 or Hb SD outside the range of 1.1-1.55 g/dL for children (6-59 mo) or 1.1-1.65 g/dL for non-pregnant WRA (15-49 y) may require further quality investigation.

Clinical and Analytic Accuracy of Simultaneously Acquired Hemoglobin Measurements: A Multi-Institution Cohort Study to Minimize Redundant Laboratory Usage

OBJECTIVES

Frequent diagnostic blood sampling contributes to anemia among critically ill children. Reducing duplicative hemoglobin testing while maintaining clinical accuracy can improve patient care efficacy. The objective of this study was to determine the analytical and clinical accuracy of simultaneously acquired hemoglobin measurements with different methods.

DESIGN

Retrospective cohort study.

SETTING

Two U.S. children's hospitals.

PATIENTS

Children (< 18 yr old) admitted to the PICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We identified hemoglobin results from complete blood count (CBC) panels paired with blood gas (BG) panels and point-of-care (POC) devices. We estimated analytic accuracy by comparing hemoglobin distributions, correlation coefficients, and Bland-Altman bias. We measured clinical accuracy with error grid analysis and defined mismatch zones as low, medium, or high risk-based on deviance from unity and risk of therapeutic error. We calculated pairwise agreement to a binary decision to transfuse based on a hemoglobin value. Our cohort includes 49,004 ICU admissions from 29,926 patients, resulting in 85,757 CBC-BG hemoglobin pairs. BG hemoglobin was significantly higher (mean bias, 0.43-0.58 g/dL) than CBC hemoglobin with similar Pearson correlation ( R2 ) (0.90-0.91). POC hemoglobin was also significantly higher, but of lower magnitude (mean bias, 0.14 g/dL). Error grid analysis revealed only 78 (< 0.1%) CBC-BG hemoglobin pairs in the high-risk zone. For CBC-BG hemoglobin pairs, at a BG hemoglobin cutoff of greater than 8.0 g/dL, the "number needed to miss" a CBC hemoglobin less than 7 g/dL was 275 and 474 at each institution, respectively.

CONCLUSIONS

In this pragmatic two-institution cohort of greater than 29,000 patients, we show similar clinical and analytic accuracy of CBC and BG hemoglobin. Although BG hemoglobin values are higher than CBC hemoglobin values, the small magnitude is unlikely to be clinically significant. Application of these findings may reduce duplicative testing and decrease anemia among critically ill children.

The relationship between hemoglobin and [Formula: see text]: A systematic review and meta-analysis

OBJECTIVE

There is widespread agreement about the key role of hemoglobin for oxygen transport. Both observational and interventional studies have examined the relationship between hemoglobin levels and maximal oxygen uptake ([Formula: see text]) in humans. However, there exists considerable variability in the scientific literature regarding the potential relationship between hemoglobin and [Formula: see text]. Thus, we aimed to provide a comprehensive analysis of the diverse literature and examine the relationship between hemoglobin levels (hemoglobin concentration and mass) and [Formula: see text] (absolute and relative [Formula: see text]) among both observational and interventional studies.

METHODS

A systematic search was performed on December 6th, 2021. The study procedures and reporting of findings followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Article selection and data abstraction were performed in duplicate by two independent reviewers. Primary outcomes were hemoglobin levels and [Formula: see text] values (absolute and relative). For observational studies, meta-regression models were performed to examine the relationship between hemoglobin levels and [Formula: see text] values. For interventional studies, meta-analysis models were performed to determine the change in [Formula: see text] values (standard paired difference) associated with interventions designed to modify hemoglobin levels or [Formula: see text]. Meta-regression models were then performed to determine the relationship between a change in hemoglobin levels and the change in [Formula: see text] values.

RESULTS

Data from 384 studies (226 observational studies and 158 interventional studies) were examined. For observational data, there was a positive association between absolute [Formula: see text] and hemoglobin levels (hemoglobin concentration, hemoglobin mass, and hematocrit (P<0.001 for all)). Prespecified subgroup analyses demonstrated no apparent sex-related differences among these relationships. For interventional data, there was a positive association between the change of absolute [Formula: see text] (standard paired difference) and the change in hemoglobin levels (hemoglobin concentration (P<0.0001) and hemoglobin mass (P = 0.006)).

CONCLUSION

These findings suggest that [Formula: see text] values are closely associated with hemoglobin levels among both observational and interventional studies. Although our findings suggest a lack of sex differences in these relationships, there were limited studies incorporating females or stratifying results by biological sex.

Exploring the Involvement of Cytokines in Pediatric Patients Afflicted by Simple Febrile Seizures: A Case-Control Study

AIM

Most children under six with seizures experience febrile seizures (FS), which occur with a temperature of 38°C or higher and no apparent infectious or metabolic causes. FS has a multifaceted etiology, involving genetic and environmental factors. This study aimed to explore the connection between the cytokine system (part of the immune system related to inflammation) and FS to uncover potential relationships.

METHOD

This research was carried out on 50 patients experiencing FS and 25 patients experiencing only fever served as cases and controls, respectively. The patient's blood was obtained under sterile circumstances from the antecubital/femoral vein as soon as feasible following the commencement of seizures. The complete hemogram analysis was done using the Mindray BC-5800 auto hematology analyzer (Mindray Medical International Limited, Shenzhen, China).

RESULT

The cases group had significantly higher interleukin-4 (IL-4) concentrations (292.85 pg/mL) than controls (81.04 pg/mL), indicating a statistically significant difference (p<0.05), respectively. In the current research, case participants had a significantly lower mean level of interleukin-6 (IL-6) than control participants. The average IL-6 concentration in cases was 28.00 pg/mL, whereas in controls was 93.09pg/mL. Patients with FS have an important function for the cytokine network to perform.

CONCLUSION

The findings showed a significant difference in cytokine concentrations between patients with FS and control subjects, highlighting a potential link between the cytokine system and FS. Additionally, lower levels of IL-6 in case participants suggest a complex role of cytokines in FS, emphasizing the importance of the cytokine network in this condition.

Association between maternal haemoglobin concentrations and maternal and neonatal outcomes: the prospective, observational, multinational, INTERBIO-21st fetal study

BACKGROUND

Anaemia in pregnancy is a global health problem with associated maternal and neonatal morbidity and mortality. We aimed to investigate the association between maternal haemoglobin concentrations during pregnancy and the risk of adverse maternal and neonatal outcomes.

METHODS

In this prospective, observational, multinational, INTERBIO-21st fetal study conducted at maternity units in Brazil, Kenya, Pakistan, South Africa, and the UK, we enrolled pregnant women (aged ≥18 years, BMI <35 kg/m2, natural conception, and singleton pregnancy) who initiated antenatal care before 14 weeks' gestation. At each 5±1 weekly visit until delivery, information was collected about the pregnancy, as well as the results of blood tests taken as part of routine antenatal care, including haemoglobin values. The outcome measures were maternal (gestational diabetes, pregnancy-induced hypertension, and preterm premature rupture of membranes) and neonatal outcomes (small for gestational age, preterm birth, and acute respiratory distress syndrome).

FINDINGS

Between Feb 8, 2012, and Nov 30, 2019, 2069 women (mean age 30·7 years [SD 5·0]) had at least one routinely haemoglobin concentration measured at 14-40 weeks' gestation, contributing 4690 haemoglobin measurements for the analysis. Compared with a haemoglobin cutoff of 110 g/L, the risk was increased more than two-fold for pregnancy-induced hypertension at haemoglobin concentrations of 170 g/L (risk ratio [RR] 2·29 [95% CI 1·19-4·39]) and higher, for preterm birth at haemoglobin concentrations of 70 g/L (RR 2·04 [95% CI 1·20-3·48]) and 165 g/L (RR 2·06 [95% CI 1·41-3·02]), and for acute respiratory distress syndrome at haemoglobin concentrations of 165 g/L (RR 2·84 [95% CI 1·51-5·35]). Trimester-specific results are also presented.

INTERPRETATION

Our data suggests that the current WHO haemoglobin cutoffs are associated with reduced risk of adverse maternal and neonatal outcomes. The current haemoglobin concentration cutoffs during pregnancy should not only consider thresholds for low haemoglobin concentrations that are associated with adverse outcomes but also define a threshold for high haemoglobin concentrations given the U-shaped relationship between haemoglobin concentration and adverse neonatal and maternal outcomes.

FUNDING

Bill & Melinda Gates Foundation.

Silk Fibroin Particles as Carriers in the Development of Hemoglobin-Based Oxygen Carriers

Oxygen therapeutics have a range of applications in transfusion medicine and disease treatment. Synthetic molecules and all-natural or semi-synthetic hemoglobin-based oxygen carriers (HBOCs) have seen success as potential circulating oxygen carriers. However, many early HBOC products stalled in development due to side effects from excess hemoglobin in the blood stream and hemoglobin entering the tissue. To overcome these issues, research has focused on increasing the molecular diameter of hemoglobin by polymerizing hemoglobin molecules or encapsulating hemoglobin in liposomal carriers. This work leverages the properties of silk fibroin, a cytocompatible and non-thrombogenic biopolymer, known to entrap protein-based cargo, to engineer a fully protein-based oxygen carrier. Herein, an all-aqueous solvent evaporation technique was used to form silk particles via phase separation from a bulk polyvinyl alcohol phase (PVA). Particles size was tuned, and particles were formed with and without hemoglobin. The encapsulation efficiency and ferrous state of hemoglobin were analyzed, resulting in 60% encapsulation efficiency and a maximum of 20% ferric hemoglobin, yielding 100 µg/mL active hemoglobin in certain sfHBOC formulations. The system did not elicit a strong inflammation response in vitro, demonstrating the potential for this particle system to serve as an injectable HBOC.

Prevalence of and factors associated with childhood anaemia in remote villages of the Peruvian Amazon: a cross-sectional study and geospatial analysis

BACKGROUND

Anaemia is a public health problem in Peru. In the Loreto region of the Amazon, ≥50% of children may be anaemic, although insufficient information exists for rural villages.

METHODS

To generate more data about childhood anaemia in the Peruvian Amazon, haemoglobin was measured as part of a trachoma survey in 21 randomly selected villages. All children 1-9 y of age from 30 randomly selected households per village were recruited. Anaemia was classified according to the World Health Organization guidelines and a socio-economic status (SES) index was created for each household using principal component analysis. Spatial autocorrelation was determined using Moran's I and Ripley's K function.

RESULTS

Of 678 children with complete haemoglobin data, 25.4% (95% confidence interval [CI] 21.2 to 30.1) had mild-or-worse anaemia and 22.1% (95% CI 15.6 to 30.3) had moderate-or-worse anaemia. Mild-or-worse anaemia was more common among children whose primary source of drinking water was surface water (prevalence ratio [PR] 1.26 [95% CI 1.14 to 1.40], p<0.001) and who were in the lowest SES tercile (PR 1.16 [95% CI 1.02 to 1.32], p=0.021). Moderate-or-worse anaemia was more common among boys (PR 1.32 [95% CI 1.09 to 1.60], p=0.005). No evidence of geospatial clustering was found.

CONCLUSIONS

Remote villages of the Amazon would benefit from interventions for childhood anaemia and the poorest households would have the most to gain. Integrating anaemia screening into neglected tropical diseases surveys is an opportunity to use public health resources more efficiently.

Diagnosing anemia: Challenges selecting methods, addressing underlying causes, and implementing actions at the public health level

Accurate and affordable tools for diagnosing anemia and its main determinants are essential for understanding the magnitude and distribution of the problem and the appropriate interventions needed for its timely prevention and treatment. The objective of this review is to address methods, equipment, and sample-related and quality control aspects of hemoglobin measurement for anemia diagnosis. Also, other iron-, infectious-, and genetic-related causes of anemia are addressed in individuals and populations. The best practice for hemoglobin determination is the use of venous blood, analyzed on automated hematology analyzers, with high-quality control measures in place. The importance of a correct anemia diagnosis is highlighted by the cost of a misdiagnosis. A false-negative diagnosis may result in missing out and not treating anemia, its causes, and its adverse effects. On the other hand, a false-positive diagnosis may result in the provision of unneeded treatment or referral for expensive laboratory tests to determine a cause of anemia, wasting valuable resources and risking causing harm. At the individual level, clinicians must understand the causes of absolute and functional anemia to diagnose and treat anemia at the clinical level. Actions toward anemia diagnosis and control at public health levels require global, regional, and country actions that should cover general and context-specific characteristics.

Factors associated with anaemia in pregnancy: A retrospective cross-sectional study in the Bolgatanga Municipality, northern Ghana

BACKGROUND

Anaemia in pregnancy (AIP) remains a severe public health problem associated with adverse outcomes. This study assessed haemoglobin levels and the prevalence of anaemia during antenatal care (ANC) registration, at 28 weeks and 36 weeks of gestation as well as the factors associated with AIP at the different stages of pregnancy.

METHODS

A retrospective cross-sectional design was implemented. Using ANC registers as the sampling frame, 372 pregnant women, within 36 and 40 weeks of gestation were randomly sampled from 28 health facilities for the study. The participants were all receiving ANC in the Bolgatanga Municipality. Data were collected via clinical records review and a questionnaire-based survey between October and November, 2020. Using the Statistical Package for the Social Sciences (SPSS), descriptive analysis of haemoglobin levels and the prevalence of anaemia were performed. In addition, binary logistic regression was used to identify the factors associated with anaemia in pregnancy. AIP was determined using the national practice of 11.0g/dl haemoglobin cut-off point and the World Health Organisation's recommended adjustment for the 2nd trimester of pregnancy was made using the cut-off of 10.5g/dl to account for the effect of haemodilution.

RESULTS

At booking, AIP prevalence was 35.8% (95%CI:30.9, 40.9) using a cut-off of 11.0g/dl and 25.3% (95%CI:20.9, 30.0) using a cut-off of 10.5g/dl for those in the 2nd trimester. At 28 weeks, AIP prevalence was 53.1% (95%CI:45.8, 60.3) and 37.5 (95%CI:30.6, 44.8) using a cut-off of 11.0g/dl and 10.5g/dl for those in the 2nd trimester, respectively. At 36 weeks, AIP prevalence was 44.8% (95%CI:39.2, 50.4) using a cut-off of 11.0g/dl. At p<0.05, registering after the first trimester (AOR = 1.87, 95%CI: 1.17, 2.98, P = 0.009) and at a regional hospital (AOR = 2.25, 95%CI: 1.02, 4.98, P = 0.044) were associated with increased odds of AIP but registering at a private hospital (AOR = 0.32, 95%CI: 0.11, 0.92, P = 0.035) was associated with decreased odds of AIP at booking. At 28 weeks, age group 26-35 years (AOR = 0.46, 95%CI: 0.21, 0.98, P = 0.044), Christianity (AOR = 0.32, 95%CI: 0.31, 0.89, P = 0.028.), high wealth (AOR = 0.27, 95%CI: 0.09, 0.83, P = 0.022) and tertiary education (AOR = 0.09, 95%CI:0.02, 0.54, P = 0.009) were associated with decreased odds of AIP. At 36 weeks, booking after first trimester of pregnancy was associated with increased odds (AOR = 1.72, 95%CI: 1.05, 2.84, P = 0.033) whilst high wealth (AOR = 0.44, 95%CI: 0.20, 0.99, P = 0.049), higher age groups-26-35 (AOR = 0.38, 95%CI: 0.21, 0.68, P = 0.001) and 36-49 years (AOR = 0.35, 95%CI: 0.13, 0.90, P = 0.024) and secondary education of spouse were associated with reduced odds (AOR = 0.35, 95%CI: 0.14, 0.88, P = 0.026) of AIP.

CONCLUSION

AIP consistently increased from registration to 36 weeks of gestation. Given the observed correlates of AIP, we recommend that interventions geared towards early ANC registration, improved household wealth, and improved maternal education are required to reduce AIP.

The Prevalence of Anemia in Children Aged 6-23 Months and its Correlates Differ by District in Kapilvastu and Achham Districts in Nepal

Background

Analyses of predictors of anemia or malnutrition often pool national or regional data, which may hide variability at subnational levels.

Objectives

We sought to identify the risk factors for anemia in young Nepali children aged 6-23 mo in 2 districts: Kapilvastu and Achham.

Methods

This is an analysis of two cross-sectional surveys that were conducted as part of a program evaluation of an infant and young child feeding and micronutrient powder intervention that included anemia as a primary outcome. Baseline and endline surveys in each district (in 2013 and 2016) included hemoglobin assessments in n = 4709 children who were representative of children 6-23 mo in each district. Log-binomial regression models accounting for the survey design were used to estimate univariable and multivariable prevalence ratios for risk factors at multiple levels-underlying, direct, and biological causes. Average attributable fractions (AFs) for the population were calculated for significant predictor biomarkers of anemia in multivariable models.

Results

In Accham, the prevalence of anemia was 31.4%; significant predictors included child's age, household asset ownership, length-for-age z-score, inflammation (CRP concentration > 0.5 mg/L; α-1 acid glycoprotein concentration > 1 mg/mL), and iron deficiency (serum ferritin concentration < 12 μg/L with BRINDA-inflammation adjustment). In Kapilvastu, the prevalence of anemia was 48.1%; significant predictors included child's sex and ethnicity, wasting and weight-for-length z-score, any morbidity in the previous 2 wk, consumption of fortified foods, receipt of multiple micronutrient powder distributions, iron deficiency, zinc deficiency (nonfasting serum zinc concentration of <65 μg/dL in the morning and that of <57 μg/dL in the afternoon), and inflammation. In Achham, average AFs were 28.2% and 19.8% for iron deficiency and inflammation, respectively. Average AFs for anemia in Kapilvastu were 32.1%, 4.2%, and 4.9% for iron deficiency, zinc deficiency, and inflammation, respectively.

Conclusions

The prevalence of anemia and its risk factors varied between districts, with inflammation contributing to a greater share of anemia in Achham than in Kapilvastu. The estimated AF for iron deficiency was around 30% in both districts; iron-delivering interventions and multisectoral approaches to anemia are warranted.

Accelerating action to reduce anemia: Review of causes and risk factors and related data needs

Anemia is a major public health concern. Young children, menstruating adolescent girls and women, and pregnant women are among the most vulnerable. Anemia is the consequence of a wide range of causes, including biological, socioeconomic, and ecological risk factors. Primary causes include: iron deficiency; inherited red blood cell disorders; infections, such as soil-transmitted helminthiasis, schistosomiasis, and malaria; gynecological and obstetric conditions; and other chronic diseases that lead to blood loss, decreased erythropoiesis, or destruction of erythrocytes. The most vulnerable population groups in low- and middle-income countries are often at the greatest risk to suffer from several of these causes simultaneously as low socioeconomic status is linked with an increased risk of anemia through multiple pathways. Targeted and effective action is needed to prevent anemia. Understanding the causes and risk factors of anemia for different population subgroups within a country guides the design and implementation of effective strategies to prevent and treat anemia. A coordinated approach across various expert groups and programs could make the best use of existing data or could help to determine when newer and more relevant data may need to be collected, especially in countries with a high anemia burden and limited information on the etiology of anemia.

Prevalence of anemia and associated factors among adults in a select population in Lagos, Southwest Nigeria

Background

Anemia is a public health problem affecting people in both the developed and developing world and has serious consequences on health.

Objective

This study determines the prevalence of anemia amongst people of different socioeconomic levels, associated factors, and the prevalence of anemia in populations other than children or pregnant women.

Methods

This is a descriptive cross-sectional study using a pretested interviewer-administered questionnaire to collect data from 387 residents. A multi-stage random sampling technique was used. Analysis of blood samples using the HemoCue301 system and data analysis using SPSS 20. Chi-square test and binary logistic regression were used to test association and determine predictors of anemia respectively, with P<0.05 considered statistically significant.

Results

The mean age of respondents was 35±11.8 years, with 28.9% of respondents being anemic. Female respondents (52.7%) were more than male respondents (47.3%). Female respondents (39.2%) had a higher prevalence of anemia than male respondents (17.5%). There was a significant association between sex, level of education, and anemia status. Being female, having no formal education, or only having a primary school level of education were significant predictors of anemia [odds ratio (OR)=2.55; 95% confidence interval (CI)=1.54, 4.23; P=0.00; OR=12.57; 95%CI=2.39, 66.27; P=0.00; and OR=2.54; 95%CI=1.16, 5.58; P=0.02 respectively].

Conclusion

There was a higher prevalence of anemia among women, younger people, and those with no or only primary levels of formal education. Awareness programs targeted at women and people with lower levels of education are necessary to reduce the overall prevalence of anemia in this region.

Association between hemoglobin and elevation among school-aged children: a verification of proposed adjustments

BACKGROUND

Anemia is defined by a hemoglobin (Hb) concentration lower than normal based on cutoffs specific to age, sex, and pregnancy status. Hemoglobin increases with elevation as an adaptive response to lower blood oxygen saturation, thus, adjusting Hb concentration for elevation is necessary before applying cutoffs.

OBJECTIVE

Recent evidence among preschool-aged children (PSC) and non-pregnant reproductive-aged women (WRA) suggests that current World Health Organization (WHO) recommended Hb adjustments for elevation need updating. To confirm these findings, we examined the cross-sectional association between Hb and elevation among non-pregnant school-age children (SAC).

METHODS

Using data from 9 population-based surveys, we examined 26,518 SAC 5-14 years (54.5% female) with data on Hb and elevation (-6 to 3,834 meters, m). We used generalized linear models to assess the association between Hb and elevation under varying conditions, including controlling for inflammation-corrected iron and vitamin A deficiency. Hemoglobin adjustments for each 500 m increase in elevation were estimated for SAC and compared to existing adjustments and those estimated for PSC and WRA. We evaluated the impact of adjustments on anemia prevalence.

RESULTS

Hemoglobin concentration (g/L) was positively associated with elevation (m). The SAC elevation adjustments were consistent with those reported among PSC and WRA and suggest current recommendations may under-adjust Hb for those residing at lower elevations (<3000 m) and over-adjust Hb for those residing at higher elevations (>3000 m). Among the surveys included, proposed elevation adjustments increased anemia prevalence among SAC by 0 (Ghana, United Kingdom) to 15 (Malawi) percentage points relative to current elevation adjustments.

CONCLUSION

Results confirm that current recommended Hb adjustments for elevation may need updating, and anemia prevalence in SAC may be higher than currently estimated. Findings will inform the WHO reexamination of global guidelines on the use of Hb adjustments for anemia assessment and may result in improved identification and treatment of anemia.

The efficacy of Bloso fish (Glossogobius giuris sp.) in improving hemoglobin, hematocrit, platelet, and albumin levels of Wistar rats with hypoalbuminemia

Tuberculosis (TB) is an infectious disease worldwide that causes death. Common clinical manifestations of patients with TB include anemia, hypoalbuminemia, and malnutrition. Most patients with TB are infected with coccus bacteria, such as Staphylococcus aureus, that commonly attack the respiratory tract. However, the consumption of heme protein sources could improve the nutritional status of patients with TB. Fish comprise one of the most widely consumed sources of heme. The bloso fish (Glossogobius giuris sp.), considered a fish without economic value is a new alternative source of heme protein. This study aimed to develop supplements using bloso fish (Glossogobius giuris sp.). This study used an experimental pretest-post-test control group design. Seven male Wistar rats were used as the negative control group. Twenty- eight male Wistar rats were administered S. aureus, fed a protein-deficient diet, and divided into the positive control group, the K1 group, which received up to 675 mg/200 g of bloso fish flour, the K2 group, which received up to 67.5 mg/200 g of bloso fish oil, and the K3 group, which received up to 675 mg/200 g of bloso fish fluor from oil extraction dregs. Treatment was administered for 28 days. The hemoglobin (Hb), hematocrit (Ht), platelet, and albumin levels in blood serum from the retroorbital vein were measured. Data were processed using a paired t-test and one-way analysis of variance. The results showed differences in Hb, Ht, platelet, and albumin levels were observed before and after treatment. Additionally, differences in Hb, Ht, platelet, and albumin levels were observed in the groups that received bloso fish flour and bloso fish oil. Bloso fish flour and bloso fish oil increased the Hb, Ht, platelet, and albumin levels of rats with hypoalbuminemia.

Smartphone-based point-of-care anemia screening in rural Bihar in India

BACKGROUND

The high prevalence of anemia in resource-constrained settings calls for easy-to-use, inexpensive screening tools. The Sanguina Smartphone App, an innovative tool for non-invasive hemoglobin estimation via color-sensitive, algorithm-based analysis of fingernail bed images, was validated in the United States. This study evaluates the performance of the App in a population with different socio-economic, ethnic, demographic and cultural composition in rural Bihar, India.

METHODS

For 272 mainly adult patients of a private health centre, hemoglobin measurement with the App is compared with the gold standard laboratory blood analysis. For a second sample of 179 children attending pre-schools, hemoglobin measurement with the App is compared to the results of the HemoCue Hb 301, a point-of-care device using a small blood sample, serving as the reference standard for field-based settings.

RESULTS

The App reaches ±4.43 g/dl accuracy and 0.38 g/dl bias of comparator values in the clinic-based sample, and ±3.54 g/dl and 1.30 g/dl, respectively in the pre-school sample. After retraining the algorithm with the collected data, the validity of the upgraded version is retested showing an improved performance (accuracy of ±2.25 g/dl, bias of 0.25 g/dl), corresponding to the results of the original validation study from the United States.

CONCLUSIONS

The initial version of the App does not achieve the accuracy needed for diagnosis or screening. After retraining the algorithm, it achieves an accuracy sufficient for screening. The improved version with the potential for further adaptions is a promising easy-to-use, inexpensive screening tool for anemia in resource-constrained point-of-care settings.

Silk Fibroin Particles as Carriers in the Development of All-Natural Hemoglobin-Based Oxygen Carriers (HBOCs)

Oxygen therapeutics have a range of applications in transfusion medicine and disease treatment. Synthetic molecules and all-natural or semi-synthetic hemoglobin-based oxygen carriers (HBOCs) have seen success as potential circulating oxygen carriers. However, many early HBOC products were removed from the market due to side effects from excess hemoglobin in the blood stream and hemoglobin entering the tissue. To overcome these issues, research has focused on increasing the molecular diameter of hemoglobin by polymerizing hemoglobin molecules or encapsulating hemoglobin in liposomal carriers, where immune responses and circulation times remain a challenge. This work looks to leverage the properties of silk fibroin, a cytocompatible and non-thrombogenic biopolymer, known to entrap protein-based cargo, to engineer a silk fibroin-hemoglobin-based oxygen carrier (sfHBOC). Herein, an all-aqueous solvent evaporation technique was used to form silk fibroin particles with and without hemoglobin to tailor the formulation for specific particle sizes. The encapsulation efficiency and ferrous state of hemoglobin were analyzed, resulting in 60% encapsulation efficiency and a maximum of 20% ferric hemoglobin, yielding 100 µg/mL active hemoglobin in certain sfHBOC formulations. The system did not elicit a strong inflammation response in vitro, demonstrating the potential for this particle system to serve as an injectable HBOC.

Causes of Moderate and Severe Anaemia in a High-HIV and TB-Prevalent Adult Population in the Eastern Cape Province, South Africa

BACKGROUND

Anaemia affects one in four adults in South Africa, with a higher prevalence in persons with HIV and tuberculosis. The aim of this study is to characterise the causes of anaemia in primary care and a district hospital setting.

METHODS

A cross-sectional study design investigated a purposive sample of adult males and non-pregnant females at two community health centres and a hospital casualty and outpatients. Fingerpick blood haemoglobin was measured with HemoCueHb201+. Those with moderate and severe anaemia underwent clinical examination and laboratory tests.

RESULTS

Of 1327 patients screened, median age was 48 years, and 63.5% were female. Of 471 (35.5%) with moderate and severe anaemia on HemoCue, 55.2% had HIV, 16.6% tuberculosis, 5.9% chronic kidney disease, 2.6% cancer, and 1.3% heart failure. Laboratory testing confirmed 227 (48.2%) with moderate and 111 (23.6%) with severe anaemia, of whom 72.3% had anaemia of inflammation, 26.5% iron-deficiency anaemia, 6.1% folate deficiency, and 2.5% vitamin B12 deficiency. Overall, 57.5% had two or more causes of anaemia. Multivariate modelling showed that patients with severe anaemia were three times more likely to have tuberculosis (OR = 3.1, 95% CI = 1.5-6.5; p-value = 0.002). Microcytosis was present in 40.5% with iron deficiency, macrocytosis in 22.2% with folate deficiency, and 33.3% with vitamin B12 deficiency. The sensitivities of the reticulocyte haemoglobin content and % hypochromic red blood cells in diagnosing iron deficiency were 34.7% and 29.7%, respectively.

CONCLUSIONS

HIV, iron deficiency, and tuberculosis were the most prevalent causes of moderate and severe anaemia. The majority had multiple causes. Iron, folate, and vitamin B12 deficiencies should be identified by biochemical testing rather than by red cell volume.

Optimization of the Hemolysis Assay for the Assessment of Cytotoxicity

In vitro determination of hemolytic properties is a common and important method for preliminary evaluation of cytotoxicity of chemicals, drugs, or any blood-contacting medical device or material. The method itself is relatively straightforward, however, protocols used in the literature vary substantially. This leads to significant difficulties both in interpreting and in comparing the obtained values. Here, we examine how the different variables used under different experimental setups may affect the outcome of this assay. We find that certain key parameters affect the hemolysis measurements in a critical manner. The hemolytic effect of compounds tested here varied up to fourfold depending on the species of the blood source. The use of different types of detergents used for generating positive control samples (i.e., 100% hemolysis) produced up to 2.7-fold differences in the calculated hemolysis ratios. Furthermore, we find an expected, but substantial, increase in the number of hemolyzed erythrocytes with increasing erythrocyte concentration and with prolonged incubation time, which in turn affects the calculated hemolysis ratios. Based on our findings we propose an optimized protocol in an attempt to standardize future hemolysis studies.

Comparison of Anemia Screening Methods Using Paired Venous Samples in Women of Reproductive Age in Southern India

BACKGROUND

Anemia is an important public health problem, and accurate estimates may inform policy and programs. Although hemoglobin (Hb) assessment of venous blood via automated hematology analyzers (AHAs) is recommended, most population-based surveys estimate anemia prevalence based on analysis of capillary blood via portable hemoglobinometers.

OBJECTIVES

We aimed to evaluate screening methods for hemoglobin and anemia assessment using paired venous samples.

METHODS

Participants were women 15-40 y who were not pregnant or lactating. Paired venous whole blood samples (n = 896) were analyzed for hemoglobin (Hb) via portable hemoglobinometer (HemoCue 301) and Coulter Counter AHA. Anemia and severe anemia were defined as Hb <12.0g/dL and <8.0 g/dL, respectively. Bland-Altman methods were used to assess the level of agreement for Hb results (mean difference, SD of differences, limits of agreement). Diagnostic accuracy parameters (sensitivity, specificity, positive predictive value, negative predictive value, accuracy) were calculated to evaluate HemoCue performance compared to the AHA reference, overall and by sociodemographic, nutritional, and metabolic characteristics.

RESULTS

The estimated anemia prevalence was significantly lower via HemoCue vs. AHA (36.3% compared with 41.6%; P value < 0.0001). The HemoCue had 84.4% accuracy for anemia screening and 98.8% for severe anemia, compared to the AHA reference. The HemoCue had 74.8% sensitivity and 91.2% specificity, compared to AHA. HemoCue sensitivity was higher in women with iron deficiency [serum ferritin (SF) <15.0 μg/L: 81.6% compared with SF ≥15.0 μg/L: 41.3%], and lower in women with metabolic risk factors, including overweight [BMI ≥25.0 kg/m2: 63.9% vs. BMI <25.0 kg/m2: 78.8%], or elevated CRP (>1.0 mg/L: 67.2% vs. ≤1.0 mg/L: 82.9%), trunk fat (>35%: 62.7% vs. ≤35%: 80.1%), or whole-body fat (>35%: 63.9% vs. ≤35%: 80.3%).

CONCLUSIONS

Findings suggest that women with anemia may be incorrectly identified as not anemic via portable hemoglobinometer, and anemia prevalence may be underestimated at the population level.This study was registered at clinicaltrials.gov as NCT04048330.

A Smartphone-Based Disposable Hemoglobin Sensor Based on Colorimetric Analysis

Hemoglobin is a biomarker of interest for the diagnosis and prognosis of various diseases such as anemia, sickle cell disease, and thalassemia. In this paper, we present a disposable device that has the potential of being used in a setting for accurately quantifying hemoglobin levels in whole blood based on colorimetric analysis using a smartphone camera. Our biosensor employs a disposable microfluidic chip which is made using medical-grade tapes and filter paper on a glass slide in conjunction with a custom-made PolyDimethylSiloaxane (PDMS) micropump for enhancing capillary flow. Once the blood flows through the device, the glass slide is imaged using a smartphone equipped with a custom 3D printed attachment. The attachment has a Light Emitting Diode (LED) that functions as an independent light source to reduce the noise caused by background illumination and external light sources. We then use the RGB values obtained from the image to quantify the hemoglobin levels. We demonstrated the capability of our device for quantifying hemoglobin in Bovine Hemoglobin Powder, Frozen Beef Blood, and human blood. We present a logarithmic model that specifies the relationship between the Red channel of the RGB values and Hemoglobin concentration.

Drops of Capillary Blood Are Not Appropriate for Hemoglobin Measurement with Point-of-Care Devices: A Comparative Study Using Drop Capillary, Pooled Capillary, and Venous Blood Samples

Population-based surveys matched by time but using different methodologies for determining hemoglobin (Hb) concentration have shown inconsistencies in estimating anemia prevalence. This study aimed to estimate measurement errors in Hb quantification in HemoCue 201+ using venous blood (VB) and capillary blood both drops (DCB) and pools (PCB), and compare the results against those of a reference method (VB analyzed in hematology analyzers based on the cyanmethemoglobin method). Children (n = 49), adult females (n = 50), and older adults (n = 50) were randomly allocated to donate VB (4 mL) and either DCB (three drops) or PCB (350 µL). Results in HemoCue were analyzed through Bland Altman and Lyn's concordance against Hb concentration by the reference method. A positive average bias (systematic error) was found for the HemoCue (0.31 g/dL) using the same VB samples. This value was then subtracted from all readings carried out in the device. After this adjustment, DCB still produced a positive bias (0.42 ± 0.81 g/dL), and the variation of single results was ±1.6 g/dL (95% CI). PCB and VB performed similarly; the average bias was negligible (-0.02 ± 0.36 and 0.00 ± 0.33 g/dL, respectively) and the variation of the results (95% CI) was ±0.7 g/dL or lower. Lyn's concordance values were 0.86, 0.96, and 0.98 for DCB, PCB, and VB, respectively. Random variation using DCB is too large to approximate the true Hb values, and therefore DCB should be discontinued for diagnosing anemia both in individuals and in populations.

Current Status of Measurement Accuracy for Total Hemoglobin Concentration in the Clinical Context

OBJECTIVE

The main objective of this investigation is to provide data about the accuracy of total hemoglobin concentration measurements with respect to clinical settings, and to devices within the categories of point-of-care and reference systems. In particular, tolerance of hemoglobin concentrations below 9 g/dL that have become common in clinical practice today determines the need to demonstrate the limits of measurement accuracy in patient care.

METHODS

Samples extracted from six units of heparinized human blood with total hemoglobin concentrations ranging from 3 to 18 g/dL were assigned to the test devices in a random order. The pool of test devices comprised blood gas analyzers, an automatic hematology analyzer, a laboratory reference method, and the point-of-care system HemoCue. To reduce the pre-analytic error, each sample was measured three times. Due to the characteristics of the tested devices and methods, we selected the mean values of the data from all these devices, measured at the corresponding total hemoglobin concentrations, as the reference.

MAIN RESULTS

The measurement results of the test devices overlap within strict limits (R² = 0.999). Only the detailed analysis provides information about minor but systematic deviations. In the group of clinically relevant devices, which are involved in patient blood management decisions, the relative differences were within the limit of +/- 5 % for values down to 3 g/dL.

CONCLUSIONS

A clinically relevant change of +/- 0.5 g/dL of total hemoglobin concentration can be detected with all selected devices and methods. Compliance with more stringent definitions-these are the relative differences of 5 % in relation to the corresponding reference values and the clinically adapted thresholds in the format of a tolerance level analysis-was achieved by the clinical devices assessed here.

Blood draw site and analytic device influence hemoglobin measurements

Anemia is a continuing global public health concern and a priority for international action. The prevalence of anemia is estimated from the hemoglobin (Hb) levels within target populations, yet the procedures for measuring Hb are not standardized and different approaches may result in discrepancies. Several analytical variables have been proposed to influence Hb measurements, but it is difficult to understand the impact on specific variables from large population or field studies. Therefore, we designed a highly controlled protocol that minimized most technical parameters to specifically investigate the impact of blood draw site and analytic device on Hb measurements. A diverse cohort of sixty healthy adults each provided a sequential capillary and venous blood sample that were measured for Hb using an automated hematology analyzer (ADVIA-2120) and two point-of-care devices (HemoCue 201+ and HemoCue 301). Comparing blood draw sites, the mean Hb content was 0.32-0.47 g/dL (2-4%) higher in capillary compared to venous blood from the same donors. Comparing different Hb measuring instruments, the mean Hb content was 0.19-0.46 g/dL (1-4%) higher measured with HemoCue devices compared to ADVIA-2120 in both capillary and venous blood from the same donors. The maximum variance in measurement was also higher with HemoCue devices using blood from venous (5-6% CV) and capillary (21-25% CV) sites compared to ADVIA-2120 (0.6-2% CV). Other variables including blood collection tube manufacturer did not affect mean Hb content. These results demonstrate that even when most technical variables are minimized, the blood draw site and the analytical device can have a small but statistically significant effect on the mean and dispersion of Hb measurements. Even in this study, the few participants identified as mildly anemic using venous blood measured by ADVIA-2120 would not have been classified as anemic using their capillary blood samples or point-of-care analyzers. Thus, caution is warranted when comparing Hb values between studies having differences in blood draw site and Hb measuring device. Future anemia testing should maintain consistency in these analytical variables.

Associations between type of blood collection, analytical approach, mean haemoglobin and anaemia prevalence in population-based surveys: A systematic review and meta-analysis

Background

Previous studies have observed that haemoglobin concentrations can be affected by type of blood collection, analysis methods and device, and that near-in-time population-based surveys report substantially different anaemia prevalence. We investigated whether differences in mean haemoglobin or prevalence of anaemia between near-in-time surveys of the same population were associated with differences in type of blood collection or analytic approach to haemoglobin measurement.

Methods

We systematically identified pairs of population-based surveys that measured haemoglobin in the same population of women of reproductive age (WRA) or preschool-aged children (PSC). Surveys were matched on geographic coverage, urban/rural place of residence, inclusion of pregnant women, time of data collection (within 18 months), and, to the extent feasible, age range. Differences in anaemia prevalence were presented graphically. Random-effects meta-analysis and meta-regression of difference in mean haemoglobin were carried out, with subgroups defined by comparison of type of blood collection and analytic approach within each survey pair.

Results

We included 23 survey pairs from 17 countries for PSC and 17 survey pairs from 11 countries for WRA. Meta-regression indicates that surveys measuring haemoglobin with HemoCue® Hb 301 found higher haemoglobin concentrations than near-in-time surveys using HemoCue® Hb 201+ in non-pregnant women ((NPW); 5.8 g/L (95% confidence interval (CI) = 3.2-8.3) mean difference, n = 5 pairs) and PSC (4.3 g/L (1.4-7.2), n = 6). Surveys collecting venous blood found higher haemoglobin concentrations than near-in-time surveys collecting capillary blood in PSC (3.8 g/L (0.8-6.7), n = 8), but not NPW (0.4 g/L (-1.9-2.8), n = 9).

Conclusions

Because this study is observational, differences in haemoglobin concentrations in near-in-time surveys may be caused by other factors associated with choice of analytic approach or type of blood collected. The source or sources of differences should be clarified to improve use of surveys to prioritize and evaluate public health programs.

Registration

PROSPERO CRD42022296553.

Towards an Innovative Sensor in Smart Capsule for Aerial Drones for Blood and Blood Component Delivery

Aerial drone technology is currently being investigated worldwide for the delivery of blood components. Although it has been demonstrated to be safe, the delivered medical substances still need to be analyzed at the end of the flight mission to assess the level of haemolysis and pH prior to the use in a patient. This process can last up to 30 min and prevent the time saved using drone delivery. Our study aims to integrating an innovative sensor for the haemolysis and pH detection into the Smart Capsule, an already demonstrated technology capable of managing transfusion transport through drones. In the proposed scenario, the haemolysis is evaluated optically by a minilysis device using LED-photodetector combination. The preliminary validation has been demonstrated for both the thermal stability of the Smart Capsule and the haemolysis detection of the minilysis device prototype. Firstly, the onboard temperature test has shown that the delivery system is capable of maintaining proper temperature, even though the samples have been manipulated to reach a higher temperature before inserting into the Smart Capsule. Then, in the laboratory haemolysis test, the trend of linear regression between the outputs from the spectrophotometer and the minilysis prototype confirmed the concept design of the minilysis device.

Acid-suppressive therapy among infants and risk of anemia at 12 months of age

Objectives:

Numerous studies have shown that links exist between exposure to acid suppression among adults and nutritional deficiencies, especially vitamin B12 and iron. While the use of acid suppression among children and infants is common, nutritional deficiency remains a concern but does not have numerous studies to support it. We conducted a cohort study to examine this concern; the hypothesis we proposed is that acid-suppressive therapy (AST) during infancy is linked to anemia in the first year of life.

Methods:

This retrospective cohort study included infants born between 2017 and 2018 who visited Legacy Community Health. The inclusion criteria were exposure to acid suppression for a minimum of 1 month and a hemoglobin reading at 12–15 months. Infants who had hemoglobinopathies, failure to thrive, or malabsorption syndromes were excluded. Mean hemoglobin was calculated, and student’s t-test was applied to find statistical differences between the two groups. Change in weight before and after treatment was recorded. Occurrence of respiratory and gastroenterological adverse events was recorded in the exposed group.

Results:

Overall, 135 exposed infants were identified 135 controls were selected. The majority of the sample included Hispanic girls. Ranitidine was the most commonly prescribed medicine. The duration of treatment was 3 months. Weight improved significantly at termination of the treatment. There was no significant difference between the hemoglobin level of cases and controls, and both were not considered anemic.

Conclusion:

AST was not linked to anemia, despite the slightly lower hemoglobin in some cases. There were few weaknesses in our study; therefore, further studies can examine this link by focusing further on medication type and close follow-up. We found that although proton pump inhibitors are considered the first line of treatment, histamine-2 receptor antagonists were more frequently prescribed. Strategies to familiarize general pediatricians with the NSAPGHAN guidelines might be needed.

Iron status and inflammation in women of reproductive age: A population-based biomarker survey and clinical study

BACKGROUND

Women of reproductive age (WRA) are at increased risk for anemia and iron deficiency. However, there is limited population-level data in India, which could help inform evidence-based recommendations and policy.

AIMS

To conduct a population-based biomarker survey of anemia, iron deficiency, and inflammation in WRA in Southern India.

METHODS

Participants were WRA (15-40 y) who were not pregnant or lactating. Blood samples (n = 979) were collected and analyzed for hemoglobin (Hb), serum ferritin (SF), soluble transferrin receptor (sTfR), C-reactive protein (CRP), and alpha-1 acid glycoprotein (AGP). Anemia and severe anemia were defined as Hb < 12.0 and < 8.0 g/dL. Serum ferritin was adjusted for inflammation using BRINDA methods. Iron deficiency was defined as SF <15.0 μg/L, iron insufficiency was defined as SF < 20.0 and < 25.0 μg/L, and iron deficiency anemia was defined as Hb < 12.0 g/dL and SF < 15.0 μg/L. Inflammation was defined as CRP > 5.0 mg/L or AGP > 1.0 g/L. Restricted cubic spline regression models were also used to determine if alternative SF thresholds should be used t to classify iron deficiency.

RESULTS

A total of 41.5% of WRA had anemia, and 3.0% had severe anemia. Findings from spline analyses suggested a SF cut-off of < 15.0 μg/L, consistent with conventional cut-offs for iron deficiency. 46.3% of WRA had SF < 15.0 μg/L (BRINDA-adjusted: 61.5%), 55.0% had SF < 20.0 μg/L (72.7%), 61.8% had SF < 25.0 μg/L (81.0%), and 30.0% had IDA (34.5%). 17.3% of WRA had CRP > 5.0 mg/L and 22.2% had AGP > 1.0 g/L. The prevalence of ID (rural vs. urban: 49.1% vs. 34.9%; p = 0.0004), iron insufficiency (57.8% vs. 43.8%; p = 0.0005), and IDA (31.8% vs. 22.4%; p = 0.01) were significantly higher in rural areas, although CRP levels were lower and there were no differences in elevated CRP or AGP.

CONCLUSIONS

The burden of anemia and iron deficiency in this population was substantial, and increased after adjusting for inflammation, suggesting potential to benefit from screening and interventions.

REGISTRATION NUMBER

NCT04048330.

Acute Cardiovascular and Metabolic Effects of Different Warm-Up Protocols on Dynamic Apnea

The aim of this study was to evaluate the acute physiological response to different warm-up protocols on the dynamic apnea performance. The traditional approach, including a series of short-mid dives in water (WET warm-up), was compared to a more recent strategy, consisting in exercises performed outside the water (DRY warm-up). Nine athletes were tested in two different sessions, in which the only difference was the warm-up executed before 75m of dynamic apnea. Heart rate variability, baroreflex sensitivity, hemoglobin, blood lactate and the rate of perceived exertion were recorded and analyzed. With respect to WET condition, DRY showed lower lactate level before the dive (1.93 vs. 2.60 mmol/L, p = 0.006), higher autonomic indices and lower heart rate during the subsequent dynamic apnea. A significant correlation between lactate produced during WET with the duration of the subsequent dynamic apnea, suggests that higher lactate levels could affect the dive performance (72 vs. 70 sec, p = 0.028). The hemoglobin concentration and the rate of perceived exertion did not show significant differences between conditions. The present findings partially support the claims of freediving athletes who adopt the DRY warm-up, since it induces a more pronounced diving response, avoiding higher lactate levels and reducing the dive time of a dynamic apnea.

Risk factors for hospitalisation and death from COVID-19: a prospective cohort study in South Sudan and Eastern Democratic Republic of the Congo

OBJECTIVES

Our study described demographic characteristics, exposures and symptoms, and comorbidities to evaluate risk factors of hospitalisation and mortality among cases in Juba, South Sudan (SSD) and North and South Kivu in eastern Democratic Republic of the Congo (DRC).

DESIGN

Prospective observational cohort of COVID-19 cases.

METHODS

Individuals presenting for care at one of five study facilities in SSD (n=1) or DRC (n=4) or referred from home-based care by mobile medical teams between December 2020 and June 2021 were eligible for enrolment. Demographic characteristics, COVID-19 exposures, symptoms at presentation, as well as acute and chronic comorbidities, were evaluated using a standard questionnaire at enrolment. Disease progression was characterised by location of care using mixed-effects regression models.

RESULTS

751 individuals were eligible for enrolment. Among cases followed to discharge or death (n=519), 375 were enrolled outpatients (75.7%). A similar number of cases were enrolled in DRC (n=262) and SSD (n=257). Overall mortality was 4.8% (95% CI: 3.2% to 6.9%); there were no outpatient deaths. Patients presenting with any symptoms had higher odds of hospitalisation (adjusted OR (AOR) 2.78, 95% CI 1.47 to 5.27) and all deaths occurred among symptomatic individuals. Odds of both hospitalisation and mortality were greatest among cases with respiratory symptoms; presence of low oxygen levels on enrolment was strongly associated with both hospitalisation (AOR 7.77, 95% CI 4.22 to 14.29) and mortality (AOR 25.29, 95% CI 6.42 to 99.54). Presence of more than one chronic comorbidity was associated with 4.96 (95% CI 1.51 to 16.31) times greater odds of death; neither infectious comorbidities evaluated, nor malnutrition, were significantly associated with increased mortality.

CONCLUSIONS

Consistent with prior literature, older age, low oxygen level, other respiratory symptoms and chronic comorbidities were all risk factors for mortality. Patients presenting with these characteristics were more likely to be hospitalised, providing evidence of effective triage and referral.

TRIAL REGISTRATION NUMBER

NCT04568499.

Validity and Predictive Performance of Mini Nutritional Assessment Tool for Institutionalized Elders in Ethiopia

Background

Despite the high burden of malnutrition in the country, there is a lack of a simple and valid tool to screen elders in Ethiopia. The Mini Nutritional Assessment (MNA) tool has been validated for comprehensive geriatric assessment to identify malnutrition in other countries. However, there is a lack of evidence on the potential validity and reliability of the tool for institutionalized elders in Ethiopia. This study was aimed at determining the validity and predictive performance of MNA tool for malnutrition among Ethiopian institutionalized elderly.

Methods

A facility-based survey was conducted on randomly selected 164 elders in geriatric centers to evaluate the validity, reliability, and predictive performance of full MNA against hemoglobin (Hgb) and ideal body weight (IBW) measured under standard procedures. The data was presented in ROC graphs, and reliability was evaluated with Cronbach alpha. The receiver-operating characteristic curve (ROC) analysis was used to assess the predictive performance of the tool. The area under the curve (AUC) with its 95% CI was reported. The Youden index, at maximum sensitivity and specificity, was used to obtain optimal cutoff points.

Results

The internal consistency of the tool was good (α = 0.80). The full MNA score can better predict Hgb (AUC = 0.845; 0.783-0.899) and percentage of IBW (AUC = 0.90; 0.842-0.941) at specified cutoff points. A full MNA can predict malnutrition or risk of malnutrition based on percentage IBW at a sensitivity and specificity of 97.3% and 72.2%, respectively.

Conclusions

The full MNA has the potential to be a reliable and valid nutritional assessment tool for institutional elders.

Field Experiences with Handheld Diagnostic Devices to Triage Children under Five Presenting with Severe Febrile Illness in a District Hospital in DR Congo

As part of a field study (NCT04473768) in children presenting with severe febrile illness to Kisantu hospital (DR Congo), we retrospectively compiled user experiences (not performance) with handheld diagnostic devices assisting triage: tympanic thermometer, pulse oximeter (measuring heart rate, respiratory rate and oxygen saturation), hemoglobinometer and glucometer. Guidance documents for product selection were generic and scattered. Stock rupture, market withdrawal and unaffordable prices interfered with procurement. Challenges at implementation included environmental temperature, capillary blood sampling (antisepsis, order of multiple tests, filling microcuvettes and glucose strips), calibration (environmental temperature, cold chain) and liability-oriented communication with a manufacturer. Instructions for use were readable and contained symbol keys; two devices had printed French-language instructions. Shortcomings were poor integration of figures with text and distinct procedures for the oximeter and its sensor. Usability interview revealed appreciations for quick results, visibility of the display and memory function (three devices) but also problems of capillary blood sample transfer, cleaning, too long of a time-to-results (respiratory rate) and size, fitting and disposal of thermometer probes. Pictorial error messages were preferred over alphanumeric error codes but interpretation of symbols was poor. Alarm sounds of the oximeter caused unrest in children and caretakers perceived the device as associated with poor prognosis.

Potential of cell tracking velocimetry as an economical and portable hematology analyzer

Anemia and iron deficiency continue to be the most prevalent nutritional disorders in the world, affecting billions of people in both developed and developing countries. The initial diagnosis of anemia is typically based on several markers, including red blood cell (RBC) count, hematocrit and total hemoglobin. Using modern hematology analyzers, erythrocyte parameters such as mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), etc. are also being used. However, most of these commercially available analyzers pose several disadvantages: they are expensive instruments that require significant bench space and are heavy enough to limit their use to a specific lab and lead to a delay in results, making them less practical as a point-of-care instrument that can be used for swift clinical evaluation. Thus, there is a need for a portable and economical hematology analyzer that can be used at the point of need. In this work, we evaluated the performance of a system referred to as the cell tracking velocimetry (CTV) to measure several hematological parameters from fresh human blood obtained from healthy donors and from sickle cell disease subjects. Our system, based on the paramagnetic behavior that deoxyhemoglobin or methemoglobin containing RBCs experience when suspended in water after applying a magnetic field, uses a combination of magnets and microfluidics and has the ability to track the movement of thousands of red cells in a short period of time. This allows us to measure not only traditional RBC indices but also novel parameters that are only available for analyzers that assess erythrocytes on a cell by cell basis. As such, we report, for the first time, the use of our CTV as a hematology analyzer that is able to measure MCV, MCH, mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), the percentage of hypochromic cells (which is an indicator of insufficient marrow iron supply that reflects recent iron reduction), and the correlation coefficients between these metrics. Our initial results indicate that most of the parameters measured with CTV are within the normal range for healthy adults. Only the parameters related to the red cell volume (primarily MCV and RDW) were outside the normal range. We observed significant discrepancies between the MCV measured by our technology (and also by an automated cell counter) and the manual method that calculates MCV through the hematocrit obtained by packed cell volume, which are attributed to the artifacts of plasma trapping and cell shrinkage. While there may be limitations for measuring MCV, this device offers a novel point of care instrument to provide rapid RBC parameters such as iron stores that are otherwise not rapidly available to the clinician. Thus, our CTV is a promising technology with the potential to be employed as an accurate, economical, portable and fast hematology analyzer after applying instrument-specific reference ranges or correction factors.

Facile hydrothermal synthesis of NiTe nanorods for non-enzymatic electrochemical sensing of whole blood hemoglobin in pregnant anemic women

Electrochemical sensing methods monitor biomolecules because of their specificity, rapid response, lower cost, and automation. Hemoglobin is an abundant protein in the human body and is correlated with various physiological processes. Levels of hemoglobin in blood are associated with anemia in pregnant women. In this research, a non-enzymatic sensor based on NiTe nanorods is developed for the detection and quantification of hemoglobin (Hb) from anemic pregnant patients. NiTe nanorods are synthesized by the single-step method. After characterizing the material, sensing parameters such as the effect of scan rate, pH, concentration, and interferences are optimized using standard hemoglobin samples. Linearity, the limit of detection (LOD), and the limit of quantification (LOQ) for NiTe nanorods are 0.99698, 0.012 nM, and 0.04 nM, respectively. Stability is measured by cyclic chronoamperometry (12 h) and voltammetry (100 cycles). Recovery of hemoglobin from blood samples is in the range of 63-90%. NiTe nanorods quantitatively determine hemoglobin from the blood samples of anemic pregnant women.

Additive Effect of Sarcopenia and Anemia on the 10-Year Risk of Cardiovascular Disease in Patients with Type 2 Diabetes

OBJECTIVE

To investigate the association between sarcopenia and anemia and the 10-year cardiovascular disease risk in diabetic patients.

METHODS

A cross-sectional study was conducted involving 4673 hospitalized patients (2271 men and 2402 women) with type 2 diabetes mellitus, with an average age of 60.66 ± 11.93 years, of whom 542 were followed up for a median follow-up period of 24 months. All participants underwent body composition measurements, and they were grouped by sex and presence of sarcopenia using the Framingham risk model to assess their 10-year cardiovascular risk. According to the changes in the cardiovascular risk during follow-up, the patients were divided into four groups: low-low, low-high, high-low, and high-high.

RESULTS

The prevalence of anemia was higher in the sarcopenia group than in the nonsarcopenia group (11.5% vs. 24.1% for men, P < 0.001; 13.9% vs. 19.7% for women, P < 0.05), and the difference remained significant after adjusting for confounders. Patients with sarcopenia and without anemia had a 46.2% increased risk of high 10-year cardiovascular disease (CVD) (odds ratio (OR) = 1.462, 95% confidence interval (CI) 1.085-1.972, P = 0.013), and the risk was twofold higher in patients with sarcopenia and anemia than in those without (OR = 3.283, 95% CI 2.038-5.289, P < 0.001). In follow-up studies, sarcopenia was associated with an increased risk of CVD at 10 years, and a reduction in appendicular skeletal muscle mass index independently predicted the increased risk of CVD.

CONCLUSION

Sarcopenia is associated with an increased risk of anemia, and the presence of both has an additive effect on the 10-year CVD risk in patients with type 2 diabetes. Loss of muscle mass can independently predict an increased CVD risk in diabetic patients.