Etiology of anemia of blood donor candidates deferred by hematologic screening

Safe blood supply in sub-Saharan Africa: challenges and opportunities

The low recruitment and retention of blood donors in sub-Saharan Africa is a grave concern for blood transfusion services in the region. This problem is exacerbated by factors such as a high prevalence of transfusion-transmissible infections and anaemia, over-reliance on family replacement donors, resource constraints, and poor communication with the public. To improve blood safety and availability, innovative intervention strategies must be developed and implemented. The primary objective of this Series paper is to discuss the available evidence in the region and to provide recommendations on how to improve safe blood supply in sub-Saharan Africa. These recommendations include a call for renewed attention to donor recruitment in blood transfusion centres, a consistent and structured educational intervention, the development and adherence to national policies on blood donor selection with focus on voluntary donations, and comprehensive screening of donations for transfusion-transmissible infections. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Causes of microcytic anaemia and evaluation of conventional laboratory parameters in the differentiation of erythrocytic microcytosis in blood donors candidates

CONTEXT AND OBJECTIVE

Microcytic anaemia results from defective synthesis of haemoglobin in the erythroid precursors, causing a reduction in its mean corpuscular volume (MCV). The most common causes of microcytosis, without the increase in HbA₂ levels, are iron deficiency anaemia (IDA) and α-thalassemia. The aim of this study was to identify the causes of microcytic anaemia and evaluate the haematological parameters from blood donors deemed ineligible (due to the low haematocrit level) that would differentiate the IDA and α-thal, whether isolated or in association.

METHODS

Genomic DNA was submitted to the polymerase chain reaction multiplex for the diagnosis of the most common allele deletions of α-thal and erythrogram and in order to verify haematological parameters. Iron deficiency (ID) was determined through the measurement of serum ferritin.

RESULTS

Of the 204 samples, 82 (40.2%) were identified with ID, 24 (17.8%) with α-thal and 10 (4.9%) with ID associated with α-thal. In the α-thal with ID group haemoglobin (Hb), MCV, mean corpuscular Hb concentration (MCHC) and mean corpuscular Hb (MCH) values were significantly lower compared to the isolated α-thal. In the group with ID Hb, MCV, MCHC and MCH values were significantly lower compared to those with isolated α-thal. The α-thal with ID group, showed Hb, MCV, MCHC and MCH significantly reduced when compared to those with IDA.

CONCLUSIONS

This study showed that the values of haematological parameters, especially haematocrit, Hb, MCV, MCH, MCHC and red blood cell distribution width (RDW), are lower in patients with IDA, especially when associated with α-thal and therefore it may be useful to discriminate between the different types of microcytic anaemia.

Insight into donor deferral pattern based on peripheral blood counts: An experience from South Pakistan

BACKGROUND

Donor deferral owing to anemia is one of the major causative factors of temporary donor rejection, which is preventable and treatable. The basic knowledge about frequency, types, and severity of anemia among donors will help plan a strategy to promote donor recruitment and overall national health.

OBJECTIVE

The objective of this study was to provide the predonation deferral rate of the healthy blood donors based on peripheral blood counts and second to determine the types of anemia along with its severity.

MATERIALS AND METHODS

Prospective records of all the reported donors were collected from January 2014 to December 2015 at Liaquat National Hospital, Karachi, Pakistan. Donor samples were analyzed on an automated hematology analyzer.

RESULTS

Overall, 36,954 potential donors reported to the blood bank, out of which 33,853 were selected and 3101 were deferred, which makes the deferral rate of 8.39%. Majority of donors (n = 2663 [7.20%]) were deferred based on peripheral blood counts. Based on peripheral count, anemia (91.8%) represents the major cause of deferral, followed by raised total leukocyte count (3.7%) and polycythemia (3.3%), and thrombocytopenia (1.0%) was the least potential cause. Microcytic-hypochromic anemia was found in 58.5% of the donors followed by normocytic and macrocytic anemia in 38.9% and 2.4%, respectively. Mild anemia was seen in 78.2% followed by moderate and severe anemia in 20.5% and 1.18%, respectively.

CONCLUSION

A high prevalence of anemia among blood donors signifies deteriorating health status not only in donor population but also in general population. This situation calls for more concerted efforts as otherwise it would lead to decreased blood donor pool.

Genetic factors associated with iron storage in Australian blood donors

BACKGROUND

Blood donors are at risk of developing iron deficiency and/or iron deficiency anaemia. This may affect their health and affect their eligibility to give subsequent donations. Investigating genetic factors that may predispose donors to high or low iron stores is of interest; this may assist with providing optimal management strategies for maintaining donor health. This study aimed to investigate whether the presence of selected single nucleotide polymorphisms (SNPs) affecting parameters of iron status were associated with ferritin levels in Australian donors.

MATERIALS AND METHODS

Samples (n=800) were collected from non-first-time blood donors in Queensland. Plasma ferritin levels were quantified and the genotypes for ten SNPs, identified by a review of relevant literature, were determined for each sample. Associations between SNPs and ferritin levels were investigated.

RESULTS

Three SNPs were associated with ferritin levels. In male donors, high ferritin levels were associated with the variant allele (G) of the SNP rs3923809 in the BTBD9 gene. An association with ferritin levels was also identified with the SNP rs235756 in the BMP2 gene in males. The SNP rs4820268 in the TMPRSS6 gene was associated with ferritin levels in females, with donors with the AG genotype being three times more likely to have low ferritin levels.

DISCUSSION

Variants in the genes TMPRSS, BTBD9 and BMP2 were associated with ferritin levels in Australian blood donors. These findings provide support that genetic testing may be useful for the generation of predictive algorithms that may allow for management strategies to be tailor-made for individual donors.

Anaemia and its association with month and blood phenotype in blood donors in Fako division, Cameroon

BACKGROUND

Anaemia is one of the main factors in the deferral (disqualification) of blood donors following haematological screening. There is paucity of data on the prevalence of anaemia in blood donors in Sub-Saharan Africa. This study was undertaken to determine the prevalence of anaemia and its association with month and blood phenotype in blood donors in Fako division of Cameroon.

METHODS

Blood donors were recruited between the 1st of January and 31st of December 2014, and their haemoglobin concentration (Hb) was determined using a haemoglobinometer. Anaemia was considered as Hb < 12 g/dl for females and Hb < 13 g/dl for males. The ABO and Rhesus blood groups were determined using standard techniques with monoclonal antibodies and the Coombs' test. The Pearson's chi-square, Pearson's correlation, student T test, ANOVA, univariate and multivariable logistic regression analyses adjusting for gender and age as categorical variable were all performed as part of the statistical analysis.

RESULTS

A total of 1896 blood donors predominantly males (91.35%) took part in the study. The mean age of the donors was 32 ± 7.81 years. On average, donors had donated blood 5.07 ± 3.54 times in their lifetime. The prevalence of anaemia observed in this study was 31.44% (95% CI: 29.35-33.58). The prevalence of anaemia was higher in females (p ≤ 0.0001) and in participants of age 20 years and below (p = 0.001). A marginal association was observed between prevalence of anaemia and season (p = 0.051). Furthermore, a significant association was observed between prevalence of anaemia and the blood group AB (p = 0.001). The risk of developing anaemia was higher in females compared to males (OR = 2.7, p < 0.0001). The mean Hb observed in this study was 13.42 ± 1.65; the mean Hb was not observed to be associated with the month or season adjusting for age and gender.

CONCLUSION

This study revealed a high prevalence of anaemia which translates to a high rate of donor deferral as a result of anaemia in the study area. The prevalence of anaemia was observed to be associated with the blood phenotype and the month, but not the season (dry or rainy). Further studies will be needed to ascertain the aetiology and associated factors for anaemia in blood donors in the study area.

Blood discard rate in a blood center in Curitiba - Brazil. Ten years of study

INTRODUCTION

Development of technologies to reduce transfusion risks of infectious diseases is a major characteristic of hemotherapy. Thus, each donation undergoes clinical and serological screening tests to ensure the donated blood do not offer risks to the receiver.

OBJECTIVE

Evaluate the prevalence of positive serology in blood donations rejected by Hemobanco (Curitiba - PR) in the period ranging from January 2003 to December 2012.

METHODOLOGY

During the period studied, we observed the total number of donations and its division according to gender. We also analyzed the number of rejected donations due to seropositivity, considering the diseases investigated routinely in blood banks in Brazil, and the frequency of discards according to age groups.

RESULTS

Within the period studied, 399,280 donations were performed. 62.0% donors were male. Comparing 2003 to 2012, we noticed a significant decrease of discards, from 10.2% to 5.0%, respectively. There was a reduction of seropositivity for HIV, HBsAg and anti-HBc and an increase for Chagas Disease, hepatitis C, syphilis and HTLV. The age group with the highest prevalence for discards changed: it used to be the 40-59 years old group in 2003, and became the 20-39 years old group in 2012.

CONCLUSION

There was an increase in the number of donations in Hemobanco and a decrease in total discards due to seropositive donations. Most donors were male. The most prevalent cause of discards only amongst seropositive donation discards is seropositivity for anti-HBc. There was a significant increase of donors aged between 20 and 39 years old.

Low-grade inflammation is associated with lower haemoglobin levels in healthy individuals: results from the Danish blood donor study

BACKGROUND AND OBJECTIVES

Chronic inflammation can lead to anaemia of chronic disease due to the sequestration of iron caused by inflammatory cytokines and the protein hepcidin. However, the effect of low-grade inflammation (LGI) on haemoglobin among healthy individuals is not known. This study examines the effect of LGI on haemoglobin among Danish blood donors.

MATERIALS AND METHODS

We performed multivariable linear regression to assess the effect of LGI (i.e. high-sensitivity C-reactive protein above 3 mg/l but below 10 mg/l) on haemoglobin in 17 322 Danish blood donors. We also performed multivariable logistic regression to evaluate the effect of LGI on the risk of having low haemoglobin (below the 10th percentile among men and women, respectively). We adjusted for donation activity, age, sex, low ferritin, oral contraceptives and menopause. All analyses were stratified by current smoking status.

RESULTS

LGI was associated with lower haemoglobin (0·08 mm lower [0·12 g/dl], 95% confidence interval (CI): -0·11-0·05) and increased risk of low haemoglobin (OR = 1·22, 95% CI: 1·05-1·43) in non-smokers. Conversely, LGI was associated with higher haemoglobin in smokers (0·12 mm [0·19 g/dl], 95% CI: 0·06-0·18).

CONCLUSION

In this first study of LGI and haemoglobin in healthy individuals, there was a negative association between LGI and haemoglobin in non-smokers. The association was positive in smokers, probably because smoking leads to both increased inflammation and increased haemoglobin through CO exposure.

Risk factors for deferral due to low hematocrit and iron depletion among prospective blood donors in a Brazilian center

Objective

Deferral of blood donors due to low hematocrit and iron depletion is commonly reported in blood banks worldwide. This study evaluated the risk factors for low hematocrit and iron depletion among prospective blood donors in a large Brazilian blood center.

Method

A case–control study of 400 deferred donors due to low hematocrit and 456 eligible whole blood donors was conducted between 2009 and 2011. Participants were interviewed about selected risk factors for anemia, and additional laboratory tests, including serum ferritin, were performed. Bivariate and multivariate analyses were performed to assess the association between predictors and deferral due to low hematocrit in the studied population and iron depletion in women.

Results

Donors taking aspirins or iron supplementation, those who reported stomachache, black tarry stools or hematochezia, and women having more than one menstrual period/month were more likely to be deferred. Risk factors for iron depletion were repeat donation and being deferred at the hematocrit screening. Smoking and lack of menstruation were protective against iron depletion.

Conclusion

This study found some unusual risk factors related to gastrointestinal losses that were associated with deferral of donors due to low hematocrit. Knowledge of the risk factors can help blood banks design algorithms to improve donor notification and referral.

Predictors of hemoglobin in Danish blood donors: results from the Danish Blood Donor Study

BACKGROUND

It is well known that blood donors are at increased risk of iron deficiency and subsequent development of iron deficiency anemia. We aimed to investigate the effect of factors influencing hemoglobin (Hb) levels.

STUDY DESIGN AND METHODS

Initiated in 2010, the Danish Blood Donor Study is a population-based study and biobank. We performed multivariable linear regression analysis to assess the effects of donation activity, physiologic and lifestyle factors, and diet on Hb levels among 15,197 donors. We also performed multivariable logistic regression to evaluate the effects of these factors on the risk of having low Hb (defined as Hb below the 10th percentile among men and women, respectively) and of a decrease in Hb greater than 0.5 mmol/L (0.8 g/dL) between successive donations. All analyses were performed stratified for sex and smoking status. We also tested a previously used model for the prediction of Hb.

RESULTS

The strongest predictors of Hb and risk of low Hb were low ferritin (<15 ng/mL) and current use of iron supplementation (yes/no). No dietary factors were found to be consistently significant in multivariable models predicting Hb levels, risk of having low Hb, or risk of a decrease in Hb greater than 0.5 mmol/L. We found similar effects to previous studies of factors in the predictive model, with little additional effect of including smoking status and ferritin.

CONCLUSIONS

As ferritin was the strongest predictor of Hb, this study supports the implementation of regular ferritin measurement as a method of risk assessment among blood donors.

A non-invasive strategy for haemoglobin screening of blood donors

INTRODUCTION

Assessing blood-donor haemoglobin (Hb) is a worldwide screening requirement against inappropriate donation. The pre-donation Hb (which should be at least 12.5 g/dL in women and 13.5 g/dL in men) is usually determined in capillary blood from a finger prick, using a spectrophotometer which reveals the absorbance of blood haemolysed in a microcuvette. New non-invasive methods of measuring Hb are now available.

MATERIALS AND METHODS

In the first semester of 3 consecutive years three different strategies were employed to screen donors for anaemia at the moment of donation. In 2011 all whole-blood donors underwent the finger-prick method using azide-methaemoglobin: the test's negative predictive value (NPV) was determined by comparison with the sub-threshold Hb values ascertained by haemocytometry of test-tube blood drawn at the start of the donation. In 2012 the donor evaluation was based on NBM 200 occlusion spectrophotometry. The same approach was kept in 2013, but a haemocytometry test was added on a pre-donation venous sample drawn from donors who, though fit to donate, had previous critical Hb values in their clinical records.

RESULTS

In 2011, the NPV (in 3,856 donors) was 86% for women and 95% for men; in 2012 (3,966 donors), the values were 85% and 95%, respectively, and in 2013 (3,995 donors) they were 91% and 97%, respectively. Fisher's test for contingency tables revealed no statistically significant differences between 2011 and 2012, but the 2013 results were a significant improvement.

DISCUSSION

Measuring Hb by finger prick is not wholly satisfactory since, above all in women, the result of this screening may subsequently be belied by the haemocytometry finding of an unacceptable Hb value. Using a non-invasive method does not diminish the selective efficiency. In women, in particular, adding a haemocytometric test on a venous sample significantly improves donor selection and avoids the risk of inappropriate donation or blood-letting.