Characterization of blood donors with high haemoglobin concentration

Analysis of JAK2V617F Tyrosine Kinase Mutation in Blood Donors with Erythrocytosis - A Pilot Study in a Tertiary Care Teaching Hospital of South India

Purpose

Transfusion services and blood centers provide immediate medical evaluation to blood donors by physical examination and hemoglobin (Hb) screening. Screening for Hb value before every blood donation is mainly aimed to rule out anemia. However, it is not uncommon to defer the donors for high Hb value which can be due to primary or secondary polycythemia. This study aimed to analyze the frequency of JAK2V617F mutation among blood donors with a high Hb of >18 g/dl.

Patients and Methods

A prospective study was conducted over a period of 18 months involving blood donors with a persistently high Hb value of >18 g/dl. Complete blood count (CBC), JAK2V617F gene mutation and Serum Erythropoietin (EPO) levels in study donors were analyzed. Descriptive statistical analysis was performed using SPSS, version 24 (IBM, USA).

Results

Of 13,798 screened donors, 48 donors (0.34%) had persistent erythrocytosis with a high Hb value of >18 g/dl. Their age ranged between 20-50 years with a mean of 31.2 ± 6.66. The CBC parameters including red blood cell (RBC) count, Hb%, hematocrit (Hct), white blood cell (WBC) count and the platelet count ranged from 4.35-8.43 million/µL (6.2 ± 0.6), 18.6-24.4 g/dl (19 ± 0.94), 51.9-83.3% (58 ± 5.02), 3.99-10.8 × 103/µL (7.8 ± 1.5), and 120-450 × 103/µL (227 ± 57.2), respectively. Estimated mean EPO value was 8.29 mIU/± 0.04. JAK2V617F mutation was detected in 2 donors (4.1%).

Conclusion

The prevalence of persistent erythrocytosis among blood donors was 0.34% and among them, two donors (4.1%) harbored the JAK2V617F mutation. Thus, blood centers play an important role in the primary screening of donors with high hemoglobin leading to early detection and management of polycythemia vera (PV).

Is high hemoglobin a hindrance factor for blood donation? A pilot observational study from the coastal region of India

BACKGROUND

Blood donors with high Hb are often deferred for the presumed risk of polycythemia vera (PV). However, adequate data to substantiate or refute this hypothesis is lacking.

METHODOLOGY

We conducted an observational study on blood donors found to have high hemoglobin (Hb≥18g/dL) during the pre-donation screening process using a portable hemoglobinometer at our blood center for four months. We adopted a cost effective methodology wherein a questionnaire was used to elicit the secondary causative factors of high hemoglobin and a complete blood count test to observe the blood cell parameters and JAK2V617F mutation test was performed in a subset of donors lacking secondary erythrocytosis (SE) history.

RESULTS

Of the total 7076 donors enrolled, 112 male donors (1.58%) had high hemoglobin. The majority (70.4%) were repeat donors with mean age of 31.4 years. About 61% of the donors had attributable factors for SE like smoking, occupational exposure to carbon monoxide. The mean hemoglobin value of capillary and venous hemoglobin demonstrated a statistically significant difference (P<0.05) where 2.7% of donors had venous Hb<18g/dL. The hematological profile of all the donors showed increased RBC but normal platelet and WBC count. Of 24 donors included for the JAK2V617F test, none had a positive report.

CONCLUSION

This study suggests high hemoglobin in blood donors is less likely due to PV. Hence, re-considering their deferral may help alleviate donor anxiety and allow donor return. However, multi-centric studies are required to develop consensus statements on PV risk status and blood donation eligibility.

Erythrocytosis in the general population: clinical characteristics and association with clonal hematopoiesis

Erythrocytosis is a common reason for referral to hematology services and is usually secondary in origin. The aim of this study was to assess clinical characteristics and clonal hematopoiesis (CH) in individuals with erythrocytosis in the population-based Lifelines cohort (n = 147 167). Erythrocytosis was defined using strict (World Health Organization [WHO] 2008/British Committee for Standards in Hematology) and wide (WHO 2016) criteria. Individuals with erythrocytosis (strict criteria) and concurrent leukocytosis and/or thrombocytosis were 1:2 matched with individuals with isolated erythrocytosis and analyzed for somatic mutations indicative of CH (≥5% variant allele frequency). One hundred eighty five males (0.3%) and 223 females (0.3%) met the strict criteria, whereas 4868 males (7.6%) and 309 females (0.4%) met the wide criteria. Erythrocytosis, only when defined using strict criteria, was associated with cardiovascular morbidity (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2-2.6), cardiovascular mortality (hazard ratio [HR], 2.2; 95% CI, 1.0-4.6), and all-cause mortality (HR, 1.7; 95% CI, 1.2-2.6), independent of conventional risk factors. Mutations were detected in 51 of 133 (38%) evaluable individuals, with comparable frequencies between individuals with and without concurrent cytosis. The JAK2 V617F mutation was observed in 7 of 133 (5.3%) individuals, all having concurrent cytosis. The prevalence of mutations in BCOR/BCORL1 (16%) was high, suggesting aberrant epigenetic regulation. Erythrocytosis with CH was associated with cardiovascular morbidity (OR, 9.1; 95% CI, 1.2-68.4) in a multivariable model. Our data indicate that only when defined using strict criteria erythrocytosis is associated with cardiovascular morbidity (especially in the presence of CH), cardiovascular mortality, and all-cause mortality.

Blood Donor Deferral Analysis in Relation to the Screening Process: A Single-Center Study from Southern India with Emphasis on High Hemoglobin Prevalence

Purpose

Donor deferral results in loss of potential, motivated blood donors, and thereby, availability of blood for needy patients. This study analyses the frequency and reasons for donor deferral, including high hemoglobin deferral, which is underreported in India.

Methods

Retrospective analysis of the deferral record of whole blood donors from January 2014 to December 2018 was performed with respect to the pre-donation screening process at our center. Accordingly, the deferrals are categorized as stage1 – evaluation of Donor History Questionnaire (DHQ), stage 2 – medical examination, stage 3 – hemoglobin (Hb) check using copper sulfate method or a gradually implemented quantitative hemoglobin analyzer, and stage 4 – before phlebotomy. Donor demographic details, donation frequency, and deferral reasons were noted. Descriptive statistical analysis was performed using SPSS version 20 (IBM, USA).

Results

Of 99,680 pre-donation screenings, 10.6% was deferred. The highest deferral (56.02%) was at stage 3 (based on hemoglobin level) contributed by low (52.45%) and high (3.75%) hemoglobin deferrals against cut-off of 12.5 to 18 g/dl. High Hb was noted only in male donors when screened by hemoglobin analyzer. Further, a steady fall in low hemoglobin but a rise in high hemoglobin deferral rate owing to the gradual implementation of hemoglobin analyzer over the study period was noted. The deferrals in stage 1, 2, and 4 were 29.64%, 13.97%, and 0.36%, respectively. Overall, the deferral rate was higher in females (49.88%), and in first-time (13.63%), and 18 to 25 yrs age-group (4.25%) donors for low Hb, underweight, and tattooing/ear piercing.

Conclusion

Insights on donor deferral reasons promote proactive measures towards donor recruitment and retention. Further, donor hemoglobin screening by quantitative method, if followed uniformly by all blood centers across the country, will help identify the true prevalence of high hemoglobin in Indian blood donors and ensures donor safety.

Validation of Two Point of Care Devices for Hemoglobin Estimation in Blood Donors

Hemoglobin (Hb) estimation is a critical investigation in prospective blood donors. There are numerous techniques for Hb estimation, choosing an appropriate method is essential. Point of care devices (POC) have made quantification of Hb possible even in the field or community settings. Validation against a standard measure is necessary before implementing it for routine practice. With this background, we aimed to validate two new POC devices against a standard hematology analyzer for Hb estimation. An observational study on 100 donor venous blood samples was conducted. Hemoglobin was estimated using a Sysmex Hematology Analyzer (reference method) along with POC devices (CompoLab TM and True Hb Hemometer). Three statistical techniques were applied to validate Hb by the two POC devices. CompoLab TM measures 0.4 units more than the reference method and True Hb measures 0.4 units less than the reference method. Measures of Hb obtained from both the equipment showed moderate agreement with that of reference method (CompoLab TM ICC-0.74 and True Hb ICC-0.72). There were no systematic or proportional differences in the comparison of the two POC devices with the reference method. Within the limitations of this study, both the devices can be used for Hb estimation, as there was a substantial agreement of the measurements with the reference method. Other factors such as cost, turnaround time (TAT), ease of utilization should be considered to decide on the choice of equipment to be used.

Hemoglobin concentration and risk of arterial and venous thrombosis in 1.5 million Swedish and Danish blood donors

INTRODUCTION

There are conflicting results whether elevated hematocrit is associated with an increased risk of thromboembolic events in individuals without polycythemia vera. To assess the risk of vascular events in relation to hemoglobin concentration, we conducted a large population-based cohort study based on Scandinavian health registers.

MATERIALS AND METHODS

We included 1,538,019 Swedish and Danish blood donors between 1987 and 2012. Hazard ratios (HRs) of arterial and venous thrombosis were estimated using Cox regression. Additionally, we fitted person-stratified models where each donor was compared only to him-/herself.

RESULTS

The risk of myocardial infarction and ischemic stroke increased with higher hemoglobin concentration in both men and women. The HRs for myocardial infarction and ischemic stroke in men with hemoglobin concentration ≥ 17.5 g/dL were 3.52 (95% confidence interval [CI], 2.85-4.36) and 2.36 (95% CI, 1.63-3.43), respectively, compared to the reference group. The corresponding HRs for women with hemoglobin concentration ≥ 16.0 g/dL were 3.22 (2.12-4.89) and 2.35 (1.37-4.02) for myocardial infarction and ischemic stroke, respectively. The risk of venous thrombosis was highest in men with subnormal hemoglobin concentration (<13.0 g/dL), HR 1.69 (95% CI, 1.40-2.04). In the person-stratified model, the association between elevated hemoglobin concentration and risk of myocardial infarction was attenuated but remained significant.

CONCLUSIONS

In this large cohort of Scandinavian blood donors, elevated hemoglobin concentration was associated with an increased risk of vascular events, primarily arterial events. Even though associations were weakened when each person served as their own control, a high hemoglobin concentration may serve as a cardiovascular risk marker.

Ethics and blood donation: A marriage of convenience

Quality, safety, risks and risk management are currently the leading words in transfusion medicine, and several approaches are necessary to correctly evaluate the fundamental basis of blood transfusion. Ethics is probably the most focused approach with which to examine the inconsistencies and conflicts of interest of the various stakeholders involved in the transfusion medicine field. In this short review, the authors will present some aspects of ethics related to blood transfusion, particularly those involving blood donation.

Blood donation and risk of polycythemia vera

BACKGROUND

It has been suggested that blood donors could have an increased risk of polycythemia vera (PV). However, no study has assessed whether frequent donors have a higher PV risk than less frequent donors.

STUDY DESIGN AND METHODS

From the Scandinavian Donations and Transfusions (SCANDAT2) database, we established a cohort of blood donors who had donated whole blood at least once between 1980 and 2012. Within this cohort we first assessed the risk of PV, comparing the donors to the general population using standardized incidence ratios (SIRs) with corresponding 95% confidence intervals (CIs). To assess the association between frequency of blood donation and risk of PV we then conducted a case-control study nested within the cohort, where we compared prior donation activity among donors who were diagnosed with PV and matched controls. Here odds ratios (ORs) were used as measures of relative risk comparing donors with different donation frequency.

RESULTS

Among 1.4 million donors in the cohort a total of 271 donors developed PV, yielding a SIR of 1.00 (95% CI, 0.89-1.13) compared to the general population. The nested case-control study showed no association between donation frequency and risk of PV. The OR of PV comparing donors who had made at least 33 donations in the period from 3 to 22 years before diagnosis of the case, to donors with one to eight donations in the same period was 1.01 (95% CI, 0.51-1.97).

CONCLUSIONS

We find no evidence of excess risk of PV among blood donors or of an association between donation frequency and PV risk.

Smoking as a contributing factor for development of polycythemia vera and related neoplasms

Smoking may be associated with accelerated erythropoiesis, leukocytosis and thrombocytosis, which are also hallmarks in patients with polycythemia vera, essential thrombocythemia and early stages of myelofibrosis (MPNs). The JAK-STAT and NF-κB signaling pathways are activated in both smokers and in patients with MPNs. Additionally, both share elevated levels of several proinflammatory cytokines, in vivo activation of leukocytes and platelets, endothelial dysfunction and increased systemic oxidative stress. Based upon experimental, epidemiological and clinical data it is herein argued and discussed, if smoking may be involved in MPN pathogenesis, considering most recent studies and reviews which are supportive of the concept that chronic inflammation with NF-κB activation and oxidative stress may have a major role - both as triggers but also as the driving force for clonal expansion in MPNs.