Establishment of reference intervals for Platelet Function Analyzer -100 closure time in Algerian adults

Seroprevalence of Human Immunodeficiency Virus, Hepatitis C Virus, and Hepatitis B Virus Among Blood Donors in Sidi Bel Abbes, West Algeria

Introduction Blood transfusions can transmit various viruses. Among them, the most common are hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). These viruses can cause fatal and life-threatening diseases. Worldwide, many people are infected with these viruses. Blood safety has made major progress in recent years. Yet, blood-borne viruses continue to be a major concern for patients, physicians, and policymakers. The aim of this study was to assess the prevalence of HIV, HBV, and HCV in blood donors. Methods A cross-sectional study was performed to assess HIV, HBV, and HCV seropositivity in blood donors. This research was carried out at the blood bank of Sidi Bel Abbes University Hospital. This was a retrospective study based on records of blood donors. All data of 10,386 donors were analyzed from January 2015 to December 2015. Biological screening was performed by enzyme-linked immunosorbent assay (ELISA) using antibodies and/or antigens. The combined HCV and HIV antigen and antibody ELISA test was utilized. To confirm the results, the blood bank and the virology laboratory used the same technique in duplicate. Results The overall seroprevalence of blood-borne viral infections (HIV, HBV, and HCV) in blood donors was 0.8%. The prevalence of HIV was found to be 0.1%, while the prevalence of HBV and HCV was 0.4%. Coinfection was rare with only one case of HBV with HIV. There was a significant difference in seroprevalence rates among blood donors compared to the general population. Significant variations were observed between the prevalence of this study and those conducted in West, East, Central, and South African countries but not with those of neighboring North African countries. The study found no association between seropositivity in blood donors and factors like age, gender, donor status, type of donation, or site. Besides, HIV, HBV, or HCV prevalence was not influenced by ABO and Rhesus blood group. Conclusion The study showed that blood donors in Algeria have a lower prevalence of blood-borne viral infections than the general population. The seropositivity rate of viral markers was similar throughout North African countries. This rate remained low compared to other African countries. Residual risk of infection persists. There is a need to increase blood safety for recipients. This report is the first comprehensive overview of blood-borne viruses among Algerian blood donors. There is a need for further nationwide studies to get a whole picture of the situation.

Harmonizing platelet function analyzer testing and reporting in a large laboratory network

INTRODUCTION

The platelet function analyzer (PFA) is a popular platelet function screening instrument, highly sensitive to von Willebrand disease (VWD) and to aspirin therapy, with moderate sensitivity to defects in platelet function and/or deficiencies in platelet number. There are two models, the original PFA-100 and the contemporary PFA-200. Normal reference ranges (NRRs) provided by the manufacturer are the same for both models, instead being based on the type of test cartridge, for which there are two main ones: collagen/epinephrine (C/Epi) and collagen/adenosine diphosphate (C/ADP).

METHODS

Comparative evaluations of PFA testing and reporting in six different sites of a large pathology network, aiming to harmonize NRRs and test reporting across all network sites. A separate comparative study of testing a range of samples (n > 150) on a PFA-100 versus that on a PFA-200. Review of contemporary literature.

RESULTS

Each site was identified to have a different reporting NRR, which after consolidating data permitted establishment of an agreed harmonized NRR for use across the network (C/Epi: 90-160; C/ADP: 70-124; based on n > 180). Similarly, each site reported and interpreted results in different ways, and after discussion and consolidation, a harmonized approach to interpretation and reporting was achieved. The separate comparative study of PFA-100 versus PFA-200 testing confirmed instrument equivalence.

CONCLUSION

We achieved harmonized NRRs and reporting for PFA testing across a large pathology network. Our approach may be useful for other laboratory networks wishing to harmonize PFA testing.

Platelet Dysfunction in Blood Donors Detected by Platelet Function Analyzer PFA-100™

Background

Platelet transfusions may be indicated to prevent and treat bleeding in patients with quantitative or qualitative platelet defects. Millions of platelet components are transfused worldwide. It is well known that platelet dysfunction predicts blood loss after surgery. Hence, the quality of the platelet donation and the resulting platelet concentrate are critical for the transfusion. The aim of this study is to assess platelet function in well-qualified blood donors.

Methodology

Blood samples from 275 blood donors were collected in 0.129 M (3.8%) sodium citrate tubes prior to routine blood donation. Platelet function was assessed by measuring the closure time (CT) on the platelet function analyzer (PFA-100™; Siemens Health Diagnostics, Marburg, Germany) using collagen/epinephrine (CEPI) and collagen/ADP (CDP) cartridges.

Results

Using the PFA-100™, 20.4% of donors had an abnormal platelet function test, of whom 9.4% had prolonged CT with two cartridges, 7% had only prolonged CEPI CTs consistent with aspirin-like defect, and 4% had prolonged CADP CTs only. We found no closure (>300 seconds) in 6.54% of donors, including 1.45% with the CEPI cartridge, 2.9% with the CADP cartridge, and 2.18% with CEPI and CADP cartridges. Level of von Willebrand factor ristocetin cofactor (vWF: RCo) activity was 112% (56-168%). Of the factors examined (age, sex, cigarette smoking, blood donation type, ABO, and Rhesus blood group), only blood group O was significantly linked with impaired platelet function test in qualified blood donors (p = 0.023; odds ratio = 1.981; 95% confidence interval (1.091-3.595)).

Conclusions

Some qualified blood donors present abnormal platelet function results. More research is required to provide greater insight into the impact of platelet dysfunction in blood donors on the clinical efficacy of their platelet components. This study has confirmed that the influence of ABO blood group on the CT PFA-100™is not wholly dependent on vWF.