Impact of cryopreservation on B cell chronic lymphocytic leukaemia phenotype.

BACKGROUND AND OBJECTIVES: Freezing is a practical approach for cell preservation for retrospective studies. The aim of this work was to check the cryopreservation impact on B cell chronic lymphocytic leukaemia phenotype. MATERIAL AND METHODS: Blood samples from 15 CLL patients were analyzed freshly and after freezing at -196 degrees C, without separation, and thawing. Results were compared by Student's paired t-test. RESULTS: The phenotype of fresh CLL cells was as follows: CD19+, CD5+, faint CD20, CD23+/-, weak CD22 and sIg, CD37+, HLA-DR+, FMC7-. After cryopreservation, the percentage of CD5 and CD23 positive cells decreased, whereas HLA-DR positive cells increased moderately. The CLL Matutes's score was modified in 6 cases out of 15 (40%). CONCLUSION: Cryopreservation modifies B cell chronic lymphocytic leukaemia phenotype, by decreasing CD5 and CD23 expression

Titre des hemolysines alpha et beta chez les donneurs de sang de groupe sanguin o et leur impact potentiel sur la securite des receveurs de produits sanguins au Burkina Faso

English Title: Titer of alpha and beta hemolysins in o group blood donors and their potential impact on blood recipients’ safety in Burkina Faso English Abstract Introduction: Some subjects, due to immunization episodes can develop anti-A and antiB allo-antibodies named hemolysins. These hemolysins can cause serious hemolytic accidents and newborn hemolytic disease. Objectives: Our study aims to assess the prevalence and titer of anti-A and anti-B hemolysins in O blood group donors and to estimate the risk of post-transfusion hemolytic reactions. Methodology: We conducted a cross-sectional study between June 27 and August 4, 2017 that included O blood group donors from the Ouagadougou Regional blood transfusion center. The hemolysins screening was carried out according to a standardized tube technique with saline solution. Results: The prevalence of anti-A and anti-B hemolysins was 37.6%. Hemolysins anti-A was present in 9.7% of cases, hemolysins anti-B in 13.8% and anti-A + anti-B in 14%. Female gender (p = 0.04) and young donors (p = 0.03) were more likely to have high prevalence of hemolysins in univariate analysis. But in multivariate analysis, only female gender (OR=1.8, CI 95% [1.1-2.9]; p=0.02) was significantly associated to the presence of hemolysins. The prevalence of hemolysins of high titer (1:64) was 0.27%. The risk of post-transfusion hemolytic reactions was 2.2 x 10-6. Keywords: Hemolysin, Universal donors, Hemolytic reactions, Anti-A and anti-B antibodies

Age-Related Changes in Human Blood Lymphocyte Subpopulations: II. Varying Kinetics of Percentage and Absolute Count Measurements

A reference range for lymphocyte populations, with particular emphasis on T lymphocyte subsets, was obtained for normal individuals covering age cohorts from birth through adulthood. This report confirms and extends findings from a developmental reference range published earlier (1). Absolute numbers of WBC, lymphocytes, and T, B, and NK subsets decline significantly during childhood. However, differences in the rate of decline of certain lymphocyte subsets leads to discordance between absolute numbers and percentages. Those lymphocyte subsets which decline less rapidly with age than the total lymphocyte count will show an increase in percentage, whereas those which decline more rapidly will show further declines in percentage values. T cell percentages were seen to increase over time whereas B cell percentages decline. Markers of immaturity such as CD45RA on CD4 cells and CD38 on CD8 cells declined in both percentages and absolute numbers. Activation markers, such as HLA-DR on CD8 cells and IL2-R on CD3 cells, increased in percentages with time but changed inconsistently in cell number from infancy to adulthood. These findings extend the lymphocyte references range to markers thought to be informative in various disease states, including HIV infection

Positive direct antiglobulin test in COVID-19 patients: Decision-making process.

In this unprecedented crisis of severe acute respiratory syndrome coronavirus 2 and its associated coronavirus disease 2019 (COVID-19), polymerase chain reaction and then serological testing platforms have been massively developed to face the important screening demand. Polymerase chain reaction and serological testing platforms are not the only actors impacted by the crisis, transfusion services are facing important difficulties. A positive direct antiglobulin test is frequently observed for patients encountering COVID-19. Patients with severe symptoms may develop anaemia and become good candidates for blood transfusions. The interpretation of a positive direct antiglobulin test for patients recently transfused and suffering from COVID-19 is complex. The differentiation between COVID-19 induced antibodies and possible associated transfusion alloantibodies is therefore crucial. In this context, the elution technique incorporated in an appropriate decision-making process plays its full role. This intricate topic is presented through a case report followed by literature review and finally decision-making process for COVID-19 patients necessitating red blood cells administration