Successful transfusion of antigen positive blood to alloimmunised patients using a monocyte monolayer assay.

BACKGROUND: Providing adequate transfusion support for alloimmunised patients for whom antigen negative blood is not readily available is hampered by the risk of a haemolytic reaction. The monocyte monolayer assay (MMA) has shown good correlation between the antibody clinical significance and the fate of antigen positive blood. MATERIALS AND METHODS: From 2006 to 2013, the clinical significance of red cell alloantibodies produced by 61 patients was evaluated using a MMA; and antigen positive blood offering the best survival advantage was selected for transfusion following a secondary MMA crossmatch. Post-transfusion, patients were evaluated for clinical signs of haemolysis. RESULTS: Overall, 19 of 61 (31·1%) of our antibodies were potentially clinically significant, with a monocyte index (MI) > 5%. There was no correlation between the clinical significance as showed by the MMA, and the specificity of the antibody or the strength of reactivity at antihuman globulin (AHG) phase. Using the MMA as a secondary crossmatch method, 31 alloimmunised patients (including: eight anti-hr(B), four anti-Yt(a), one each anti-Rg1, -Co(a), Er(a), Le(b), -LW, -Sl1) received 103 antigen positive blood units with no clinical sign of a post-transfusion reaction. For three patients (one each anti-Jo(a), -AnWj, unidentified 'HTLA'), initial MMA was performed as part of an investigation of a suspected haemolytic reaction. In each case, the MMA accurately identified the unit responsible for the reaction. CONCLUSION: Used as a crossmatch surrogate, the MMA provided valuable information in the decision of transfusing antigen positive blood to alloimmunised patients, avoiding delay because of the search of rare antigen negative units.

Retrospective surveillance of HIV prevalence in blood donors can help in the selection of the best social group for blood donation in Mali.

The National Centre for Blood Transfusion, Bamako, Mali has collected data that characterizes trend in HIV prevalence over 10 years by gender, age, occupation, marital status and donor category. These data help to describe national HIV prevalence and assist in formulating blood donation policies. Donations from 1993 to 2002 were categorized by donor age (decade), occupation (student, military and other), marital status (single, married and other), gender and donor status (volunteer, occasional and family). Comparisons were made using conservative estimates of donation frequency/donor category. Donations increased by more than 400%. By 1999, increased HIV prevalence in donations from women was consistently present. Donations from the age group of 30-39 years showed an increased prevalence beginning in 2000, which by 2002 was almost 10 times greater than in the low-prevalence (<20 years) group (5.9 vs. 0.6%). By 2000, both categories - students and military were less likely to be HIV positive than those from other occupational categories, and donations from married persons were less likely to be HIV positive by 1997. The highest prevalence was observed in the 'occasional' donor category, which increased to >14% by 2001; volunteer donation HIV positive peaked at 2.3% in 1999. HIV prevalence in blood donations in Bamako, Mali, demonstrates important trends from 1993 to 2002. The prevalence of > 14% in donations from occasional donors and significant trends by decade, gender, marital status and occupation argue for increased analysis of the blood donor population to improve blood safety and to understand the demographics of HIV infection in Mali.

Mitochondrial DNA variation in Mauritania and Mali and their genetic relationship to other Western Africa populations.

Mitochondrial DNA (mtDNA) variation was analyzed in Mauritania and Mali, and compared to other West African samples covering the considerable geographic, ethnic and linguistic diversity of this region. The Mauritanian mtDNA profile shows that 55% of their lineages have a west Eurasian provenance, with the U6 cluster (17%) being the best represented. Only 6% of the sub-Saharan sequences belong to the L3A haplogroup a frequency similar to other Berber speaking groups but significantly different to the Arabic speaking North Africans. The historic Arab slave trade may be the main cause of this difference. Only one HV west Eurasian lineage has been detected in Mali but 40% of the sub-Saharan sequences belong to cluster L3A. The presence of L0a representatives demonstrates gene flow from eastern regions. Although both groups speak related dialects of the Mande branch, significant genetic differences exist between the Bambara and Malinke groups. The West African genetic variation is well structured by geography and language, but more detailed ethnolinguistic clustering suggest that geography is the main factor responsible for this differentiation.