MMA can be reliably performed on whole blood samples drawn into ACD and kept at RT for up to 36 hours and when physiologic pH is maintained during the assay. Future studies are required to confirm whether use of these conditions with patient monocytes can provide accurate determination of alloantibody significance in patients requiring blood transfusion.

These results suggest that adamantylGb3 may provide a new basis for blocking HIV infections, irrespective of HIV envelope/chemokine co-receptor preference or resistance to other therapeutics.

Several human histo-blood groups are glycosphingolipids, including P/P1/P k . Glycosphingolipids are implicated in HIVhost-cell-fusion and some bind to HIVgp120 in vitro. Based on our previous studies on Fabry disease, where P k accumulates and reduces infection, and a soluble P k analog that inhibits infection, we investigated cell surface-expressed P k in HIV infection. HIV-1 infection of peripheral blood-derived mononuclear cells (PBMCs) from otherwise healthy persons, with blood group P 1 k , where P k is overexpressed, or blood group p, that completely lacks P k , were compared with draw date-matched controls. Fluorescenceactivated cell sorter analysis and/or thin layer chromatography were used to verify P k levels. P 1 k PBMCs were highly resistant to R5 and X4 HIV-1 infection. In contrast, p PBMCs showed 10-to 1000-fold increased susceptibility to HIV-1 infection. Surface and total cell expression of P k , but not CD4 or chemokine coreceptor expression, correlated with infection. P k liposome-fused cells and CD4 ؉ HeLa cells manipulated to express high or low P k levels confirmed a protective effect of P k . We conclude that P k expression strongly influences susceptibility to HIV-1 infection, which implicates P k as a new endogenous cell-surface factor that may provide protection against HIV-1 infection. (Blood. 2009;113:4980-4991)

These studies indicate that pharmacologic strategies that target SH groups on mononuclear phagocytes may have future efficacy for the treatment of immune cytopenias.