Retraction. Target platelet antigen in homosexual men with immune thrombocytopenia

The non-classical MHC molecule HLA-G protects human muscle cells from immune-mediated lysis: implications for myoblast transplantation and gene therapy

HLA-G is a non-classical MHC class I molecule with highly limited tissue distribution which has been attributed chiefly immune-regulatory functions. We previously have reported that HLA-G is expressed in inflamed muscle in vivo and by cultured myoblasts in vitro. Here, we used the in vitro models of human myoblasts or TE671 muscle rhabdomyosarcoma cells to characterize the functional role of HLA-G for muscle immune cell interactions. Gene transfer of the two major isoforms of HLA-G (transmembranous HLA-G1 and soluble HLA-G5) into TE671 rendered these cells resistant to alloreactive lysis by direct inhibition of natural killer (NK) cells, and CD4 and CD8 T cells. Further, HLA-G reduced alloproliferation, interfered with effective priming of antigen-specific cytotoxic T cells and reduced antigen-specific alloreactive lysis. HLA-G pre-induced on cultured myoblasts inhibited lysis by alloreactive peripheral blood mononuclear cells. This protection was reversed by a neutralizing HLA-G antibody. Interestingly, a few HLA-G-positive cells within a population of HLA-G-negative muscle target cells conveyed significant inhibitory effects on alloreactive lysis. Our results reveal further insights into the immunobiology of muscle and suggest that ectopic expression of HLA-G may promote the survival of transplanted myoblasts in the future treatment of hereditary muscle diseases. Further, HLA-G could represent a novel self-derived anti-inflammatory principle applicable in strategies against inflammatory aggression.

The natural history of HIV disease in haemophilia

Patients with haemophilia, particularly that due to factor VIII deficiency, have been exposed to a wide range of infective agents transmitted through blood products that have in other ways revolutionized their care. The most devastating of these transfusion transmitted infections has been the human immunodeficiency virus (HIV). AIDS in haemophilic patients was first described in 1982 and it has significantly reduced the life expectancy of these patients. In this article, the impact of the HIV epidemic within haemophilic patients treated with coagulation factor concentrate is discussed. The effect of age at time of exposure to HIV and the value of disease markers such as P24 antigenaemia and CD4 counts are considered in detail. The relationship between HIV disease and coexisting hepatitis C infection is described and the incidence of secondary malignancies such as lymphoma is reviewed. In this patient population the recent elucidation of the life cycle and dynamics of HIV as well as the technological advances in the development of the HIV RNA PCR assay for HIV viral load have revolutionalized the diagnosis, prognosis, management and treatment of HIV infection.