Normal levels of allo- but increased levels of potentially autoreactive antibodies against ABO histo-blood group antigens in AIDS patients.

The aim of our study was to investigate the immune response of human immunodeficiency virus (HIV)-infected patients in relation to the naturally occurring ABO histo-blood group antibodies. Despite markedly elevated levels of total IgM/G/A, anti-A/B isotypes revealed no significant different mean levels in AIDS patients compared to controls. However, 12 A-type AIDS sera out of 17 (70%) had anti-A IgA levels that were increased by >2 SD above normal range; anti-A IgM and anti-A IgG were increased in 7/17 (41%) and 2/17 (12%) of A-type AIDS sera, respectively. We conclude that the specific response to ABO histo-blood group antigens remains at levels similar to normal and does not follow hypergammaglobulinemia. As yet, certain A-type AIDS patients may form auto-anti-A as suggested by a portion of our data.