Haptoglobin polymorphism in human immunodeficiency virus infection: Hp0 phenotype limits depletion of CD4 cell counts in HIV-1-seropositive individuals

Patients seropositive for human immunodeficiency virus (HIV) type 1 and ser onegative control subjects were categorized by their haptoglobin phenotypes , which were determined by electrophoresis of hemoglobin-supplemented plasm a samples followed by benzidine staining. The CD4 cell counts, determined b y flow cytometry from peripheral blood mononuclear cells according to subje ct categories, were severely diminished in seropositive patients with the H p2-2 phenotype (P < .025). In contrast, the CD4 cell counts for patients wi th the Hp0 phenotype remained relatively high (P < .025), compared with tho se of the controls. In seronegative patients, CD4 cell counts were generall y high (P < .005), but they were more elevated in subjects with Hp2-2 and H p1-1, although the differences were not significant. Thus, the Hp2-2 phenot ype is associated with poor outcome in HIV-1 infection, whereas the Hp0 phe notype is associated with a better prognosis once the patient is infected w ith HIV-1. Haptoglobin polymorphism plays a significant role in HIV-1 infec tion and transmission.