Evidence of B Cell Clonal Expansion in HIV Type 1-Infected Patients

HIV-1 infection results in a gradual decrease in CD4+ T cell counts and progressive immune deficiency. Increased T cell turnover in HIV-1-infected patients, which can be interpreted as T cell clonal expansion, has been thought to be relevant to its pathogenesis. To investigate whether B cell clonal expansion also occurs in HIV-1-infected patients, we examined the expressed VHDJH gene sequences of peripheral B cells in HIV-1-infected patients with hypergammaglobulinemia. Identical VHDJH gene rearrangements with additional nucleotide differences in VH genes were analyzed as a marker of clonally related B cells. From healthy individuals and HIV-1-uninfected patients with hypergammaglobulinemia, clonally related B cells were detected in none of 10 (0%) and 2 of 10 (20%), respectively. No clonally related B cells were detected in any of the nine HIV-1-infected patients with detectable viral loads and normal Ig levels (0%). In contrast, from 9 of 14 HIV-1-infected patients with hypergammaglobulinemia (64%), clo...