Qualitative change in antibody responses of human immunodeficiency virus-infected individuals to pneumococcal capsular polysaccharide vaccination associated with highly active antiretroviral therapy

Variable region gene family 3 (V_H3) is the predominant immunoglobulin (Ig) gene family used in human antibodies to pneumococcal capsular polysaccharide (PPS). This study examined whether highly active anti-retroviral therapy (HAART) restores the ability of human immunodeficiency virus (HIV)-infected individuals to generate a V_H3-positive response to PPS. The IgM, IgG, and V_H3 (represented by antibodies expressing the determinant recognized by the monoclonal antibody D12) responses to PPS were determined for first-time recipients of a 23-valent PPS vaccine, both receiving and not receiving HAART, and second-time vaccine recipients receiving HAART. The results showed that only the individuals receiving HAART manifested a V_H3-(D12)-positive response to PPS, despite a similar IgG response in each group. There was also a negative correlation between HIV load and PPS response for the groups receiving HAART. These findings suggest that HAART may influence qualitative aspects of the PPS response by restoring expression of certain V_H3 genes used in the normal PPS response.