IgG2 deficiency in children with human immunodeficiency virus infection.

Infection with the human immunodeficiency virus (HIV) induces a polyclonal B-cell activation. Despite elevated serum immunoglobulin levels, a significant deterioration of the antigen specific humoral immune response exists in most cases. We studied the influence of HIV infection on the serum levels of IgG subclasses in children. We investigated 76 children (aged 15 months to 18 years) with HIV-1-infection. Most children (88%) showed elevated serum immunoglobulin levels. IgA (87%) and IgM (74%) were more often above normal levels for age than IgG (60%). IgG subclass serum levels were significantly altered. The increase in total IgG was mainly due to a marked augmentation of the IgG1 fraction. In most cases IgG3 was simultaneously elevated. Ten children (13%) had very low IgG4 levels (less than 0.03 g/l). Out of 61 patients older than 2 years 8 (13%) had a profound IgG2 deficiency with normal or elevated total IgG. Four of them also had low IgG4 levels (less than 0.03 g/l). A correlation between IgG2 deficiency and HIV infection according to the Centres for Disease Control classification for acquired immunodeficiency syndrome could not be demonstrated (three patients with symptomatic and five with asymptomatic infection).