Serum and salivary antibodies to a mycobacterial 65-kDa stress protein are elevated in HIV-positive patients and modified by oral candidiasis.

Serum immunoglobulin G (IgG) and IgA, and salivary IgA antibodies to a mycobacterial stress protein (mSP65) were determined in human immunodeficiency virus (HIV)-positive patients, acquired immunodeficiency syndrome (AIDS) patients and HIV-negative controls with or without oral candidiasis. Serum IgG antibodies were elevated in patients with HIV infection and AIDS and especially in subjects with candidiasis compared with controls (P < 0.02, P < 0.005). This was not apparent with serum IgA. In the absence of candidiasis, salivary IgA antibodies were elevated in HIV-positive patients compared with AIDS (P < 0.005) patients and healthy controls (P = 0.001). The relative avidity of serum IgG antibodies to mSP65 in controls with candidiasis was lower than healthy controls (P < 0.0001). In saliva there was a decrease in the relative avidity of IgA antibodies in AIDS patients with candidiasis compared with HIV patients (P < 0.03). In patients without candidiasis, the relative avidity was higher in HIV patients than healthy controls (P = 0.02). The results suggest that HIV infection leads to raised serum and salivary antibodies to heat shock proteins. Concurrent Candida infection may modify both the titer and relative avidity differently for serum and saliva.