The effects of antiviral therapy on the levels of neutralizing antibodies and antibodies mediating antibody-dependent cellular cytotoxicity in HI-1 seropositive patients /

This study consists of evaluating the effects of zidovudine or ribavirin treatment on the humoral response to human immunodeficiency syndrome (HIV-1) in a cohort of 36 HIV-1 seropositive patients. Viral neutralization antibodies were demonstrated against HTLV$ sb{ rm IIIb}$ virus while titers of circulating antibody-dependent cellular cytotoxicity (ADCC) antibodies were measured against the HIV-1 envelope protein, gp120, using the vaccinia virus expression system which has been successfully used to express foreign viral proteins in target cells. Virologic (viral isolation) and immunologic (CD4$ sp+$ cells) parameters were also monitored pre and post antiviral therapy.The results indicate that patients receiving zidovudine for 36 weeks, have a diminished anti-HIV-1-ADCC directing antibody response, while the levels of these antibodies in patients receiving ribavirin or placebo remain constant. The titers of neutralizing antibodies and CD4 counts remain stable regardless of the treatment except for patients receiving ribavirin, where a decline in CD4 cells is observed. The decrease in the HIV-1 specific ADCC during zidovudine treatment parallels with the decrease in the amount of viral burden. This suggests that the two effects are somehow correlated. The impact of a washout period was also assessed. An increase in viral burden during cessation of AZT was reported which may reflect the inability of the treated host to mount a rapid immune response. As a consequence, this may lead to the deterioration of the immune status and the progression of the disease. The implications of these findings will be discussed in this study