Longitudinal study of cytomegalovirus antibodies in individuals infected with the human immunodeficiency virus.

Cytomegalovirus (CMV) antibody profiles were studied in 25 HIV-infected patients over periods of up to 56 months. Specific antibodies against CMV antigen components were monitored by complement-fixation (CF) test, EIA, Western blot and a neutralization assay. Three subjects remained CMV seronegative throughout the study. Marked fluctuations were observed in anti-CMV antibodies assayed by the CF test as compared to a control group. Fluctuations on immunoblots of purified virion antigens were also observed in the HIV-infected patients; neutralizing antibodies and anti-CMV nucleocapsid antibodies showed less variability. Seven of 22 individuals exhibited an increase in CF-test titre of up to 64-fold without clinically apparent CMV disease. On Western-blot testing of IgG reactivity with disrupted virions, ten individuals exhibited increasing reactivity to pp65, and only three of these also showed a titre rise in the CF test. In contrast, 7 of 22 showed low reactivity to the pp28 antigen. The homosexual patient group exhibited the highest levels of anti-CMV antibody. In conclusion, many asymptomatic HIV-infected subjects showed fluctuations at different levels of their antibody response to CMV, thought to be indicative of CMV reactivation/reinfection. Western-blot findings indicated that some CMV antibodies increased in level while others were lost.