Diversity of clinical spectrum of HTLV-III infection.

In a prospective follow-up volunteer study lasting 4 to 16 months, 17 of 200 homosexual men living in Finland had antibodies to human T-lymphotrophic virus type III (HTLV-III). 1 man who initially had a low titre of HTLV-III antibodies became seronegative within 6 months without any symptoms developing, and a seronegative man became seropositive. 14 men had high titres of HTLV-III antibodies when they first joined the study and during the study titres rose in all other HTLV-III-positive men except those with AIDS. Initially 9 men were symptom-free, 3 had lymphadenopathy syndrome (LAS), 3 had AIDS-related complex (ARC), and 2 had AIDS. During follow-up LAS developed in 3 symptom-free HTLV-III positive men but none of those with LAS or ARC progressed to AIDS. Most HTLV-III-positive men, including those who were otherwise symptom-free, had mucocutaneous lesions generally associated with immune deficiency. Regardless of the symptoms, those with increasing HTLV-III antibody titres showed lowered T helper/T suppressor ratios, decreased numbers of T helper cells, and/or diminished responses to tuberculin antigen (PPD). These results suggest that the clinical spectrum of HTLV-III infection ranges from transient infection through chronic provirus state, asymptomatic virus producer state, LAS or ARC, and rarely full-blown AIDS. Cofactors probably determine the final outcome of infection in the individual.