Characterization of a distinct subgroup of high-risk persons with Kaposi's sarcoma and good prognosis who present with normal T4 cell number and T4:T8 ratio and negative HTLV-III/LAV serologic test results.

Three homosexual male patients with biopsy-proved Kaposi's sarcoma were classified as having the acquired immune deficiency syndrome (AIDS) by Centers for Disease Control criteria when first seen in 1983 and 1984. These patients, however, differed from most patients with AIDS and Kaposi's sarcoma in having normal CD4 cell numbers and normal CD4:CD8 ratio. Furthermore, these immunologic parameters remained normal for eight to 24 months of follow-up, and the disease did not progress. Results of recent testing of serum from these patients were negative for HTLV-III/LAV antibodies. The Kaposi's sarcoma was limited to skin (stage I tumors) and the patients did not have persistent lymphadenopathy, fever, night sweats, or weight loss. In contrast to AIDS, the serum immunoglobulin levels (IgG, IgA, IgM) and number of B cells that were spontaneously forming immunoglobulin were within normal range with no evidence of polyclonal activation. The lymphocyte proliferative responses to phytohemagglutinin and Candida were reduced in two of the three patients, and skin test anergy was observed in the two patients tested. These findings are not frequently encountered in other healthy, homosexually active men or in classic Kaposi's sarcoma. They may be indicative of functional T cell changes (without numerical changes) induced by factors other than HTLV-III/LAV virus, which made these homosexually active men susceptible to development of low-grade Kaposi's sarcoma lesions.