Ultrastructural markers in circulating lymphocytes of subjects at risk for AIDS.

One hundred random lymphocytes in each of 168 buffy coat preparations from 59 subjects at risk for AIDS (50 homosexuals, 7 hemophiliacs, and 2 combined, all with T4:T8 ratios of less than or equal to 1.2) were screened for the presence of ultrastructural markers, "tubuloreticular structures" (TRS), and "test tube and ring-shaped forms" (TRF). Twenty-six (44%) of the subjects were TRS positive (71 specimens) and 12 (20%) were TRS/TRF positive (34 specimens). TRF were only observed in TRS-positive specimens. There was an inverse relationship between the incidence and abundance of markers and the T4:T8 ratios, i.e., mean T4:T8 +/- SE for TRS-negative, TRS-positive, and TRS/TRF-positive subjects were 0.59 +/- 0.05, 0.42 +/- 0.05, and 0.19 +/- 0.06, respectively. Markers were present for as long as 16 months before AIDS was diagnosed in four subjects and before the appearance of features suggestive of AIDS in two others. The assessment of TEM markers in peripheral blood lymphocytes is a simple method for screening at-risk subjects in whom AIDS is likely to develop.