Retrospective analysis of clinical and laboratory factors associated with lymphoma in simian AIDS

A nonhuman primate model for AIDS-associated Non-Hodgkin's lymphoma (AIDS-NHL) has been described in which animals inoculated with simian immunodeficiency virus (SIV) develop simian AIDS (SAIDS) and SAIDS-NHL. The objective of the present study was to describe statistically the major trends observed in clinical and laboratory data collected longitudinally on a large cohort of nonhuman primates that developed SAIDS-NHL. Clinical and laboratory data were collected longitudinally on each animal from the time of SIV infection throughout progression to lymphoma. Data were analyzed retrospectively with regard to species, gender, age at SIV inoculation, survival, cause of death, CD4+ T-cell and B-cell counts, SIV antigenemia, persistent lymphoid hyperplasia and lymphocryptovirus infection. Median survival time (354 days: 95% CI 309-388) was not related to gender, age at SIV inoculation, cause of death, or RhLCV infection. Survival was not related to CD4+ T-cell count at the time of SIV infection (P = 0.5531), but increased survival was significantly related to a slower rate of CD4+ T-cell decline (P = 0.0256). A B-cell expansion was observed at the midpoint of disease. A steep rise in SIV antigenemia was detected in the first 21 days of infection followed by a rapid decline. This pattern did not occur in animals inoculated with SIV as infants or yearlings. Of 45 cases, 9 exhibited marked, persistent lymphoid hyperplasia. These results describe trends identified in clinical and laboratory factors associated with SAIDS-NHL in the largest collection of such samples in the world. The results contribute to an understanding of the etiology of SAIDS-NHL and to the future development of useful predictors of SAIDS- or AIDS-related lymphoma.