An association of disseminated Mycoplasma fermentans in HIV-1 positive patients with non-Hodgkin's lymphoma

We examined the relationship between the haematogenous dissemination of Mycoplasma fermentans and non-Hodgkin's lymphoma (NHL) in 265 HIV-1 positive patients. A polymerase chain reaction (PCR) assay was used to detect M. fermentans in peripheral blood mononuclear cells (PBMCs) from 50 patients enrolled consecutively from an HIV outpatient clinic in 1991 (cohort 1), 56 patients with lower respiratory tract infection who underwent bronchoscopy in 1992 (cohort 2), and 159 patients who were enrolled into a natural history cohort study in 1994 (cohort 3). The incidence of NHL among the patients was determined in 1998. The PBMCs of 29 patients (10.9%) were positive for M. fermentans (8 in cohort 1, 13 in cohort 2 and 8 in cohort 3) and 11 patients (4.2%) developed NHL which was confirmed histologically (3 in cohort 1, 4 in cohort 2 and 4 in cohort 3). We found a statistically significant association between the presence of M. fermentans and the development of NHL in the combined cohort (risk ratio [RR]=6.78 [95% confidence interval (CI) 2.21--20.84], P=0.003 Fisher's exact test [FET]). This association remained significant even after adjustment in a multivariate analysis for CD4 cell count and HIV disease status at the time of M. fermentans testing (RR=7.97 [95% CI=2.16--29.47], P=0.002).