Serum antibodies to Trichomonas vaginalis in invasive cervical cancer patients.
OBJECTIVE--To evaluate, by seroepidemiology, the possible role of the sexually-transmitted flagellate, Trichomonas vaginalis, in invasive cervical cancer. SUBJECTS AND METHOD--Sera from 121 invasive cervical cancer patients and 242 random age-matched female controls. Antibodies to T. vaginalis were detected by the western blot technique. RESULTS--Antibodies to T. vaginalis were detected in the sera of 41.3% (50/121) of invasive cervical cancer patients compared with only 5.0% (12/242) of female controls. All the reactive sera reacted strongly with the immunogenic surface membrane proteins of T. vaginalis of molecular weights of about 92 and 115 kDa, with variable reactivity to other immunogenic proteins of T. vaginalis. CONCLUSION--The significantly increased relative risk, RR = 3.42 (95% CI = 1.73-6.78), is comparable to the RRs derived in seroepidemiological studies of human papillomavirus, suggesting that T. vaginalis may be even more closely associated with invasive cervical cancer than previously realized.