Higher plasma AFB1 concentration is associated with increased risk of HPV 16 and HPV 18 detection and persistence among Ugandan women.

Introduction: Aflatoxins are environmental hazards; potent carcinogenic and immunosuppressive agents that contaminates corn and other crops. A high proportion of hepatocellular carcinoma cases are caused by exposure to dietary aflatoxins. Cervical cancer is common among Ugandan women; this malignancy is caused by persistent infection with oncogenic HPV types. An analysis was performed to examine associations between plasma aflatoxin B (AFB) detection and oncogenic HPV detection (HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) and persistence among Ugandan women.

Methods: Ugandan women were enrolled in a prospective cohort study. Annual cervical swabs (Enrollment, Month 12 and Month 24) were tested for oncogenic HPV. Plasma AFB concentration was measured (as AFB-lysine conjugate, or AFB-lys) at Enrollment and Month 12. Multivariable regression models were fitted to examine associations of plasma AFB-lys concentrations and oncogenic HPV controlling for demographic and behavioral characteristics.

Results: The analytical sample consisted of 114 women with a mean age of 33.2 years; 60 women were living with HIV; 59 were receiving antiretroviral therapy (ART) at enrollment. AFB-lysine adducts (AFB-lys) was detected in plasma from all 114 women. Multivariable regression models showed that plasma AFB-lys concentration was associated with a higher risk of detection of HPV 16 (OR = 2.64, 95% CI = 1.42-4.90, p = 0.002) and HPV 18 (OR = 2.24, 95% CI = 1.27-3.96, p = 0.005), and persistence of HPV 16 (OR = 3.16, 95% CI = 1.59-6.26, p = 0.001) and HPV 18 (OR = 2.06, 95% CI = 1.09-3.90, p = 0.025), controlling for age, marital status, years of education, home ownership, distance to health care, number of lifetime sex partners, age of first sex, and HIV status.

Conclusions: AFB is an environmental hazard that is prevalent among Ugandan women. Higher plasma AFB-lys concentration was associated with detection and persistence of HPV 16 and HPV 18; this association was independent of HIV status. As a result, these women may be at increased risk of cervical cancer. Further studies are needed to determine the mechanisms involved.