Association between HPV-16 and HPV-18 viral loads and severity of cervical pre-invasive lesions in women with and without HIV in Botswana

Background: Cervical cancer is an important global health problem, including in Botswana. Human papillomavirus (HPV) and human immunodeficiency virus (HIV) are responsible for a considerable burden of the disease globally. The significance of HPV viral load in the detection of pre-invasive cervical lesions in patients with and without HIV is still controversial. The present study aimed to explore the correlation between HPV-16 and HPV-18 genotype viral loads and the severity of cervical lesions in pre-cervical cancer patients with and without HIV in Botswana. Methods: A cross-sectional convenience sampling was adopted using 109 archived residual tissue blocks collected from pre-cervical cancer patients in Gaborone, Botswana, during 2017-2019. Viral load for HPV-16 and HPV-18 has been quantified in pre-invasive cervical lesions using quantitative PCR to evaluate its potential as a predictor of disease severity, and examined correlations with HIV status and pre-cancer stage. Results: Of the 109 patients, HPV-16 was detected in 33.94% and HPV-18 in 14.68%. Only 3 (2.75%) patients were co-infected with both genotypes, while the remaining patients 56 (48.6%) tested negative for both genotypes. In this study 70.6% of the 109 samples were infected with HIV while 29.4% were HIV-uninfected. For HPV-16, higher cervical intraepithelial neoplasia (CIN) grade was associated with increased HPV viral load, while HPV-18 exhibited a more variable pattern, with the highest HPV viral load observed in CIN II. The presence of HPV-16 and elevated HPV-16 viral load were significant risk factors for CIN III. In contrast, the presence of HPV-18 and higher HPV-18 viral load were associated with increased risk for CIN II, but did not have a significant impact on the risk for CIN III. HIV status did not have a significant impact on viral load of these HPV genotypes. Conclusions: Higher HPV-16 viral loads are linked to more severe cervical lesions while HPV-18 is more associated with CIN II than CIN III. However, HIV status was not associated with higher viral loads. Larger studies are needed to confirm these findings and improve screening.