High-risk human papillomavirus genotype distribution among women living with and at risk for HIV in Africa

OBJECTIVE

Cervical cancer is a common preventable cancer among African women living with HIV (WLWH). Molecular diagnostics for high-risk human papillomavirus (HR-HPV) genotypes are standard components of cervical cancer screening in resource-rich countries but not in resource-limited settings. We evaluated HR-HPV genotypes among women with and without HIV in four African countries to inform cervical cancer preventive strategies.

METHODS

The African Cohort Study (AFRICOS) enrolled participants with and without HIV at 12 clinics in Tanzania, Kenya, Uganda, and Nigeria. Cervical cytobrush specimens from women were genotyped for 14 HR-HPV types using the multiplex Seegene Anyplex real-time PCR assay. Robust Poisson regression was used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for factors associated with HR-HPV in WLWH.

RESULTS

From January 2015 to March 2020, 868 WLWH and 134 women living without HIV (WLWoH) were tested for HR-HPV with prevalence of 50.9 and 38.1%, respectively ( P  = 0.007). Among WLWH, 844 (97.4%) were antiretroviral therapy (ART)-experienced and 772 (89.7%) virally suppressed 1000 copies/ml or less. The most frequent HR-HPV types among WLWH were HPV-16 (13.5%), HPV-52 (9.5%), and HPV-35 (9.3%). HR-HPV infection was more common among Tanzanian WLWH (adjusted RR: 1.23, 95% CI 1.05-1.44, P  = 0.012). Also, WLWH with CD4 + T cells of less than 200 cell/μl had 1.51-fold increased risk of having HR-HPV (95% CI 1.23-1.86, P  < 0.001).

CONCLUSION

HR-HPV was common in WLWH in four African countries, particularly among women with low CD4 + cell count. Scale up of HPV vaccines and development of vaccines with broader activity against less common HR-HPV types may improve cervical cancer prevention in Africa.

Increased HIV Incidence in Wuchereria bancrofti Microfilaria Positive Individuals in Tanzania

Background: Infections with Wuchereria bancrofti are associated with reduced immunity against concomitant infections. Indeed, our previous study described a 2.3-fold increased HIV incidence among individuals with W. bancrofti infection, as measured by the circulating filarial antigen of the adult worm. This new study aimed to retrospectively determine microfilariae status of the participants to assess if the previously described increased HIV susceptibility was associated with the presence of MF in the same cohort. Methods: CFA positive but HIV negative biobanked human blood samples (n = 350) were analyzed for W. bancrofti MF chitinase using real time PCR. Results: The PCR provided a positive signal in 12/350 (3.4%) samples. During four years of follow-up (1109 person years (PY)), 22 study participants acquired an HIV infection. In 39 PY of W. bancrofti MF chitinase positive individuals, three new HIV infections occurred (7.8 cases per 100 PY), in contrast to 19 seroconversions in 1070 PY of W. bancrofti MF chitinase negative individuals (1.8 cases per 100 PY, p = 0.014). Conclusions: In the subgroup of MF-producing Wb-infected individuals, the HIV incidence exceeded the previously described moderate increased risk for HIV seen in all Wb-infected individuals (regardless of MF status) compared with uninfected persons from the same area.

HPV Type Distribution in HIV Positive and Negative Women With or Without Cervical Dysplasia or Cancer in East Africa

Background

Women living with HIV in sub-Saharan Africa are at increased risk to develop cervical cancer (CC), which is caused by persistent infection with 13 oncogenic human papilloma viruses (HR-HPVs). It is important to accurately identify and target HIV-positive women at highest risk to develop CC for early therapeutic intervention.

Methods

A total of 2,134 HIV+ and HIV− women from South-West Tanzania were prospectively screened for cervical cancer and precancerous lesions. Women with cervical cancer (n=236), high- and low-grade squamous intraepithelial lesions (HSIL: n=68, LSIL: n=74), and without lesion (n=426) underwent high-resolution HPV genotyping.

Results

Eighty percent of women who were diagnosed with HSIL or LSIL were living with HIV. Any lesion, young age, HIV status, and depleted CD4 T cell counts were independent risk factors for HPV infections, which were predominantly caused by HR-HPV types. While multiple HR-HPV type infections were predominant in HIV+ women with HSIL, single-type infections predominated in HIV+ CC cases (p=0.0006). HPV16, 18, and 45 accounted for 85% (68/80) and 75% (82/110) of HIV+ and HIV− CC cases, respectively. Of note, HPV35, the most frequent HPV type in HSIL-positive women living with HIV, was rarely detected as a single-type infection in HSIL and cancer cases.

Conclusion

HPV16, 18, and 45 should receive special attention for molecular diagnostic algorithms during CC prevention programs for HIV+ women from sub-Saharan Africa. HPV35 may have a high potential to induce HSIL in women living with HIV, but less potential to cause cervical cancer in single-type infections.

Depletion of Human Papilloma Virus E6- and E7-Oncoprotein-Specific T-Cell Responses in Women Living With HIV

Background

Cervical cancer - caused by persistent High Risk Human Papilloma Virus (HR HPV) infections - is the second most common cancer affecting women globally. HIV infection increases the risk for HPV persistence, associated disease progression and malignant cell transformation. We therefore hypothesized that this risk increase is directly linked to HIV infection associated dysfunction or depletion of HPV-oncoprotein-specific T-cell responses.

Methods

The 2H study specifically included HIV+ and HIV- women with and without cervical lesions and cancer to analyze HPV oncogene-specific T cell responses in relation to HPV infection, cervical lesion status and HIV status. Oncoprotein E6 and E7 specific T-cell responses were quantified for the most relevant types HPV16, 18 and 45 and control antigens (CMV-pp65) and M.tb-PPD in 373 women, using fresh peripheral blood mononuclear cells in an IFN-γ release ELISpot assay.

Results

Overall, systemic E6- and E7-oncoprotein-specific T-cell responses were infrequent and of low magnitude, when compared to CMV-pp65 and M.tb-PPD (p < 0.001 for all HR HPV types). Within HIV negative women infected with either HPV16, 18 or 45, HPV16 infected women had lowest frequency of autologous-type-E6/E7-specific T-cell responses (33%, 16/49), as compared to HPV18 (46% (6/13), p = 0.516) and HPV45 (69% (9/13), p = 0.026) infected women. Prevalent HPV18 and 45, but not HPV16 infections were linked to detectable oncoprotein-specific T-cell responses, and for these infections, HIV infection significantly diminished T-cell responses targeting the autologous infecting genotype. Within women living with HIV, low CD4 T-cell counts, detectable HIV viremia as well as cancerous and precancerous lesions were significantly associated with depletion of HPV oncoprotein-specific T-cell responses.

Discussion

Depletion of HPV-oncoprotein-specific T-cell responses likely contributes to the increased risk for HR HPV persistence and associated cancerogenesis in women living with HIV. The low inherent immunogenicity of HPV16 oncoproteins may contribute to the exceptional potential for cancerogenesis associated with HPV16 infections.

Depletion and activation of mucosal CD4 T cells in HIV infected women with HPV-associated lesions of the cervix uteri

BACKGROUND

The burden of HPV-associated premalignant and malignant cervical lesions remains high in HIV+ women even under ART treatment. In order to identify possible underlying pathophysiologic mechanisms, we studied activation and HIV co-receptor expression in cervical T-cell populations in relation to HIV, HPV and cervical lesion status.

METHODS

Cervical cytobrush (n = 468: 253 HIV- and 215 HIV+; 71% on ART) and blood (in a subset of 39 women) was collected from women in Mbeya, Tanzania. Clinical data on HIV and HPV infection, as well as ART status was collected. T cell populations were characterized using multiparametric flow cytometry-based on their expression of markers for cellular activation (HLA-DR), and memory (CD45RO), as well as HIV co-receptors (CCR5, α4β7).

RESULTS

Cervical and blood T cells differed significantly, with higher frequencies of T cells expressing CD45RO, as well as the HIV co-receptors CCR5 and α4β7 in the cervical mucosa. The skewed CD4/CD8 T cell ratio in blood of HIV+ women was mirrored in the cervical mucosa and HPV co-infection was linked to lower levels of mucosal CD4 T cells in HIV+ women (%median: 22 vs 32; p = 0.04). In addition, HIV and HPV infection, and especially HPV-associated cervical lesions were linked to significantly higher frequencies of HLA-DR+ CD4 and CD8 T cells (p-values < 0.05). Interestingly, HPV infection did not significantly alter frequencies of CCR5+ or α4β7+ CD4 T cells.

CONCLUSION

The increased proportion of activated cervical T cells associated with HPV and HIV infection, as well as HPV-associated lesions, together with the HIV-induced depletion of cervical CD4 T cells, may increase the risk for HPV infection, associated premalignant lesions and cancer in HIV+ women. Further, high levels of activated CD4 T cells associated with HPV and HPV-associated lesions could contribute to a higher susceptibility to HIV in HPV infected women.

Wuchereria bancrofti infection is linked to systemic activation of CD4 and CD8 T cells

Background

Susceptibility to HIV has been linked to systemic CD4+ T cell activation in cohorts of seronegative individuals with high HIV-exposure risk. We recently described an increased risk of HIV transmission in individuals infected with Wuchereria bancrofti, the causative agent for lymphatic filariasis, in a prospective cohort study. However, the reason for this phenomenon needs further investigation.

Methodology/Principal findings

Two-hundred and thirty-five HIV negative adults were tested using Trop Bio ELISA for detection of W. bancrofti infection and Kato Katz urine filtration and stool based RT-PCR for detection of soil transmitted helminths and schistosomiasis. FACS analysis of the fresh peripheral whole blood was used to measure T cell activation markers (HLA-DR, CD38), differentiation markers (CD45, CD27), markers for regulatory T cells (FoxP3, CD25) and the HIV entry receptor CCR5. Frequencies of activated HLA-DR^pos CD4 T cells were significantly increased in subjects with W. bancrofti infection (n = 33 median: 10.71%) compared to subjects without any helminth infection (n = 42, median 6.97%, p = 0.011) or those with other helminths (Schistosoma haematobium, S. mansoni, Trichuris trichiura, Ascaris lumbricoides, hookworm) (n = 151, median 7.38%, p = 0.009). Similarly, a significant increase in HLA-DR^posCD38^pos CD4 T cells and effector memory cells CD4 T cells (CD45RO^posCD27^neg) was observed in filarial infected participants. Multivariable analyses further confirmed a link between W. bancrofti infection and systemic activation of CD4 T cells independent of age, fever, gender or other helminth infections.

Conclusions/Significance

W. bancrofti infection is linked to systemic CD4 T cell activation, which may contribute to the increased susceptibility of W. bancrofti infected individuals to HIV infection.

The importance of CD4 T cell activation for HIV susceptibility has been emphasized in several studies focusing on HIV transmission and prevention. Particularly, activated HLA-DR+ CD4 T cells may play a major role in HIV susceptibility. In this analysis we describe systemic activation of CD4 T cells in individuals infected with W. bancrofti the causative agent of lymphatic filariasis. This helminth disease leads to debilitating pathology in some of the individuals; however, the majority of infected persons remain asymptomatic. We recently described an increased HIV incidence in subjects infected with W. bancrofti compared to uninfected individuals from the same area. To decipher underlying reasons for this phenomenon, we measured immune activation parameters in CD4 and CD8 T cells. The increased percentage of HLADR positive and HLADR/CD38 positive CD4 T cells and also effector memory CD4 T cells that we describe here could be a possible mechanism to explain our previous findings of increased HIV incidence in individuals infected with this filarial nematode.