Lucy Muchiri

Distribution of human papillomavirus in a family planning population in nairobi, kenya.

Background In sub-Saharan Africa, cervical cancer is the leading cancer among women. The causative role of different human papillomavirus (HPV) types in cervical cancer is established, but the distribution of HPV types within this region is largely unknown. Goal The goal was to study the distribution of HPV among family planning clinic attendees in Nairobi, Kenya. Study Design This was a cross-sectional study of persons attending a family planning center in Nairobi, Kenya. Results HPV data of 429 women were analyzed; 7.0% had low-grade intraepithelial lesions, 6.8% had high-grade intraepithelial lesions, and 0.23% had invasive cancer. One hundred ninety samples (44.3%) were HPV-positive (28.4% were positive for multiple types). The most common HPV types were HPV 52 (17.9% of positive samples), HPV 16 (14.7%), HPV 35 (11.6%), and HPV 66 (9.0%). The risk of high-grade squamous intraepithelial lesions (HSIL) was 88.5 times higher (95% CI, 8.5–1.4 × 105) in HPV 16-positive women than in HPV-negative women. Relative risks were 54.3 (95% CI, 4.0–1.4 × 105) for HPV 35, 49.2 (95% CI, 3.6–9.5 × 104) for HPV 52, and 21.7 (95% CI, 0.0—1.9 × 105) for HPV 18. The prevalence of HSIL was not increased in association with HIV-positivity, yet HIV-1 was significantly associated with high-risk HPV types (P < 0.00001). Conclusion The pattern of HPV distribution in this population was different from that in other regions in the world, which has important consequences for HPV vaccine development.

Comparison of pap smear, visual inspection with acetic acid, human papillomavirus DNA-PCR testing and cervicography

To assess the test qualities of four screening methods to detect cervical intra‐epithelial neoplasia in an urban African setting.

Risk factors for human papillomavirus and cervical precancerous lesions, and the role of concurrent HIV-1 infection

Objectives: To identify risk factors for human papillomavirus (HPV) infection and squamous intraepithelial lesions (SIL) of the cervix, and to measure the impact of concurrent HIV‐1 infection. Methods: Women were studied at a family planning clinic in Nairobi, Kenya. Demographic and historical information was obtained using a semi‐structured questionnaire and specimens were collected for sexually transmitted diseases (STDs), HPV, cervical cytology, and HIV‐1 testing. Results: HPV was detected in 87 of 513 women (17%), including 81 (93%) oncogenic types (16, 18, 31, 33 and others) and six (7%) non‐oncogenic types (6 and 11). HIV‐1 prevalence was 10%. HPV detection was associated with HIV‐1 infection [adjusted odds ratio (aOR) 3.9, 95% confidence interval (CI), 2.0–7.7], sexual behavior indicators including the number of sex partners and inflammatory STDs, as well as the number of pregnancies (0 or 1 vs. ≥3, aOR 0.4; 95% CI, 0.2–0.9). SIL was detected in 61 women (11.9%), including 28 (46%) with low‐grade lesions (LSIL) and 33 (54%) with high‐grade lesions (HSIL). HPV infection was strongly associated with HSIL (OR 14.9; 95% CI, 6.8–32.8). In a multivariate model predictors of HSIL included HIV‐1 serpositivity (aOR 4.8; 95% CI, 1.8–12.4), the number of lifetime sex partners (0–1 vs. ≥4; aOR 3.8; 95% CI, 1.1–13.5), and older age (<26 vs. >30; OR 3.9; 95% CI, 1.1–13.6). An analysis stratified by HIV‐1 showed a stronger association between HPV and HSIL in HIV‐1 negative women (OR 17.0; 95% CI, 6.4–46.3) then in HIV‐1 positive women (OR 4.5; 95% CI, 0.8–27.4). Conclusions: Our results indicate that HSIL and even invasive cancer are highly prevalent in this setting of women on reproductive age considered to be at low risk for STDs, suggesting that routine Pap smear screening may save lives.

The effects of HIV-1 Tat protein on cell cycle during cervical carcinogenesis

The role of HPV in the carcinogenesis of intraepithelial and invasive anogenital lesions is currently well established. E6 and E7 oncoproteins of high risk HPV genotypes are known to inactivate p53 and pRb pathways. Several studies have described an increased prevalence and recurrence of both cervical HPV infection and invasive cervical cancer among HIV-1 positive women compared to HIV-1 negative cases. For these reasons, cervical cancer is considered an AIDS-defining neoplasm. Unlike other AIDS-associated neoplasms, the occurrence of cervical cancer is independent of immune suppression. HIV-1 infection in patients with high grade precancerous lesions and cervical cancers results in a therapy refractory and more aggressive disease phenotype, which is not yet well understood at the molecular level. An upregulation of HPV E6 and E7 gene expressions by HIV-1 proteins such as Tat has been documented by some authors. However, the role of HIV-1 in cervical carcinomas is still unclear. It is already known that HIV-1 Tat protein is able to influence cell cycle progression. Altogether, these facts led us to investigate the effects of Tat on the expression of cell cycle regulator genes. After transfection of HeLa cells with Tat, we analyzed the expression of cell cycle regulators from these cells by IHC and Real-time PCR. A significant reduction in the expression of cell cycle inhibitors of transcription and an increase in the levels of proliferation markers were observed. These results suggest that HIV-1 may enhance cervical carcinogenesis by promoting cell cycle progression. We also found that this HIV-1 Tat-induced cell proliferation was not dependent on the E2F family of transcription factors, and therefore postulate that Sp factors may be involved.

A retrospective study on interobserver variation of Pap smear reporting at Kenyatta National Hospital (KNH) cytology laboratory, Nairobi, Kenya

Background: Interobserver variation in the cytological diagnosis of cervical lesions poses a problem for public health screening programs. This study assessed the degree of discordant diagnoses between the primary and review results. Cohens kappa was used to compare the degree of consensus. Data was analyzed using SPSS version 20. Aim: To determine the interobserver variation in pap smear reporting using the Bethesda System (2001) at KNH cytology laboratory. Method: Total of 372 Pap smears, previously reported as ASCUS or worse at KNH cytology laboratory were selected. They were examined to determine the cervical changes and graded first by the principal investigator then together with the supervising pathologists. The results: were compared with the primary report. Results: Mixed pathology (squamous+glandular) which had been missed in the primary report was noted. 22.04% cases were downgraded to NILM. Significant ‘overcalls’ and ‘undercalls’ were noted. ASCUS had a &kgr; of 0.049, LSIL 0.045, HSIL 0.126, ASCH 0.231, SCC 0.376 and glandular lesions 0.125.Overall &kgr; was 0.327. Discussion: Overall interobserver agreement was fair, but the performance was lower compared to other studies. LSIL and ASCUS lesions had very high discordance. This could be due to different application of criteria for classification of lesions by different pathologists.

P16 expression in subsets of head and neck squamous cell carcinoma reported in Kenyatta National Hospital Nairobi, Kenya

Background: Human papilloma virus associated HNSCC differ from the non HPV-associated HNSCC in that HPV-HNSCC affects younger patients and has better prognosis. These subgroups cannot be readily differentiated on H/E; however, P16 immunohistochemistry can be used to separate these tumours. Data on HPV associated HNSCC from our region is lacking. Objective: To determine p16 expression and prevalence of HPV associated tumours in subsets of HNSCC at Kenyatta National Hospital (KNH). Methods: A hundred and three HNSCC cases diagnosed from 2008 to 2013 were analyzed for P16 expression by IHC on FFPE blocks. Results: Of the 103 cases, males were 73.8% while females 26.2%. Mean age was 57.4 years. Most tumours were well differentiated (63.1%), then moderately differentiated (28.2%), while 8% were poorly differentiated. Immunohistochemistry was done, of which 14.6% were positive for P16. Oral cavity had the highest (46.67%), then larynx (26.67%) and pharynx (26.67%). The majority of p16 positive HNSCC were found amongst males 66.7%. Poorly differentiated tumours had increased risk of being HPV associated (OR 2.1, 95% C.I 0.4–11.9). Conclusion: HNSCC were more common in males, the majority being from the oral cavity. The overall HPV prevalence was 14.6% with poorly differentiated tumours having an increased risk of HPV association.

The utility of p16INK4A expression in uterine cervical biopsies reported negative and positive for dysplasia at Kenyatta National Hospital, Nairobi, Kenya

Background: Hematoxylin and eosin (H&E) stained cervical tissue sections are subject to substantial rates of discordance among pathologists. p16INK4a immunohistochemistry has shown valuable additional information in the interpretation of cervical histology and reduced inter-observer disagreement of conventional histology. Objective: To determine the utility of p16ink4a expression in cervical biopsies reported negative and positive for dysplasia. Method: A total of 91 cases of colposcopic biopsies diagnosed as negative for dysplasia and cervical intraepithelial neoplasia, from 2011 to 2013, were reviewed on H&E stain and immunostained with p16INK4a. Results: Primary reports: negative for dysplasia 16, CIN1 23, CIN2 37 and CIN3 15. Age range: 21–65 years; mean age: 40.2 years. On review, negative for dysplasia were 32, CIN1 19, CIN2 16 and CINIII 24 (p < 0.001, with kappa value of agreement: 0.568). p16INK4A expression: All negative for dysplasia cases were non-immunoreactive; 19/23 and 18/19 cases of CIN1, primary and review results respectively, were negative (p < 0.001); 48.6% and 69% of CINII, primary and review results, respectively, were positive; and finally 80% and 96% of CIN3, primary and review results respectively, stained positive (p < 0.001). Conclusion: There is significant inter-observer variation in interpretation of cervical biopsies on H&E. p16INK4a expression correlates well with high grade lesions.