Analysis of manual liquid-based cytology, histopathology and HPV DNA testing among HIV positive women at Machakos level 5 hospital, Machakos County, Kenya
Liquid-based cytology is a technique of preparing a monolayer of cells by washing the cells in a phial of liquid fixative and spreading a thin layer of the sample on a glass slide. This enables a better morphological assessment of the cells, thus increasing the detection rate of cytological abnormalities. In the developed countries, the liquid based cytology technique is fully automated; however, in developing countries, the approach is undermined by its unavailability and related costs. Although conventional Pap smear examination is the primary approach for early detection of cervical cancer, it has shortcomings such as presence of obscuring materials like blood, mucus, and inflammation; hence, the sensitivity is reduced considerably. Contrary, manual liquid based cytology technique increases specimen adequacy rate and improves precursor lesions and cervical cancer detection by its ability to overcome the shortcomings experienced in Conventional Pap Smear. The main objective of this research was to compare the performance of manual liquid based technique versus that of histopathology and assess the utility of its remnant samples in detection of high risk Human Papilloma Virus. Through the use of a Manual liquid-based cytology, a prospective study of 400 cases was evaluated for pre-cancerous lesions and cervical cancer at Machakos County Hospital among women attending the Comprehensive Care Centre. Purposive sampling method was applied to obtain the study population. The principal investigator screened all the Pap smears and a pathologist reviewed all the abnormal smears. All participants with features of high-grade squamous intraepithelial lesions and above based on cytological results were referred for histopathology. In all remnant samples with abnormal lesions encompassing atypical squamous cells of unknown significance and above, detection of Human Papilloma Virus 16 and 18 was done using a real time Polymerase Chain Reaction. Chi-Square test was used to relate the groups’ nominal categorical data appropriately. Cohen Kappa test was performed to establish the exact level of agreement among HPV DNA testing, histopathology, and Manual liquid based cytology. The prevalence of cervical lesions in this study was 7.8%. There were 41 (10.3%) cases of bacterial vaginosis recorded in this study. Out of the 25 samples tested for High-risk HPV DNA, 18 (72%) were positive while 7 (28%) were negative. Ten women were referred for biopsy and histopathological examination. Of those 10, 4 (40%) had CIN II, 3 (30%) had CIN III, 2 (20%) showed features of squamous cell carcinoma while 1 (10%) was found to have chronic cervicitis. There was moderate agreement between histopathology and high risk HPV DNA testing; k=0.574, (95% CI, .41 to .60), p =0.11. There was substantial agreement between histopathology and high risk HPV DNA testing; k=0.615, (95% CI, .61 to .80), p =0.035. Overall, manual liquid based cytology was found to have a moderate level of agreement with histopathology with ability to preserve remnant samples for adjunctive tests such as HPV DNA detection; therefore, it can be considered a substitute screening method in limited resource settings.