Pulmonary microthrombosis and associated demographics in fatal covid-19 cases at Mulago national referral hospital, Kampala.

Abstract

Pulmonary micro thrombosis (PMT) emerged as a consequential complication in fatal COVID-19, significantly impacting morbidity and mortality globally (WHO, 2022) Despite its recognized significance, there existed a paucity of data concerning its prevalence and associated demographic factors and comorbidities in sub-Saharan African settings, such as Kampala, Uganda. This knowledge gap hindered evidence-based management of the disease in such settings. Objective: This study sought to determine the prevalence of pulmonary microthrombi and establish its association with sex, age and comorbidities namely diabetes, hypertension, and HIV among patients who died of COVID-19 and had an autopsy done at Mulago National Referral Hospital. Methods: A cross-sectional study with a retrospective approach on archived formalin fixed paraffin embedded (FFPE) lung tissue blocks of COVID-19 patients who died and had an autopsy done at Mulago National Referral Hospital (MNRH) from June 2020 to September 2021 were studied. The sample size was 120, Hematoxylin and Eosin, and and Modified Carstairs stain were used. Results: 120 lung tissue cases were enrolled and analysed. The mean age of the deceased from where the specimens were taken was 59, standard deviation ±15. The majority were males, 52.5% (n=63) and most, 86.7% (n=104) had an unknown HIV status. Slightly less than half, 46.7% (n=56) were hypertensive, and most, 67.5% (n=81) didn’t have diabetes or unknown to have diabetes. There was an association between pulmonary microthrombi in fata COVID-19 and sex at MNRH. Conclusion: The prevalence of pulmonary microthrombi among patients who died of COVID19 and had an autopsy done at Mulago National Referral Hospital was high (65%). In this autopsy-based study, male sex was the only independent predictor of pulmonary microthrombosis. On multivariate logistic regression, females were significantly less likely to exhibit microthrombi compared to males (aOR ≈ 0.4, p = 0.035). In contrast, age, HIV infection, diabetes mellitus, and hypertension showed no statistically significant associations with pulmonary microthrombosis, as their odds ratios approximated unity and p-values exceeded the 0.05 threshold. These results highlight sex-specific vulnerability, while the non significant variables may reflect limitations of retrospective data capture and study power rather than absence of biological effect.