Th17 overexpression in severe COVID-19: a prospective observational study.

INTRODUCTION: The objective of the study was to determine T-cell subtypes, Natural Killer cell activity and cytokines in COVID-19 patients with mild to moderate disease and compare them between patients who had recovered and those who had progressed to severe disease. METHODS: Peripheral blood samples of COVID-19 patients were collected at the time of hospital admission and after one week. These samples were analysed for interleukins (IL-6, IL-17a) using chemiluminescence ELISA. The T-cell subsets (T naïve, T regulatory, Th17, Th1, Th2, CD8+ T cells] were studied using flow cytometry. Mild, moderate and severe COVID-19 are defined as per CDC guidelines. RESULTS: Nineteen COVID-19-positive patients were enrolled between June 2020 to December 2021. Nine had mild COVID-19 and 10 had moderate COVID-19 at recruitment. All mild cases recovered without progression to severe disease, while five patients from the moderate group progressed to severe disease. Overall, there is a decrease in lymphocyte count in patients with moderate-severe disease, but the ratio of Th17 [5.91 (2.69-12.01)] was higher compared to Th1 [1.12 (0.27-3.13)] and Th2[2.34 (2-3.5)]. The high baseline level of IL-6 observed in patients with moderate disease leads to the proliferation of more Th17 type of CD4+ T-cells(p=0.002) and suppression of Treg cells. A higher Th17 subset leads to neutrophilic inflammation in patients with severe COVID-19. CONCLUSION: Interpretation conclusions: Higher baseline IL-6 leads to depletion of regulatory T-cells, Th1 Th2 CD4 cells. IL-6 leads to the proliferation of Th17 type of CD4+ subsets in moderate COVID-19. Higher Th17 cells in moderate COVID-19 patients lead to the production of IL-17a, which may result in intense neutrophilic inflammatory response and cytokine storm.

Risk factors for Coronavirus disease-associated mucormycosis.

BACKGROUND: The epidemiology of the Coronavirus-disease associated mucormycosis (CAM) syndemic is poorly elucidated. We aimed to identify risk factors that may explain the burden of cases and help develop preventive strategies. METHODS: We performed a case-control study comparing cases diagnosed with CAM and taking controls as recovered COVID 19 patients who did not develop mucormycosis. Information on comorbidities, glycemic control, and practices related to COVID-19 prevention and treatment was recorded. Multivariate regression analysis was used to identify independent predictors. RESULTS: A total of 352 patients (152 cases and 200 controls) diagnosed with COVID-19 during April-May 2021 were included. In the CAM group, symptoms of mucormycosis began a mean of 18.9 (SD 9.1) days after onset of COVID-19, and predominantly rhino-sinus and orbital involvement was present. All, but one, CAM cases had conventional risk factors of diabetes and steroid use. On multivariable regression, increased odds of CAM were associated with the presence of diabetes (adjusted OR 3.5, 95% CI 1.1-11), use of systemic steroids (aOR 7.7, 95% CI 2.4-24.7), prolonged use of cloth and surgical masks (vs. no mask, aOR 6.9, 95%CI 1.5-33.1), and repeated nasopharyngeal swab testing during the COVID-19 illness (aOR 1.6, 95% CI 1.2-2.2). Zinc therapy was found to be protective (aOR 0.05, 95%CI 0.01-0.19). Notably, the requirement of oxygen supplementation or hospitalization did not affect the risk of CAM. CONCLUSION: Judicious use of steroids and stringent glycemic control are vital to preventing mucormycosis. Use of clean masks, preference for N95 masks if available, and minimizing swab testing after the diagnosis of COVID-19 may further reduce the incidence of CAM.

Post COVID-19 sequelae: A prospective observational study from Northern India.

Post COVID-19 sequelae are a constellation of symptoms often reported after recovering from COVID-19. There is a need to better understand the clinical spectrum and long-term course of this clinical entity. The aim of this study is to describe the clinical features and risk factors of post COVID-19 sequelae in the North Indian population. This prospective observational study was conducted at a tertiary healthcare centre in Northern India between October 2020 and February 2021. Patients aged >18 years with laboratory-confirmed COVID-19 were recruited after at least two weeks of diagnosis, and details were captured. A total of 1234 patients were recruited and followed up for a median duration of 91 days (IQR: 45-181 days). Among them, 495 (40.1%) had persistent symptoms post-discharge or recovery. In 223 (18.1%) patients, the symptoms resolved within four weeks; 150 (12.1%) patients had symptoms till 12 weeks, and 122 (9.9%) patients had symptoms beyond 12 weeks of diagnosis/symptom-onset of COVID-19. Most common symptoms included myalgia (10.9%), fatigue (5.5%), shortness of breath (6.1%), cough (2.1%), insomnia (1.4%), mood disturbances (0.48%) and anxiety (0.6%). Patients who were hospitalized were more likely to report fatigue as a feature of long COVID. Hypothyroidism (OR: 4.13, 95% CI: 2.2-7.6, p-value < 0.001) and hypoxia (SpO2 ≤ 93%) (OR: 1.7, 95% CI: 1.1-2.4, p-value 0.012) were identified as risk factors for long COVID sequelae. In conclusion, long COVID symptoms were common (22%), and 9.9% had the post COVID-19 syndrome. Myalgias, fatigue and dyspnoea were common symptoms. Patients with hypothyroidism and hypoxia during acute illness were at higher risk of long COVID.