Diagnostic value of interleukin 6 (IL-6) in COVID-19: a report from Kano, Nigeria

Abstract

Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SASR-CoV-2), the aetiologic agent of Coronavirus Disease 2019 (COVID-19) causes dysregulation of the immune system, with excessive, ineffective immune stimulation, resulting in severe lung
injury, immunosuppression, multi-organ failure and cytokine storm.
Aim: The study aimed to investigate the association between serum interleukin 6 (IL-6) level and clinical characteristics of a cohort of COVID-19 patients during the first wave of SARS-CoV-2 infection in Kano, northwestern Nigeria.
Methods: COVID-19 status was initially checked using SARS-CoV-2 point-of-care antigen test and confirmed by one-step real-time RT-PCR. Enzyme Link Immunosorbent Assay was used for the IL-6 quantification and the results obtained compared using independent student T and Mann Whitney U tests.
 Results: The mean age of the participants was 39.5±14.8 years, the minimum was 22 years and the maximum was 45 years, males constituted 64.4%. Fever and cough were the most common presenting symptoms and hypertension was the major comorbidity. Mean serum IL-6 level was significantly higher in COVID-19 individuals than the controls (mean diff = 11.62; 95%CI: -13.41 to 9.83; P < 0.001). Among the COVID-19 cases, IL-6 was significantly expressed in those with sore throat (P = 0.013) and bodyache (P = 0.035), and also among hypertensive individuals (P = 0.029).
Conclusion: This study provides several aspects of clinical data and highlights the relevance of IL-6 in COVID-19, thereby suggesting its role as a surrogate marker of SARSCoV-2 infection, especially in places with limited clinical virology laboratory capacity.