Anti-rheumatic drugs as potential anti-inflammatory, immunomodulatory agents against COVID-19: A systematic review

Background: The effective responses of both innate and adaptive immunity are crucial in combating Novel-Coronavirus-2 infection. An excessive response may lead to cytokine storm, which is a challenging problem in therapeutic strategies. Methods: A systematic review was carried out by searching OVID MEDLINE, PUBMED, Google Scholar, and Cochrane library databases from inception until August 2, 2020, for anti-inflammatory and immunomodulatory drugs against coronavirus disease 2019 (COVID-19). Results: The results of the effectiveness of Hydroxychloroquine are just like a sinusoidal diagram and in a state of ambiguity. Thalidomide was effective in some cases but has not yet been proven. Low-dose Corticosteroids may be effective in the early stages of the illness as a bridge. There is no evidence of benefits or adverse outcomes for the use of non-steroidal anti-inflammatory drugs and Cyclosporine-A. In some critically ill patients, Interleukin-6 (IL-6) and IL-1 blockers and to some extent Tumor-Necrosis-Factor-α and Janus-Kinase inhibitors are useful. Finally, high-dose intravenous immunoglobulin reversed the deterioration of patients in most trials. Conclusion: One strategy behind the treatments for COVID-19 is based on breaking the cytokine storm. Although avoiding the suppression of anti-viral immunity is crucial by choosing the weaker and more selective anti-inflammatories, some strategies are kept for hyper-inflammatory situations. Scheduling of treatment is also important. Although low-dose steroids may be effective in the early stages of the illness, "Tocilizumab" is more effective in severe situations, when the IL-6 level is high and other drugs are ineffective. Therefore, consideration should be given to each patient separately.