Understanding the Systemic Effects of COVID-19: Possible Clues to Potential Therapeutic Approaches

Abstract

The novel coronavirus disease (COVID-19) is an infectious disease caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is an acute respiratory disease that causes life-threatening symptoms. This virus directly or indirectly affects the various systems of the body. In the respiratory system, it causes pulmonary edema, impaired oxygen diffusing capacity, difficulty in breathing, etc. In the nervous system, it causes encephalitis, thrombo-embolitic stroke, Guillan-Barre syndrome (GBS), etc. In the cardiovascular system, it causes ischemic heart diseases, myocardial injury, arrhythmias, etc. In the renal system, it causes tubular necrosis, vacuole degeneration, and consequently a renal failure. In the neuromuscular system, it causes areflexia, ataxia, paresthesia, and body weaknesses. In hematological indices and immune system, it causes lymphopenia, increased monocyte and macrophages, increased neutrophils, decreased eosinophils and basophils, decreased platelet count, and exaggerated immune response. In the gastrointestinal system, it causes diarrhea, liver damage, anorexia, abdominal pain, etc. In the endocrine system, it causes acute diabetes, decreased cortisol stress response, hypothalamic-pituitary axis disorders, etc. In the reproductive system, it causes germ cell destruction, low sperm count, and erectile dysfunctions in males. In females, it causes decreased menstrual volume, cycle prolongation, preterm birth, and abnormal fetal development during pregnancy. The SARS-CoV-2 has effects on various systems of the body although the majority of the clinical manifestations of the disease are related to the respiratory system because it is the route of entry and the major target of the disease. Meanwhile, many of its clinical symptoms are also manifested in the other systems of the body such as the nervous system, cardiovascular system, etc. Numerous researches have been done and are still ongoing on therapeutic approaches to tackle COVID-19. Here, we review the effect of COVID-19 on various physiological systems of the body and the mechanisms by which they occur. Also, we briefly highlight the potential therapeutic approaches to tackle COVID-19.