Multi-organ effects of covid on the body

DR MAXWELL ADEYEMI

The covid19 virus does not only affect the respiratory organ, but virtually all organs in the body, causing a variety of complex pathophysiological problems such as inflammation, vasoconstriction, hypercoagulation, edema, thrombosis, embolism, infarction, neurological and psychological issues.

The virus can affect any organ in the body. It binds to the angiotensin converting enzyme 2 (ACE 2) receptors that are present in the inner lining of blood vessels, lungs, heart, brain, kidneys, intestine, liver, pharynx, and other tissue. It can damage these organs and the systemic disorders caused by the virus can lead to organ malfunction. Injury to organs may become apparent long after the acute infection has subsided. The disease may affect different organs at different times and rehabilitation can be long and difficult.

Severe body inflammation

Covid19 can lead to a huge production of inflammatory chemicals called cytokines. This cytokine release syndrome, otherwise referred to as cytokine storm, is a maladaptive response that often lead to systemic inflammatory response syndrome, acute respiratory distress syndrome, multi-organ injury, shock and death. The inflammatory response may continue to increase even when the viral load is reducing during the infection. The SARScoV2 virus usually attack the inner linings of the blood vessels, the endothelium, causing endothelitis and narrowing of the blood vessels, which results in edema and reduced blood flow to organs, leading to injury and organ ischemia.

Coagulation or clotting problems

While bleeding is not common in covid19, deep vein thrombosis, pulmonary embolism, ischemic strokes and heart attacks have been reported. This is caused by severe inflammation, platelet activation, increased tendency to clotting, endothelial damages, constriction of blood vessels, low oxygen saturation or hypoxia and stasis. Fever and inflammation cause a high tendency to clotting. During this period the liver increases the production of pro-coagulants substances, and there is an increased tendency for the body to have disseminated intravascular coagulation or widespread clotting within the vessels, which leads to death in most instances.

Lung

The virus causes disruption of the blood vessels and the lungs’ functional cells. There is airway inflammation, alveolar and intestinal swelling and compromised oxygen delivery, which causes severe respiratory distress and poor oxygen saturation. Pneumonia may then complicate the respiratory assault by covid19, and most of the lung tissues are basically wiped out on chest X-rays.

Heart

Cardiac complications can occur in the absence of lung complications. Invasion of heart cells by the virus and systematic inflammatory response such as cytokine storm can cause heart muscle inflammation or myocarditis, which can lead to heart failure or arrhythmias. Vascular risk factors of diabetes, obesity, age, hypertension also have greater association with mortality than respiratory disorders.

Kidney

Covid19 complicates the management of patients on dialysis. The virus is found in the glomerular cells, and other functional cells of the kidney. The cytokine storm experienced in covid19 can cause drastic reduction in blood flow to the kidney tissue and cause acute kidney damage.

The brain

The ACE 2 receptors are present in the cerebral cortex and brain stem. Some patients may have meningitis and encephalitis, as the virus invade the nervous system. Altered oxygen and carbon dioxide levels may lead to neurological symptoms such as dizziness, headaches, impaired consciousness, confusion and delirium.

Cytokine storm can cause brain inflammation and brain swelling and lead to seizure-like symptoms. The blockage of cerebral artery can cause a stroke, especially in young patients. Cranial nerves may be damaged, leading to impaired sense of smell and taste. Nerve pain, muscle weakness, muscle pain, tingling and numbness of hand and feet may occur.

Eye

The virus can invade the ocular cells in the cornea, the eye lids, and white of the eye, causing patient to develop conjunctivitis. Eye surface cells are portals of entry and reservoir of the virus. Ocular virus shedding is a source of infection and the virus can persist in the eye for up to three weeks.

Gastrointestinal tract

Symptoms such as loss of appetite, nausea, vomiting, diarrhea and abdominal pain may occur in covid19 infection. The lower gastro-intestinal tract is rich in ACE-2 receptors, and viral invasion of the gut may lead to fecal shedding in some patients which may take longer to clear.

Skin

Skin manifestation may include patchy rash-like lesions; hives; chicken pox-like blisters; measles-like rashes; tiny red, flat spots that appear on the skin; chilblain rash; covid toes and fingers (frost bite-like areas with red or purple rash or hives).

Psychological effect

Post covid19 infection, patients can experience psychological problems, developmental health problems such as anxiety, depression and post-traumatic stress disorder. Long-term effects can include the development of Alzheimer’s and Parkinson disease.

Effect on penile tissue

The presence of angiotensin converting enzyme 2 receptors in the penis and testicular tissue enables the virus to cause damage in the blood vessels in the penis and the cells of the testes. This can result in erectile dysfunction and infertility.