The dysfunction to the organs is not necessarily the doing of the viral infection but can also be a way for the body to respond to the infection, writes Dr Noor Gill
It’s been a year of new revelations. From finding our inner artists to tying the apron and donning the chef’s hat after ordering food from the lady downstairs for most of our adult lives. Who knew we had so much unexplored talent, waiting to be probed. But with all these exciting aspects of our personalities coming out like a four-year-old colouring a drawing, so came the news of the dreadful coronavirus. What started as a respiratory infection, is now wreaking havoc on other organs as well. Turns out it’s not just us humans that have tuned into other aspects of life, viruses are also catching up on the trend and tapping into other organs.
The coronavirus, though still a respiratory virus and problem, it also now observed that the virus is causing damage to the other organs as well. The dysfunction to the organs is not necessarily the doing of the viral infection. But can also be a way for the body to respond to the infection.
The organs that have been run-down by the virus include the heart and blood vessels, kidneys, gut, and brain. To understand why the virus is doing what it’s doing, we need to know how it’s doing it.
The virus enters the cells by binding to the receptors on an enzyme calledAngiotensin-Converting Enzyme-II(ACE-2) which is found in the respiratory tract, to start with, mostly but not exclusively. These receptors are not only richly present in the alveoli of the lungs (air sacs) but also seen in other organs.
These ACE-2 receptors present in the alveoli act as the entertainment site for the virus. The alveoli, also known as air sacs, help in exchange of oxygen between the lungs and the blood vessels. It is through this mechanism that oxygen is carried from the lungs to the vessels and into the organs – vital for their functioning.So, when the virus enters these cells, the immune system mounts an all-out battle against the virus. This disrupts oxygen transfer and makes breathing difficult, this is also associated with cough, which is the respiratory systems attempt at getting the foreign body (in this case the virus) out of its system.
Heart and Blood Vessels – It has been noticed that the organ that is most likely to get affected after the lungs, is the heart. The virus does not directly disrupt the functioning of the heart, but instead the disruption is due to the virus entering the blood.The viral disruption reaches the heart through the blood, and on its way causes blood clots and an irregular rhythm.
Large blood clots can constrict the vessels and thus and so, cut the supply of blood and oxygen to the viral organs. It is being considered that the affect that the virus has on the blood vessels could be the reason why patients who are a known case of hypertension or diabetes are at a higher risk of developing complications due to the coronavirus.
Brain – The restriction in the supply of oxygen and blood can further affect the brain, causing damage to the nervous system and so can also restrict the supply to the brain and can cause neurological damage and symptoms. The symptoms can vary from seizure or seizure-like episodes/symptoms, stroke – due to restriction in the supply of blood to the brain, and it can also cause suppression of the brain stem reflexes – which regulates the heart rate, respiratory rate and other involuntary activities even during sleep. In very rare cases, the patients also develop meningitis and encephalitis – which is the inflammation of the protective layers of the brain and the spinal cord due to infection. This infection can be a result of supra – added infection on top of the viral infection.
Kidneys – The kidneys are also affected as a result of the virus. This could either be due to the decreased blood supply to the kidneys or because of the binding of the virus to the ACE-II receptors which are also present in the proximal convoluted tubules of the kidneys. Some patients might also need a rental transplant.
Lungs and ARDS – Some people are asymptotic. Most people present with the common symptoms that are associated with coronavirus, which primarily include fever, cough anddifficulty in breathing. But for a few others, the infection tends to become severe and leads to complications and involving and affecting more than one system.
For patients who develop complications, it starts with cough, progresses to difficulty in breathing (dyspnoea), increases in severity to cause Acute Respiratory Distress Syndrome (ARDS). ARDS can cause rapid breathing, a fast heart rate, dizziness, and sweating. It damages the tissues and blood vessels in your alveoli. The dead tissues and the debris continue to collect within the air sacs, turning the spongy, easily expandable air sacs into harder sacs that make the exchange of gases and breathing harder, sometimes even impossible.
Gastrointestinal Tract (Intestines and Liver) – Some patients, at the time of presentation come with the complaint of nausea, diarrhoea. Although these are not as common as the presenting symptoms that bring the patient to the hospital.
While coronavirusesseem to gain access into an individual’s body through his respiratory tract, the GI system is not completely out of the reach of the virus once it has entered the body.
Recent studiesin the New England Journal of Medicine found that the stool samples of some patients admitted for Covid-19,tested positive for the virus in the stools. Indicating that the virus has, according to the studies, gained access to the intestines.
Some patients develop liver enlargement or damage as a result of the infection. These enlarged hepatocytes (liver cells) can cause a leak in the enzymes this raising their values above the normal range.
A lot ofdamage in the body during Covid-19 is due tosepsis syndrome –which is defined as infection associated with a systemic inflammatory response. The infection due to the virus tends to trigger an intense inflammatory response in the body that can affect the working and function of multiple organs and can also lead to end organ failure, of not caught and managed in time. The coronavirus attaches to the ACE-II receptions and hijacks the healthy cells, taking over the body. With the immune system trying to fight back the foreign body (true virus) love brave soldiers, some healthy cells are also killed in the process.