Think of it this way — the human body is a kingdom which is healthy, prosperous and functions peacefully. Every once in a while, invaders from the pathogen kingdom attack the body. But the human kingdom has a strong army — the immune system — which defeats these germy foes. However, an army cannot win every battle, can it? Sometimes, there is an error in judgement, and too many good soldiers — named cytokines — are sent to battle. What follows is utter chaos, called hypercytokinemia.
What are cytokines?
“Simply put, cytokines are small proteins which tell the immune cells to go and kill the bacteria or virus that enters the body,” said Dr Saadvik Raghuram Y, HOD, medical oncology and haematology at Arête Hospitals in Gachibowli.
Defining hypercytokinemia
Also called the ‘cytokine storm’, hypercytokinemia is a condition where too many cytokines are released. “They over-trigger the immune system. It’s like a war — if the opposite side has 10,000 soldiers, why would you send far more than that?” he quipped.
What triggers the condition?
Dr Rajesh Vukkala, chief consultant - internal medicine, Renova Hospitals, Sanathnagar, said that viral infections can trigger hypercytokinemia. “The usual effects of an infection are sore throats, cold, or fevers. But some people are more likely to develop a toxic reaction to the illness, like the release of extra cytokines,” he explained.
But why is this so? The senior doctor added that each person naturally has a different immune response, pointing out, “Someone with more allergies or a person with a family history of autoimmune diseases has a higher chance of developing this condition.”
But immunotherapy drugs, such as the chimeric antigen receptor (CAR) T-cell therapy — a cancer treatment that uses a patient’s own modified T cells to fight cancer — are the main cause of hypercytokinemia. “It is used to treat patients with leukemia and lymphoma. A patient may start to have fever, chills, and fatigue. As doctors, we first start treatment for the infection but constantly stay suspicious,” said Dr Saadvik.
Domino effect
Hypercytokinemia causes inflammation, which damages the organs. “In this condition, the immune system randomly attacks anything and everything in an uncontrolled manner,” noted Dr Rajesh.
Dr Saadvik stated that the condition can affect any organ, but explained its impact on the lungs, heart, and brain.
Lungs: The immune system attacks the lung cells, causing the lung tissue to get inflamed. One can feel sharp pains in the chest and also suffer from pulmonary edema, where too much fluid accumulates in the lungs. The patient can also get acute respiratory distress syndrome (ARDS).
Heart: The immune system attacks the heart muscles, causing tachycardia, where the heart rate is faster than 100 beats per minute. Main functions such as pumping blood and maintaining blood pressure are affected. The blood pressure starts to drop, which is called hypotension, and the heart stops.
Brain: The immune system attacks the neuronal cells. One may have simple symptoms like headaches but can also experience delirium or confusion. Dizziness, fits, and unconsciousness are also effects.
Treatment
Drugs like tocilizumab target specific cytokines, while high doses of corticosteroids — anti-inflammatory drugs — are also administered. Symptom-based treatments are given to patients as well, added Dr Rajesh.
Although hypercytokinemia cannot be prevented, doctors maintain a high level of clinical suspicion and take precautions. “If we are giving cancer patients CAR T-cell therapy in the morning, we make sure we have tocilizumab and corticosteroids on hand. This is because symptoms can start to show up as early as the same evening,” noted Dr Saadvik.
How to identify hypercytokinemia?
The tricky part about this condition is that its symptoms aren’t very different from those that point to a regular, seasonal illness — cough, fever, chills, nausea, vomiting, diarrhoea, headaches, and so on. But both experts advised vigilance.
Dr Rajesh said, “If a paracetamol just doesn’t cure your fever, head to your doctor. Being cautious is the best thing you can do.”