As the race to find a vaccine or cure for the novel coronavirus drags on, convalescent plasma therapy has gained a lot of traction after showing early promise in the fight against COVID-19. However, its efficacy as a treatment for the disease is still being investigated by researchers.
Health authorities are discouraging the administration of plasma therapy to cases outside the ambit of controlled clinical trials, according to bdnews24.com.
Several hospitals have, nevertheless, applied the experimental procedure to critically ill patients at the insistence of their relatives. But in some cases, it proved to be futile with experts reiterating the need to proceed with caution as they await more data.
The treatment's chances of success are low if the patient is not given a sufficient concentration of antibody-rich plasma in the early stages of the infection.
As the number of coronavirus cases began to spiral out of control, many developed nations, including the United States and United Kingdom, began to use plasma collected from recovered patients to treat the infected.
Plasma is a clear part of blood that is left when the blood cells have been removed. It contains antibodies and other proteins.
The immune system of an infected person creates natural antibodies to fight the virus. The antibodies grow in number over time in the plasma of an infected person. Through plasma therapy, the antibodies are used to treat other infected patients.
The use of plasma therapy to treat COVID-19 patients in Bangladesh was touted by Dr MA Khan, professor of Dhaka Medical College's hematology department, in early April.
The health directorate subsequently put him in charge of a four-strong committee overseeing the clinical trial of plasma therapy in the country.
The procedure has since found favour with doctors in the country after delivering positive results in many cases.
But experts warned that applying plasma therapy at the wrong stage of treatment or to the wrong patient without determining the quantity of antibodies will be of little use.
In many cases, using the procedure on critically ill COVID-19 patients does not bring any benefit, they said.
Research is being conducted at Bangabandhu Sheikh Mujib Medical University Hospital, Dhaka Medical College Hospital, Sheikh Hasina National Burn and Plastic Surgery Institute and Mugda General Hospital to determine the point at which the use of plasma therapy will bring the best results.
The treatment has been administered to 144 patients outside the scope of the study, said Dr Ashraful Alam, one of the researchers. Among them, 27 patients died despite being given the therapy.
Plasma therapy showed positive results in some cases but it should be used at the right time, he said. Besides, there is no guarantee that it will work in all cases.
“Research has going on for ages as we can't say with absolute certainty that it will work. It was never declared as the first line of treatment. It can’t save everyone," he said.
"The procedure only increases the chances of recovery for a patient when it is applied at the perfect time. However, the patient may suffer from other complications.”
As of now, 313 patients, including 45 policemen, have received plasma therapy from the Central Police Hospital, said Dr Hasan Ul Haider, director of the hospital.
Among the 45 policemen who took the treatment, 10 have died after falling critically ill, he said.
“Those patients had their lungs infected and went under artificial ventilation. They needed a lot of oxygen. We've noticed that using plasma therapy earlier brings better results. As for those who have survived the coronavirus infection, it is not because they received the plasma but rather the other medications played an important role. However, all of these treatment options need more research.”
On Jun 15, former mayor of Sylhet Badar Uddin Ahmed Kamran died in Combined Military Hospital after contracting COVID-19. He was given 200 ml plasma, his son Dr Shiplu Kamran said.
“We couldn’t figure out if the plasma was effective as almost 70 percent of my father’s lungs were infected,” said Shiplu.
The wife of the health services division secretary and Prof Shakil Uddin Ahmed of Dhaka University's Soil, Water and Environmental Science Department also succumbed to the disease despite undergoing plasma therapy.
A number of factors determine the success of plasma therapy, said Dr Khan.
It is important to determine the amount of antibodies in the donor’s blood before plasma therapy is used, which has not been the case in the country, according to him. “Therefore, it does not have any effect on the patient.”
“In most of the cases in our country, plasma therapy is given to the patients after they are taken to the ICU or placed under artificial ventilation. It should be applied in the beginning, which we call the viral phase, when plasma works against the virus. If administered at the right time, it increases the chances of recovery.”