After New Delhi, Chennai got its first plasma bank at the Rajiv Gandhi Government General Hospital (RGGGH) on July 22nd at a cost of Rs 2.34 crore. While a vaccine for COVID is still in the works and a proven cure for COVID remains elusive, convalescent plasma therapy has yielded some positive results in cases, although clinical trials of the same are still underway. 

But, what is convalescent plasma therapy? How does a plasma bank work? Who can donate plasma, and where in our city can it be done?

We attempt to address these and other common queries from citizens in this FAQ.  

What is plasma therapy? Can it really cure COVID?

Plasma therapy is a treatment where the plasma (the straw-coloured, liquid component of blood that acts as a transporting medium) from a recovered patient is injected in the body of an infected patient. It has been observed that the antibodies present in the recovered patient’s blood neutralise the virus present in the COVID patient’s body. Thus, the treatment is being suggested for patients who are moderately affected by the virus. Plasma can be donated once in 14 days.

However, as Dr Ram Gopalakrishnan, Senior Consultant – Infectious Diseases, Apollo Hospitals points out, plasma therapy is still being conducted on trial basis and does not promise a cure. 

Who gets plasma therapy?

Among the three categories of COVID patients (severe, moderate and mild), plasma therapy is suggested for patients who have been moderately infected by the virus. The oxygen saturation of the moderately-infected patient would be below 90% (average value) and he would need external oxygen support.

Patients with mild condition often recover easily themselves, whereas the chances of recovery in a severely-infected patient are slim, hence the therapy is suggested by the respective medical teams for moderately-infected patients.

However, as the therapy is still under trial, the medical institution seeks permission from the patient or the family before administering plasma treatment.

Why do we need a plasma bank? 

The function of a plasma bank is the same as that of blood banks — to store plasma collected from donors and make it available to patients in need. Across cities, plasma banks have been set-up specifically with COVID patients in mind, who are currently undergoing treatment and have been suggested plasma therapy. 

Where does Chennai stand in plasma trials/therapy?

At present, three hospitals in Chennai — RGGGH, Kilpauk Medical College and Hospital (KMCH) and Tamil Nadu MGR Medical College — are authorised by the Indian Council of Medical Research (ICMR) to conduct trials.

“Plasma trials have been conducted in 26 patients in Chennai and the results so far have been positive and safe. Of them, 24 patients have been discharged,” says a doctor-in-charge from RGGGH, who did not wish to be named. 

Besides RGGGH, sources state that 10 patients at KMCH, subjected to plasma therapy, have recovered. 

The state government is planning to set-up plasma banks at Stanley Government College and Hospital, Omandurar Multi-specialty Hospital and Tamil Nadu MGR Medical College in Chennai soon. 

Who can donate plasma? What are the guidelines for donating plasma? 

COVID recovered persons are actively encouraged to donate plasma to treat other patients. A plasma donor should fulfil the following criteria

• Recovered people aged between 18 and 60 are eligible to donate. Plasma from pregnant women and subjects with comorbid conditions should be avoided for COVID treatment.
• The haemoglobin level of the donor should be above 12.5 g/dL and weight 55 kgs at the least.
• The donor must have been admitted at the hospital for COVID treatment. Asymptomatic patients are ineligible to donate.
• The donor’s plasma should have antibodies for treating COVID. Antibodies develop automatically once they have recovered. A report certifying the presence of antibodies should be produced before plasma donation.
• Plasma can be donated 14 days after getting discharged.
• The donor should have a COVID test report certifying the negative result, if they are donating between 14 days and 28 days after discharge. If the donor does not have the report, the test can be taken before donating plasma at the hospital.
• Test reports are not needed if the recovered person donates after more than 28 days from the date of discharge. “If the person is hale and healthy after the window period, it signifies that the virus is neutralised with the antibodies. Hence, reports are not mandatory and tests need not be taken before donation,” added the doctor-in-charge.

What are the tests carried out before plasma donation?

Besides the antibody test and COVID-negative tests, haemoglobin, HIV, Hepatitis-B, Hepatitis-C, Syphilis and Malaria tests will be carried out before plasma donation. 

What is the process of plasma donation like?

Plasmapheresis is a process through which plasma is collected. It is conducted in cycles where the whole blood is drawn. The plasma is separated and the remaining components like as red blood cells (RBCs) is returned to the donor’s body. The entire process takes about 30 minutes.

The infrastructure at RGGGH supports plasma retrieval simultaneously from seven people. 

Are there any side effects while donating plasma?

For COVID treatment, up to 500 ml plasma is collected from a donor’s body. New plasma gets generated from the donor’s bone marrow within 24-72 hours. Since the amount of plasma is less, doctors say it does not affect the donor.

Plasma donated, however, can be used for treating several other conditions. To treat Guillain-Barre Syndrome (a rare disorder where one’s immune system attacks the nerves), for example, a patient requires a large volume of plasma. Up to a full litre is collected for treatment from a healthy patient. This results in huge protein loss for the donor. In such cases, the donor should be immediately infused with normal plasma to prevent hypoproteinemia. Doing this helps avert any side effects.

How will the plasma be stored? How long does it last?

Plasma from a donor’s blood is stored in an apheresis machine for up to one year at – 40 degrees Celcius. When there is a need, the frozen plasma is thawed and used for treatment. Doctors say that frozen/stored plasma is equally effective in curing diseases.

What are the other conditions that plasma can cure? 

Plasma is also widely used in a range of conditions. It is used for treating hypoproteinemia diseases and in surgeries, if the patient has undergone heavy blood loss. 

How long are the antibodies effective in a recovered patient’s body?

A doctor in Noida was reported to be re-infected with the coronavirus 45 days after recovery. Hence, experts feel plasma therapy may not be a guaranteed solution.

A study carried out by scientists at King’s College of London showed that the potency of the antibodies fell to 17% from 69% three months after treatment. The research further stated that the antibodies were untraceable after three months in a few cases. However, the efficacy of the antibodies is found to be strong and long-lasting in patients who were particularly severely impacted by the virus but recovered.

(with inputs from a government doctor (wishing to be anonymous), Dr K Selvarajan, retired Professor – Department of Transfusion Medicine, Madras Medical College and Dr Ram Gopalakrishnan, Senior Consultant – Infectious Diseases, Apollo Hospitals.)