COVID-19: PGIMER to check antibody concentration in plasma donors for CPT

Naina Mishra
Tribune News Service
Chandigarh, December 4

Finding a potential donor for plasma is now going to be even more stringent as the Post Graduate Institute of Medical Education and Research (PGIMER) is going to check a required concentration of antibodies in the donors before extracting plasma for covid-19 treatment.

This is in line with an advisory issued by the Indian Council of Medical Education and Research (ICMR) for the use of convalescent plasma therapy (CPT).

The ICMR has specified a required concentration of antibodies that should be measured through various tests from the donors.

Prof Ratti Ram from Department of Transfusion, PGIMER said, “Recently, we have evaluated antibody titres (a test that detects the presence and measures the number of antibodies within a person's blood) of some of the donors and found that some had less concentration of antibodies than what is specified in the protocol.

We are checking the cut off value of 13 AU (arbitrary units) while conducting an antibody test in plasma donors as the literature suggests that such donors have a significant amount of antibodies. Another test being conducted among the donors is to find IgG antibody against covid titre of 1:640.”

Prof Ram added, “The rationale behind the change in protocol is to prevent malpractice and inappropriate use of plasma donation. The available literature also suggests that the plasma units given in a specified concentration of antibodies were more useful in covid-19 patients.”

“It is speculated that convalescent plasma having a low concentration of specific antibody against SARS-CoV-2 may be less beneficial for treating COVID-19 patients as compared to plasma with a high concentration of such antibodies,” said ICMR advisory.

The PLACID Trial (in which PGI was also a trial site) published in British Medical Journal also suggested that there was potentially no benefit of convalescent plasma collected from young survivors of mild covid-19 and administered to elderly patients with moderate or severe disease who have a robust antibody response. As per the study, symptomatic patients had higher antibody positivity and median neutralizing antibody titres than the donors of convalescent plasma.