Convalescent plasma therapy doesn't really help beat COVID-19: ICMR-backed study

No lowering of mortality in multi-centre trial; disease progression towards severity also not impacted; shortness of breath reduced

By Banjot Kaur
Published: Wednesday 09 September 2020
What proves good for Europe may or may not be the template for countries across the world, the study's authors said Photo: Pixabay

A trial of convalescent plasma (CP) therapy on 464 patients of the novel coronavirus disease (COVID-19) failed to lower mortality rates among patients, results showed.

The therapy in trial, funded by the Indian Council of Medical Research, also did not hamper the progression of mild illness into a severe form of the disease.

The trial, at 39 public and private sites, compared results in patients who were given only the best standard of care (BSC) with those administered CP along with BSC. The results were published in preprint server MedRxiv September 8, 2020.

BSCs are generally accepted treatment protocol, used widely by clinicians. In case of COVID-19, BSC in India include:

  • Antivirals (eg Hydroxychloroquine, Remdesivir, Lopinavir / Ritonavir, Oseltamivir, etc)
  • Antibiotics
  • Immunomodulators
  • Steroids
  • Tocilizumab
  • Supportive management (masks, ventilation etc)

The plasma therapy was combined with BSC for 235 patients while 229 were administered only BSC. The first — intervention arm — comprised two doses of 200 millilitre CP each, transfused 24 hours apart.

The neutralising antibody titres — the rate of production of antibodies that could help fight the disease — were identical in patients of the two arms, the study found.

Neutralising antibodies are those that fight off the virus, in this case SARS-CoV-2.

“This suggests that there may not be any benefit of CP collected from young, mild COVID -19 recovered donors to moderate to severely sick elderly patients, who have a robust antibody response,” authors of the study paper said.

Convalescent plasma therapy, however, showed a higher negative conversion of viral RNA (ribonucleic acid) — recipients of the transfusion were able to be lose the virus faster.

Researchers, however, did not spot any lowering in inflammatory markers — those reflecting the extent of infection — among intervention arm patients. This could explain why the line of treatment didn’t reduce mortality though it led to quicker RNA negativity.

The CP transfusion did lead to better results vis-à-vis symptoms like shortness of breath (after seven days of transfusion) and the need for artificial oxygen (after three-five days), the paper noted.  

The transfusion was also labelled safe with minimal adverse events, none life-threatening.

A recent Cochrane review of 20 studies flagged uncertainty regarding effectiveness of CP in improving mortality or clinical improvement in COVID-19 patients.

In India, CP has been approved by the drug regulator on an off-label basis (without trials) — an emergency measure. Governments in state after state have encouraged it though, as has the private sector.

The latest data should be peer-reviewed the soonest possible by ICMR and published, said Anant Bhan, former president of Interntional Association of Bioethics.

“Now it would seem that the inordinate focus on CP seems futile as it does not seem to prevent progression to severe disease or death compared to standard treatment. Minor benefits mentioned in the study probably are not meaningful enough for CP usage at such large scale,” Bhan told Down To Earth.

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