Karnataka to audit blood groups of critical Covid-19 patients

The recent publication of two international studies which stated that Covid-19 is more severe in patients with blood group A or AB, has pushed the state government into conducting an audit on the blood groups of critical patients.

The studies, conducted in Denmark and Canada, have found that people with type O are less likely to catch Covid-19 or develop major complications and die. Meanwhile, individuals with blood types A and AB are most vulnerable to the disease.

The state audit could be a boon, as the Indian Council of Medical Research (ICMR) has not undertaken a survey to check for the association of the ABO blood group for indices of disease severity in Covid-19 sufferers.

The data collection, which began earlier this week, will trawl city and taluk hospitals for blood work results for critically ill and deceased Covid-19 patients.

“We will be able to collate data in hospitals where they have collected it,” explained Dr Thrilok Chandra, Head, Critical Care Support Unit (CCSU), which oversees medical treatment of heavily symptomatic patients.

Data available

“There is already some data regarding blood tests, but it is not granular enough to make an assessment,” Dr Chandra added.

One of the key challenges is that for most Covid-19 patients in India, blood group testing would not have been done at the outset, because investigating medicos are generally more preoccupied with critical investigations such as renal function tests (RFT) and checking for alarm markers.

“Consequently, we will now have to forge through individual case sheets and find it. However, manpower is a challenge,” Dr Chandra explained.

Some blood typing data is already available as part of the plasma programme. Dr Vishal Rao of HCG Hospital, who set up Karnataka’s plasma therapy programme, said that initial data suggests that there are no significant differences in outcomes from blood groups.

“Out of 12 patients with AB type blood, mortality was 75%. Of 44 patients with Type A blood, mortality was 38%. However, mortality among 78 Type B patients was worse at 51.2%, while among 88 patients with Type O, 47.7% people died,” he said.

He, however, added that this could be due to the efficacy of plasma therapy.

Another large sample is Victoria Hospital, where over 6,000 Covid-19 patients have been subjected to routine bloodwork. “The study says type O’s are less likely to catch Covid-19 but our wards are full of them,” a government researcher said. However, data about the scale of severity among the various groups was unavailable.

Dr C Shivram, head of transfusion services at Manipal Hospital said there are regional differences to be considered.
“For example, Type AB blood is extremely rare in India,” he pointed
out.

“The true implication of the multinational study is why some blood groups have lesser antigens, which signifies reduced immunity,” Dr Vishal Rao said.