Currently, there are no approved treatments for COVID-19. In the clinical management protocol issued by the Union Health Ministry, off-label use of convalescent plasma therapy is approved for COVID-19 patients with moderate disease who are not improving despite the use of steroids.
Even as it remains an experimental treatment, demand for blood plasma for moderate and severe patients is soaring. Most of these donor requests mention a common note in the end: ‘Women who have kids cannot give plasma’.
How much of this is true? What explains this exclusion? FIT explains.
Donor Eligibility by ICMR
Indian Council of Medical Research (ICMR) is conducting clinical trials across various hospitals in the country to test if this experimental treatment helps treat COVID patients. As per its trial protocol released on 22 April, males or nulliparous female donors (along with other requirements which need to be met) can qualify to donate plasma.
Nulliparous is the medical term for a woman who has never given birth, as opposed to multiparous women, who have given birth to more than one child. This would, by default, mean that women who have children are excluded as donors of blood plasma.
Dr Sangeeta Pathak, Senior Consultant and Head Blood Bank, Transfusion Medicine, Max Super Speciality Hospital, Saket, elaborates on what qualifies a female as a plasma donor. She tells FIT, “In females, only nulliparous women are accepted for the plasma donation. Women who have given birth cannot be a donor of plasma because these females have antibodies which can lead to TRALI (a lung condition).”
She adds that this is an international standard for plasma donation, and does not apply to regular blood donation. For instance, the US FDA, which has approved plasma treatment as an investigational therapy, also states as part of its donor eligibility: “Male donors, or female donors who have not been pregnant, or female donors who have been tested since their most recent pregnancy and results interpreted as negative for HLA antibodies.”
Why Can’t Women With Children Donate Blood Plasma?
Plasma from these female donors is not currently used (except in some coronavirus trials) because they are more likely to have certain antibodies that can cause a rare but potentially fatal transfusion reaction, called, transfusion-related acute lung injury (TRALI) in the plasma recipient.
Dr Tanya Petraszko, director of medical services and hospital relations, at Canadian Blood Services, explains that TRALI occurs when human lymphocyte antigen (HLA) antibodies in the donor’s plasma interact with white blood cells lining the lungs of the recipient.
HLAs are part of our immune system and help our body recognise self from non-self. When our body detects a non-self entity, it develops antibodies.
Pregnant women develop this specific kind of antibodies as a reaction to the fetus. The more children a woman has, more of these antibodies are produced. It is believed that some recipients of transfused plasma from women react negatively to these antibodies in the plasma.
These antibodies are normal in pregnancy and do not harm the fetus, but can cause TRALI in the recipient. The same is also the case with women who have had miscarriages.
Is There a Timeline Beyond Which Female Donors Can be Considered?
“These antibodies remain in the body forever, so women who have been pregnant in the past will always be ineligible for donating plasma,” said Dr Sangeeta Pathak from Max Hospital.
The US FDA states that a woman may qualify as a plasma donor if she tests negative for HLA antibodies. When asked whether such tests can be conducted in our context, Dr Pathak explained that these are not easily available. “This is why we take the donor’s entire history. If she has had two or more kids, then it’s a definite no. In some rare cases, females with only one child may be considered. But this depends on individual assessment. As a general rule for plasma donation, we only prefer nulliparous women. This is universal and extends to other purposes as well, not just for COVID-19. Women with children can donate blood, not plasma.”
Eligibility Criteria for Donating Plasma for COVID
She outlines the following eligibility criteria for plasma donors:
- Blood group match for donor and recipient
- Donor should between 18-60 years
- Donor should be fit in all criteria for a blood donation
- Weight should be more than 55 KGs
- In females only Nulliparous females are accepted for the plasma donation. Multiparous females cannot be a donor of plasma because these females have antibodies which can lead to TRALI
- Unmarried females who have no children can also donate
- 12.5 and above hemoglobin is required
- Hypertension should be under control
- If the donor has diabetes, he/she should not be on insulin
- Donor should not have any chronic disease like tuberculosis, Cirrhosis, Renal and other similar chronic diseases
- If the patient has tooth extraction, then he/she cannot donate for 6 months
- If on antibiotic, then there should be a 72 hours gap
- If he/she has donated plasma, they can donate again after 2 weeks
- If the donor's result of COVID test is negative, then after 14 days there will be a re-test of the COVID and antibodies and after that the donor can donate the plasma.
- If the individual has recovered and crossed a 28-Day period, then a re-test for COVID is not required