Why are platelet donations not allowed when the donor has hypothyroidism?

[Wrichik Basu]

TL;DR Summary

Why is platelet donation not allowed when the donor suffers from hypothyroidism?

Yesterday, my father, along with some of his colleagues, went to donate platelets to another colleague who had recently recovered from COVID-19 but was suffering from a multi-organ failure. Many of the people who went with Dad did not meet the requirements, so they could not donate. One person had satisfied all the requirements except one: he had hypothyroidism, and he too was dismissed. At the end, only two people could donate their platelets.

So, here is my question: why is platelet donation not allowed when the donor suffers from hypothyroidism? (Note that the person takes medicines daily for the disease.)

I found one paper that states that hyperthyroidism is associated with increased platelet production. Does that mean that hypothyroidism lowers platelet production rate?

 

[FactChecker]

Was he correcting it with thyroid medicine like Synthroid? In the blood donation sites that I went to, they would take a small sample and check the platelet count. I took medicine for years that, in fact, lowered my natural thyroid activity to nearly zero but they never rejected me for that reason.

 

[Wrichik Basu]

Was he correcting it with thyroid medicine like Synthroid?

A Google search reveals that the composition of the medicine is levothyroxine, which is the same as that of medicines available here. So, the answer to your question should be yes.

 

[FactChecker]

A Google search reveals that the composition of the medicine is levothyroxine, which is the same as that of medicines available here. So, the answer to your question should be yes.

I took levothyroxine while I donated platelets regularly for many years, so at least some donation centers accepted it. I do not know why your friend was not allowed to donate. The rules may have changed. Are you sure there was no other reason, like not having a high enough platelet count or having an unacceptable blood pressure?

 

[Wrichik Basu]

Are you sure there was no other reason, like not having a high enough platelet count or having an unacceptable blood pressure?

Quite sure. Dad said that he had the required platelet count and acceptable blood pressure.

 

[FactChecker]

Here is an excerpt from the Royal Pharmaceutical Journal that might apply:
"Thyroid disease Patients with thyroid disease may not donate if the condition is under investigation or if malignancy is suspected. Anyone on maintenance therapy with levothyroxine must be stabilised for at least three months before donation. An over- or an underactive thyroid increases the risk of heart disease. Patients who have had radioactive iodine therapy must wait at least six months before giving blood. (See also main text regarding carbimazole.)"
These are rules for the UK. I don't know how universal they are, but they seem reasonable. So the next two questions are whether the condition was under investigation and whether his thyroid levels had stabilized.

 

[Wrichik Basu]

An interesting piece of information: Dad came to know that the hospital has informed his office that anyone with high blood pressure and/or hypothyroidism will not be allowed to donate platelets. So, now it turns out that it was not a problem with that specific donor, but the hospital does not want platelets from anyone who has hypothyroidism, irrespective of whether his/her TSH levels have returned to normal after taking medicines.