Neuro suddenly wants JCV blood test

I’ve had RRMS for over 20 years and have had many DMTs. In the last 5 years, I’ve had 2 rounds of alemtuzumab, but then had a relapse (alongside developing hypothyroidism), so switched to Kesimpta in May 2023. Since being on Kesimpta, my lymphocyte count has hit the floor - so much so, I’ve been asked by my neuro to take two “breaks” (so have skipped two months since I’ve been on it at two points).

Yesterday, out of the blue, I had a frantic call from an MS nurse asking me to go in this coming Monday for a JCV test. She’ll meet me at the blood test area and then take the test to the lab :dizzy_face: . Now, I only saw a neuro a couple of weeks ago, and none of this was discussed. I’d had an MRI but the results were not available, so the consultant I saw couldn’t comment. However, she was NOT my “assigned” consultant - I’ve actually only met her once in 6 years. But when I asked the MS nurse why I suddenly needed the JCV test, she said, “Prof XXX wants it done”.

Now, me being utterly paranoid, is concerned that a) surely I had a screening test for JCV before I had alemtuzumab? b) are my MRI results back and she’s worried about PML? or c) should I stop trying to second-guess everything and chill-out?!

Huge thanks for any advice/assistance/words of wisdom


Sorry no real or informed advice from me other than you might just have to be patient. For all you know the neurologist is simply reviewing your case and being thorough by investigating all possibilities.

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