placebo079“Uniformly” low is also a clue; in CVID they are not.+32019-05-24T12:22:38Z
tea-cats-biscuitsThis makes sense, though what really threw me off was that in Classic Bruton’s Agammaglobulinemia there’s near-zero B counts though (or at least that’s what FA and UTD says, “Absent B cells in peripheral blood” FA 116, 2018). The Q says the leukocyte count was normal though. Wouldn’t the leukocyte count include lymphocytes in the differential? And wouldn’t lymphocytes be low due to the near complete lack of B cells in peripheral circulation if it was BA?+12019-05-24T12:25:35Z
partybrockk@tea-cats-biscuits Bruton’s is a failure of B cells to /MATURE/. So you get normal lymphocyte counts, decreased levels of immunoglobulins, and absent germinal centers.+32019-05-24T12:27:36Z
tea-cats-biscuits@partybrockk That makes sense to me, but I keep getting hung up on how that’s not what either FA or UTD says about the classic lab findings of XLA. UTD specifically says this: “Laboratory findings include hypogammaglobulinemia/agammaglobulinemia, deficient antibody responses to immunizations, and absent or markedly reduced B cells in the blood,” and I previously quoted FA. I suppose it doesn’t really matter, but it’s definitely a bit frustrating unless I’m missing something about how absent B cells in the blood wouldn’t correlate to a decreased lymphocyte count ...+22019-05-24T12:29:53Z
temmyplease correct me if i am wrong cos i might be but my logic was there is decreases immunoglobulin uniformly meaning the B cells are uniformly absent and since they develop in the germinal center, the germinal center will be absent.+12019-07-25T10:42:56Z
keycompanyI think we are all overthinking this question (and it is remarkably simple). I don't think this question is testing us on any of the UFAP immunodeficiency syndromes, per say.
What they are really asking is "what would also be absent if there are no immunoglobulins and everything else is normal"? The answer is absent germinal centers b/c that's where Ig is synthesized. I think they put all other aspects of the history in this stem just to help you rule out any of the other answers.+52019-06-04T15:03:36Z