Pernicious - Oh, Dang!

In the midst of all the excitement with the Waldenström Macroglobulinemia, another problem that the hematologist noticed hasn't been addressed fully.  In addition to the unusual proteins in the blood that led to the Waldenström diagnosis, he noticed a vitamin B12 deficiency.  A couple weeks ago, at my weekly blood test, he ordered a test for intrinsic factor.  What's that, I wondered.  Off to Google I went, to learn about it.  It's a protein that needs to be present for proper absorption of the vitamin.  A lack of it, along with a B12 deficiency and low hemoglobin, indicates something called pernicious anemia.  Boy, that doesn't sound very pretty!  It's also characterized by a wide distribution of red blood cell sizes.  Oh dang - my blood test results show that RDW - Red blood cell Distribution Width - is high.  So my red blood counts are low (anemia); the cell sizes are widely distributed; and now we're testing for intrinsic factor.  I spent a week worrying about pernicious anemia.

The following week, when the test came back, the nurses said the test was negative.  "Is 'negative' a good thing, or a bad thing, in this case?" I asked.  They said it was a good thing.  Unfortunately, the hematologist wasn't available to discuss it that morning (last Monday), but I had an appointment to talk to him today.  "So, no pernicious anemia, eh?" I asked him.  He clarified: the test looks for an antibody that destroys intrinsic factor, and the negative result meant that the antibody is not present.  That doesn't mean I do have enough intrinsic factor and that I don't have pernicious anemia.  Oh dang, again.  He said that the next test would be endoscopy, where they stick fiber optics down your throat and look around inside your stomach.  Apparently there is pathology that can be observed to diagnose pernicious anemia.  That would be consistent with the RDW numbers, which I forgot to ask him about.  Meanwhile, he's not particularly worried, especially since I'm taking B supplements every day.  He said let's wait for the WM to settle down a bit, then do the endoscopy.