Hello doctor, I am a 53 year old woman diagnosed with polycythemia vera (PV) three years ago. I am being treated with phlebotomy. I have fatigue at times, as well as some thinking impairment at times. Over time I have developed various anomalies in my blood test results, which my doctor explained as normal. For instance, I typically have 1+ Anisocytosis, 2+ Hypochromia and 2+ Microcytes. I have had occasional ovalocytes mentioned as well as large platelets and at times giant platelets. My last CBC mentioned there were a few schistocytes. My question is this: I understand that these are all blood cells that are misshapen due to the PV or to the chronic phlebotomies I receive. Are these misshapen cells a danger in and of themselves, or are they only indicators of a problem? How many weird cells can I have running around inside of me before it is worrisome?
Hi. Based on your query regarding polycythemia, my opinion is as follows: Due to nutritional deficiencies, secondary to excessive RBC (red blood cell) production and also mild dyserythropoiesis (defective development of red blood cells), you can find microcytic hypochromic cells ( due to iron deficiency) and ovalocytes (due to vitamin B12 and folic acid deficiency). Vitamin B12 and folic acid can impact other cell line resulting in hypersegmented neutrophils and giant platelets also.  As there is iron deficiency, anisocytosis (unequal sized red cells) and poikilocytosis (abnormal shaped red cells) is seen. More the iron deficiency, more the percentage of anisopoikilocytosis. Schistocytes (irregularly shaped red cells) could be due to marrow fibrosis or red cell trapping in fibrin fragments. The former usually occurs in marrow at a later stage of polycythemia vera. At present schistocytes could be due to dyserythropoiesis in marrow. No fibrin trapping can be thought of. Things that need to be watched are - any reduced counts of red blood cells, white blood cells or platelets. This will occur before increase of schistocytes. Bone marrow fibrosis due to burning out phase will lead onto pancytopenia (deficiency of RBC, WBC and platelets) and schistocytes. As all other counts are normal, you need not worry about schistocytes for now. Schistocytes percentage more than 5% or specifically 10% should be worrisome. It usually does not occur in PV, unless it is late stage and with marrow fibrosis and pancytopenia. Revert back to a hematologist online for further follow up -->