Q. I am having trouble differentiating between mild thalassemia and iron-deficiency anemia. I am not sure why the red cell distribution width would be lower in thalassemia than IDA. Could you please explain this and list other ways to tell them apart?
A. As iron-deficiency anemia progresses, and the patient’s serum iron drops lower and lower, each successive wave of new red cells gets smaller and smaller. So there are some kind of small cells, and some really small cells (as you can see in the image of iron-deficiency anemia above). The red cell distribution width (RDW) is high in iron deficiency anemia because there is a wide variation in red cell size. In mild thalassemia (alpha or beta), the red cells are strangely all the same size; there is virtually no variation. So the RDW is low. This difference in RDW is helpful when you’re trying to differentiate IDA and thalassemia; if you have a microcytic, hypochromic anemia, the next thing you’d do is look at the RDW (or just look at the blood smear). If the RDW is low (the cells are mostly the same size), then it’s probably thalassemia. If the RDW is high (the cells vary a lot in size), then it’s probably iron deficiency anemia.
Another thing to do is look at the RBC. In IDA, the RBC is low (there isn’t enough iron around, so the bone marrow makes fewer cells). In mild thalassemia, however, the RBC tends to be normal or even elevated. The reasons for this are unclear.
To definitively diagnose IDA, you need to do iron studies; to definitively diagnose thalassemia, you need to do hemoglobin electrophoresis. But you can get a pretty good idea by looking at the things discussed above.
Tagsacute leukemia acute lymphoblastic leukemia acute myeloid leukemia acute promyelocytic leukemia Add new tag anemia b cells blood smear bone marrow brain tumors carcinoma cases chronic myelofibrosis chronic myeloid leukemia chronic myeloproliferative disorders coagulation cortisol cytochemistry cytogenetics essential thrombocythemia heart hemophilia immunology infection inflammation kaplan kidney laboratory tests lymphocyte lymphocytes lymphoma macrophages neoplasia neutrophil normal photoblog polycythemia vera red blood cells red cells sickle cell anemia skin squamous cell carcinoma stains student questions t cells
- Anton said Big thanks!
- Sannie said really enlightening..I actually picked A
- Kristine said Thanks, Joyce – yes – you are absolutely correct: the PTT tests the intrinsic pathway an...
- Simon Downes said Thank you! This was driving me crazy! Now I will never forget it!! I will share it with my buddies!
- Ana Maramadaumasu said This answers my question and i can understand better than what i learn in school,,,thank you very mu...
- Sri said Thank you for the detailed explanation.. It is so clear and creates an enthusiasm to read all the to...
- Joyce said Kristine, this is regarding your comment to Janarthan on 8/3/15 @1:10PM. You seem to have the intrin...
- madelyn said thank you!!!!! You made this seem so simple! =)
- Nisha said Perfectttttttt explanation!!!
- chis said very simple and power-packed explanation! i really appreciate that.
- Trude said Wow, thanks! I believe this also rules for other mutations in tumor suppressos genes. I have been se...
- joly said hi….tanx for coment