4 October 2014 (Saturday) - Bodies Beginning with "H"
There were Howell-Jolly bodies in the most recent EQA morphology survey. Apparently...
Howell-Jolly bodies are little fragments of the red cell nucleus. They are most commonly seen in patients with splenectomies purely because the spleen gets rid of them. They can be seen them without any special staining. They appear dark, round dots in the red cells.
Interestingly whilst Howell Jolly bodies were fresh in my mind I read this article on Facebook. (Facebook isn't all drivel - it's a useful source of CPD!!)
Because they both begin with the letter "H" there are those who get Howell-Jolly bodies confused with Heinz bodies. (Apparently). I found this odd - you can't see Heinz bodies without doing supravital staining. I'm old enough to remember Heinz bodies being an unwelcome complication of reticulocyte counting, but realistically who counts retics that way these days?
Heinz bodies are most commonly found in G6PD deficiency. They are denatured globin chains formed when the haemoglobin molecule undergoes oxidative attack. When this happens the haem molecules are recycled, but the globin chains adhere to the inside of the red cell membrane forming Heinz bodies. These are present in cases of G6PD deficiency, but cannot actually be seen without performing supravital staining.
It is worth bearing in mind that macrophages in the spleen chop Heinz bodies out of red cells forming the things traditionally called "bite cells", so on seeing bite cells it may well be worth considering performing a supravital stain.
Having said that I perform a G6PD assay (on a patient as opposed to an EQA sample) about once a year, and in thirty years I think I've only once seen a result which hinted at a deficiency, so Heinz bodies are firmly in the "obscure" category whereas Howell-Jolly bodies are seen on a weekly basis (if not more often).
Labels: on-line morphology