Q. Love your website, its helped me remember some super key concepts. Im kinda confused on something though. Whats the difference between howell jolly bodies and heinz bodies?
A. Great question! Howell-Jolly bodies are little fragments of the red cell nucleus. You see them most commonly in patients with splenectomies (normally, the spleen just bites them out). You can see them without a special stain – they look like dark, round dots.
Heinz bodies are seen in G6PD deficiency. They represent denatured globin chains. When there’s not enough G6PD around, the bonds between heme and globin are attacked. Heme is just recycled, but the globin chains become denatured, forming a little ball that sticks to the inside of the red cell membrane. This is the Heinz body. You can’t see it unless you do a special stain (like the supravital stain, above). Macrophages in the spleen bite Heinz bodies out (the resulting red cells are actually called bite cells!).
Erythrocytes do not have a nucleus
Science buff:
They used to.
Google RBC maturation
science buff, while I appreciate you might know a lot of science, any med tech who has ever looked at a newborn’s smear knows there is a nucleus in an erythrocyte. In a healthy state, NRBC’s are rarely seen, but after splenectomy (removal of the spleen), and in many diseased states you will commonly see erythrocytes with nuclear material present.
Thanks Cindy – was going to reply but you beat me to it 🙂 Yes – red cells have nuclei as they develop in the bone marrow. During the next-to-last stage of maturation (the orthochromatic erythroblast) the nucleus is extruded; the red cell then becomes a polychromatophilic erythroblast (or reticulocyte) and is released into the bone marrow. Rarely, a bit of the nucleus remains in the red cell – but with a healthy spleen, this bit of nucleus is removed immediately.
So nice explanation, you make pathology simple and comprehensive
Mature RBCs do not have nucleus but immatures can have.
Yes – red cells begin their maturation with a large nucleus, which gets progressively smaller until it is extruded. Mature red blood cells do not have a nucleus.
You are amazing you seem as a miracle in hemopathology field
thanks a lot my loving teacher….kristine krafts
Hello,
Thanks for the info on Howell Jolly bodies.
I have had these critters consistently since my
splenectomy 3 years ago. I guess I will always have
them now.
Funny,… with all the new critters in my blood post splenectomy it will be interesting to see when I’m much older if any MD can detect if I get a serious hematologic disorder.
So would a normal person also have “bite” cells in blood smear because the splenic macrophages remove these Howell-Jolly bodies?
Amazing website by the way; really satisfies me when I get OCD about a topic!!
Great question! No, normally the spleen does not leave bites when it removes Howell-Jolly bodies. Most likely it just removes the entire red cell.
Please correct me if I’m wrong. I heard bite cell is seen in usual staing since heinz body can not be stained. That is, it’s just a staining artefact.
You’re partly right! It’s true that Heinz bodies are not visible in a regular Wright-Giemsa blood stain (you have to do a supravital stain to see them). However, bite cells are not artifacts! They are real cells that exist in the blood of patients with G6PD who have had some sort of oxidant exposure. They look like they’ve had a bite taken out of them because macrophages in the spleen have removed a chunk of the red cell, leaving what looks like a bite mark. Macrophages can “see” Heinz bodies in red cells, and as they remove Heinz bodies, a chunk of the red cell gets removed in the process.
This is amazing Sir. You have provided a great hub of learning.