Hi Ash,
retics are immature (precursors of) red blood cells. Thalassemia major patients are often hypertransfused so that their bone marrow does not attempt to make retics, because although the bone marrow attempts to retic it is not able to make viable blood. Bones and spleens of undertransfused patients often expand in an attempt to make retics. In response to low blood counts, the bone marrow "thinks" that by increasing its surface area it can make more red blood cells. By keeping the hg higher - above 90 (now docs think it is better to keep it even higher) - this can be prevented, therefore allowing the bone marrow to remain suppressed, the spleen to remain normal in size and the body to be better nourished with blood and oxygen - for optimal function.
It is important to know if the patient is beta zero (very serious deletions or mutations in the beta gene) - in which case you want to prevent the bone marrow from "kicking in" because a few negative affects can occur as a result - bone damage, changes in facial features, *enlarged spleen, and the retics can cause clotting in the blood vessels. For this reason it is important to keep pretransfusion hg higher.
If the patient is not beta zero, and the retics are resulting in viable red blood cells then it is worth considering if the patient is a thal intermedia and if a hg inducer may be worth trying in place of transfusions.
This is my understanding, perhaps one of our other members can provide a more thorough explanation,
Play keep us posted and let us know what the docs say after bone marrow testing,
Best,
Sharmin
*remember also, an enlarged spleen means more hemolysis, increased transfusion requirement, increased iron load and increased requirement for chelation. It is better to transfuse adequately in the first place. It is ideal these days to keep the spleen small, and to not have it removed because long term studies indicate that removing the spleen may lead to long term complications.