Acquired haemolytic anaemia Flashcards
Define how one can develop anaemia?
There is too few RBC, RBC are not functioning as they should or from the premature destruction of RBC
What can cause the premature destruction of RBC?
Something outside of the cell attacking it (acquired) or defects within the red cells that cause its destruction (inherited)
What is a symptom of haemolytic anaemia?
Enlarged spleen - splenomegaly
What happens to a RBC constituents when it is phagocytosed by a macrophage?
Globin is converted to amino acids, iron is bound by transferrin to be recycled, while haem is composed of protoporphyrin ring that is converted into biliverdin, then to bilirubin, which is taken to the liver to be conjugated
Through the constant destruction of red blood cells, what happens to the abundance of unbound haemoglobin?
The haemoglobin can go one of 3 ways, it can be bound to haptoglobin, which is then recognised by macrophages and degraded. Haemoglobin in the ferric state binds to albumin to become methaemalbumin, or free haemoglobin can go to the kidneys and be excreted in the urine
What are alloantibodies?
Antibodies produced to the immune recognition of foreign RBC
What is the direct antiglobulin test (DAT)?
Using the patient’s blood to detect antibodies
What is the indirect antiglobulin test (IAT)?
uses patients plasma to detect antigens, used to detect IgG
What is autoimmune haemolytic anaemia?
A rare autoimmune disease where patients possess autoantibodies against own red cell antigens, can be divided into two types, hot and cold depending whether the antibody reacts more strongly at 37 degrees or 4 degrees
What are characteristics of warm AIHA?
Red cells are coated with IgG, extravascular, haemolysis tends to be more severe and conditions associated with lymphoma. Blood contains lots of spherocytes and larger polychromic cells are reticulocytes
What are characteristics of cold AIHA?
Red cells are coated with IgM and is intravascular
