Anemia
Due to HemolysisIntroduction Hemolysis
is a process that dissolves red blood cells, so that they live shorter than the
normal 120 days. This can occur because of changes in the red blood cells themselves
or because of factors outside of the red blood cells. Damaged RBC’s are removed
by phagocytic cells, called “reticulocytes”, in the liver, spleen and in the
bone marrow. These reticulocytes are equipped to dismantle the RBC’s. However,
this is done by reutilizing the iron of the hemoglobin molecule and rescuing the
heme part as bilirubin. Normally there are a number of enzymes that take care
of this automatically. The iron is transported to the bone marrow for reutilization
of the iron so that new RBC’s can be made there. The hemoglobin is converted
by the liver into bilirubin and bound to glucuronide. Bilirubin glucuronide is
excreted by the liver into the bile ducts and ends up in the stool where further
enzymatic reactions change it into stercobilin. This gives the stool its brown
color. Each enzymatic step is known to be able to be interrupted by a congenital
abnormality. Some of these abnormalities are of clinical significance, others
are minor. Symptoms The symptoms are similar to
other forms of anemia. However, hemolysis may present with more pronounced symptoms
such as chills, an elevated body temperature, pain in the abdomen and in the back
with general malaise. In severe cases of hemolysis the patient may have excruciating
pain all over and even get into shock. Jaundice and splenomegaly (enlarged spleen)
are often also present.
Diagnostic tests
When
blood tests of a patient with these symptoms show anemia and reticulocytosis (meaning
large numbers of reticulocytes in the blood), the physician would suspect hemolysis
as a possible cause of the illness. A blood smear is obtained and the hematologist
looks for possible causes of hemolysis. For instance with spherocytosis the pathologist
would find spherically shaped red blood cells. An enlarged spleen is found and
there is a family history of similar findings. Osmotic fragility tests show an
increased fragility of the red blood cell membrane. The Coombs’ tests shows
whether there are autoimmune antibodies that cause autoimmune hemolytic anemia.
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