Download auto- immune hemolytic anaemia

IMMUNE HEMOLYSIS
Definition :
red cell life span is shortened because abnormalities in
the components of the immune system are specifically
directed against the patients own erythrocytes.
1.Auto-immune hemolytic anaemia.
2.Transfusion related hemolysis.
3.Drug-related immune hemolysis.
AUTO- IMMUNE HEMOLYTIC ANAEMIA
The auto antibodies can be activated by either
heat or cold.
Warm reactive auto immune hemolysis (37oC)
Causes :
1- idiopathic
2- secondary :
I. Drugs (Methyldopa)
II. Connective tissue disease (SLE)
III. Lymphoproliferative (CLL, HD, NHL)
CLINICAL MANIFESTATION
Onset rapid lead to anaemia, tiredness,
fatigue.
Elderly pts. with atherosclerosis lead to
chest pain.
Splenomegaly and Jaundice, may be absent
in acute phase.
Abdominal pain and fever may also occur.
Diagnosis
spherocytosis, reticulocytosis, increase LDH,
decrease serum haptoglolbin, increase
indirect bilirubin
positive direct coomb’s test; Patient’s
CELLS are tested for surface Ab’s
Around 10% of all warm autoimmune
haemolytic anaemias are Coombs testnegative.
Treatment
1.Removal of the underlying cause
2.Corticosteroid : 1mg/kg prednisone (3-4 weeks /
check-Hb. & retics.)70-80% response,then slow
tapering over about 10 weeks.
3.Splenectomy : In case of steroid failure, or decrease
Hb following cessation / reduction of steroid.
4. Immunosuppressive therapy with azathioprine or
cyclophosphamide.
5.The anti-CD20 (B cell) monoclonal antibody,
rituximab.
6. Blood transfusion?.
*Cold-reactive auto immune hemolysis
Auto Antibodies usually are IgM. Occasionally
IgG.
Low temp make the antigen(Ag) more prominent
on the membrane lead to antibodies reaction.
Warm temp hiding the Ag below the membrane
below the lipid component lead to prevention of
Ag-Antibodies(Ag-Ab.) reaction
.
This can be chronic when the antibody is monoclonal,
or acute or transient when the antibody is polyclonal
CAUSES
1.Idiopathic
2.Secondary:
*Infection(mycoplasma pneumonia,
infectious mononucleosis)
*Lymphoma
Chronic cold agglutinin disease; It causes
a low-grade intravascular haemolysis with cold, painful
and often blue fingers, toes, ears or nose (so-called
acrocyanosis).
Other causes of cold agglutination
Paroxysmal cold haemoglobinuria is a very rare
cause seen in children, in association with viral or
bacterial infection.
An IgG antibody binds to red cells in the
peripheral circulation but lysis occurs in the
centralcirculation when complement fixation takes
place
Paroxysmal Nocturnal Hemoglobinuria (PNH)
GlycosylphosPhatidylInositol
ACQUIRED, NOT INHERITED like all the
previous hemolytic anemias were ACQUIRED
mutations in phosphatidylinositol glycan A (PIGA)
It is “P” and “N” only 25% of the time.
Triad of intravascular hemolysis,pancytopenia and
thrombosis.
PNH is also associated with hypoplastic bone marrow failure,
aplastic anaemia and myelodysplastic syndrome.
Management
Diagnosis:
Flow-cytometry shows reduced cluster of
differentiation (CD) CD55 & CD59.
Treatment:
* supportive with transfusion and treatment of
thrombosis.
* Anti-complement C5 monoclonal antibody
eculizumab was shown to be effective in
reducing haemolysis.