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AUTOIMMUNE HAEMOLYTIC
ANAEMIA
BY

DR IHEJI CHUKWUNONSO

OUTLINE
 Introduction
 Epidemiology
 Classification/ Causes
 Pathophysiology
 Clinical features
 Diagnosis
 Treatment
 Prognosis
 References

 Literature review

INTRODUCTION
 Autoimmune haemolytic anaemia (AIHA) can be defined as a ↓

Hb conc, resulting from a shortened RBC lifespan, caused by
autoantibodies directed against antigens on the patient's RBCs
...

 The degree of haemolysis can vary considerably and may occur

in the absence of anaemia
...

 In the paediatric population, it is commoner in the
early years of life when it can develop following viral
infections and vaccinations

EPIDEMIOLOGY
 Incidence: 1-3 per 100,000 annually
 Age:

- Children: generally < 5 years of age, male more
common
- Adults: generally ≥ 65 years of age, female more
common
 Race: None (Nig Study)
 Type: 70-80% warm reactive
15-20% cold reactive
10% mixed-type

CLASSIFICATION
 Based 0n aetiology
 Primary (idiopathic) AIHA: Accounts for

>50% of cases

 Secondary (associated) AIHA

• Systemic Lupus Erythematosus (SLE)
• Chronic Lymphocytic Leukemia (CLL)
• Evans Syndrome (ES) – AIHA + ITP
• Drug induced eg ά-methyldopa, penicillins
• Post-infection

Classification contd
Based on DAT reaction:

 Warm-Reactive (wAIHA)
 Cold-Reactive AIHA (cAIHA)

• Cold Agglutinin Disease (CAS)
• Paroxysmal Cold Haemoglobinuria (PCH)
 Mixed-type

wAIHA
Acute (Trasient)

Chronic

 Last 3 - 6 months

 More prolonged

 Age: 2 - 12yr

course, upto years
 Infants and >12yrs
 Very rare

 Accounts for 50-70% of

cases
 Usually preceded by an
infection, esp
respiratory

 Usually follow systemic

diseases eg SLE

Acute Contd

Chronic Contd

 The spleen is usually

 Slenomegally not common

enlarged and is the primary
site of destruction of
immunoglobulin G (IgG)–
coated RBCs
...


 the response to

glucocorticoids is variable
and inconsistent
...


PATHOPHYSIOLOGY
 AIHA can be caused by a number of different classes

of antibody, with IgG and IgM being the main
causative classes
...

 IgG is not very effective at activating complement

and effectively binds the Fc receptor (FcR) of
phagocytic cells, Therefore AIHA involving IgG is
generally characterized by phagocytosis of RBCs
...

 IgM also leads to phagocytosis of RBCs however,
because phagocytic cells have receptors for the
bound complement (rather than FcRs as in IgG
AIHA)
...


 Phagocytic AIHA is termed extravascular, whereas

complement-mediated lysis of RBCs is termed
intravascular AIHA
...

 Each IgM molecule has the potential to activate a C1
molecule so that large amounts of complement are found
on the RBCs in cold agglutinin disease
...


 AIHA cannot be attributed to any single

autoantibody
...

 Antibodies with high activity at physiological
temperature (approximately 37 °C) are termed
warm autoantibodies
...

 Patients with cold-type AIHA, therefore, have higher
disease activity when body temperature falls into a
hypothermic state
...

 The range of temperature associated with RBC
agglutination is called the thermal amplitude
...

 When very high titers of cold antibodies are present and
active near body temperature, severe intravascular
hemolysis with hemoglobinemia and hemoglobinuria
may occur and be heightened on a patient's exposure to
cold
...
A minimum of 260–500 molecules of IgG
per cell is necessary on the RBC membrane to
produce a positive reaction
...

 It mat be extremely difficult to find compatible
blood; blood with the least in vitro reaction by the
Coombs technique should be chosen
...

Failure to transfuse a profoundly anaemic infant
may lead to serious morbidity and even death
...

 Some wAIHA are self limiting; while most responds

to corticosteriod
 cAIHA has the poorest prognosis
 The prognosis of the Secondary type depends on the
primary illness
...
D
...
D
...
D
...
D
...
D
...
56(1):61–69
 The records of 80 children with autoimmune hemolytic
anemia (AHA) followed up in the Centre Departmental
de Transfusion Sanguine, Boulevard Diderot, Paris,
France between 1962 and 1971 were reviewed
...


Predominance among males was noted
...
Two main clinical patterns were
distinguished: an acute transient type and a
prolonged chronic type
...
High titer cold agglutinins were very
rarely observed
...


 Although the onset was sometimes dramatic, all the

patients with acute transient type recovered rapidly
...
2 per cent
...
Corticosteroid
therapy was of constant effectiveness in transient
cases but its results were variable in chronic cases
...
Response was favorable in
patients with significant splenic sequestration of
51Cr-labeled red cells
...

By Salawu L and Durosinmi MA
 Afr J Med Med Sci
...

 Aim: The study was aimed at investigating the
pattern of presentation and management outcome of
patients with AHA seen over a period of 10 years
(June 1988 to May 1998) at the Obafemi Awolowo
University Teaching Hospitals Complex, Ile-Ife
...

Diagnosis was based on laboratory features of haemolytic
anaemia and/or a positive direct anti-human globulin
(Coombs') test after excluding other causes of haemolytic
anaemia
...
13
patients with AHA (7 females, 6 males) aged 6-70 (median,
42) years were identified
...

Laboratory evidence of haemolysis (bone marrow erythroid
hyperplasia and hyperbilirubinaemia) was found in all cases,
while the direct Coomb's test was positive in 10 (76
...


 All the patients had moderate-severe anaemia within

the course of the disease, requiring blood
transfusion
...
Follow-up period post-remission
ranged between 1 and 78 months
...
It also shows that
steroid therapy (prednisolone) is quite effective,
especially, in idiopathic AHA, and that red cell
transfusion could be useful in life-threatening
anaemia
...
Kliegman, Richard E
...


Jenson, Bonita F
...
Nelson Textbook of
Paediatrics e-dition 18th Ed, 2007; Saunders
Elsevier, Philadelphia
 Azubuike JC
...
, Paediatrics and
Child Health in a Tropical Region, 2nd ed, 2007;
African Educational Services, Owerri, Nigeria
 Michel M
...
2011 Dec;4(6):60718

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