aiha in children

1. Diagnosis and management of
Autoimmune haemolytic anaemia
By: Kumar Abhinav
Dr. Amit Yadav
Dr. Narendra Arya

2. Case Summary
 A 12 year old girl presented to the Emergency Department with – H/O fever, headache,
abdominal pain, vomiting and yellowish discoloration of eyes of 5 days duration.
 O/E - marked pallor, fever, tachycardia, tachypnoea and icterus. No lymphadenopathy, edema,
rash, petechiae or bruises.
• CVS - revealed a 3/6 systolic murmur along the left sternal border.
• P/A - A non tender soft hepatomegaly with a span of 14 cm and a soft spleen 3 cm below
the left costal margin was noted.
• R/S - Lung fields were clear and neurological examination was normal.
• Fundoscopy - revealed disc edema, roth spots, fusiform dilatation of veins with
extravasation and arteriolar haemorrhages.

3.  Inv –
• TLC – normal with normal differentiation
• Platelet count - normal .
• Hb - 3 g/dl (N- 12.0–16.0) with evidence of macrocytosis MCV—128.1 fl
(N- 79-98)
• MCH - 50.9 pg (N - 25-35)
• MCHC - 39.7 g/dl (N - 32-36)
• Agglutination of red blood cells was noted on peripheral smear
examination with separation on warming the slides.

4. • Peripheral Smear - showed anisopoikilocytosis with predominant
macrocytes, hypochromia and nucleated red blood cells. Malarial parasite
was absent.
• Reticulocyte count was 10% (N<2%).
• DCT was strongly positive.
• LFT – TSB- 4.5 mg/dl with an indirect S.B of 3.2 mg/dl.
• AST/ALT - Normal.
• Urine analysis was normal.

5. AIHA
 Immune hemolytic anemia is a type of extra-corpuscular hemolytic anemia. It
can be either isoimmune or autoimmune.
i. Isoimmune hemolytic anemia results from a mismatched blood transfusion or
from hemolytic disease of the newborn.
ii. Autoimmune hemolytic anemia (AIHA) shortened red cell survival is due to
immunoglobulins with or without the participation of complement on the red
cell membrane.

6. INCIDENCE
 AIHA is children is relatively rare, annual incidence of 1 in 80,000 persons in
the general population
 AIHA can affect children of any race or nationality and can present in infancy,
especially after an infection, and throughout childhood
 Teenagers who present with AIHA are more likely to have an underlying
systemic illness

7.  The red cell autoantibodies may be of three types –
i. Warm
ii. Cold, and
iii. Mixed, with both types present, or the cold Donath Landsteiner type.
 Complement participation is usually confined to the immunoglobulin M (IgM)
type of antibody; only rarely is it associated with IgG.
 AIHA may be idiopathic or secondary to a number of conditions listed below.

8. Etiologies of AIHA
IgG only; complement only; mixed IgG and complement, other antibody mediated
mechanisms –
I. Idiopathic
• Warm antibody
• Cold antibody
• Cold-warm hemolysis (Donath-Landsteiner antibody)

9. II. Secondary
i. Infection
a) Viral: infectious mononucleosis: Epstein Barr virus (EBV), cytomegalovirus
(CMV), hepatitis, herpes simplex, measles, varicella, influenza A, coxsackie
virus B, HIV;
b) Bacterial: streptococcal, typhoid fever, E.coli septicemia, Mycoplasma
pneumonia (atypical pneumonia)
ii. Drugs and chemicals
quinine, quinidine, phenacetin, p-aminosalicylic acid, sodium cephalothin
(Keflin), ceftriaxone, penicillin, tetracycline, rifampin, sulfonamides,
chlorpromazine, pyradone, dipyrone, insulin; lead.

10. iii. Hematologic disorders:
leukemias, lymphomas, lymphoproliferative syndrome, paroxysmal cold
hemoglobinuria, paroxysmal nocturnal hemoglobinuria.
iv. Immunopathic disorders:
SLE, PAN, scleroderma, dermatomyositis, RA, ulcerative colitis,
agammaglobulinemia, Wiskott Aldrich syndrome, dysgamma-globulinemia, IgA
deficiency, thyroid disorders, giant cell hepatitis, Evans syndrome (immune-
mediated anemia associated with immune thrombocytopenia), autoimmune
lymphoproliferative syndrome (ALPS), common variable immune deficiency
v. Tumors:
ovarian teratomata, dermoids, thymoma, carcinoma, lymphomas.

11.  The possibility of secondary AIHA should be considered particularly in patients
with –
a) thrombocytopenia (Evans syndrome),
b) marked hepatosplenomegaly,
c) a history of recent viral infection, or
d) use of certain drugs (e.g- one of several antibiotics, or probenecid).

13.  Coombs reagent (also known as Coombs antiglobulin or antihuman
globulin) - used in both the direct Coombs test and the indirect Coombs test.
 Coombs reagent is antihuman globulin.
 It is made by injecting human globulin into animals, which produce polyclonal
antibodies specific for human immunoglobulins and human complement system
factors. More specific Coombs reagents or monoclonal antibodies can aslo be
used.

14. Pathophysiology of red cell destruction
 IgG-coated erythrocytes are removed primarily by the spleen, regardless of the
presence of complement.
 The amount of surface IgG is correlated with the rate of splenic clearance because
Fc receptors on macrophages bind and phagocytose IgG-coated erythrocytes.
 In contrast to IgG-mediated hemolysis, IgM-coated erythrocytes are cleared
rapidly within the liver.
 The amount of complement affects the clearance of IgM-coated cells, with
macrophage complement receptors responsible for binding and phagocytosis of
erythrocytes

16. Warm AIHA
 Antibodies of the IgG class are most common in AIHA in children.
 Rarely, IgA and IgM antibodies may be responsible for hemolytic anemia.
 IgG antibody is directed is one of the Rh erythrocyte antigens in more than 70% of cases.
 Its maximal activity is at 37⁰ C and the resultant hemolysis is called warm antibody-induced
hemolytic anemia.
 Erythrocyte survival is generally proportional to the amount of antibody on the erythrocyte
surface.
 Although rarely hemolysis can occur in patients with too few antibodies on the surface of the
red cell to cause a positive DAT (DAT-negative hemolytic anemia).

17.  Clinical Features
1) Sudden onset of pallor, jaundice, dark urine.
2) Splenomegaly.
 Physical signs
1) Often, tachycardia is present,
2) systolic flow murmur, reflecting a high-output anemic state;
3) however, cardiovascular compromise (eg, congestive failure) is rare.

18.  Laboratory Findings
1) Hb: very low in fulminant disease or normal in indolent disease.
2) Reticulocytosis: common although often the reticulocytes are destroyed by the
antibody as well and reticulocytopenia may occur.
3) MCHC may be elevated.
4) Smear: prominent spherocytes, polychromasia, macrocytes, autoagglutination
(IgM), nucleated red blood cells, erythrophagocytosis.

19. 5) Neutropenia and thrombocytopenia (occasionally).
6) Increased osmotic fragility and auto-hemolysis proportional to spherocytes.
7) DAT positivity establishes the diagnosis of AIHA.
8) Hyperbilirubinemia.
9) Serum LDH – raised.
10)Haptoglobin level is markedly decreased.
11)Hemoglobinuria usually only at first presentation, increased urinary
urobilinogen.

20. Management
 Monitoring : -
a) Hemoglobin level (every 4 h).
b) Reticulocyte count (daily).
c) Splenic size (daily).
d) Hemoglobinuria (daily).
e) Haptoglobin level (weekly).
f) DAT (weekly).
 supportive care like folic acid supplementation, hydration status, urine output,
and cardiac status also noted.

21. Treatment
 Blood Transfusion
• no truly compatible blood can be available so transfusion should be avoided if
possible.
the survival of transfused cells in this situation is quite limited and may fail to
elevate the hemoglobin level.
• If the hemoglobin level is above 10 g/dL, no need of transfusion.

22.  Clinical judgment is important at Hb-5 to 8 g/dL. At this level, many patients
with AIHA transfused unless the anemia is not progressing and the patient has no
critical symptoms of anemia on close observation.
 At a level of hemoglobin level below 5 g/dL, most patients will require
transfusion.
 Use the “least incompatible” blood.
 The guidelines listed below should be followed for transfusion:
1) If a specific antibody identified, most compatible donor selected. The antibody
usually behaves as a panagglutinin and no totally compatible blood can be found.
2) Washed packed red cells should be used from donors whose erythrocytes show
the least agglutination in the patient’s serum.

23. 3) The volume of transfused blood just sufficient to relieve any cardiopulmonary
embarrassment from the anemia. Aliquots of 5 ml/kg are taken from a single unit
and transfused at a rate of 2 ml/kg/h.
4) The use of such incompletely matched blood is made relatively safe by –
i. biologic cross-matching,
ii. transfusing of relatively small volumes of blood at any given time and
iii. concomitant use of high-dose corticosteroid therapy.

24. Corticosteroid Therapy
i. High-dose corticosteroid therapy maintained for several days. Prednisone 2-10 mg/kg/day
orally or methylprednisone 4-8 mg/kg/day IV (q 6 hrly) for 3 days f/b oral prednisone.
ii. Thereafter, slowly tapered over a 3- to 4-week period.
iii. When the hemoglobin stabilizes, the corticosteroids discontinued.
iv. continued positive DCT does not prolong steroids as long as hemoglobin is stable or rising
and reticulocytosis continues to decrease or remain normal.
v. 50% of patients respond within 47 days to corticosteroid therapy, but there are a number of
patients who continue with profound hemolysis for the first week after initiation of therapy.
vi. For these patients and patients who appear dependent on steroids alternative treatment needs
to be considered.

25. Intravenous Ig
i. IV Ig doses in the range of 15 g/kg have been employed but response in children
is poor.
ii. IV Ig is considered in patients with severe hemolysis who are requiring
transfusion and are having poor responses to transfusion.

26. Rituximab
 In patients not responding early or exhibiting steroid dependence. Rituximab (a
manufactured antibody targeting CD20) used.
 Dose - 375 mg/m2 once a week for 4 weeks.
 It has a very high rate of remission induction in AIHA in children.
 The short-term side effects include (Allergic):
i. Itching.
ii. Hives.
iii. Hypotension.
iv. Chest pain.

27.  These can be prevented through premedication with : -
i. PCM 15 mg/kg,
ii. diphenhydramine 1 mg/kg, or
iii. corticosteroids.
Patients should be monitored carefully during each infusion.
Although rituximab eliminates the B-cell compartment, there have not been
increased rates of infection, and IV Ig has been administered to offset the loss of B-
cell function.

28.  Plasmapheresis
i. Used in severe IgG-induced immune hemolytic anemia. The effect is short-
lived.
ii. Removes antibodies
iii. Should always be combined with moderate immunosuppression (e.g.,
rituximab).
So that both antibody production and antibody titer reduction are employed
concomitantly

29.  Immunomodulating Agents
1. Mycophenolate mofetil (MMF)
2. Cyclosporine.
3. Danazol.
 Antimetabolites
Azathioprine and 6-mercaptopurine
 Alkylating Agents
Cyclophosphamide
 Mitotic Inhibitors
Vincristine and vinblastine
 Splenectomy
It is beneficial in 60-75% of patients.

30. Giant Cell Hepatitis and DAT-Positive AIHA
This is a specific rare entity of unknown etiology
An autoimmune component has been suggested due to the association of DAT-
positive AIHA and response to immunosuppression.
 Clinical Findings -
i. Age: 6-24 months, occasionally older age.
ii. Fever.
iii. Pallor.
iv. Jaundice (progressing to cirrhosis and liver failure).
v. Firm hepatomegaly and splenomegaly.
vi. Associated convulsions.
vii.Prognosis Poor.

31.  Laboratory Findings :-
i. DCT: mixed (IgG and complement)
ii. Hemolytic anemia
iii. LFT:
a) high direct bilirubin,
b) high transaminase,
c) high serum globulin values
d) high prolonged prothrombin time.

32. Liver histology:-
a) marked lobular fibrosis,
b) extensive necrosis with central-portal bridging, and
c) giant cell transformation.
 Treatment:- Survival has been achieved with more intensive
immunosuppression.
a. Corticosteroids in combination with other immunosuppressive agents as
steroids alone cannot typically control the hemolysis.
b. Cytoxan, rituximab, cyclosporine, splenectomy, and azathioprine have all
been used.

33. Cold AIHA
 IgM antibody-associated hemolysis.
 Occurs less often in children than in adults.
 Most of these are cold agglutinins / cold hemagglutinin disease and almost
always caused by an IgM antibody.
 Cold agglutinins, or cold autoantibodies, occur naturally in nearly all individuals.
These natural cold autoantibodies are in low titers, < 1:64 at 4 °C, and have no
activity at higher temperatures.
 Pathologic cold agglutinins occur at titers > 1:1000 and react at 28-31 °C and
sometimes at 37 °C.

34.  A common complaint among patients with cold agglutinin disease is painful
fingers and toes with purplish discoloration associated with cold exposure.
 In chronic cold agglutinin disease, the patient is more symptomatic during the
colder months.
 Typically associated with –
a) Mycoplasma pneumoniae infection (MC),
b) Infectious mononucleosis,
c) CMV,
d) mumps, and
e) rarely other infections.

35.  It is usually due to the production of antibodies targeting the I/i antigens
(precursors of the ABH and Lewis blood group substances) on RBCs.
 The association of the infecting organism with the red blood cell may alter the
antigenic structure of red blood cell membrane antigen, rendering it
immunogenic.
 In children, the IgM antibody is usually polyclonal and immunologically
heterogeneous.

36. Clinical Features
 This disease may be idiopathic but is more frequently seen in conjunction with
other infections such as –
a) M. pneumoniae (atypical pneumonia) and
b) less commonly with lymphoproliferative disorders.

37.  The features are:
i. Hemoglobin is usually normal or mildly decreased and the reticulocyte count
may be elevated.
ii. The blood smear may show agglutination and polychromatophilia.
iii. Spherocytosis is usually absent.
iv. The DAT is positive for complement (polyspecific and anti C3-agents) only and
is negative for anti-IgG.
v. Most blood banks do cold agglutinin testing only when the DAT is positive for
complement.

38. Treatment
1. Control underlying disorder.
2. Transfusions may be necessary for symptomatic patients. “least incompatible”
unit of blood. Warming the blood to 37⁰C during administration by means of a
heating coil or water bath is indicated to avoid further temperature activation of the
antibody.
3. Warm the patient’s room. Keeping a patient warm will help diminish hemolysis
and peripheral agglutination.
4. Plasmapheresis is very efficient for the treatment of IgM disease as IgM is largely
intravascular. Patients with severe hemolysis should undergo plasmapheresis.

39. 5. Autotransfusion of warmed RBCs can be performed. With the patient’s arm
warmed by hot pads. The warm unit can be separated quickly by centrifugation
and the red cells returned to the patient through an efficient in-line blood warmer.
6. Drug therapy. If the anemia is severe. Rituximab and cyclophosphamide have
been used with plasmapheresis.
7. Steroids are of marginal value in cold agglutinin disease.

40. Paroxysmal Cold Hemoglobinuria Due to Donath-Landsteiner Cold Hemolysin
 Historic association with syphilis
 More commonly : in children after a viral or bacterial infection
 On exposure to cold: experiences paroxysms of hemoglobinuria with or without
constitutional symptoms (fever, back pain, leg pain, abdominal cramps, and
rigors, palpable spleen & liver)
 Post viral fulminant disease: intravascular hemolysis and its associated signs of
hemoglobinemia, jaundice, severe anemia, and sometimes renal failure
 Usually self limiting but sometimes life threatening due to severity of anemia
 24

41. Clinical Features
1. The most common clinical finding is a sudden bout of hemolysis with a drop in
hemoglobin and hemoglobinuria.
2. The hemoglobin drop is often serious enough to require transfusion (and sudden
death from this disease has been reported).
3. Illness short-lived, explosive where the antibody is only produced for a short
time.
4. Although blood for transfusion will appear compatible, all red cells carry the P
blood group specificity against which the antibody is directed.

42. Pathophysiology
 Donath-Landsteiner antibody produced often in response to a viral infection
 IgG antibody; target as P blood group antigen
Laboratory Test
 IAT & DAT : negative
 Donath Landsteiner Test:
 25

43.  A positive complement test is present on antiglobulin testing.
Treatment
 No specific treatment
 Prednisone is not useful
 Keeping a patient warm is the mainstay of treatment and warming blood in a blood warmer
prior to transfusion is important.
 Patients with ongoing severe hemolysis may benefit from plasmapheresis despite the fact that
the disease is caused by an IgG antibody.
 Rituximab may be effective.

44. Parameter Warm-reactive AIHA
Paroxysmal cold
hemoglobinuria
Cold agglutinin disease
Autoantibody isotype IgG IgG IgM
Optimal thermal reactivity Warm Cold Cold
Ability to fix complement Variable Yes Yes
Positive DAT (Coombs test) IgG, ± C3 C3, ± IgG C3
Erythrocyte autoantigen Rh, others P I or i
Type of hemolysis* Extravascular Intravascular Both
First-line therapy Corticosteroids Avoidance of cold Avoidance of cold
Secondary therapy Splenectomy, Rituximab• Corticosteroids Plasmapheresis
AIHA: autoimmune hemolytic anemia; C3: complement.
* Extravascular or intravascular hemolysis.
• This is an off-label use of rituximab.

47. Thank you