AUTOIMMUNE HEMOLYTIC ANAEMIA AIHA

Dr DEEPAN P SHAH (MD)

Autoimmune Hemolytic Anaemia (AIHA) also called Immunohemolytic Anaemia is an autoimmune condition where in there are antibodies driven against our own Red Blood Cells. Due to which there is excessive destruction of RBC reducing oxygen carrying capacity of blood.

Pathophysiology

Causes of AIHA

Autoimmune Hemolytic Anaemia (AIHA) is believed to be caused due to genetic predisposition and environmental insults on the genome. Still no specific HLA locus has been found which can be related with AIHA in other words, no Human Leucocyte Antigen association has been established yet.

It can be also be secondary to other Autoimmune diseases, Cancers and Infections as mentioned below

1) Autoimmune diseases

  • Systemic Lupus Erythematosus (SLE)
  • Rheumatoid Arthritis(RA)
  • Crohn’s Disease
  • Ulcerative Colitis
  • Scleroderma
  • Autoimmune Hepatitis
  • etc

2) Cancers

  • Chronic Lymphocytic Leukemia
  • Non-Hodgkin’s Lymphoma
  • Other Blood Cancers

3) Infections

  • Mycoplasma infections
  • Cytomegalovirus(CMV)
  • Epstein-Barr Virus
  • Human Immunodeficiency Virus (HIV)
  • Infectious Mononeucleosis
  • Viral Pneumonitis
  • Viral Hepatitis

Differentiation of AIHA

Based on optimal temperature required for reaction of autoantibody of IgG class and autologous erythrocytes AIHA can be differentiated into

  • Warm Autoimmune Hemolytic Anaemia (wAIHA)
  • Cold Autoimmune Hemolytic Anaemia, further classified into i)Cold Aglutinin Disease (CAD) and ii) Paroxysmal Cold Heamoglobinuria(PCT). These both subtypes can be acute or chronic.
  • Mixed Type
  • Atypical (DAT- negative, IgM -wAIHA)
  • Drug Induced

Classification of AIHA

Clinically AIHA can be clasified as Primary or Secondary

Primary AIHA – It is also called Idiopathic AIHA has no known underlying causative factor and presents itself with hemolysis as predominant feature and other complaints are secondary to it. This type can either be cold or warm thermal relation to reaction mention in above differentiation.

Secondary AIHA – It is usually associated with some primary underlying disease condition. This type usually shows cold thermal relation in reaction that is Cold Agglutinin Disease Category.

Pathogenesis

Autoimmune Hemolytic Anaemia characterises itself by presence of Anti-RBC autoantibodies with or without activation of Complement-Cascade causing excessive destruction of Erythrocytes(RBC).

There are many mechanisms involved in pathogenesis of AIHA. It is a complex scenario with many mechanisms involing Autoantibodies, Phagocytosis, Antibody Dependent Cell-Mediated Cytotoxity, B Lymphocutes and T Lymphocytes, T regs, Cytokines, and Complement System.

Antibody Dependent Cell-Mediated Cytotoxicity (ADCC)

Auto-antibodies are formed by both tissue and circulating self reactive B-Lymphocytes in co-ordination with T-Helper Lymphocytes.IgG sub-classes IgG1 IgG2 IgG3 and IgG4 are involved in ADCC.

Cytotoxic CD8+ T cells and NK cells opsonize the RBC’s with fc portion of IgG for attracting fc receptors on macrophages thus resulting in destruction of RBC by phagocytosis. Occurs in Spleen and lymphoid organs.

Note- Spleenectomy in most cases doesnt have much effect on the disease as in slpeen the erythrolysis is in very lesser proportion in most AIHA cases.

Activation of Final Components of Complement Cascade (Membrane Attack Complex)- DIRECT LYSIS.

IgM dependent- IgM mediated compliment activation results in direct osmotic lysis of RBC, through sequential activation of Membrane attack complex(MAC), in circulation. Also C3b opsonisation of red blood cells by compliment activation results into extracellular erythrolysis by kufper cells of liver, 10 folds more destruction of RBC if compared to ADCC. IgG1 and IgG3 are also responsible in compliment activation to some degree. Majority of erythrolysis is extravascular especially in liver by kufper cells.

SIGNS AND SYMPTOMS

Symptoms develop gradually over months with presenting symptoms usually proportionate to degree of anaemia

  • General signs of anaemia depending on degree of anaemia like weakness, lethargy, breathless, etc
  • signs of Red blood cell destruction.
  • Heamoglobinuria
  • Spherocytes in RBC morphology
  • Increased LDH
  • Spleenomegaly
  • Hepatomegaly
  • Reticulocytes in Circulation
  • Hepatoglulin
  • Jaundice which may be mild to moderate or even severe
  • Angina

DIAGNOSIS of AIHA

  • COOMB’s Test
  • DAT test
  • CBC
  • LDH

HOMEOPATHIC TREATMENT FOR AUTOIMMUNE HEMOLYTIC ANAEMIA (AIHA)

  • Ferrum Metallicum
  • Ferrum Phosphoricum
  • Calcarea Phosphoricum
  • Calcarea Flourica
  • Ruta
  • Calcarea Carbonica
  • Lycopodium
  • Cinchonna Officinalis
  • Arsenicum Album
  • Lachesis
  • Naja
  • Chelidonium Majus

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