Auto Immune hemolytic anemia

Nada Mohamed Ahmed ,MD, MT (ASCP)i

Nada Mohamed Ahmed ,MD, MT (ASCP)i

Auto Immune hemolytic anemia

HEMOLYTIC ANEMIA

1. Membrane defects

- Hereditary spherocytosis

- Hereditary elliptocytosis

- Hereditary pyropoikilocytosis

- Hereditary stomatocytosis

2. Enzyme defects

-G6PD

3. -Hemoglobin defects -.Hemoglbinopathies(sickle cell disorders) - Hb SS, CC, SC & S-B-

- Thalassemias

NON-IMMUNE

1. Hypersplenism

2. Infections (Malaria),,

3-mechanical trauma to RBCs

4. Liver dz (Spur cell)

AUTO-IMMUNE

1. Warm Ab

2. Cold Ab

3. Transfusion reactions

4. Drug associated

ExtracorpuscularOUTSIDE THE RED CELL

Intracorpuscular

WITHIN THE RED CELL

Hereditary Acquired

Membrane defects

PNH

Objectives • Acquired hemolytic anemia Immune mediated non.immune mediated

Cold warm infections physical agent

Nonimmune Hemolytic Anemia

• These anemias represent a group of conditions that lead to the shortened survival of red cells by various mechanisms.

• Causes– Antagonists

• Hemolysis precipitated by either injury to the RBC membrane or to denaturation of Hb

• Toxins, infectious agents

– Physical trauma• Hemolysis caused by physical injury to RBC

Antagonists: Infectious Agents• Parasites: Intracellular infections

• Malaria– Carried by mosquito– Release of the parasite from the cell causes cell lysis – Species of malaria include:

» Plasmodium vivax» P. faciparum - most fatal» P. malariae - uncommon» P. ovale - uncommon

– Peripheral smear examination will reveal intracellular parasites

• Babesiosis – Tick-borne– Peripheral smear examination will reveal intracellular parasites

Antagonists• Venoms– Some spiders contain enzymes that lyse the red cell

membrane (i.e Brown Recluse). Snake venoms rarely cause lysis directly.

• Burns– Burns over more than 15% of the body can cause

hemolysis. – Anemia occurs within 24-46 hours post-burn– It is thought that the direct effect of the heat on

spectrin, causes the red cells to fragment and burst.

Physical Injury or Trauma

• Intravascular and/or extravascular hemolysis

• Striking abnormal shapes of the circulating blood, such as fragments and helmut cells

Autoimmune Hemolytic Anemia

• Definition • Causes • Types • Antibody Characteristics• Types • lab Diagnosis

Definition

• It is defined as a group of hemolytic anemias that results from the development of auto-antibodies

• They are directed against the antigen on the surface of the patient’s own cell

Etiology

1. Breakdown of T-cell regulation for the B-cells2. Change in the structure of the antigens on

the red blood cells that recognized as non-self by the immune system

Etiology

3-It also depends on the efficiency of the destruction mechanism

4-The degree of anemia depends on the rate & acuteness of the destruction

5- Also on the capacity of the B.M to compensate

Antibody Characteristics

• Can be catagorized by Direct comb’s test (DCT) & it’s thermal range:

1. Immunoglobulin class: detected by monospecific AHG against IgG, IgM, IgA & C3c & C3d using DAT

2. Warm-acting antibodies: are most active at 375C invitro

• They are found to be polyclonal & predominantly IgG

Antibody Characteristics

• It has Rh blood group complex specificity

• In the serum Abs are detected using IAT

• The percentage of detecting will rise to 90% in enzyme treated cells

• They can also be eluted from the surface of red cells to determine their specificity

Antibody Characteristics

3. Cold acting antibodies• Predominantly are IgM most active at 45C to bind

the antigen

• Cold antibodies act as both agglutinins & lysins invitro with different thermal range.

Definition of Autoimmune Hemolytic Anemia

• Result from RBC destruction due to RBC autoantibodies: Ig G, M, E, A

• Most commonly-idiopathic• Classification– Warm AI hemolysis: Ab binds at 37degree Celsius– Cold AI Hemolysis: Ab binds at 4 degree Celsius

1.Warm AutoImmune Hemolytic Anemia– Can occurs at all age groups– F > M– Causes:• 50% Idiopathic• Rest - secondary causes:

1.Lymphoid neoplasm: CLL, Lymphoma, Myeloma2.Solid Tumors: Lung, Colon, Kidney, Ovary, Thymoma3. SLE, Systemic lupus erythematosus4.Drugs: Alpha methyl DOPA, Penicillin , Quinine,

Chloroquine

IMMUNOHEMOLYTIC ANEMIA

MACROCYTE

SPHEROCYTE

1.WARM AIHA

Lab Fingings1. Anemia, in which Hb varies with anemia 2. Reticulocytosis3. Spherocytosis4. +ve DCT (Direct comb’s test )This is the typical blood picture5. demonstrates microspherocyte, polychromatic

macrocyte & few schistocytes

Direct antiglobulin test demonstrating the presence of autoantibodies (shown here) or complement on the surface of the red blood cell.

complement

2. Cold AI Hemolysis– Usually Ig M– Acute or Chronic form– Chronic:

– Elderly patients – Cold , painful & often blue fingers, toes, ears, or

nose ( Acrocyanosis)

• Other causes of Cold Agglutination:– Infection: Mycoplasma pneumonia,Mononucleosis

Cold AIHA

Mainly induced by IgM that causes intravascular hemolysis due to it’s ability to fix complement.

Cold AIHA

• lab Diagnosis

- Autoagglutination ,shistocytes,- Reticulocytosis ,numerous spherocyes, -+ve DCT