nada mohamed ahmed, md, mt (ascp)i nada mohamed ahmed, md, mt (ascp)i
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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