Autoimmune hemolytic anemia

Autoimmune hemolytic anemia

1. AUTO IMMUNE HEMOLYTIC ANEMIA CHAIR PERSON:DR SACHIN HOSKATTI STUDENT: AKSHATHA K

2. H EMOLYTIC A NEMIA  Definition:  Those anemias which result from an increase in RBC destruction coupled with increased erythropoiesis  Classification:  Congenital / Hereditary  Acquired

3. CLASSIFICATION OF HEMOLYTIC ANEMIAS INTRACORPUSCULAR EXTRACORPUSCULAR DEFECTS FACTORS HEREDITARY •HEMOGLOBINOPATHIES •ENZYMOPATHIES •MEMBRANE- CYTOSKELETAL DEFECTS •FAMILIAL HEMOLYTIC UREMIC SYNDROME ACQUIRED •PAROXYSMAL •MECHANICAL DESTRUCTION NOCTURNAL [MICROANGIOPATHIC] HEMOGLOBINURIA •TOXIC AGENTS •DRUGS •INFECTIOUS •AUTOIMMUNE

4. C LASSIFICATION Intravascular hemolysis  MAHA  Transfusion rx  PNH  Infections  Snake bite Extravascular hemolysis  Hemoglobinopathies  Enzymopathies  Membrane defects  AIHA

5. H OW TO DIAGNOSE HEMOLYTIC ANEMIA  New onset pallor or anemia  Jaundice  Splenomegaly  Gall stones  Dark colored urine  Leg ulcers

6. GENERAL FEATURES OF HEMOLYTIC DISORDERS  GENERAL EXAMINATION - JAUNDICE, PALLOR BOSSING OF SKULL  PHYSICAL FINDINGS  HEMOGLOBIN  MCV  RETICULOCYTES  BILIRUBIN  LDH  HAPTOGLOBULIN - ENLARGED SPLEEN - FROM NORMAL TO SEVERELY REDUCED - USUALLY INCREASED - INCREASED - INCREASED[MOSTLY UNCONJUGATED] - INCREASED - REDUCED TO ABSENT

7. H EMOLYTIC FACIES - CHIPMUNK FACIES

8. Laboratory Evaluation of Hemolysis Extravascular Intravascular HEMATOLOGIC Routine blood film Reticulocyte count Bone marrow examination PLASMA OR SERUM Polychromatophilia Erythroid hyperplasia Polychromatophilia Erythroid hyperplasia Bilirubin Unconjugated Unconjugated Haptoglobin , Absent Absent Plasma hemoglobin N/ Lactate dehydrogenase (Variable) (Variable) URINE Bilirubin + + Hemosiderin + Hemoglobin +  severe cases

9. Case scenario 1 A young male patient who is a soldier presented with complaints of passage of dark urine immediately following physical exertion in the upright position, occasionally accompanied by nausea, abdominal cramps, aching in the back or legs, a “stitch in the side,” or a burning feeling in the soles of the feet . Physical examination is transient jaundice usually unrevealing, hepatosplenomegaly and transient jaundice have been rarely reported

10. Post exercise, his urine sample was reddish brown in color with a specific gravity of 1.030, pH 5.5, 1+ protein, 3+ blood, 0 to 2 RBC/high powered field (HPF) and 0 to 2 white blood cells/HPF. His urine microscopy revealed 1 to 2 RBC/ HPF.

11. MARCH HEMOGLOBINURIA (Intravascular hemolysis )

12. Immune hemolytic anemia: When erythrocytes are destroyed prematurely by an immune mediated process (antibody and/or complement), the disorder is referred to as an immune hemolytic anemia(IHA). Autoimmune hemolytic anemia Drug-induced hemolytic anemia Alloimmune hemolytic anemia

13. AUTOIMMUNE DRUG INDUCED ALLOIMMUNE Warm-reactive antibodies Primary or idiopathic Secondary 1. Autoimmune disorders (SLE,RA, and others) 2. Chronic lymphocytic leukemia and other immunoproliferative diseases 3. Viral infections 4. Neoplastic disorders 5. Chronic inflammatory diseases Cold-reactive antibodies Primary or idiopathic (cold hemagglutinin disease) Secondary 1. Infectious diseases ( mycoplasma pneumoniae , EBVand other organisms) 2. Lymphoproliferative disorders 3. Paroxysmal cold hemoglobinuria Mixed - type Drug adsorption Immune complex Autoantibody induction Membrane modification Hemolytic transfusion reaction Hemolytic disease of the fetus and newborn

14. CLINCAL SCENARIO 2 Zohra begum,40yrs,female Chief complaints: yellowing of skin,fatigue since 5 months,ulcer at back since 3 months On examination:pallor+,icterus + P/A examination splenomegaly + Other systemic examination normal I/V: Retic count :3.6% LDH:1062U/L DIRECT COOMB’S + ANA +

15. Autoimmune hemolytic anemia

16. Autoimmune hemolytic anemia AIHA is a complex and incompletely understood process characterized by an immune reaction against self-antigens and shortened erythrocyte survival . Individuals produce antibodies against their own erythrocyte antigens ( autoantibodies ). The autoantibodies characteristically react not only with the erythrocytes of the individual but also with the erythrocytes of other individuals carrying the antigen.

17. SITES AND FACTORS THAT AFFECT HEMOLYSIS Hemolysis can be intravascular or extravascular Erythrocytes sensitized with antibody or complement components attach to macrophages in the spleen or liver via macrophage receptors for the Fc portion of immunoglobulin or the C3b component of complement. These cells are then phagocytized . Intravascular hemolysis occurs if the complement cascade is activated through C9 (the membrane attack complex). INTRAVASCULAR EXTRAVASCULAR

18. Mechanism of hemolysis IgG - Mediated Hemolysis Complement Mediated Hemolysis IgM-Meddiated Hemolysis

19. IgG – Mediated Hemolysis

20. IgG mediates erythrocyte destruction by first attaching to the erythrocyte membrane antigens through the Fab portion of the Ig molecule. Fc receptors on macrophages in the red pulp of the spleen bind to the Fc portion of the attached IgG After binding, the macrophage pits the antigen antibody (Ag/ Ab ) complex, fragmenting the cell membrane spherocyte RIGID LESS DEFORMABALE Phagocytosed by splenic macrophages

21. Complement mediated hemolysis

22. IgM MEDIATED HEMOLYSIS Macrophages doesn’t have receptors for Fc portion IgM IgM is efficient activator of complement EXTRAVASCULAR: - complement activation incomlete - C3b coats RBCs and sensitised cells destroyed extravascularly via CR1 and CR3 receptors on macrophages IgM can agglutinate cells in addition to activating complement.

23. LABORATORY IDENTIFICATION OF SENSITIZED RED CELLS When immune hemolytic anemia is suspected, tests to detect and identify the causative antibody are indicated. In general, two distinct techniques are used: • Agglutination in saline, which will detect antibodies of the IgM class • Antihuman globulin (AHG) test, which will detect antibodies of the IgG class and/or complement

24. Antihuman globulin test: IgM antibodies can be detected by agglutination reactions between test sera and appropriate erythrocytes suspended in saline. Erythrocytes Zeta potiential (25nm) Direct: detects erythrocytes coated with antibody in vivo Indirect: detects antibodies in the plasma or serum

25. WARM AUTOIMMUNE HEMOLYTIC ANEMIA Most common form of AIHA (70% of cases) Incidence-1/50,000 -75,000 Mediated by IgG antibodies whose maximal reactivity is at 37°C. • Primary or idiopathic: no underlying disease • Secondary: underlying disease present • Lymphoproliferative disease • Neoplastic diseases • Autoimmune disoders • Viral and bacterial infections • Vaccinations

26. Diseases or Conditions Associated with Warm Autoimmune Antibodies Autoimmune disorders   Systemic lupus erythematosus   Rheumatoid arthritis   Scleroderma   Ulcerative colitis    Antiphospholipid antibodies Lymphoproliferative disorders   Chronic lymphocytic leukemia   Acute myelocytic leukemia   Hodgkin lymphoma   Non-Hodgkin lymphoma    Waldenström macroglobulinemia   Other lymphoproliferative disorders   Multiple myeloma

27. Other neoplastic disorders    Thymoma   Ovarian dermoid cyst    Teratoma   Kaposi sarcoma   Carcinoma Viral infections   Epstein-Barr virus   Hepatitis C virus   HIV/AIDS Other   Diphtheria- pertussis -tetanus vaccinations   Pregnancy   Bone marrow transplantation   Congenital immune deficiency states    Hypogammaglobulinemia    Dysglobulinemia

28. Antibody Characteristics Immunochemistry and Origin Most antibodies are IgG (IgG1>IgG3) Blood Group Specificity Warm autoantibodies are panagglutinins Rh is the most common (70%), Other blood group include Wright ( Wr b ), En a , Duffy ( Fy b ), Gerbich ( Ge ), Kidd ( Jk a ), Kell (K), Lutheran (Lu), LW, M, N, S, Pr, A, B, I T , Sc3, U, Vel , and Xg a .

29. Pathophysiology The warm autoantibody in AIHA is reactive with antigens on the patient’s erythrocytes. Specificity of the antibody is directed against antigens of the Rh system. Most hemolysis in WAIHA is extravascular via splenic macrophages. If both antibody and complement are on the cell membrane, phagocytosis is enhanced. Direct complement- mediated intravascular hemolysis associated with IgM antibodies in warm AIHA is rare.

30. CLINICAL FEATURES : Idiopathic AIHA: Progressive weakness, Dizziness, Dyspnea on exertion, Back or abdominal pain, Jaundice. Secondary AIHA: patient can present with signs and symptoms of both the underlying disease and hemolysis or just the disease.

31. Laboratory Findings Associated with WAIHA Common findings Other laboratory findings that can be associated with hemolysis in WAIHA Positive DAT Normocytic , normochromic anemia Increased reticulocytes Spherocytes and other erythrocyte abnormalities Presence of autoantibody in the serum Increased serum bilirubin (total and unconjugated ) Decreased serum haptoglobin Positive antibody screen with all cells including autocontrol Incompatible crossmatches with all donors Increased osmotic fragility Increased urine and fecal urobilinogen Hemoglobinemia ,* hemoglobinuria , methemoglobinemia , hemosiderinurea

32. Therapy: CORTICOSTEROIDS: Glucocorticoids are the initial therapy of choice for warm AIHA Dose:1.0 to 1.5 mg/kg or 40 mg/m 2 /day of prednisone or its equivalent. Response: noticeable by 7 days. Tapering: Rapid responders can reduce their dose by 50% over 4 to 6 weeks, tapering should proceed more slowly over 3 to 4 months

33. SPLENECTOMY Splenectomy is indicated in those surgical candidates who have not responded to prednisone, And who requires prednisone doses >10-20 mg/day to maintain remission, or Intolerable side effects.

34. IMMUNOSUPPRESSIVE THERAPY Immunosuppressive regimen might include

35. Rituximab : is a chimeric human/ murine monoclonal anti-CD20 antibody Mycophenolate mofetil : Doses begin at 1 g/day and are then increased to 2 g/day . Cyclosporine A: Doses of 3 mg/kg/day with target serum levels of 200–400 ng /ml

36. Other Therapies Intravenous immunoglobulin (IVIG) has not enjoyed the success in AIHA that it has in immune thrombocytopenia. Escalating the dose from the standard 0.4 g/kg/day (× 5 days) to 1.0 g/kg/day may be helpful. Plasmapheresis

37. COLD AUTOIMMUNE HEMOLYTIC ANEMIA (AIHA) Cold AIHA, also termed cold agglutinin disease (CAD), is associated with an IgM antibody that fixes complement and is reactive below 37°C. This disorder, which comprises 16–30% of the AIHAs IgA and IgG antibodies rarely have been implicated in hemolysis in CAD

38. Antibody Characteristics Immunochemistry and Origin : Cold agglutinins are IgM . Specificity for the I antigen: I antigen-90% i antigen-10% Adult RBCs are used to detect anti-I agglutinins and cord RBCs are needed to detect anti- i agglutinins. M. pneumoniae induces anti-I antibodies in the majority of patients is potentially related to the finding that sialylated I/ i antigens serve as specific Mycoplasma receptors

39. Secondary Cold Agglutinin Disease Secondary Cold Agglutinin Disease Neoplasms    Waldenstrom macroglobulinemia    Angioimmunoblastic lymphoma   Other lymphomas   Chronic lymphocytic leukemia   Kaposi sarcoma   Myeloma    Nonhematologic malignancy (rare) Infections    Mycoplasma pneumoniae   Mononucleosis (Epstein-Barr virus)   Adenovirus   Cytomegalovirus   Encephalitis   Influenza viruses   Rubella

40.   Rubella    Varicella   Human immunodeficiency virus   Mumps    Ornithosis   Legionnaires disease   Escherichia coli    Subacute bacterial endocarditis    Listeriosis   Syphilis    Trypanosomiasis   Malaria Other   Autoimmune diseases   Tropical eosinophilia

41. Pathophysiology : The severity of CAD is related to the thermal range of the antibody(up to 32%) I antigen specificity Cold-reacting antibody is usually directed against the I antigen. The second most common specificity for cold autogglutinins is anti-Pr.1.

42. CLINICAL FEATURES Mild, chronic hemolytic anemia with exacerbations in the winter. and jaundice may occur if the rate of hemolysis is greater than the endogenous capability to metabolize bilirubin . Intermittent bursts of hemolysis associated with hemoglobinemia and hemoglobinuria on exposure to cold. Acrocyanosis can occur from agglutination of RBCs in the cooler vessels of the hands, ears, nose, and feet. Digits may become cold, stiff, painful, or numb and may turn purplish Chronic CAD patients have mild splenomegaly or hepatomegaly

43. THERAPY The most effective therapy is usually achieved by keeping the individual’s extremities warm. Chemotherapy using cyclophosphamide or chlorambucil can be instituted(Underlying lymphoproliferative disease) Plasma exchange. Rituximab has been used as treatment in both primary and secondary disease. Chlorambucil , beginning with 2 to 4 mg/day and increasing by 2 mg every 2 months Pulse therapy with cyclophosphamide (250 mg/day) and prednisone (100 mg/day × 4 days) every 2 to 3 weeks

44. Case scenario 3 A four-year-old male presents to the emergency department with a history of six days of fever and acute onset of red colored urine. There has been no recent travel. He was seen by his Doctor approximately five days ago for evaluation of cough and rhinorrhea and was prescribed Antibiotics for an ear infection.No h/o dysuria , bloody stools, hemoptysis , or epistaxis . He has no increased bruising, no petechiae , and no extremity pain. He has been having intermittent fevers for three days. Physical Exam: (+) scleral icterus , (+) jaundice, (+) soft flow murmur on cardiac exam. Physical exam is otherwise normal.

45. Labs: Initial hemoglobin 10.4 g/ dL --& gt ; decreased to 6.3 g/ dL 12 hours later, Platelets 153,000 cells/UL, Reticulocyte count 0.4%, White blood cells 11.1 x10 3 cells Coagulation studies normal. Liver function test are normal. LDH is 5056 Units/ml, Haptoglobin 12 mg/ dL (low). Unconjugated bilirubin is 3.7 mg/ dL , Conjugated bilirubin is 1.2 mg/ dL . Electrolytes are all within normal limits. Viral panel is pending. DAT: IgG , C3 (+). Urinalysis: dark, red-brown urine, 3+ blood, 3+ protein, 0-4 RBCs/ hpf , 0-4 WBCs/ hpf , urobilinogen >8mg/ dL .

46. PAROXYSMAL COLD HEMOGLOBINURIA Characterized by massive intermittent acute hemolysis and hemoglobinuria . Can occur at any age ,frequently seen in children less than 5 years. The infections linked to PCH include Epstein-Barr virus, Cytomegalovirus, Measles, mumps, Heamophilus influenzae , Klebsiella pneumoniae . Parvovirus 19, Onset : 5 days to 3 weeks after onset of the infection

47. Pathophysiology Donath -Landsteiner (D-L) antibody. Biphasic refers to the two temperatures necessary for optimal lysis of the erythrocytes. The antibody reacts with erythrocytes in the capillaries at temperatures less than 20°C and avidly binds the early acting complement components. The antibody molecule disperses from the cell, but the membrane attack complement components are activated on the cell membrane causing cell lysis . TEMP <20°C TEMP @37°C

48. Clinical Findings Hemoglobinuria Jaundice Pallor Hepatosplenomegaly Raynaud’s phenomenon

49. LAB INVESTIGATIONS Neutropenia . Reticulocytopenia . Serum bilirubin , BUN, and LD are elevated Serum complement and haptoglobin are decreased. DAT with anticomplement antisera :Weakly positive. IAT can be positive if performed in the cold D-L antibodies :low titres(1:32)

50. therapy PCH associated with acute infections terminates upon recovery from the infection. Steroids are not usually helpful. Transfusion can be required if the hemolysis is severe. In rare cases when the hemolysis persists, plasmapheresis can be used. Rituximab (anti-CD20) has also been used as therapy

51. MIXED-TYPE AIHA Mixed-type AIHA is characterized by the presence of a warmreacting IgG autoantibody and a cold-reacting IgM autoantibody that has both high titer and increased thermal amplitude. About 50% of the cases are idiopathic. Associated with diseases such as systemic lupus erythematosus , lymphoma, and HIV. Patients usually respond well to treatment with corticosteroids and do not require transfusion. Rituiximab has been used in cases with underlying lymphoproliferative disease

52. DRUG-INDUCED HEMOLYTIC ANEMIAS It is recognized that certain drugs can cause immune cytopenias that involve one or several cell lines including neutrophils , platelets, and erythrocytes. Three classic hypotheses • Drug absorption • Immune complex formation • Autoantibody induction

53. Case scenario 32 yr old presented 4 days history of distention of abdomen and rt hypochondrial pain and has h/o passage of dark colored urine at night for weeks  On USG- hepatomegaly,gross ascites,hepatic vein thrombosis Lab : Hb – 7gm%. WBC- 2200, PLC- 80,000 LDH- 600, S.BR- 4 mg% urine bile pigment +, heme dip stick++ What is the diagnosis

54. Case scenario 14 YR old female present with anemia, jaundice Rt hypochondrial pain o/e-vitals stable.pallor+,icterus+,splenomegaly + Usg - cholilithiasis Lab; elevated ,LDH, S.Bilirubin Peripheral smear shows

55. Case scenario 25 yr old male with RHD – severe MR done MVR,after 10 days presented with pallor, palpitation,jaundice CBC shows Hb – 7.5 gm %, Hct -22 % Lab : S.bilirubin -4.5mg% LDH -600 Retic count 10% Peripheral smear –

56. References: Wintrobe’s Clinical Hematology 12th Edition Williams Hematology 9E Harrison’s principles of Internal Medicine Pearson New International Edition Clinical Laboratory Hematology Shirlyn B. McKenzie Second Edition

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