AUTOIMMUNE HEMOLYTIC ANEMIA - LABORATORY PREDICTERS OF CLINICAL OUTCOME, RESPONSE AND PROGNOSIS DR.SANOOJA PINKI 1, DR .MATHEW THOMAS2 (1.Dept of Transfusion Medicine 2. Dept. of Clinical Hematology) KERALA INSTITUTE OF MEDICAL SCIENCES, TRIVANDRUM, KERALA

BACKGROUND Heterogeneous group of disorders characterized by autoantibody mediated destruction of red blood cells (RBCs) A positive DAT with no other obvious cause of hemolysis- clinical hallmark Degree of hemolysis-quantity, specificity, thermal amplitude, complement activation and bind tissue macrophages PRBC Transfusion - severity of hemolysis, progression of anemia & clinical findings

AIMS & OBJECTIVES To analyze the trends in pre transfusion testing of AIHA cases To find the association between DAT strength and in vivo hemolysis To find the effect of PRBC transfusions in the patient outcome

Prospective study, Sample size- 26 METHODOLOGY 12 MONTHS Prospective study, Sample size- 26 Clinical and laboratory evidence of hemolysis with positive DAT & AC in first presentation IAT ANTIBODY SCREENING & IDENTIFICATION BLOOD GROUPING DISCREPANCY DAT IN CTT MONOSPECIFIC DAT RESOLUTION SENSITISATION EVENT ADSORPTION-ELUTION STUDIES

Severity of Hemolysis-Classification Laboratory parameters taken to describe the severity of hemolysis are: Hemoglobin <9 g/dl Percentage of reticulocyte >2% Total serum Bilirubin >2mg/dl LDH >500 IU/ml Ref: Wikman et al ; characterization of red cell autoantibodies in consecutive DAT positive patients with respect to invivo hemolysis Ann hematol 84, 150-158 SEVERE HEMOLYSIS – 4 out of 4 MODERATE HEMOLYSIS- 2/3 out of 4

TRANSFUSION Given to patients who showed clinical manifestations of chronic anemia Slow transfusion of best compatible unit under close monitoring Once diagnosed, IV methyl prednisolone (1 mg/kg) along with immunosuppressants were started for 5 to 7 days Number of cross matches, No : of transfusions, C/T ratio Mean hemoglobin increment Transfusion reactions Response to treatment were also assessed 24 hours post transfusion as well as at discharge

STATISTICAL TOOLS Data collected will be tabulated using MS Excel and analysed using SPSS version 16.0. Categorical variables are represented using frequencies and percentages. Continuous variables are reported using mean and SD. Association between categorical variables were analysed using Chi square test. A p value was calculated to understand the significance level

RESULTS No drug was incriminated as a cause of hemolysis 26 AIHA 812 REQUESTS 183 POSITIVE No drug was incriminated as a cause of hemolysis 1 had direct hyperbilirubinemia due to obstructive jaundice 1 had thromboembolic complication-ruled out APLA

MC Clinical presentation on Admission Parameters values Mean Age 48 (2-80) Male: Female 1 :1.6 MC Clinical presentation on Admission Fatigue( 34.6 %) >dyspnea (20 %) Severity Severe (39%), moderate( 61%) Mean hemoglobin at presentation (g/dl) Severe : 4.9 (3.2-8.4) Moderate : 7.1 ( 5.6-8.7) Type of AIHA Secondary 61% > primary(39) Secondary % SLE & RA 40 Evans 20 infections Carcinoma 6.6 CAS 13.4

TYPE OF AUTOANTIBODIES - frequency

PATTERN OF PRE TRANSFUSION TESTING BLOOD GROUPING Most common discrepancy was Type 1V Association between cold AIHA and grouping discrepancy (p <0.001) 81.3 % resolved by prewarming 18.7 % resolved by cold auto adsorption 36 % WAIHA 36 % MIXED RESOLUTION 28 % CAD Blood grouping was performed in column agglutination technology (Ortho vision), discrepant samples were repeated in tube method and resolved

DAT – CAT VS CTT DAT ALONE POSITIVE : 34.6 % ; n=9 DAT ALONG WITH IAT POSITIVE : 65.4% , n=17 76.5% (13/17)– had history of sensitization event; so adsorption elution was performed, to differentiate autoantibody from underlying alloantibody. 15.3 % (2/13) showed the presence of alloantibody anti c, anti e 15.3 % (2/13) showed autoantibody with specificity –auto anti c and auto anti c, e 69.4 % showed autoantibody with no alloantibody or specificity DAT – CAT VS CTT 84.6% had CAT GRADE > CTT GRADE 15.4% had CAT GRADE = CTT GRADE There was one case where CAT is positive(3+ grade) and CTT is negative SENSITIVITY of CTT is 96 .4% whereas 100 % with CAT

DAT STRENGTH * INVIVO HEMOLYSIS

TRANSFUSION SUPPORT 19 out of 26 required Transfusion All severe patients required transfusion(p=0.001) Total 174 crossmatches 48 best compatible units 35 units taken for transfusion Mean TAT-4 hours 5 minutes (excluding alloantibody cases) Mean Hb increament after 1st txn is 0.99g/dL; 2nd-1.1g/dL (n=5) No HTR 1FNHTR was reported C:T =4.94 (Auto antibodies alone) Average PRBC transfusion is 1.58/patient

Mean hospital stay is 5.5 days (idiopathic) Effect of PRBC transfusion P=0.05 Mean hospital stay is 5.5 days (idiopathic)

Discussion Most common Grouping discrepancy was type IV Extra reactions in the serum grouping is due to the free antibodies in serum after binding to autologous RBCs Association between cold AIHA and blood group discrepancy can be explained by 90% of cold agglutinins are IgM by nature and produce spontaneous agglutination We observed CAT to be a good alternative to CTT in terms of sensitivity of 100% Hence its better to repeat the DAT in CAT technology, if the patient is having clinical and laboratory evidence of hemolysis and negative DAT in CTT

15.3 % of the patients developed alloantibodies supports the evidence that , approximately 12 - 40 % of patients with previous sensitization can develop clinically significant alloantibodies 2 patients had autoantibody with specificity– auto anti c,e & auto anti e Supports the finding that, nearly 50% of all AIHA patients have autoantibodies specific for epitopes on Rh proteins We have observed a significant correlation between DAT strength and in vivo hemolysis Grade 4 + reaction being associated with high incidence of severe hemolysis This supports the assumption that the concentration of antibodies is important for the recognition of reticulo endothelial system and in vivo hemolysis

Mean Hb increment after each PRBC transfusion is 0.99; Various studies reported Hb increments ranging from 1.40–1.70 g/dL Implies that Serological incompatibility does not necessarily mean that the RBC will be destroyed in vivo The efficacy of blood transfusion may be explained by the natural limitation of Fc- and C3b-mediated phagocytosis (Ref: Taluk Dar et al) Our CT ratio was 4.9, comparable to that of Das et al (6.4) could be due to the increased number of crossmatches to get a best compatible unit High turn around time of PRBC issue can be attributed to the time taken to resolve the blood group discrepancy as well as to get a best compatible unit

CONCLUSION DAT strength had a correlation with disease severity Performing the serological investigations at the earliest may help in the early diagnosis and management Transfusion support should not be denied to any patient because of serological incompatibility Institutional policy should be made for the transfusion support of AIHA patients