1. 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

2. 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

3. 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

4. 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

5. 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,
SEVERE HEMOLYSIS – 4 out of 4
MODERATE HEMOLYSIS- 2/3 out of 4

6. 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

7. STATISTICAL TOOLS
Data collected will be tabulated using MS Excel and analysed using SPSS version
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

8. 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

9. 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 ( )
Moderate : 7.1 ( )
Type of AIHA
Secondary 61% > primary(39)
Secondary %
SLE & RA 40
Evans 20
infections
Carcinoma
6.6
CAS
13.4

10. TYPE OF AUTOANTIBODIES - frequency

11. 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

12. 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

13. DAT STRENGTH * INVIVO HEMOLYSIS

14. 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

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

16. 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

17. 15.3 % of the patients developed alloantibodies
supports the evidence that , approximately % 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

18. 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

19. 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