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CC BY-NC-ND 4.0 · J Lab Physicians 2022; 14(03): 223-230
DOI: 10.1055/s-0041-1741442
Original Article

A Study of Clinical and Serological Correlation of Positive Direct Antiglobulin Test in Blood Bank at a Tertiary Care Center

Alisha Suresh Kerkar
1   Department of Transfusion Medicine, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
,
Swarupa Nikhil Bhagwat
1   Department of Transfusion Medicine, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
,
Jayashree Harihara Sharma
1   Department of Transfusion Medicine, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
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Funding None.
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Abstract

Objectives Detection of red cell bound immunoglobulins and/or complement by direct antiglobulin test (DAT) is a crucial serological assay in the diagnosis of autoimmune hemolytic anemia (AIHA). However, DAT may be positive in a variety of clinical conditions with or without hemolysis. We aimed at evaluating the clinical and serological correlation of positive DAT by categorizing the clinical conditions associated with positive DAT, estimating the presence of in vivo hemolysis in case of positive DAT with polyspecific and monospecific antisera and correlating the strength of positive DAT with the presence of hemolysis.

Materials and Methods The prospective observational study was performed on 200 samples that were positive for DAT with polyspecific antiglobulin reagent as the baseline investigation. These samples were further tested with anti-immunoglobulin G and anti-C3 monospecific DAT reagents to evaluate the type of protein responsible for positive DAT. The antiglobulin tests were performed by tube technique. DAT positivity was graded (1+ to 4 + ) in each patient. Autocontrol test was included. The patients with positive polyspecific DAT were categorized into different clinical conditions. The presence or absence of in vivo hemolysis was evaluated in all clinical categories and also for each grade of positivity with polyspecific and monospecific antiglobulin reagents.

Statistical Analysis Binomial logistic regression and Mann–Whitney U test were applied to between the group analyses. For categorical variables, Fisher's exact test and relative risk were used. The qualitative data were expressed in numbers and percentages.

Results The highest number of patients (75/200, 37.5%) belonged to the autoimmune diseases group. Tuberculosis and hepatitis C were the main infectious diseases associated with positive DAT. Out of 200 DAT-positive patients, 98 (49%) had in vivo hemolysis and 102 (51%) did not have hemolysis. AIHA (22) and systemic lupus erythematosus (18) were the commonest clinical conditions associated with in vivo hemolysis. All the 11 samples that showed positivity with only anti-C3 reagent did not show any hemolysis. There was statistically significant increase in the incidence of in vivo hemolysis with increasing grades of DAT positivity with all the three antihuman globulin reagents.

Conclusion There are different disease conditions which show positive DAT with or without hemolysis. So, it is important to clinically and serologically correlate positive DAT results.

Keywords

direct antiglobulin test - in vivo hemolysis - autoimmune hemolytic anemia - connective tissue disorders

Note

The study was presented at a CME at Kokilaben Dhirubhai Ambani Hospital, Mumbai on August 29, 2019.


Authors' Contribution

A.K. contributed in writing the introduction and methodology sections. S.B. contributed in writing the results, discussion, and bibliography sections. J.S. contributed in reviewing the article.


Ethical Approval

The study was approved by the Institutional Ethics Committee Seth GS Medical College and KEM Hospital, Mumbai as per letter: IEC (I)/OUT/1022/16.




Publikationsverlauf

Artikel online veröffentlicht:
18. Januar 2022

© 2022. The Indian Association of Laboratory Physicians. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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