Strength of Direct Antiglobulin Test as an Indicator of Disease Severity in Autoimmune Hemolytic Anemia

Sep 17, 2026

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Autoimmune hemolytic anemia (AIHA) is a rare disorder with limited epidemiological data. Appropriate diagnosis relies on laboratory findings showing anemia via low hemoglobin, evidence of hemolysis through elevated lactate dehydrogenase, and immune involvement via a positive direct antiglobulin test (DAT). This study evaluated AIHA incidence at a single institution and assessed correlations between DAT strength and disease severity. DAT strength correlated positively with severity and negatively with hemoglobin, while age related to AIHA type depending on DAT strength. Findings support further DAT evaluation as a severity indicator and possible clinician-oriented flagging.

LanguageEnglish

CategoryResearch & Report

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Pages6

Reading Time15 min

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Abstract

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Materials and Methods - Sample

RESEARCH AND REPORTS Strength of Direct Antiglobulin Test as an Indicator of Disease Severity in Autoimmune Hemolytic Anemia HERVÉ NYENTI, RAJKUMAR RAJENDRAN, JULIE SODER, CAROL A . CARMAN, JUAN U . ROJO ABSTRACT Autoimmune hemolytic anemia (AIHA) is a rare disorder for which epidemiological studies are limited. Proper diagnosis of AIHA is supported by clinical laboratory data that demonstrate all aspects of the disease including evidence of anemia by low hemoglobin (Hb), indication of hemolysis by elevated lactate dehydrogenase, and demonstrating involvement of the immune system by a positive direct antiglobulin test (DAT) . The purpose of this study was to investigate the incidence of AIHA at our institution and establish a correlation between DAT strength of reaction and AIHA disease severity. Here, we identiﬁed that AIHA is more prevalent among children and patients ages 61 to 70 years old that are female and Caucasian/White Hispanic. A positive correlation between DAT strength and disease severity was observed, and a negative correlation between DAT strength of reaction and Hb was identiﬁed. Our ﬁndings also showed a positive correlation between age and AIHA type that is dependent on DAT strength. The results from this study propose the further evaluation of DAT as a laboratory value that can indicate severity of the disease and possibly implementing a ﬂag value for DAT when communicating results to clinicians. ABBREVIATIONS: AIHA-autoimmune hemolytic anemia, DAT - direct antiglobulin test, Hb - hemoglobin, ICD International Classiﬁcation of Diseases, LDH-lactate dehydrogenase, RBC - red blood cell, wAIHA - warm autoimmune hemolytic anemia. INDEX TERMS: direct antiglobulin test (DAT), autoimmune hemolytic anemia (AIHA), hemoglobin (Hb), lactate dehydrogenase (LDH), epidemiology, disease severity, autoimmunity. Hervé Nyenti, University of Texas Medical Branch Rajkumar Rajendran, University of Texas Medical Branch Julie Soder, University of Texas Medical Branch Carol A. Carman, University of Texas Medical Branch Juan U. Rojo, University of Texas Medical Branch Address for Correspondence: Juan U. Rojo, University of Texas Medical Branch, [jurojo@utmb.edu](jurojo@utmb.edu) Clin Lab Sci 2024;00(0):1–6 INTRODUCTION Autoimmune hemolytic anemia (AIHA) is a rare disease whose epidemiology is not well deﬁned. Studies conducted in Denmark and France estimate the incidence of AIHA at 1.77 per 100 000 individuals and 2.44 per 100 000 individuals, respectively.1-3 This disease is characterized by decompensated acquired hemolysis as the result of the immune system acting against its own red blood cell (RBC) antigens, leading to their destruction.4 The breakdown of RBCs is usually driven by autoantibodies and/or complement that binds to surface antigens and, together with macrophages, T lymphocytes, and cytokines, marks them for removal from the body. AIHA is classiﬁed according to serological types depending on the type of antibody involved and temperature phase at which the antibodies react.5 The serological types include warm AIHA (wAIHA), cold agglutinin disease, paroxysmal cold hemoglobinuria, and mixed-type AIHA. There is also a subset of atypical direct antiglobulin test (DAT)-negative AIHA cases.6,7 The disease can be primary, in which diagnosis can only be made when there is no other apparent cause of hemolysis, or it can be secondary due to the presence of underlying disease, such as lymphoproliferative and autoimmune disorders, immunodeﬁciencies, infections, and tumors. Diagnosis of AIHA is usually conﬁrmed using a combination of laboratory evidence of hemolysis, with demonstration of immune system involvement, and clinically via symptomatic anemia.8 Laboratory evidence of hemolysis is established by the presence of anemia by low hemoglobin (Hb) and indices of hemolysis, mainly elevated lactate dehydrogenase (LDH), haptoglobin, and bilirubin. In clinical practice, these hemolysis indices are usually eva

FAQs

What was the main purpose of the study?

To investigate AIHA incidence at the institution and determine how DAT strength of reaction correlates with AIHA disease severity.

Which correlations were observed between DAT strength and clinical indicators?

DAT strength showed a positive correlation with disease severity and a negative correlation with hemoglobin (Hb).

How was the AIHA patient population analyzed in terms of demographics and disease type?

The study examined demographic distribution and found age was positively correlated with AIHA type depending on DAT strength.

Sep 17, 2026

Uploaded by Ophelia