False Positive Result of the Direct Antiglobulin Test (DAT): The Role of the Elevated Level of Immunoglobulin G

Bıçakçı, Zafer; Öztürkmen, Seda; Akyay, Arzu; Olcay, Lale

doi:10.3109/08880018.2012.695440

Cited by 10 publications

(4 citation statements)

References 15 publications

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“…It is important to remember that a DAT test may be positive in many conditions other than the presence of autoantibody including intravenous administration of immunoglobin G (IgG), patients with neonatal hemolytic disease, bone marrow transplantation, administration of some drugs, infections, acute and chronic leukemia and is rarely positive in healthy individuals. [ 11 ] We assumed the presence of autoantibody in patients with positive DAT result since the prevalence of the abovementioned conditions was quite rare in our study population. However, definitive identification of an autoantibody requires that all DAT positive samples are subjected to the elution process, and the eluted antibody is subsequently identified using a panel of reagent RBCs.…”

Section: Methodsmentioning

confidence: 99%

Study of alloimmunization and autoimmunization in Iranian β-thalassemia major patients

Davari

Soltanpour

2016

Asian J Transfus Sci

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Background:Thalassemia is one of the most common monogenic disorders characterized by reduced production of globin chains. Although regular red blood cell (RBC) transfusion support is the main treatment for these patients, it may be associated with complications such as RBC alloimmunization.Aim:The study aimed to determine the incidence of alloimmunization and autoimmunization to RBC antigens in β-thalassemia major patients from Zanjan, Zanjan Province, Iran.Materials and Methods:A total of 49 β-thalassemia major patients comprising 24 females and 25 males (mean age: 18.59 ± 8.16 years; range: 2-40 years) from Northwest Iran were included in a cross-sectional study. Alloantibody screening and identification were done using 3-cell and 10-cell reagent red blood cells, respectively. Autoantibody detection was performed using direct Coomb's test.Results:The incidence of alloimmunization was 16.32% with 10 alloantibodies identified in 8 patients. The most common clinically significant alloantibody identified in alloimmunized patients was anti-Kell (K-antigen) (60%) followed by anti-Rhesus (Rh) (E, c-antigens). The rate of alloimmunization was significantly lower in patients transfused with leukoreduced RBCs compared with those transfused with nonleukoreduced RBCs (9.53% vs 57.14%, P = 0.001). There was no significant correlation between alloantibody formation and the age, gender, hemoglobin levels, number of transfused units, and splenectomy.Conclusion:Transfusion of leukoreduced and phenotypically matched red blood cells for Kell (K) and Rh (E, c) antigens may help reduce the alloimmunization rate in Iranian β-thalassemia major patients. Moreover, autoimmunization to RBC antigens was rare in our patients.

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Section: Methodsmentioning

confidence: 99%

Study of alloimmunization and autoimmunization in Iranian β-thalassemia major patients

Davari

Soltanpour

2016

Asian J Transfus Sci

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“…In patients with a higher level of IgG, the treatment of the concomitant disease resulted in normalization of the IgG level and led to a negative DAT test. 18 Tuberculosis is known to be associated with polyclonal gammopathy. This could be the cause for positive DAT.…”

Section: Discussionmentioning

confidence: 99%

Untitled

2022

J Lab Physicians

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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 MethodsThe 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 (1þ to 4 þ ) 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 DATwith or without hemolysis. So, it is important to clinically and serologically correlate positive DAT results.

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“…Alternatively, false‐positive DAT can be generated in conditions such as viral infections, immunodeficiency, chronic leukemia, lymphomas, and intravenous administration of immunoglobulins. An incidence of 1/1000–1/36 000 DAT‐positive tests among healthy blood donors has been reported . To control for false‐positive results, in this study we included a group of ‘control patients’ who are donors with diseases that predispose to AIHA, but did not have evidence of hemolysis in vivo .…”

Section: Discussionmentioning

confidence: 99%

Simultaneous detection of IgG, IgM, IgA complexes and C3d attached to erythrocytes by flow cytometry

Alzate

Manrique

Bolaños

et al. 2014

Int J Lab Hematology

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False Positive Result of the Direct Antiglobulin Test (DAT): The Role of the Elevated Level of Immunoglobulin G

Cited by 10 publications

References 15 publications

Study of alloimmunization and autoimmunization in Iranian β-thalassemia major patients

Study of alloimmunization and autoimmunization in Iranian β-thalassemia major patients

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Simultaneous detection of IgG, IgM, IgA complexes and C3d attached to erythrocytes by flow cytometry

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