Diagnostic Value of Serological Tests (IgA, IgG, IgM) Against A-60 Antigen in Tuberculosis

authors:

avatar keyghobad ghadiri 1 , * , avatar Babak Izadi 1 , avatar Mandana Afsharian 1 , avatar Siavash Vaziri 1 , avatar Mansour Rezaei 1 , avatar Sohbatollah Namdari 1

Infection Disease Research Center, Kermanshah University of Medical Sciences, Kermanshah, IR Iran

how to cite: ghadiri K, Izadi B, Afsharian M, Vaziri S, Rezaei M, et al. Diagnostic Value of Serological Tests (IgA, IgG, IgM) Against A-60 Antigen in Tuberculosis. Arch Clin Infect Dis. 2008;3(4):e93396. 

Abstract

Background: Tuberculosis (TB) is a common infectious disease worldwide especially in developing countries. Diagnosis of TB is difficult and often needs paraclinical studies. Measuring immunoglobulin's against A-60 antigen of TB microorganism has been reported as a useful technique. The aim of the present study was to evaluate the diagnostic value of serologic test (IgA, IgM, IgG) against A-60 antigen in tuberculosis.
Patients and methods: For this case-control study, 176 TB patients (124 patients with smear-positive pulmonary TB and 52 patients with extra pulmonary TB) and 283 healthy controls were enrolled. Then, all subjects were tested for IgM, IgA and IgG against A-60 antigen using ELISA technique.
Results: Sensitivities of IgM, IgG and IgA test were 15%, 25% and 40%, respectively while the following specificities were also reported 100%, 75% and 90%, respectively. Positive predictive values (PPV) were 100%, 57% and 72%, however, negative predictive values (NPV) were 65%, 72% and 70%, respectively. Combination of immunoglobulins' results increased sensitivity, for which the most sensitivity was observed in combination of IgG and IgA results.
Conclusion: Our results revealed the usefulness of serologic testing in TB diagnosis. Although its sensitivity is not high enough, combination of immunoglobulin results may improve the sensitivity.

References

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