Diagnostic value of serum IgG by Eliza to detecting Mycobacterium tuberculosis

In developing countries, which is an endemic region in terms of tuberculosis, there is an urgent need for fast, accurate, and inexpensive serological testing. The aim of this study was to determine the diagnostic value of patient serum IgG antibodies by ELISA in the diagnosis of Mycobacterium tuberculosis.

This case-control study was performed on patients with pulmonary tuberculosis in 2017-2020. After selecting the case (n = 30) and control (n = 30) subjects according to inclusion criteria, their blood samples were obtained and analyzed in the reference laboratory by standard kits for immunoglobulin G against 16, 36, and 40 kDa antigens of mycobacterium tuberculosis.

The mean age of the subjects was 47.07 (15.57%). The majority of participants were 46 (51.1%) women. There was no significant difference between the two groups regarding sex and age. serological examination of patients with pulmonary tuberculosis showed 25 positive results and only 4 of the control group had a positive result. Sensitivity, specificity, positive and negative predictive values of serology test were 83.3%, 86.67%, 86.20% and 87.88% respectively.

Despite the acceptable sensitivity of the serologic immunoglobulin G test, according to the statement of World health organization (WHO), it did not possess an acceptable specificity. It is recommended that a a wider range of different antigens to be studied also it is essential to evaluate the diagnostic value of the other immunoglobulins inpatient in different stages of the disease.