Role of Fragment Crystallizable Gamma Receptor 1 A (FCGR1A) gene expression in differentiating active from latent tuberculosis infection

Abstract

Abstract Background Despite the availability of diagnostic methods of tuberculosis, differentiating active tuberculosis (TB disease) from latent tuberculous infection remains challenging. FCGR1A reflects immune activation during active disease, while prealbumin decreases in inflammatory and malnourished states, making both potential indicators of disease activity. Aim To evaluate the role of FCGR1A gene expression and plasma prealbumin levels, either alone or in combination, in distinguishing TB disease from latent tuberculous infection. Patients and methods This cross sectional analytic study included 90 participants divided into three equal groups: patients with active tuberculosis (Group I), individuals with latent tuberculosis infection (Group II), and healthy controls (Group III). All participants underwent clinical evaluation, radiological assessment, and routine laboratory investigations. Plasma prealbumin was measured using ELISA, while FCGR1A gene expression was assessed using quantitative real-time PCR. Statistical analysis was performed to compare the groups and determine the diagnostic value of the studied markers. Results Patients with active tuberculosis (Group I) had significantly higher values of FCGR1A gene expression (median fold change 8.76) compared to Groups II and III. Plasma prealbumin was lower in Group I (median 100.7 µg/ml). Both prealbumin (≤ 111.48 µg/ml, AUC = 0.737) and FCGR1A (> 2.23 fold change, AUC = 0.797) effectively distinguished TB disease from latent infection, with sensitivities of 73–80% and specificities of 66–77%. Conclusions FCGR1A gene expression and plasma prealbumin are promising and useful biomarkers in the diagnosis of tuberculosis. Their combined assessment may improve the accuracy of distinguishing TB disease from latent tuberculosis infection.