Association Of Serum Adenosine Deaminase with Sputum Conversion at the End of Second Month and at the End of The Anti-Tuberculous Drug Treatment among New Smear Positive Pulmonary Tuberculosis Patients

Abstract

Background: Tuberculosis (TB) is global public health problem. Sputum microscopy for AFB is a well-known method for treatment monitoring in case of smear positive PTB patients. But it is not always easy to obtain sputum samples at the end of treatment. Many studies have proved the role of ADA in diagnosis of tuberculosis in effusion fluids and a decrease in ADA activity at the end of treatment. But association between serum ADA level with treatment monitoring in sputum smear positive PTB cases is not widely studied.

Objective: To determine the association of serum adenosine deaminase with sputum conversion at the end of second month and at the end of the treatment among new smear positive pulmonary tuberculosis patients.

Materials & Methods: This prospective observational study was conducted in the department of respiratory medicine of National Institute of Diseases of the Chest and Hospital (NIDCH) from June 2020 to September 2021. Ninety-eight new smear positive pulmonary tuberculosis patients were enrolled in this study according to inclusion and exclusion criteria of the study. Sputum sample was collected from each subject for microscopic examination at initial, at the end of the 2nd month and at the end of 6th month. Blood was collected from each subject for measurement of serum ADA level at initial, at the end of 2nd month and at the end of 6th month. Serum ADA was measured by enzymatic photometric method using MICROEXPRESS ADA-MTB reagent and result was expressed as U/L. Data analysis was done through Statistical Package for Social Science (SPSS) version 23.

Results: Mean age of the study subject was 39.7±13.0 years with male (82.8%) predominance. Ultimately 10 patients were lost to follow-up and 1 died during the study period. Rest of the study subjects (87 out of 98) showed that their sputum were converted at the end of 2nd month and remained negative at the end of 6th month. Mean serum ADA level was significantly decreased at the end of 6th month (21.8±5.7 U/L) than 2nd month (25.1±8.3 U/L) and baseline (29.8±11.5 U/L) (P value = 0.001). To see the association between serum ADA level and sputum smear for AFB, Analysis of Variance test was done and it revealed that at the end of 2nd month and 6th month mean serum ADA level was significantly higher among patients with higher bacillary load ( P value =0.001). Multivariate regression analysis was done which found independent relationship between serum ADA and sputum for AFB 3+.

Conclusion: This study showed there is significant association between serum ADA level and sputum smear conversion among the new smear positive pulmonary tuberculosis patients.

Chest Heart J. 2022; 46(1) : 34-40