Profile of Adenosine Deaminase and the Impact of Age and Female Sex on Its Level in 157 Patients with Pleural Effusion Syndrome

Abstract

Background: The profile of adenosine deaminase enzyme and the impact of demographic data on its level are important in patients with pleural effusion syndrome (PES). Objective: To evaluate the levels of adenosine deaminase (ADA) in the pleural fluids (P-ADA) of untreated and non-surgically manipulated female and male adult patients with several confirmed causes of PES. Methods: This observational, retrospective cohort study in the State of Rio de Janeiro, Brazil, involved 157 patients. The study variables were age, total P-ADA determined using a commercial kit, and male and female sex. Results: The causes, prevalence, and median P-ADA (n/%/U/L) were tuberculosis (44/28.0/42.0), adenocarcinoma (37/24.0/9.75), transudate (33/21.0/6.85), simple parapneumonic pleural effusions (PPE; 15/10.0/9.38), complicated PPE/empyema (8/5.0/32.9), lymphoma (7/4.0/401.2), squamous cell carcinoma (7/4.0/13.11), and others (6/4/15.2). For P-ADA, Dunn's post hoc test revealed significance for tuberculosis vs. transudates, vs. simple PPE, and vs. adenocarcinoma (all P<0.05), and not significant for CPPE/empyema, lymphoma, SCC, and others (all P>0.05). For age, Dunn’s post hoc test revealed significance for tuberculosis vs. transudates, vs. simple PPE, and vs. adenocarcinomas (all P<0.05). Sex was not significant in the overall PES group (Chi=0.062, P=0.8028). Kendall's correlation of the relationship between P-ADA and age for pleural tuberculosis (n=41) was significant after 1000 iterations with bootstrap for 95% CI (Tau=-0.213, 95% CI - 0.449-0.0833, P=0.0490). A negative LOESS regression was evident between P-ADA and age >40 years. Conclusions: Evaluation of pleural ADA levels is useful for diagnosing pleural tuberculosis, while sex is not. A negative and significant relationship between P-ADA level and age >40 years was evident.