Tired of the confusion around pleural effusions: Adenosine deaminase detection sets the record straight!

Table 1 Basic study information

Item	Content
Study type	Retrospective cohort study
Objective	To evaluate the diagnostic performance of P-ADA as a biomarker for inflammatory pleural diseases
Sample size	157 patients (exudates: 124 cases; transudates: 33 cases)
Key methods	ROC curve analysis to determine optimal P-ADA cutoff; diagnostic parameters evaluated using Youden’s index
Main conclusion	P-ADA ≥ 9.00 U/L demonstrates high diagnostic performance for inflammatory pleural effusions (AUC = 0.81, sensitivity = 77.69%)

AUC: Area under the curve; P-ADA: Pleural adenosine deaminase; ROC: Receiver operating characteristic.

Table 2 Diagnostic performance parameters (Receiver operating characteristic curve analysis)

Parameter	Result, %	95%CI
Optimal cutoff (U/L)	≥ 9.00	-
Sensitivity	77.69	69.22-84.75
Specificity	68.75	49.99-83.88
Positive predictive value	90.38	83.03-95.29
Negative predictive value	44.90	30.67-59.77
AUC value	81.07	0.7174-0.8754
Diagnostic accuracy	75.82	68.24-82.37

AUC: Area under the curve.

Table 3 Distribution of pleural effusion etiologies

Etiology category	n (%)	Notes
Transudates (Non-inflammatory)	33 (21)	Congestive heart failure (26 cases), cirrhosis (3 cases), etc.
Exudates (Inflammatory)	124 (79)	Tuberculous effusion (44 cases), adenocarcinoma (37 cases), etc.
Other notable etiologies	-	Empyema (8 cases), lymphoma (7 cases), etc.