Adenosine deaminase and tuberculous pericarditis--a systematic review with meta-analysis.

BACKGROUND: Adenosine deaminase (ADA) activity in pericardial fluid is a valuable aid in the diagnosis of tuberculous pericarditis (TP), but there is no systematic review performed to evaluate the benefits of ADA activity as an adjunctive test for TP diagnosis. The objective of this systematic review was to evaluate the utility of ADA activity as a diagnostic marker of TP on patients presenting with pericardial effusion.

METHODS: MEDLINE, LILACS and Cochrane Library databases (1980-2005) searches to identify articles related to adenosine deaminase activity on TP diagnosis. Articles with patients with at least one TP diagnostic criteria were included. The controls were patients with other pericardial diseases with moderate or large pericardial effusion. To calculate the sensitivity, specificity, as well as positive and negative likelihood ratios we extracted the total number of confirmed TP cases over all patients with pericardial effusion as well as the number of cases with ADA activity values of 40 U/L and over.

RESULTS: Thirty one studies met our initial inclusion criteria and five articles were selected. The heterogeneity limited the specificity analysis (p=0.004). The method yielded a sensitivity and specificity of 88% and 83%, respectively. The SROC curve presented an area with a tendency towards 1 (value of 0.9539) and corroborates the diagnostic value of ADA activity.

CONCLUSIONS: The present study confirms the clinical value of ADA activity as adjunctive diagnostic marker of TP among other causes of pericardial effusion.