Abstract 13521: T cell-Based Assay on Peripheral Blood and Pericardial Fluid Mononuclear Cells for Diagnosis of Tuberculous Pericardial Effusion

Abstract

Background: The clinical values of M. tuberculosis-specific enzyme-linked immunosorbent spot (ELISPOT) assay for the diagnosis of tuberculous pleuritis and other extrapulmonary tuberculosis have been reported. However, its role for the diagnosis of tuberculous pericardial effusion (TPE) has not been demonstrated.

Methods: A total of 35 patients with newly developed moderate to large amount of pericardial effusion were prospectively enrolled. All patients underwent pericardiocentesis or pericardial window operation. ELISPOT assays with M. tuberculosis-specific antigens (ESAT-6 and CFP-10) were performed using peripheral blood and pericardial effusion, and adenosine deaminase (ADA) activities in pericardial effusion were also measured. Final diagnosis of TPE was made based on the criteria widely accepted.

Results: Twelve patients (34%) were diagnosed as TPE. ROC curve analysis showed that areas under the curves of ELISPOT assays on peripheral blood were 0.737 and 0.792 for Δ[ESAT-6 - negative control (NC)] and Δ(CFP-10 - NC), while they were 0.931, 0.895 and 0.895 for ADA, Δ(ESAT-6 - NC) and Δ(CFP-10 - NC) on pericardial effusion, respectively. Sensitivities and specificities by best cutoff values were 92% and 89% by ADA level (≥42 U/L), 92% and 87% by Δ(ESAT-6 - NC) (≥39), and 75% and 100% by Δ(CFP-10 - NC) (≥92) on pericardial effusion, respectively. Area under the curve was 0.981 when combination of ADA and ELISPOT assay results on pericardial effusion was used for the diagnosis of TPE (Fig.). When positive results in 2 or more variables out of 3 variables [ADA, Δ(ESAT-6 - NC) and Δ(CFP-10 - NC) on pericardial effusion] were used as diagnostic criteria for TPE, sensitivity, specificity, and positive and negative predictive values were 92%, 100%, 100% and 95%, respectively.

Conclusion: ELISPOT assay on pericardial effusion is a useful diagnostic method for TPE, and diagnostic specificity can be enhanced when it is used in combination with ADA.