ADENOSINE-DEAMINASE AND CARCINOEMBRYONIC ANTIGEN IN PERICARDIAL-EFFUSION DIAGNOSIS, ESPECIALLY IN SUSPECTED TUBERCULOUS PERICARDITIS

Background Adenosine deaminase (ADA) and carcinoembryonic antigen (CEA ) have been measured in pleural fluid to help distinguish malignant fr om benign effusions, especially in tuberculous pleurisy. We investigat ed ADA and CEA levels in patients with moderate to large pericardial e ffusions of different etiologies. Methods and Results We performed dia gnostic and therapeutic pericardiostomy with drainage and biopsy. We m easured ADA and CEA levels in the pericardial fluid in 26 patients wit h moderate to large pericardial effusion and 19 control patients. Pati ents were included in a prospective protocol from August 1991 to Augus t 1993. Patients were grouped as follows: group 1, 9 patients with tub erculous pericarditis (TP) confirmed by bacteriologic culture or histo logy of pericardial biopsy; group 2, 5 patients with clinically strong ly suspected TP; group 3, 12 patients with malignancy (8) and acute pe ricarditis (4); group 4, 19 control patients without pericardial disea se. We treated patients with TP with isoniazid, rifampin, and either s treptomycin or ethambutol for 12 months and pyrazinamide for 2 months. We observed for symptoms and signs of recurrent pericarditis or const rictive pericarditis on follow-up. In group 1 the ADA activity was sig nificantly higher (101+/-14 U/L) than that in group 3 (22+/-5 U/L) or that in group 4 (17+/-2 U/L) (P<.05). There was no significant differe nce between ADA activity in group 1 (101+/-14 U/L) and that in group 2 (100+/-26 U/L). With a cutoff value for ADA activity of 40 U/L, sensi tivity was 93% and specificity 97% in the diagnosis of TP. In benign d iseases, the CEA level was significantly lower (1.0+/-0.3 ng/mL) than that in malignant diseases (135.1+/-79.7 ng/mL) (P<.05). With a cutoff value for CEA level of 5 ng/mL, sensitivity was 75% and specificity 1 00% in the diagnosis of malignant pericarditis. Follow-up study (mean, 12.9, 19.8, and 11.8 months in groups 1, 2, and 3, respectively, show ed no symptoms or signs of constrictive pericarditis, except for 1 pat ient. Conclusions Pericardial fluid ADA and CEA are useful for the dif ferential diagnosis of pericardial effusion of various causes. They al so have great value in early diagnosis of TP, particularly when the re sults of other clinical and laboratory tests are negative.