Diagnostic Potential of an Enzyme-Linked Immunospot Assay in Tuberculous Pericarditis

Tuberculous pericarditis is a rare disease in developed countries. The diagnosis is difficult to set since there are no robust rapid tests, and culture of pericardial fluid for Mycobacterium tuberculosis is often negative. T-SPOT.TB, an enzyme-linked immunospot (ELISPOT) test, measures the gamma interferon response of lymphocytes against tuberculosis antigens and can be performed on blood and body fluids. We describe a patient with tuberculous pericarditis for which the diagnosis was rapidly set by positive T-SPOT.TB results, which were confirmed by isolation of Mycobacterium tuberculosis in pericardial fluid culture. We performed a literature search to assess the diagnostic potential of ELISPOT testing in tuberculous pericarditis. The limited data on this subject indicate that T-SPOT.TB aids in diagnosing active tuberculosis (TB) infection and results in a more rapid decision to start antituberculosis treatment. Enumerating TB-specific lymphocytes and testing blood/compartmental fluid simultaneously can provide useful information on active tuberculous pericarditis.