Setting: An academic hospital in the Western Cape, South Africa.
Objective: To evaluate cytokine production (interferon-gamma [IFN-gamma], interleukin-1 [IL-1], interleukin-2 [IL-2], interleukin-6 [IL-6], interleukin-10 [IL-10], interleukin-4 [IL-4] and tumour necrosis factor-alpha [TNF-alpha]) in patients with tuberculous pericarditis.
Design: Subpopulation of a consecutive prospective case series.
Patients: Thirty patients presenting with pericardial effusions due to tuberculosis (n = 19), malignancy (n = 6) and non-tuberculous infections (n = 5), and five control subjects who had undergone open heart surgery.
Results: The concentration of IFN-gamma was significantly higher in tuberculous pericardial effusions than in the other diagnostic classes (P < 0.0005). The concentration of TNF-alpha was similar in both infective and tuberculous effusions, but was significantly higher than that of malignant effusions. IL-1 and IL-2 were undetectable in malignant effusions, but elevated in both infective and tuberculous pericardial effusions. The levels of IL-1 and IL-2 were furthermore significantly higher in pericardial effusions due to infective compared to tuberculous causes. The concentration of IL-6, while elevated in all diagnostic classes, was significantly higher in the malignant group. Elevated levels of IL-10 and undetectable levels of IL-4 were observed in all three diagnostic groups.
Conclusion: These findings suggest that tuberculous pericardial effusions arise due to a hypersensitivity reaction that is orchestrated by the TH-1 lymphocytes.