['The mineralocorticoid receptor antagonist spironolactone (SPIR) reduces the mortality and morbidity in patients with congestive heart failure (CHF). Overexpression of proinflammatory cytokines contribute to the development and progression of CHF.', 'We examined the effect of SPIR on in vitro cytokine production by human peripheral blood mononuclear cells (PBMC). PBMC were cultured with 10-1000 microM SPIR and stimulated with lipopolysaccharide or phytohaemagglutinin-P. Tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, IL-1beta, and interferon (IFN)-gamma were measured in culture supernatants by enzyme-linked immunosorbent assay and mRNA expression of the cytokines was determined by real-time reverse transcriptase polymerase chain reaction (PCR).', 'SPIR inhibited the stimulated production of TNF-alpha, IL-6, and IFN-gamma, whereas the release of IL-1beta was not significantly affected. The SPIR-induced cytokine inhibition occurred at the transcriptional level and was independent of antimineralocorticoid and antiandrogen activities.'] Does spironolactone inhibit production of proinflammatory cytokines by human mononuclear cells?