Quantification of proinflammatory cytokines in the urine of congestive heart failure patients. Its relationship with plasma levels

AIMS: Proinflammatory cytokines are important mediators for the development of heart failure and increased plasma levels of these cytokines have been reported in patients with this condition. The purpose of the study was to investigate whether urine, a non-invasively obtained biological sample, was an appropriate medium in which to measure the concentration of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in patients in the advanced stages of the disease. METHODS AND RESULTS: Thirty consecutive patients who had severe congestive heart failure (NYHA classes III and IV) and 30 matched healthy control subjects were enrolled. Plasma and the first urine of the day were collected and TNF-alpha and IL-6 were quantitatively analyzed by enzyme-linked immunosorbent assays. For every subject there were no differences in the amount of cytokine determined in plasma and urine. Both urine and plasma levels of IL-6 and TNF-alpha were greater in heart failure patients than in controls. CONCLUSION: Our results show that plasmatic and urinary levels of proinflammatory cytokines did not differ significantly. Thus, urine may be a good milieu in which to study these cytokines and may have diagnostic, prognostic and therapeutic implications.