Strong inflammatory cytokine response in male and strong anti-inflammatory response in female kidney transplant recipients with urinary tract infection

Abstract

Urinary tract infection (UTI) is the most common post-transplant infection in renal transplant recipients. The relationship of plasma and urine cytokines with UTI after kidney transplantation has not yet been delineated and literature reports on cytokine and UTI are rare. In a retrospective study, we compared post-transplant plasma and urine cytokine levels of 132 outpatient renal transplant recipients with or without UTI. Soluble interleukin-1 receptor antagonist (sIL-1RA), IL-2, sIL-2R, IL-3, IL-4, IL-6, sIL-6R, IL-8, IL-10, transforming growth factor-beta2 (TGF-beta2), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) levels were determined using commercially available enzyme-linked immunosorbent assay (ELISA) kits. We found gender-related urine cytokine patterns. Anti-inflammatory sIL-1RA was significantly higher in females than in males and this gender-related difference was more pronounced in bacteriuric (P < 0.0001) than in nonbacteriuric (P = 0.001) patients. Urine proinflammatory cytokines IL-6 (P = 0.001) and IL-8 (P = 0.007) were significantly higher in male patients with bacteriuria than in males without bacteriuria and sIL-2R (P = 0.001) and sIL-6R (P = 0.03) were significantly higher in males with leukocyturia than in males without leukocyturia. Bacteriuria in males was associated with higher doses of immunosuppressive drugs (P = 0.02). Male renal transplant recipients with UTI have a strong inflammatory cytokine response with activation of IL-6, IL-8, sIL-2R and sIL-6R producing cells, whereas female patients with UTI block the inflammatory response to UTI by production of sIL-1RA.