Negative regulatory responses to metabolically triggered inflammation impair renal epithelial immunity in diabetes mellitus.

Diabetes mellitus is characterized by chronic inflammation and increased risk of infections, particularly of tissues exposed to the external environment. However, the causal molecular mechanisms that affect immune cells and their functions in diabetes are unclear. Here we show, by transcript and protein analyses, signatures of glucose-induced tissue damage, chronic inflammation, oxidative stress, and dysregulated expression of multiple inflammation- and immunity-related molecules in diabetic kidneys compared with non-diabetic controls. Abnormal signaling involving cytokines, G-protein coupled receptors, protein kinase C isoforms, mitogen-activated protein kinases, nuclear factor-κB (NFκB), and Toll-like receptors (TLR) were evident. These were accompanied by overexpression of negative regulators of NFκB, TLR, and other proinflammatory pathways, e.g., A20, SOCS1, IRAK-M, IκBα, Triad3A, Tollip, SIGIRR, and ST2L. Anti-inflammatory and immunomodulatory molecules, e.g., IL-10, IL-4, and TSLP that favor TH2 responses were strongly induced. These molecular indicators of immune dysfunction led us to detect the cryptic presence of bacteria and human cytomegalovirus in more than one third of kidneys of diabetic subjects but none in non-diabetic kidneys. Similar signaling abnormalities could be induced in primary human renal tubular epithelial (but not mesangial) cell cultures exposed to high glucose, proinflammatory cytokines and methylglyoxal, and were reversed by combined pharmacological treatment with an antioxidant and a PKC inhibitor. Our results suggest that diabetes impairs epithelial immunity as a consequence of chronic and inappropriate activation of counter-regulatory immune responses, which are otherwise physiological protective mechanisms against inflammation. The immune abnormalities and cryptic renal infections described here may contribute to progression of diabetic nephropathy.

Does periprostatic block increase the transrectal ultrasound (TRUS) biopsy sepsis rate in men with elevated PSA?

INTRODUCTION: Periprostatic nerve block (PPNB) is a common local anaesthetic technique in transrectal ultrasound-guided (TRUS) prostate biopsy, but concerns remain over the increased theoretical risks of urinary tract infection (UTI) and sepsis from the additional transrectal needle punctures. This study reviewed our biopsy data to assess this risk. MATERIALS AND METHODS: Retrospective data collected from 177 men who underwent TRUS biopsy between July 2007 and December 2009 in a single institution were analysed. PPNB was administered using 1% xylocaine at the prostatic base and apex and repeated on the contralateral side under ultrasound guidance. Complications, including UTI sepsis, bleeding per rectum and acute retention of urine (ARU) were noted. Every patient was tracked for the first 2 weeks for complications until his clinic review. Demographic profi le, biopsy parameters and histological fi ndings were reviewed. Univariate and multivariate analysis of possible risk factors for development of sepsis after TRUS biopsy were performed. Statistical analysis was performed using SPSS 17.0. RESULTS: Ninety (51%) men received PPNB and 87 (49%) did not. The groups were matched in age (PPNB: mean 62.7 ± 5.8 years; without PPNB: mean 64.4 ± 5.7 years) and prebiopsy prostate specific antigen (PSA) levels (PPNB: mean 8.2 ± 3.9 ng/mL; without PPNB: mean 8.3 ± 3.7 ng/mL). The PPNB group had a larger prostate volume, with more cores taken (P <0.05). On univariate and multivariate analysis controlling for age, PSA, prostate volume, number of cores taken and histological prostatitis, PPNB was not a significant risk factor for sepsis. Sepsis rates were 5.6% in the PPNB group and 5.7% in the other group (P = 0.956). Overall prostate cancer detection rate was 33.3%. CONCLUSION: The risk of sepsis was not increased in patients who received PPNB, even though this group had larger gland volumes and more biopsy cores taken.