Humoral alloreactivity, manifested by the capillary deposition of complement C4d in about 50% of biopsied renal grafts, exerts a strong impact on graft survival when it operates within six months after transplantation.

BackgroundNasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is a well defined risk factor for subsequent bacteremia and death in various groups of patients, but its impact on outcome in patients receiving long-term hemodialysis (HD) is under debate.MethodsThis prospective interventional cohort study (performed 2004 to 2010) enrolled 289 HD outpatients of an urban dialysis-unit. Nasal swab cultures for MRSA were performed in all patients upon first admission, at transfer from another dialysis facility or readmission after hospitalisation. Nasal MRSA carriers were treated in a separate ward and received mupirocin nasal ointment. Concomitant extra-nasal MRSA colonization was treated with 0.2% chlorhexidine mouth rinse (throat) or octenidine dihydrochloride containing antiseptic soaps and 2% chlorhexidine body washes (skin). Clinical data and outcome of carriers and noncarriers were systematically analyzed.ResultsThe screening approach identified 34 nasal MRSA carriers (11.7%). Extra-nasal MRSA colonization was observed in 11/34 (32%) nasal MRSA carriers. History of malignancy and an increased Charlson Comorbidity Index were significant predictors for nasal MRSA carriers, whereas traditional risk factors for MRSA colonization or markers of inflammation or malnutrition were not able to discriminate. Kaplan-Meier analysis demonstrated significant survival differences between MRSA carriers and noncarriers. Mupirocin ointment persistently eliminated nasal MRSA colonization in 26/34 (73.5%) patients. Persistent nasal MRSA carriers with failure of this eradication approach had an extremely poor prognosis with an all-cause mortality rate >85%.ConclusionsNasal MRSA carriage with failure of mupirocin decolonization was associated with increased mortality despite a lack of overt clinical signs of infection. Further studies are needed to demonstrate whether nasal MRSA colonization represents a novel predictor of worse outcome or just another surrogate marker of the burden of comorbid diseases leading to fatal outcome in HD patients.

The MMF reduces anti-HLA class I and II antibody production and consequently DSA production in renal allograft recipients. Our data indicate this effect to be more pronounced in patients given MMF immediately after transplantation than in those in whom MMF is introduced some time later. The presence of DSA in the serum of renal allograft recipients is associated with poorer graft function (higher serum creatinine and more rejection episodes).

Human peritoneal mesothelial cells (HMC) contribute to the activation and control of inflammatory processes in the peritoneum by their potential to produce various inflammatory mediators. The present study was designed to assess the effect of glucose, the osmotic active compound in most commercially available peritoneal dialysis fluids, on the synthesis of the C-C chemokine monocyte chemoattractant protein-1 (MCP-1) in cultured HMC. The MCP-1 concentration in the cell supernatants was determined by enzyme-linked immunosorbent assay and the MCP-1 mRNA expression was examined using Northern blot analysis. Incubation of HMC with glucose (30–120 mM) resulted in a time- and concentration-dependent increase in MCP-1 protein secretion and mRNA expression. After 24 h the MCP-1 synthesis was increased from 2.8 ± 0.46 to 4.2 ± 0.32 ng/10⁵ cells (n = 5, p < 0.05) in HMC treated with 60 mM glucose. In contrast, osmotic control media containing either the metabolically inert monosaccharide mannitol or NaCl did not influence MCP-1 production. The stimulating effect of high glucose on MCP-1 expression in HMC was mimicked by activation of protein kinase C (PKC) with the phorbol ester PMA (20 nM). Coincubation of the cells with glucose and the specific PKC inhibitor Ro 31–8220 completely blunted glucose-mediated MCP-1 expression. In summary, our results indicate that glucose induces MCP-1 synthesis by a PKC-dependent pathway. Since osmotic control media did not increase MCP-1 release, it is suggested that the effect of glucose is mainly related to metabolism and not to hyperosmolarity. These data may in part explain elevated steady-state levels of MCP-1 found in the dialysis effluent of continuous ambulatory peritoneal dialysis patients.

Heat shock proteins (HSPs) are a group of highly conserved proteins that show extensive homology at the DNA and protein level among bacterial and mammalian species. Furthermore, bacterial HSPs induce specific cellular and humoral immune responses in mammals. Cross-reacting antibodies may therefore be induced in chronic infections. Recently, it has been claimed that patients with arteriosclerosis (AS) of the carotid arteries have significantly elevated antibody titers to mycobacterial HSPs. In this study, we extended the spectrum of vascular diseases and analyzed sera from patients with systemic vasculitis and systemic lupus erythematosus (SLE) for the presence of anti-HSP antibodies. Anti-HSP antibodies, tested in an ELISA with recombinant mycobacterial HSP 65, were significantly elevated in patients with vasculitis (n = 56; p < 0.01) and AS (n = 29; p < 0.0001), but only marginally in patients with SLE (n = 22; p > 0.05) compared to healthy controls (n = 90). These findings further support the concept of infection-induced immune reactions playing a pathogenic role in the development of both AS and vasculitis.