Interferon-{alpha}2b treatment of chronic hepatitis C in haemodialysis patients

Nineteen haemodialysis (HD) patients with chronic hepatitisC were treated with interferonalpha2b (IFN-) at a dose of 3or 1 MU thrice weekly for 6 months and were followed-up foranother 14 months without treatment. Six patients discontinuedtreatment because they either presented severe side-effectsto IFN- or had complications of their primary disease. Levelsof AST and ALT were within normal limits on the 2nd month oftreatment and remained so throughout the treatment and the follow-upperiod in all patients except one who showed an elevation oftransaminase levels 2 months after the end of treatment. SerumHCVRNA became negative in 10/13 patients at the end of treatmentand was negative in all patients on the 6th month and in 12/13patients on the 14th month during the follow-up period. Levelsof 2'5' oligosynthetase were increased significantly on the2nd and 4th month of treatment and returned to pretreatmentvalues the 2nd month after treatment. These findings demonstratethat haemodialysis patients with chronic hepatitis C respondwell to interferon treatment and that a long-term response isachieved in a high proportion of patients.     

Urinary tumour necrosis factor-alpha excretion independently correlates with clinical markers of glomerular and tubulointerstitial injury in type 2 diabetic patients.

BACKGROUND: Inflammation is a potential factor in the development and progression of diabetic nephropathy. The aim of this study was to analyse the relationship between the pro-inflammatory cytokine tumour necrosis factor-alpha (TNFalpha) and clinical markers of glomerular and tubulointerstitial damage [urinary albumin excretion (UAE) and urinary N-acetyl-beta-glucosaminidase (UNAG), respectively] in a large group of type 2 diabetic patients. METHODS: A total of 160 diabetic patients and 32 healthy controls were included in the study. High-sensitive C-reactive protein (hs-CRP) as well as serum and urinary levels of TNFalpha were measured. UAE and UNAG were determined by 24-h urine collection. RESULTS: Serum hs-CRP and TNFalpha were significantly higher in diabetic than in control subjects, as well as UAE and UNAG. Diabetic patients had increased urinary TNFalpha compared to non-diabetics [14.5 (2-29) vs 4 (0.8-12), P < 0.001]. Serum hs-CRP and TNFalpha in diabetics with increased UAE were elevated compared to diabetics having normoalbuminuria. Urinary TNFalpha was also higher in diabetic subjects with micro- or macroalbuminuria than in patients with normal UAE [10.5 (4-20) and 18 (9-29) vs 7 (2-18) pg/mg, P < 0.0001, respectively]. Multiple regression analysis showed that urinary TNFalpha (P < 0.0001), hs-CRP (P < 0.0001), serum TNFalpha (P < 0.01) and HbA1c (P < 0.05) were independent of and significantly associated with UAE, whereas duration of diabetes (P < 0.001), urinary TNFalpha (P < 0.01), HbA1c (P = 0.01), hs-CRP (P < 0.05) and serum creatinine (P < 0.05) were associated with UNAG. CONCLUSIONS: In patients with type 2 diabetes, urinary TNFalpha excretion is elevated and correlates with severity of renal disease in terms of both glomerular and tubulointerstitial damage, suggesting a significant role for TNFalpha in the pathogenesis and progression of renal injury in diabetes mellitus.     

Interleukin-8 during peritonitis in patients treated with CAPD; an in-vivo model of acute inflammation

CAPD-related peritonitis was used as an in-vivo model to studyI1-8 during peritoneal inflammation. Eleven episodes were studiedin nine patients, who were followed on 8 consecutive days fromthe start of peritonitis and once after recovery (control).I1-8 was measured in dialysate (night dwells) and serum. TheI1-8 time course was compared to I1-6 and TNF. In addition,an in-vivo relationship between dialysate I1-8 and intraperitonealaccumulation of neutrophils was studied. A highly increased peritoneal appearance rate of I1-8 was foundin the acute phase that decreased to control values during recovery.A remarkable parallelism was observed for dialysate I1-8 andI1-6 with respect to the time course and the peritoneal appearancerate. In contrast, the appearance rate of TNF was much lessand had a different time course. In three of four cases wherethe dialysate I1-8 peak occurred on day 2, the dialysate I1-6peak still coincided with I1-8, in contrast to TNF (always day1). Dialysate I1-8 generally exceeded serum concentrations duringthe entire follow-up, indicating intraperitoneal I1-8 synthesis.A positive correlation was present between the dialysate I1-8peak and the maximal number of neutrophils in dialysate. Thisrelationship was absent for I1-6 and TNF. In five of six episodeswhere neutrophils were quantified on both day 1 and 2, the I1-8peak occurred simultaneously with the neutrophil peak. Thesefindings suggest that I1-8 is involved in the recruitment ofneutrophils towards the dialysate during peritonitis.     

Non-endotoxinic tumour necrosis factor-{alpha}-inducing factors in haemodialysis

A transmembrane passage of endotoxins may account for the dysfunctionof cytokine production which has been often reported in haemodialysis.We developed an assay based on the ability of patient serumto stimulate tumour necrosis factor (TNF) secretion in normalperipheral blood mononuclear cells. Three groups of subjectswere investigated: normal controls (n=14), patients with chronicrenal failure, CRF (n=15), and patients dialysed with poly-acrylonitrile(n=7), polysulphone (n=8), and cellulose acetate (n=7). Serafrom dialysed patients displayed a significantly higher TNF-inducingactivity than those of controls and CRF patients. The abilityof serum to elicit TNF secretion was neither modified duringthe dialysis session nor influenced by the type of haemodialysismembrane. TNF-inducing activity in serum was not inhibited bypolymyxin B, known to impair endotoxin-dependent cell responses,thus suggesting that it was not related to circulating endotoxins.We conclude that non-endotoxinic factors are present in serumfrom dialysed patients and are able to induce cytokine secretion.     

Hypoxia reduces the expression and anti-inflammatory effects of peroxisome proliferator-activated receptor-gamma in human proximal renal tubular cells.

BACKGROUND: Peroxisome proliferator-activated receptor (PPAR)-gamma may counteract tissue fibrosis via its anti-inflammatory actions, while hypoxia, a new pro-fibrotic factor, reportedly modifies PPAR-gamma expression. However, the effects of hypoxia on the expression and anti-inflammatory actions of PPAR-gamma have yet remained to be clarified in renal tubular cells. METHODS: Confluent human proximal renal tubular epithelial cells (HPTECs) were exposed to hypoxia (1% O2) and/or TNF-alpha at 10 ng/ml for up to 48 h. The cells were incubated with PPAR-gamma agonists, 15d-PGJ2 or pioglitazone, for 30 min before stimulation. Precise amounts of PPAR-gamma and MCP-1 mRNA and protein were measured by TaqMan quantitative PCR and immunoblot or ELISA, respectively. RESULTS: A cDNA array analysis identified PPAR-gamma as one of the hypoxia-affected genes in HPTECs. Hypoxia reduced mRNA levels of PPAR-gamma at 24 and 48 h and protein levels at 6 and 48 h. Knockout of hypoxia-inducible factor-1alpha (HIF-1alpha) with its dominant negative form did not block the hypoxia-induced reduction in PPAR-gamma expression. PPAR-gamma's activation with 15d-PGJ2 or pioglitazone reduced basal and TNF-alpha-stimulated MCP-1 expression at mRNA and protein levels at 24 h under normoxia. MCP-1 reduction rates at basal mRNA and protein levels were slightly but significantly lower during hypoxia than normoxia (9 vs 69% and 36 vs 42%, respectively, for 15d-PGJ2, and 0 vs 34% and 12 vs 21%, respectively, for pioglitazone). Finally, a specific inhibitor for PPAR-gamma, GW9662, weakened the MCP-1-decreasing effect of 15d-PGJ2 by about 30%, under basal conditions, while it abolished the effect of pioglitazone almost completely. CONCLUSIONS: Hypoxia-induced loss of function of PPAR-gamma reduces anti-inflammatory effects of PPAR-gamma activation, possibly modulating inflammatory responses in the diseased kidney.     

T gamma/delta lymphocytes in renal transplant recipients.

T gamma/delta lymphocytes are able to perform allospecific cytotoxicity and natural killer cytotoxicity in vitro. However, very little is known about their function in vivo. To investigate the possible involvement of T gamma/delta lymphocytes in the immune response to renal allografts, fine-needle aspiration biopsies and peripheral blood of 15 renal transplant recipients were studied during the first 4 weeks after transplantation. In addition peripheral blood of patients before transplantation, half a year and one year after transplantation was studied. No increase in the percentage of T gamma/delta lymphocytes in the fine-needle aspiration biopsies, including those taken during acute rejection episodes, was found. A significant decrease in the percentage of T gamma/delta lymphocytes was observed in peripheral blood after transplantation. We conclude that T gamma/delta lymphocytes seem to play no major role in the immune response to renal allografts.     

Effect of calcium-channel blocker on tumour necrosis factor alpha (TNF{alpha}) production in cyclosporin-treated renal transplant recipients

PURPOSE OF THE STUDY.: The influence of calcium-channel blocker treatment on in-vitroTNF production by peripheral blood mononuclear cells (PBMC)from renal transplant recipients treated with cyclosporin wasstudied. DESIGN.: We compared spontaneous and OKT3-induced TNF production of 12renal transplant recipients treated with calcium-channel blockertherapy with that of 18 renal transplant recipients who werenever treated with a calcium antagonist. RESULTS.: The two groups were similar with regards to age, time aftertransplantation, dosage of immunosuppressive drugs, and bloodcyclosporin levels. Spontaneous (481±161 versus 319±74pg/ml, n.s.) and OKT3-induced (745±182 versus 632±112pg/ml, n.s.) TNF production were similar in both groups. CONCLUSIONS.: The results indicate that in cyclosporintreated renal transplantrecipients calcium-channel blockers do not affect TNF production.     

Interleukin-8 in chronic renal failure and dialysis patients

A total of 105 patients participated in this study, including10 with chronic glomerulonephritis with normal renal function(CGN patients), 36 uraemic patients (CRF patients), 19 continuousambulatory peritoneal dialysis patients (CAPD) without peritonitis,three CAPD patients with peritonitis, 37 patients undergoingchronic haemodialysis (HD) divided into short-term HD, 15 patients;medium-term HD, 12 patients; and long-term HD, 10 patients.IL-8 and two other proinflammatory cytokines, IL-6 and TNFweretested using a specific immunoassay. IL-8, IL-6, and TNFc serumlevels were significantly increased in patients with chronicrenal failure compared to their levels in normal individuals(P<0.000l, P<0.05 and P<0.000l respectively). The mostpronounced incre ment in IL-8, IL-6 and TNF serum levels wasobserved in CAPD patients (P<0.000l). CAPD patients withoutperitonitis showed relatively low levels of IL-8 or IL-6 inperitoneal dialysate effluents (PDE), whereas PDE-TNF were notdetectable in almost all patients tested. Patients with peritonitisshowed very high serum and PDE levels of IL-8, IL-6 and TNF.The clinical recovery from peritonitis was characterized bya rapid fall in IL-8, IL-6 and TNF in serum and dialysate. HDpatients showed a significant increase in serum levels of IL-8and also IL-6 and TNFcompared to normal individuals (P<0.05,P<0.05 and P<0.01 respectively). HD duration influencedserum levels of IL-8 and TNF since they were significantly higherin short-term HD patients than medium- or long-term HD patients(respectively P<0.05, P<0.00l for IL-8, and P<0.01,P<0.001 for TNF Pre-HD IL-6 levels were not influenced byHD duration. No major modification of IL-8 serum levels couldbe evinced after and before HD sessions in the short-term group,but concentrations of this cytokine were significantly higherafter HD in medium- and long-term HD patients (P<0.05, P<0.0lrespectively). In contrast, HD session did not influence IL-6and TNF levels. We conclude that the cytokine profile is perturbedin uraemia and during dialysis, and that this should be consideredas an inflammatory status.     

p38 MAPK phosphorylation and NF-kappa B activation in human crescentic glomerulonephritis.

BACKGROUND: p38 mitogen-activated protein kinase (p38 MAPK) followed by the activation of NF-kappa B participates in the intracellular signal transduction and production of cytokines and chemokines. The pathophysiological roles of p38 MAPK and NF-kappa B in human glomerulonephritis, however, remain to be investigated. METHODS: We investigated the phosphorylated p38 MAPK (p-p38 MAPK) and activated NF-kappa B immunohistochemically in the kidneys of 34 patients with crescentic glomerulonephritis and 26 control patients with thin basement membrane disease and minimal change nephrotic syndrome. We also explored the co-localization of p-p38 MAPK with CCR5, the signal of which leads to p38 MAPK activation. Furthermore, urinary levels of MIP-1 alpha, the cognate ligand for CCR5, were determined by enzyme-linked immunosorbent assay. RESULTS: p-p38 MAPK-positive cells and activated NF-kappa B-positive cells were mainly detected in crescentic lesions, tubular epithelial cells, and interstitial mononuclear infiltrates. The number of p-p38 MAPK-positive cells in patients with crescentic glomerulonephritis was higher than that in control patients. The number of p-p38 MAPK-positive cells in glomeruli was well correlated with the percentage of cellular crescents, the number of CD68-positive cells, and urinary MIP-1 alpha levels. In addition, the number of activated NF-kappa B-positive cells was well correlated with the number of p-p38 MAPK-positive cells in glomeruli. Dual staining revealed that most of CCR5-positive cells were positive for p-p38 MAPK. Finally, p-p38 MAPK-positive cells and activated NF-kappa B-positive cells decreased during glucocorticoid therapy-induced convalescence. CONCLUSIONS: We conclude that the phosphorylation of p38 MAPK associated with the activation of NF-kappa B may be involved in the upregulation of intrarenal MIP-1 alpha and the utilization of CCR5 signalling, which may result in human crescentic glomerulonephritis.     

Morphology and distribution of chandelier cell axon terminals in the mouse cerebral cortex and claustroamygdaloid complex

Chandelier cells represent a unique type of cortical --aminobutityricacidergic interneuron whose axon terminals (Ch-terminals) onlyform synapses with the axon initial segments of some pyramidalcells. Here, we have used immunocytochemistry for the high-affinityplasma membrane transporter GAT-1 and the calcium-binding proteinparvalbumin to analyze the morphology and distribution of Ch-terminalsin the mouse cerebral cortex and claustroamygdaloid complex.In general, 2 types of Ch-terminals were distinguished on thebasis of their size and the density of the axonal boutons thatmade up the terminal. Simple Ch-terminals were made up of 1or 2 rows of labeled boutons, each row consisting of only 3–5boutons. In contrast, complex Ch-terminals were tight cylinder-likestructures made up of multiple rows of boutons. Simple Ch-terminalswere detected throughout the cerebral cortex and claustroamygdaloidcomplex, the complex type was only occasionally found in certainregions, whereas in others they were very abundant. These resultsindicate that there are substantial differences in the morphologyand distribution of Ch-terminals between different areas andlayers of the mouse cerebral cortex. Furthermore, we suggestthat the distribution of complex Ch-terminals may be relatedto the developmental origin of the different brain regions analyzed.     

Rosiglitazone ameliorates cisplatin-induced renal injury in mice.

BACKGROUND: Inflammatory mechanisms may play an important role in the pathogenesis of cisplatin nephrotoxicity. Agonists of the peroxisome proliferator-activated receptor-gamma (PPARgamma), such as rosiglitazone, have been recently demonstrated to regulate inflammation by modulating the production of inflammatory mediators and adhesion molecules. The purpose of this study was to examine the protective effects of rosiglitazone on cisplatin nephrotoxicity and to explore the mechanism of its renoprotection. METHODS: Mice were treated with cisplatin with or without pre-treatment with rosiglitazone. Renal functions, histological findings, aquaporin 2 (AQP2) and adhesion molecule expression, macrophage infiltration and tumour necrosis factor-alpha (TNF-alpha) levels were investigated. The effect of rosiglitazone on nuclear factor (NF)-kappaB activity and on viability was examined using cultured human kidney (HK-2) cells. RESULTS: Rosiglitazone significantly decreased both the damage to renal function and histological pathology after cisplatin injection. Pre-treatment with rosiglitazone reduced the systemic levels of TNF-alpha and down-regulated adhesion molecule expression in addition to the infiltration of inflammatory cells after cisplatin administration. Rosiglitazone restored the decreased AQP2 expression after cisplatin treatment. Pre-treatment with rosiglitazone blocked the phosphorylation of the p65 subunit of NF-kappaB in cultured HK-2 cells. Rosiglitazone had a protective effect via a PPARgamma-dependent pathway in cisplatin-treated HK-2 cells. CONCLUSION: These results showed that pre-treatment with rosiglitazone attenuates cisplatin-induced renal damage through the suppression of TNF-alpha overproduction and NF-kappaB activation.     

Alphav integrin regulates TNF-alpha-induced nitric oxide synthesis in rat mesangial cells--possible role of osteopontin.

BACKGROUND: Tumour necrosis factor-alpha (TNF-alpha) induces nitric oxide (NO) synthesis in rat mesangial cells (MCs). We previously demonstrated that osteopontin (OP), a matrix protein that mainly interacts with the alphav integrin family, increased time-dependently by TNF-alpha stimulation at gene and protein levels. The regulation of NO synthesis by integrins or matrix proteins is unclear. METHODS: We examined whether integrin, especially alphav integrin, regulates NO synthesis in rat MCs and whether OP, an alphav integrin ligand, has an effect on TNF-alpha-induced NO synthesis. Furthermore, OP and inducible NO synthase (iNOS) gene expression was examined by Northern blotting. RESULTS: TNF-alpha increased NO synthesis in MCs in a time-dependent manner. Synthetic GRGDSP peptide, which is known to inhibit various integrins that interact with RGD-containing extracellular matrices, increased TNF-alpha-induced NO levels in a dose-dependent manner. Cyclical RGD peptide, the specific inhibitor of alphav integrin, also exhibited a dose-dependent effect of increasing NO levels, while GRGESP peptide, which has very low affinity to integrins, had no effect. In addition, NO synthesis was found to be significantly reduced when MCs were plated on OP-coated dishes compared to type I or IV collagen-coated dishes. Furthermore, anti-OP antibody increased NO synthesis in MCs. iNOS mRNA levels were increased by TNF-alpha, and were abruptly diminished after OP mRNA was significantly induced. CONCLUSIONS: The present study demonstrated the involvement of alphav integrin in TNF-alpha-induced NO synthesis in rat MCs, and the possible role of OP was suggested in the mechanism. TNF-alpha and extracellular matrices can co-operate to regulate the behaviour of MCs at least partly through NO synthesis, which may participate in the course of glomerular diseases.