Immunoglobulin G levels can predict non-diabetic renal disease in patients with type 2 diabetes mellitus.

BACKGROUND: Proteinuria in patients with diabetes mellitus (DM) is sometimes caused by glomerular diseases other than diabetic nephropathy. In patients with type 2 DM (T2DM), specific predictors for non-diabetic renal disease (NDRD) are needed in addition to the traditional indicators for renal biopsy. METHODS: From 1 January 2000 to 31 March 2011, we retrospectively enrolled 54 T2DM patients with proteinuria who had undergone renal biopsies into the present study. Associations between NDRD and 20 potential biomarkers, including serum levels of Igs and proteins associated with kidney function, and urinary protein and red blood cell levels, and hepatitis virus carrier status, were analyzed by multivariate logistic regression. RESULTS: Multivariate logistic regression showed that reduced serum IgG (odds ratio [OR] 0.997; P = 0.006; 95% confidence interval [CI] 0.94-0.998) and creatinine (Cr; OR 0.587; P = 0.014; 95% CI 0.348-0.897) were predictors of NDRD. The area under the receiver operating characteristic curve (AUC(ROC) ) confirmed the good discriminatory power of IgG (AUC(ROC) 0.857 ± 0.058; 95% CI 0.744-0.970; P < 0.001) and Cr (AUC(ROC) 0.838 ± 0.054; 95% CI 0.732-0.943; P < 0.001). The IgG level below which the risk for NDRD increased, as calculated by obtaining the best Youden index, was 919.5 mg/dL (sensitivity 91.7%; specificity 83.3%), and the corresponding Cr level was 4.1 mg/dL (sensitivity 58.3%; specificity 96.7%). CONCLUSION: Serum IgG levels <919.5 mg/dL and serum Cr levels <4.1 mg/dL are associated with NDRD in T2DM patients.

Colchicine overdose-induced acute renal failure and electrolyte imbalance.

Colchicine has been used to control gouty arthritis for long time; colchicine overdose, however, causes multiple organ dysfunction. To date, no investigation has revealed the site of kidney lesion or dysfunction. This investigation describes the case of a male with a history of gout who ingested a large amount of colchicine and developed renal, hematopoietic, gastrointestinal, muscular, electrolytic, and hepatic disorder. Glucosuria was noted during hospital days. Colchicine intoxication is shown to induce proximal tubule damage. Severe electrolytes imbalance was noted, including hypomagnesemia, hypophosphatemia, and hypocalcemia. After management, the renal function and serum electrolyte of the patient recovered on the sixth day of hospitalization.

Xanthogranulomatous pyelonephritis and malacoplakia of the bladder in a middle aged female.

We describe the case of a female with xanthogranulomatous pyelonephritis and malacoplakia of the bladder, presenting with recurrent urinary tract infection and renal mass. The genitourinary tract should be explored to evaluate the coexistence of these two diseases. Nephrectomy and bladder mass resection is warranted to maintain sterile urine. This case represents an unusual instance of the synchronic appearance of xanthogranulomatous pyelonephritis and malacoplakia of the bladder, implying a common pathogenesis for two related diseases from a different histological spectrum, in which the urinary obstruction serves as a promoting factor for the stepwise transformation of morphogenesis.

Aristolochic acid-related nephropathy associated with the popular Chinese herb Xi Xin.

Chinese herbs nephropathy is known as a subacute interstitial nephritis attributed to aristolochic acid. This work describes the case of a 49-year-old male who displayed subacute renal failure induced by ingestion of herbal powder containing Xi Xin, which includes aristolochic acid. Since Xi Xin is a common ingredient in traditional formulae, care needs to be taken in the future to identify the aristolochic acid concentration of different components of Xi Xin. Xi Xin containing aristolochic acid should be forbidden for use in remedies in order to prevent the harmful effects of aristolochic acid.

Does hepatitis C virus affect the reactivation of hepatitis B virus following renal transplantation?

BACKGROUND: Hepatitis B virus (HBV) is endemic in Taiwan. Transplantation followed by long-term immunosuppressive medications may precipitate HBV reactivation. Interference of hepatitis C virus (HCV) with HBV gene expression and replication has been confirmed in many studies involving non-transplant populations. This study investigates the incidence of HBV reactivation following renal transplantation and compares the clinical outcome, especially the liver outcome, of patients with or without HCV co-infection. METHODS: Fifty-one of 512 renal transplant recipients were positive for hepatitis B surface antigen before surgery, and were followed for 81.6+/-7.5 (4-120) months. Seventeen of 51 patients acquired HCV before transplantation and six patients acquired HCV after renal transplantation. RESULTS: At the end of this assessment, we had 28 patients who suffered HBV reactivation and another 23 patients who suffered no HBV reactivation. Initially, we found a significant difference of HCV carriage (P<0.05) between patients with (seven out of 28 or 25%) or without (21 out of 23 or 91.3%) HBV reactivation. Further inspection showed that 21 of the 28 patients without HCV co-infection and seven of the 23 patients with HCV co-infection suffered HBV reactivation. After comparison, we found a lower incidence of HBV reactivation in patients with HCV co-infection than in patients without HCV co-infection (P<0.05). In contrast to the latter, we found that patients with HCV co-infection suffering HBV reactivation tended to have a late onset of HBV reactivation (P<0.05). Otherwise, there was no difference in hepatitis severity, in terms of peak alanine aminotransferase, total bilirubin levels and hepatitis reactivation-related death, between these two groups of patients. Finally, a multivariable analysis also revealed that HCV carriage was indeed an independent variable leading to the reduced incidence of HBV reactivation in patients with HCV co-infection. CONCLUSION: HCV might affect the reactivation of HBV by decreasing the incidence or delaying the onset of HBV reactivation in renal transplant recipients carrying both HBV and HCV.

Leptospiral membrane proteins stimulate pro-inflammatory chemokines secretion by renal tubule epithelial cells through toll-like receptor 2 and p38 mitogen activated protein kinase.

BACKGROUND: Leptospiral membrane proteins extracted from pathogenic Leptospira santarosai serovar Shermani (LMPS) stimulated pro-inflammatory chemokines production in cultured mouse proximal tubule epithelial cells (PTECs) and implicated its role in the pathogenesis of leptospira-induced tubulointerstitial nephritis. PTECs express the functional TLR2 and TLR4, which have been shown to play essential roles in innate immunity. This study investigated the roles of Toll-like receptors (TLRs) and mitogen-activated protein kinases (MAPKs) signalling pathways in the pathogenesis of leptospira-induced tubulointerstitial nephritis. METHODS: The immortalized mouse PKSV-PR late PTECs were used as the model system. The genes expression and secretion of CCL2/monocyte chemoattractant protein-1 (CCL2/MCP-1) and CXCL2/macrophage inflammatory protein-2 (CXCL2/MIP-2) were measured by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA). We investigated MAPKs signalling pathways by Western blot and their reciprocal roles by specific inhibitors. A specific TLR2 neutralizing antibody was applied to evaluate the crosstalk between TLR2 and MAPKs. RESULTS: The LMPS stimulated extracellular signal-regulated kinases (ERK1/2), c-Jun N-terminal kinases (JNKs) and p38 mitogen-activated protein kinase (p38 MAPK), initiated the nuclear transcription factor kappaB (NF-kappaB), and enhanced the secretion of CCL2/MCP-1 and CXCL2/MIP-2. The LMPS also unregulated the level of TLR2 mRNA expression in PTECs through time- and dose-dependent effects. The LMPS enhanced the secretion of CCL2/MCP-1 and CXCL8/interleukin-8 (CXCL8/IL-8) in TLR-defective human embryonic kidney (HEK) 293 cells only when transfected with a TLR2 expressing plasmid. The secretions of CCL2/MCP-1 and CXCL2/MIP-2 stimulated by LMPS were significantly reduced by incubating PTECs with SB203580, an inhibitor of p38 MAPK. Furthermore, a neutralizing anti-mouse TLR2 antibody hindered the phosphorylation of p38 and LMPS-stimulated secretion of CCL2/MCP-1 and CXCL2/MIP-2. CONCLUSION: These findings demonstrate that activation of p38 MAPK and release of chemokines by LMPS are mediated by TLR2 in renal proximal tubule cells. These results also implicate the crucial role of innate immunity in leptospira-induced tubulointerstitial nephritis.

Acute renal failure induced by a Brazilian variety of propolis.

Propolis is a resinous substance collected by honeybees and used in hive construction and maintenance. Cumulative evidence suggests that propolis may have anti-inflammatory, antibiotic, antioxidant, antihepatotoxic, and antitumor properties. In addition to topical applications, products containing propolis have been used increasingly as dietary supplements. Although reports of allergic reactions are not uncommon, propolis is reputed to be relatively nontoxic. Its systemic toxicity is rarely reported and hence may be underestimated. This is the first report of propolis-induced acute renal failure. A 59-year-old man required hemodialysis for acute renal failure. The patient had cholangiocarcinoma and had ingested propolis for 2 weeks before presentation. Renal function improved after propolis withdrawal, deteriorated again after reexposure, and then returned to a normal level after the second propolis withdrawal. This case indicates that propolis can induce acute renal failure and emphasizes the need for vigilance and care when propolis is used as a medicine or dietary supplement.

Ultrapure dialysate improves iron utilization and erythropoietin response in chronic hemodialysis patients - a prospective cross-over study.

BACKGROUND: The impact of ultrapure dialysis on dialysate-related chronic inflammatory status and anemia in uremic patients on maintenance hemodialysis (HD) remains uncertain. We evaluated ultrapure dialysate effects on erythropoietin (EPO) response and inflammatory status in a prospective, randomized, cross-over study. METHODS: Thirty-four HD patients were divided into two groups. One group was treated with conventional dialysate and the other group with ultrapure dialysate for 6 months and crossed over for another 6 months. Bacteria growth and dialysate endotoxin were examined. Parameters including C-reactive protein (CRP), recombinant human erythropoietin (rHuEPO) dose, ferritin, iron saturation and serum albumin were measured at the start, and at 6 and 12 months. RESULTS: The endotoxin levels reduced significantly in the ultrapure dialysate by adding a dialysate ultrafilter. After a 6-month treatment with ultrapure dialysate, there were statistically significant differences in the systemic inflammation markers between both groups. Changing from conventional to ultrapure dialysis fluid significantly reduced CRP (7.01 +/- 5.059 to 4.461 +/- 3.754 mg/L, p<0.05), and resulted in reduced rHuEPO doses (12500 +/- 7060 to 10440 +/- 7050 U/month, p<0.05). Continuous conventional dialysate use was not associated with significant alternations in CRP (from 5.849 +/- 7.744 to 6.187 +/- 7.997 mg/L, p=0.456) and rHuEPO dose (14060 +/- 6210 to 15060 +/- 7250U/month, p>0.05). The ferritin level reduced significantly (422 +/- 183 to 272 +/- 162 mcg/L, p<0.05) in the ultrapure dialysate group. After another 6-month cross-over, the study parameters were reversed among the two groups indicating the beneficial effect of ultrapure dialysis. CONCLUSIONS: Through endotoxin reduction in conventional dialysate, ultrapure dialysis in dialysis patients manifested a reduced inflammatory parameter, reduced rHuEPO dose and improved iron utilization; and therefore, could be beneficial in anemia treatment.

Improved iron utilization and reduced erythropoietin resistance by on-line hemodiafiltration.

BACKGROUND: Recent investigation has shown that on-line hemodiafiltration (HDF) can reduce the amount of recombinant human erythropoietin (rhEPO) deemed necessary to reach the target hematocrit. The aim of this study was to analyze the potential effect of on-line HDF on rhEPO resistance in relation to iron utilization and anemia-related parameters, when compared to conventional hemodialysis (HD). METHODS: Ninety-two chronic uremic patients were treated with conventional HD and then shifted to on-line HDF. Measurements of various erythropoiesis-related parameters were collected during HD and on-line HDF periods for statistical analysis for erythropoietin resistance. RESULTS: Patients treated with on-line HDF switching from conventional HD significantly contributed to the reduction of EPO dose to reach a higher mean hematocrit level (31.8 +/- 4.4% vs. 29.5 +/- 3.9%, p < 0.001) and a reduction of the serum ferritin level (322.5 +/- 268.4 vs. 544.9 +/- 642.4, p < 0.001). The median EPO/Hct ratio was greater in the HD period (504.6 +/- 310.1) than in the on-line HDF period (307.6 +/- 334.4) (p < 0.001). These results indicated a reduced EPO resistance and improved iron utilization by on-line HDF. By multiple regression analysis, the significant predictors of EPO resistance are ferritin, transferrin, albumin, and TACurea (Time average concentration of urea) in HD treatment. In on-line HDF modality, in addition to ferritin and albumin, the duration of on-line HDF is a negative predictor in EPO resistance. CONCLUSION: When on-line HDF is recommended to chronic dialysis patients, long-term use of this technique provides an efficient means of achieving the goal of an elevated hemoglobulin by reducing EPO resistance, improved iron utilization and may further improve the quality of life.

Leptospira outer membrane protein activates NF-kappaB and downstream genes expressed in medullary thick ascending limb cells.

Tubulointerstitial nephritis is the main manifestation of acute renal damage caused by leptospirosis, but the mechanism remains unexplored. Patients infected with LEPTOSPIRA: shermani in Taiwan disclosed tubular dysfunction particularly in the medullary thick ascending limb of loop of Henle (mTAL), and the related renal damage seems to be underestimated. To elucidate the mechanism of tubular damage, outer membrane protein extract from LEPTOSPIRA: was administered to a model of cultured mTAL cells derived from normal mice. The addition of outer membrane protein extract from L. shermani to cultured mTAL cells induced a significant nuclear DNA binding of the NF-kappa B transcription factor by electrophoresis mobility shift assay. Forty-eight h after adding the outer membrane protein extract (0.2 microg/ml) to the cultured cells, the expression of inducible nitric oxide mRNA increased by 4.2-fold, monocyte chemoattractant protein-1 by 3-fold, and tumor necrosis factor-alpha by 2.4-fold when compared with untreated cells examined by reverse transcription competitive-PCR. Supernatant nitrite, monocyte chemoattractant protein-1, and tumor necrosis factor-alpha protein levels also increased by 1.8-, 7.1-, and 5-fold, respectively. An antiserum raised against L. shermani largely prevented these effects. Outer membrane protein extract from L. bratislava induced fewer effects than L. shermani, and the avirulent nonpathogenic L. biflexa serovar patoc did not induce significant effects in the mTAL cells. In conclusion, L. shermani infection may cause mTAL cell damage and inflammation through the NF-kappa B-associated pathway. Findings of this study may be important in understanding the pathogenesis of tubulointerstitial nephritis caused by these organisms.