Acquired perforating dermatosis (APD) is a skin disorder occurring in the patients with chronic renal failure (CRF), diabetes mellitus (DM) or both. The purpose of this study was to clarify the clinical and histopathological features of APD, and evaluate role of scratching in the pathogenesis of APD. Twelves patients with APD associated with CRF and DM were enrolled in the study. In six patients who required hemodialysis, the lesions appeared 2-5 yr (mean 3 yr) after the initiation of dialysis, 18-22 yr (mean 19.3 yr) after the occurrence of DM. The other patients who did not receive hemodialysis noted the lesions 4-17 yr (mean 9.5 yr) after the onset of DM. All patients had an eruption of generally pruritic keratotic papules and nodules, primarily on the extensor surface of the extremities and the trunk. The histologic features of our cases showed a crateriform invagination of the epidermis filled by a parakeratotic plug and basophilic cellular debris. The period of treatment for patients who suffered from severe (7 cases) or very severe (3 cases) on the pruritus intensity was longer than that of patients who had mild pruritus (2 cases). These data showed that scratching appear to play a critical part in the pathogenesis of APD.

Background/AimsIn several recent studies, renal biopsies in patients with type 2 diabetes and renal disease have revealed a heterogeneous group of disease entities. Our aim was to study the prognosis and clinical course of nondiabetic renal disease (NDRD) and to determine risk factors for NDRD in patients with type 2 diabetes.MethodsRenal biopsy reports of 110 patients with type 2 diabetes who were seen at Kyung Hee University Medical Center and Kyung Hee University Hospital at Gangdong, Seoul, Korea between January 2000 and December 2011 were retrospectively analyzed.ResultsOf 110 patients with type 2 diabetes, 41 (37.3%) had diabetic nephropathy (DN), 59 (53.6%) had NDRD, and 10 (9.1%) had NDRD superimposed on DN. Immunoglobulin A nephropathy (43.5%) was the most common NDRD. Patients with NDRD had a shorter duration of diabetes, lower frequency of diabetic retinopathy, and better renal outcomes, which might have resulted from the use of aggressive disease-specific treatments such as steroids and immunosuppressants in patients with NDRD.ConclusionsCompared with DN, NDRD was associated with better renal outcomes in patients with type 2 diabetes, as evidenced by a higher cumulative renal survival rate and lower rate of end-stage renal disease (ESRD). Shorter duration of diabetes and absence of retinopathy were independent predictors of NDRD in patients with type 2 diabetes and renal involvement. Renal biopsy is recommended for patients with type 2 diabetes and risk factors for NDRD, to obtain an accurate diagnosis, prompt initiation of disease-specific treatment, and ultimately better renal outcomes with the avoidance of ESRD.

The mechanism of glomerular infiltration of monocytes remains unknown in diabetic nephropathy. We examined the effect of a high glucose concentration on monocyte chemotactic peptide 1 (MCP-1) expression in human mesangial cells (MCs) by using enzyme-linked immunosorbent assay and reverse transcription coupled with polymerase chain reaction (PCR). More than a 50% increase in the MCP-1 protein production was observed in MCs cultured in high-glucose medium (450 mg/dl) as compared to normal glucose (100 mg/dl; 1,496 ± 75 vs. 966 ± 15 pg/ml after 24 h, 1,910 ± 93 vs. 1,250 ± 55 pg/ml after 48 h). Semiquantitative PCR showed that phorbol myristate acetate (100 nM) increased the ratio of PCR products for MCP-1 to housekeeping gene glyceraldehyde-3-phosphate dehydrogenase on densitometric results at 24 h by 2.7-fold, which was prevented by calphostin C (200 nM) pretreatment. High glucose increased the ratio by 3-fold as compared to normal glucose at 24 h (0.72 ± 0.11 vs. 0.24 ± 0.01). This was also suppressed by calphostin C pretreatment. These findings demonstrate that high glucose can directly increase MCP-1 expression in MCs, which may contribute to monocyte infiltration in diabetic nephropathy, and this is regulated by protein kinase C.

Background: Oxidative stress and inflammation are known to play central roles in the development of diabetic nephropathy (DN). Febuxostat is a novel non-purine xanthine oxidase (XO)-specific inhibitor developed to treat hyperuricemia. In this study, we investigated whether febuxostat could ameliorate DN via renoprotective mechanisms such as alleviation of oxidative stress and anti-inflammatory actions. Methods: Male Sprague-Dawley rats were divided into three groups: a normal group, a diabetes group (DM group), and a febuxostat-treated diabetes group (DM+Fx group). We administered 5 mg/kg of febuxostat to experimental rats for 7 weeks and evaluated clinical and biochemical parameters and XO and xanthine dehydrogenase (XDH) activity in hepatic tissue. The degree of oxidative stress and extent of inflammation were evaluated from urine samples and renal tissue collected from each group. Results: Diabetic rats (DM and DM+Fx groups) had higher blood glucose and kidney weight relative to body weight than normal rats. Albuminuria was significantly reduced in febuxostat-treated diabetic rats compared with untreated diabetic rats. Quantitative analysis showed that hepatic XO and XDH activities were higher in the DM groups, but decreased after treatment with febuxostat. Urinary 8-OHdG concentrations and renal cortical nitrotyrosine also indicated reduced oxidative stress in the DM+Fx group relative to the DM group. The number of ED-1-stained cells in the glomerulus and tubule of diabetic renal tissue decreased in febuxostat-treated diabetic rats relative to that of non-treated diabetic rats. Diabetic rats also expressed higher transcript levels of inflammatory genes (E-selectin and VCAM-1), an inflammation-induced enzyme (COX-2), and inflammatory mediators (ED-1 and NF-κB) than control rats; expression of these genes was significantly reduced by treatment with febuxostat. Conclusions: Febuxostat prevents diabetic renal injury such as albuminuria. This renoprotective effect appears to be due to attenuation of the inflammatory and oxidative effects of diabetes-induced renal damage through inhibition of XO and XDH activities.

Background: Anti-phospholipase A2 receptor antibody (PLA2R-Ab) is useful in diagnosing idiopathic membranous nephropathy (IMN). We investigated the clinical relevance of PLA2R-Ab enzyme-linked immunosorbent assay (ELISA) in patients with IMN. Methods: We measured PLA2R-Ab with an ELISA kit from the serum of 160 patients with IMN (n = 93), secondary MN (n = 14) and other glomerulonephritis (n = 41) as well as healthy controls (n = 12) at the time of renal biopsy and investigated the correlation of titers of PLA2R-Ab with clinical parameters. Results: PLA2R-Ab was positive in 41 of 93 patients (44.1%) with IMN. No samples from the patients with secondary MN and other glomerulonephritis or healthy controls were positive with the ELISA test. The PLA2R-Ab-positive patients showed severe disease activity and a low remission rate. The PLA2R-Ab titer positively correlated with proteinuria and was negatively associated with renal function and serum albumin. The patients with a high titer of PLA2R-Ab had significantly decreased remission rates. The cumulative probabilities of remission was significantly lower in patients with PLA2R-Ab (p = 0.01) and even so in patients with a high titer of PLA2R-Ab (p = 0.04). When we compared the ELISA titers with Western blot (WB) data of 43 patients who had been enrolled in our previous study, 18 and 30 patients were positive on ELISA (41.9%) and WB (69.8%), respectively. WB and ELISA had a concordance rate of 72.1% and were positively correlated (r = 0.590, p < 0.001). Conclusion: The presence, as well as a high titer, of PLA2R-Ab on ELISA was associated with poor prognosis of IMN. Assessment of PLA2R-Ab with ELISA is an easy and reliable tool for the diagnosis and guidance of therapeutic plans.