Global DNA methylation as a possible biomarker for diabetic retinopathy.

BACKGROUND: We evaluated whether global levels of DNA methylation status were associated with retinopathy as well as providing a predictive role of DNA methylation in developing retinopathy in a case-control study of 168 patients with type 2 diabetes. METHODS: The 5-methylcytosine content was assessed by reversed-phase high-pressure liquid chromatography of peripheral blood leukocytes to determine an individual's global DNA methylation status in the two groups, either with or without retinopathy. RESULTS: The global DNA methylation levels were significantly higher in diabetic retinopathy patients compared with those in non-retinopathy patients (4.90 ± 0.12 vs. 4.22 ± 0.13, respectively; p = 0.001). There was a significant increasing trend in global DNA methylation levels in terms of progressing retinopathy (without retinopathy, 4.22 ± 0.13; non-proliferative diabetic retinopathy, 4.62 ± 0.17; proliferative diabetic retinopathy, 5.07 ± 0.21) (p = 0.006). Additionally, global DNA methylation independent of retinopathy risk factors, which include dyslipidaemia, hypertension, hyperglycaemia and duration of diabetes, was a predictive factor for retinopathy (OR = 1.53, p = 0.015). CONCLUSIONS: Global DNA methylation is modulated during or possibly before the primary stage of diabetes. This observation verifies the metabolic memory effect of hyperglycaemia in early stage of an aetiological process that leads to type 2 diabetes and its associated complications.

Aberrant DNA methylation patterns in diabetic nephropathy.

BACKGROUND: The aim of this study was to evaluate whether global levels of DNA methylation status were associated with albuminuria and progression of diabetic nephropathy in a case-control study of 123 patients with type 2 diabetes- 53 patients with albuminuria and 70 patients without albuminuria. METHODS: The 5-methyl cytosine content was assessed by reverse phase high pressure liquid chromatography (RP-HPLC) of peripheral blood mononuclear cells to determine individual global DNA methylation status in two groups. RESULTS: Global DNA methylation levels were significantly higher in patients with albuminuria compared with those in normal range of albuminuria (p = 0.01). There were significant differences in global levels of DNA methylation in relation to albuminuria (p = 0.028) and an interesting pattern of increasing global levels of DNA methylation in terms of albuminuria severity. In patients with micro- and macro albuminuria, we found no significant correlations between global DNA methylation levels and duration of diabetes (p > 0.05). In both sub groups, there were not significant differences between global DNA methylation levels with good and poor glycaemic control (p > 0.05). In addition, in patients with albuminuria, no differences in DNA methylation levels were observed between patients with and without other risk factors including age, gender, hypertension, dyslipidaemia and obesity. CONCLUSIONS: These data may be helpful in further studies to develop novel biomarkers and new strategies for clinical care of patients at risk of diabetic nephropathy.

Incidence of malignancy after living kidney transplantation: a multicenter study from iran.

Malignancy is a common complication after renal transplantation. However, limited data are available on post-transplant malignancy in living kidney transplantation. Therefore, we made a plan to evaluate the incidence and types of malignancies, association with the main risk factors and patient survival in a large population of living kidney transplantation. We conducted a large retrospective multicenter study on 12525 renal recipients, accounting for up to 59% of all kidney transplantation in Iran during 22 years follow up period. All information was collected from observation of individual notes or computerized records for transplant patients. Two hundred and sixty-six biopsy-proven malignancies were collected from 16 Transplant Centers in Iran; 26 different type of malignancy categorized in 5 groups were detected. The mean age of patients was 46.2±12.9 years, mean age at tumor diagnosis was 50.8±13.2 years and average time between transplantation and detection of malignancy was 50.0±48.4 months. Overall tumor incidence in recipients was 2%. Kaposis' sarcoma was the most common type of tumor. The overall mean survival time was 117.1 months (95% CI: 104.9-129.3). In multivariate analysis, the only independent risk factor associated with mortality was type of malignancy. This study revealed the lowest malignancy incidence in living unrelated kidney transplantation.

Distribution of albuminuria and low glomerular filtration rate in a rural area, Shahreza, Iran.

INTRODUCTION: Chronic kidney disease (CKD) is becoming a major public health problem worldwide. A remarkable part of health budget is designated annually to control end-stage renal disease in most countries. The aim of this study was to screen for CKD among the general population of the rural area of Shahreza, in the central region of Iran. MATERIALS AND METHODS: In a study of rural area around Shahreza, Iran, in 2009, a total of 1400 participants aged over 30 years old were selected by systematic randomized sampling. Glomerular filtration rate (GFR) was used as an index of kidney function and albuminuria, as an index of kidney damage. The simplified Modification of Diet in Renal Disease Study equation was used for estimation of GFR. RESULTS: A GFR less than 60 mL/min/m2 was found in 4.7% of the study population (1.8% in men and 6.1% in women). Microalbuminuria and macroalbuminuria were present in 16.2% of the participants (15% of men and 16.8% of women). Pyuria and hematuria rates were 12.3% and 12.6%. The prevalence of a GFR less than 60 mL/min/1.73 m2 was significantly increasing by age groups in both genders. CONCLUSIONS: Considering its high prevalence, CKD needs measures to identify the disease sooner and requires an active national screening program to identify patients in earlier stages. It seems reasonable to integrate such programs in the primary healthcare system.

Renal involvement in patients with hepatitis C virus infection.

INTRODUCTION: Hepatitis C virus (HCV) infection is a hepatotropic virus causing a variety of extrahepatic immunological manifestations and is a risk factor of a variety of extrahepatic diseases, such as mixed cryoglobulinemia and membranoproliferative glomerulonephritis (MPGN), which is the most common glomerulonephritis. The aim of this study was to evaluate renal involvement in HCV-infected patients. MATERIALS AND METHODS: A total of 300 randomly-selected HCV antibody-positive outpatients at the HCV clinic of Shariati hospital were enrolled. Serum creatinine was measured and glomerular filtration rate was estimated accordingly. Urine proteinuria was measured in 24-hour urine samples. RESULTS: The patients were 249 men (83.2%) and 51 women (16.8%) with a mean age of 37.8 +/- 11.7 years (range, 18 to 70 years). Proteinuria was found in 12 HCV antibody-positive adults (4%), 1 of whom underwent biopsy. He was a 55- year-old man with a 4-month history of facial and lower extremities edema and 3-g proteinuria with a normal kidney function (glomerular filtration rate, 85 mL/min) and normocomplementemia. Kidney biopsy specimens showed MPGN. The frequency of low glomerular filtration rate was 0.7% (2 patients) in the HCV antibody-positive adults. There was no significant relationship between HCV seropositivity and low glomerular filtration rate. CONCLUSIONS: Our observations showed renal involvement in HCV antibody-positive patients. Among immune complex glomerular kidney diseases, MPGN without cryoglobulins is thought to be the most common in these patients.