The evolution of untreated borderline and subclinical rejections at first month kidney allograft biopsy in comparison with histological changes at 6 months protocol biopsies

Our study sought to identify the possible implications of histological findings of borderline and subclinical rejections as well as histological markers of chronic allograft nephropathy (CAN) in protocol biopsies at 1 and 6 months after living-related kidney transplantation. Twenty-eight paired allograft biopsies were blindly reviewed using Banff '97 criteria, among which only 10.7% (6/56) showed no histopathological lesions. BR was found in 9/28 (32.1%) and 6/28 (21.4%), and SR in 3/28 (10.7%) and 10/28 (35.7%) of the patients, in the 1 and 6 month biopsies, respectively. The mean CAN score (sum of histological markers for chronicity) increased significantly at 6 months biopsy, 1.57 +/- 1.36 vs. 4.36 +/- 2.32 (p < 0.01). When compared according to chronicity index (CI < 5 >), the high CI group had a mean CAN score of 2.36 +/- 1.15 at 1 month, which increased to 5.14 +/- 1.99 at 6 months biopsy (188.9%). The proportion of these changes in low CI group were also increased from 0.79 +/- 1.12 to 3.57 +/- 2.38 (451.9%). In conclusion, a protocol 1 month biopsy may uncover a high prevalence of BR or SR in stable allografts. The presence of an untreated BR or SR in biopsies with low chronicity index showed greater susceptibility to histological deterioration on the 6 month biopsy, associated with rapid impairment of graft function and chronic allograft nephropathy.     

A Computational Gene Expression Score for Predicting Immune Injury in Renal Allografts

Background

Whole genome microarray meta-analyses of 1030 kidney, heart, lung and liver allograft biopsies identified a common immune response module (CRM) of 11 genes that define acute rejection (AR) across different engrafted tissues. We evaluated if the CRM genes can provide a molecular microscope to quantify graft injury in acute rejection (AR) and predict risk of progressive interstitial fibrosis and tubular atrophy (IFTA) in histologically normal kidney biopsies.

Methods

Computational modeling was done on tissue qPCR based gene expression measurements for the 11 CRM genes in 146 independent renal allografts from 122 unique patients with AR (n = 54) and no-AR (n = 92). 24 demographically matched patients with no-AR had 6 and 24 month paired protocol biopsies; all had histologically normal 6 month biopsies, and 12 had evidence of progressive IFTA (pIFTA) on their 24 month biopsies. Results were correlated with demographic, clinical and pathology variables.

Results

The 11 gene qPCR based tissue CRM score (tCRM) was significantly increased in AR (5.68 ± 0.91) when compared to STA (1.29 ± 0.28; p < 0.001) and pIFTA (7.94 ± 2.278 versus 2.28 ± 0.66; p = 0.04), with greatest significance for CXCL9 and CXCL10 in AR (p <0.001) and CD6 (p<0.01), CXCL9 (p<0.05), and LCK (p<0.01) in pIFTA. tCRM was a significant independent correlate of biopsy confirmed AR (p < 0.001; AUC of 0.900; 95% CI = 0.705–903). Gene expression modeling of 6 month biopsies across 7/11 genes (CD6, INPP5D, ISG20, NKG7, PSMB9, RUNX3, and TAP1) significantly (p = 0.037) predicted the development of pIFTA at 24 months.

Conclusions

Genome-wide tissue gene expression data mining has supported the development of a tCRM-qPCR based assay for evaluating graft immune inflammation. The tCRM score quantifies injury in AR and stratifies patients at increased risk of future pIFTA prior to any perturbation of graft function or histology.     

Digital pathology evaluation of complement C4d component deposition in the kidney allograft biopsies is a useful tool to improve reproducibility of the scoring

Complement C4d component deposition in kidney allograft biopsies is an established marker of antibody-mediated rejection. In the Banff 07 classification of renal allograft pathology, semi-quantitative evaluation of the proportion of C4d-positive peritubular capilaries (PTC) is used. We aimed to explore the potential of digital pathology tools to obtain quantitative and reproducible measure of C4d deposition in the renal allograft tissue.34 routine kidney allograft biopsies immunohistochemically stained for C4d were included in the study and were evaluated by a qualified pathologist twice, recording an approximate percentage of positive PTC and glomerular area. The same slides were scanned by Aperio ScanScope scanner. Two layers of annotations were created: layer of glomeruli and the remaining non-glomerular area. Image analysis was performed with Aperio Positive Pixel Count algorithm to quantify the proportion of C4d-positive pixels in the area analysed. The percentage of positive (defined as 2+ and 3+) pixels in glomeruli and non-glomerular area was obtained and compared to the percentage of C4d-positive PTC and C4d-positive area of glomeruli recorded by the pathologist. The correlation of digital and manual C4d-positive area scoring in glomeruli was very high (r= 0.89, p<0.0001), while the correlation for non-glomerular (digital) and PTC (manual) area was moderate (r=0.60, p<0.001). The correlation between digital and manual evaluation of C4d in non-glomerular area after exclusion of C4d-positive arterioles from analysis did not improve substantially (r = 0.59, p < 0.001). Reproducibility of digital and manual results was evaluated. For C4d deposition in PTC, agreement between the first and the second digital C4d evaluation (after re-drawing annotations) was perfect (κ=0.96, CI 0.91÷1.00) while agreement between two subsequent manual C4d scorings was substantial (κ = 0.67, CI 0.47 ÷ 0.88). Similarly, for C4d deposition in the glomeruli, agreement of digital evaluation was perfect (κ=1) while for manual scorings it was substantial (κ = 0.76, CI 0.64 ÷ 0.88). Digital evaluation of C4d deposition in allograft kidney correlates with pathologist's scoring and exceeds the latter in reproducibilty. Therefore, it provides a useful tool to control for intraobserver and interobserver variability and may serve as quality assurance measure for allograft pathology diagnosis and research.     

Sarcoidosis in Native and Transplanted Kidneys: Incidence,Pathologic Findings,and Clinical Course

Renal involvement by sarcoidosis in native and transplanted kidneys classically presents as non caseating granulomatous interstitial nephritis. However, the incidence of sarcoidosis in native and transplant kidney biopsies, its frequency as a cause of end stage renal disease and its recurrence in renal allograft are not well defined, which prompted this study. The electronic medical records and the pathology findings in native and transplant kidney biopsies reviewed at the Johns Hopkins Hospital from 1/1/2000 to 6/30/2011 were searched. A total of 51 patients with a diagnosis of sarcoidosis and renal abnormalities requiring a native kidney biopsy were identified. Granulomatous interstitial nephritis, consistent with renal sarcoidosis was identified in kidney biopsies from 19 of these subjects (37%). This is equivalent to a frequency of 0.18% of this diagnosis in a total of 10,023 biopsies from native kidney reviewed at our institution. Follow-up information was available in 10 patients with biopsy-proven renal sarcoidosis: 6 responded to treatment with prednisone, one progressed to end stage renal disease. Renal sarcoidosis was the primary cause of end stage renal disease in only 2 out of 2,331 transplants performed. Only one biopsy-proven recurrence of sarcoidosis granulomatous interstitial nephritis was identified.

Conclusions

Renal involvement by sarcoidosis in the form of granulomatous interstitial nephritis was a rare finding in biopsies from native kidneys reviewed at our center, and was found to be a rare cause of end stage renal disease. However, our observations indicate that recurrence of sarcoid granulomatous inflammation may occur in the transplanted kidney of patients with sarcoidosis as the original kidney disease.     

Post-Bypass Dexmedetomidine Use and Postoperative Acute Kidney Injury in Patients Undergoing Cardiac Surgery with Cardiopulmonary Bypass

Background

And Objectives: The aim of this retrospective investigation was to study the relationships among chronic kidney disease, acute kidney injury (AKI), and potential benefits by post-bypass dexmedetomidine use in patients undergoing cardiac surgery.

Methods

The patient data were reviewed from the institutional Society of Thoracic Surgeons National Adult Cardiac Surgery Database after IRB approval. 1,133 patients were identified and divided into two groups: those who received dexmedetomidine or those who did not during the post-bypass period. The postoperative outcomes include the incidence of AKI, any complication and all cause of mortality.

Results

Post-bypass dexmedetomidine use was associated with significantly reduced the incidence of total AKI (26.1% vs. 33.75%; adjusted OR, 0.7033; 95%CI, 0.540 to 0.916; p=0.0089). In addition, post-bypass dexmedetomidine use was more likely to reduce the incidence of AKI in these patients with preoperative normal kidney function (Stage1; 32.8% to 22.8%; p=0.0233) and mild CKD (Stage 2; 32.8% to 24.7; p=0.0003) after cardiac surgery. Post-bypass infusion of dexmedetomidine was associated with significantly reduced incidence of any complication and 30-day mortalities.

Conclusions

Post-bypass dexmedetomidine use is associated with a significant reduction in the incidence of AKI, especially mild AKI in patients with preoperative normal renal function and mild CKD undergoing cardiac surgery.     

In vivo endothelial gene regulation in diabetes

Background

In comparison to the well established changes in compliance that occur at the large vessel level in diabetes, much less is known about the changes in compliance of the cardiovascular system at the end-organ level. The aim of this study was therefore to examine whether there was a correlation between resistance of the intrarenal arteries of the kidney and compliance of the left ventricle, as estimated by measurements of diastolic function, in subjects with type 2 diabetes.

Methods

We studied 167 unselected clinic patients with type 2 diabetes with a kidney duplex scan to estimate intrarenal vascular resistance, i.e. the resistance index (RI = peak systolic velocity-minimum diastolic velocity/peak systolic velocity) and a transthoracic echocardiogram (TTE) employing tissue doppler studies to document diastolic and systolic ventricular function.

Results

Renal RI was significantly higher in subjects with diastolic dysfunction (0.72 ± 0.05) when compared with those who had a normal TTE examination (0.66 ± 0.06, p < 0.01). Renal RI values were correlated with markers of diastolic dysfunction including the E/Vp ratio (r = 0.41, p < 0.001), left atrial area (r = 0.36, p < 0.001), the E/A ratio (r = 0.36, p < 0.001) and the E/E' ratio (r = 0.31, p < 0.001). These associations were independent of systolic function, hypertension, the presence and severity of chronic kidney disease, the use of renin-angiotensin inhibitors and other potentially confounding variables.

Conclusion

Increasing vascular resistance of the intrarenal arteries was associated with markers of diastolic dysfunction in subjects with type 2 diabetes. These findings are consistent with the hypothesis that vascular and cardiac stiffening in diabetes are manifestations of common pathophysiological mechanisms.     

Prospective study of BKV nephropathy in 117 renal transplant recipients

Nephropathy caused by poliomavirus (BKVAN) in transplant recipients is responsible for the loss of the transplanted organ. In this study we suggest a non-invasive diagnostic protocol for the early identification of BKVAN during follow-up treatments. In 117 kidney transplant recipients follow-up was performed every three months during a two year period after transplantation and a positive screening result was confirmed and assessed by quantitative assays (BKV DNA load in plasma and urine). The definitive diagnosis of BKV requires allograft biopsy. Of the 117 patients 4 had BKVAN (3.4%), and the consequential reduction of immunosuppression improved kidney function and plasma clearance of the virus was achieved.     

Twelve-week monotherapy with the DPP-4 inhibitor vildagliptin improves glycemic control in subjects with type 2 diabetes.

Inhibition of dipeptidyl peptidase-4 enhances the activity of incretin hormones, improving glycemic control in subjects with type 2 diabetes. This twelve-week randomized, double-masked, placebo-controlled study assessed the efficacy and tolerability of the specific and potent oral dipeptidyl peptidase-4 inhibitor, vildagliptin (25 mg, bid, n=70) VS. placebo (bid, n=28) in previously diet-treated subjects with type 2 diabetes. Standardized meal tests were performed at baseline and endpoint. The between-group difference in adjusted mean change in HbA1c from baseline to endpoint was - 0.6 +/- 0.2 % (p=0.0012) for the whole cohort (baseline 8.0 %) and -1.2 % for subjects with baseline HbA1c 8.0 - 9.5 %. Fasting glucose and mean prandial glucose were reduced by 1.1 +/- 0.4 (p=0.0043) and 1.9 +/- 0.5 mmol/l (p <0.0001), respectively. The between-group differences in corrected insulin response at peak glucose and mean prandial C-peptide were + 0.06 +/- 0.02 (p=0.0258) and + 0.10 +/- 0.03 nmol/l (p=0.0031), respectively. Vildagliptin had no effect on fasting lipid levels or body weight. The incidence of adverse events was similar in subjects receiving placebo (71.4 %) and vildagliptin (55.7 %). CONCLUSION: monotherapy with vildagliptin is well tolerated and improves glycemic control in diet-treated subjects with type 2 diabetes. Concomitant improvements in beta-cell function were also observed. Subjects with higher baseline HbA1c levels showed greater response.     

A Novel Therapy to Attenuate Acute Kidney Injury and Ischemic Allograft Damage after Allogenic Kidney Transplantation in Mice

Ischemia followed by reperfusion contributes to the initial damage to allografts after kidney transplantation (ktx). In this study we tested the hypothesis that a tetrapeptide EA-230 (AQGV), might improve survival and attenuate loss of kidney function in a mouse model of renal ischemia/reperfusion injury (IRI) and ischemia-induced delayed graft function after allogenic kidney transplantation. IRI was induced in male C57Bl/6N mice by transient bilateral renal pedicle clamping for 35 min. Treatment with EA-230 (20–50mg/kg twice daily i.p. for four consecutive days) was initiated 24 hours after IRI when acute kidney injury (AKI) was already established. The treatment resulted in markedly improved survival in a dose dependent manner. Acute tubular injury two days after IRI was diminished and tubular epithelial cell proliferation was significantly enhanced by EA-230 treatment. Furthermore, CTGF up-regulation, a marker of post-ischemic fibrosis, at four weeks after IRI was significantly less in EA-230 treated renal tissue. To learn more about these effects, we measured renal blood flow (RBF) and glomerular filtration rate (GFR) at 28 hours after IRI. EA-230 improved both GFR and RBF significantly. Next, EA-230 treatment was tested in a model of ischemia-induced delayed graft function after allogenic kidney transplantation. The recipients were treated with EA-230 (50 mg/kg) twice daily i.p. which improved renal function and allograft survival by attenuating ischemic allograft damage. In conclusion, EA-230 is a novel and promising therapeutic agent for treating acute kidney injury and preventing IRI-induced post-transplant ischemic allograft injury. Its beneficial effect is associated with improved renal perfusion after IRI and enhanced regeneration of tubular epithelial cells.     

TGF-beta1 expression and chronic allograft nephropathy in protocol kidney graft biopsy

Chronic allograft nephropathy (CAN) represents a frequent and irreversible cause of long-term renal graft loss. TGF-beta1 is a key profibrogenic cytokine associated with CAN pathogenesis. Because of clinical diagnostic inaccuracy, protocol biopsy has been suggested to be a beneficial method for early CAN detection. Protocol core biopsy was carried out in 67 consecutive cyclosporine-based immunosuppression-treated kidney transplant recipients with stable renal function 12 months after renal transplantation. Biopsy specimens were analyzed morphologically according to Banff-97' criteria and immunohistologically for TGF-beta1 staining. The data obtained were correlated with plasma TGF-beta1 levels and clinical data. CAN (grade I-III) was found in 51 patients (76 %). CAN grade I was found to be the most frequent one (44 %). A normal finding within the graft was made in only 12 patients (18 %). Clinically silent acute rejection Banff IA was present in 4 patients (6 %). In 8 patients (12 %) with CAN, borderline changes were present. We found a significant correlation between CAN grade and creatinine clearance, as measured by the Cockroft-Gault formula (p<0.01) as well as body mass index (p<0.01). There was a significant correlation between chronic vasculopathy (Banff cv) and creatinine clearance, and between the degree of TGF-beta1 staining and chronic vasculopathy (p<0.01). There were no relations between morphological findings and TGF-beta1 plasma levels, cyclosporine levels, plasma lipids, HLA-mismatches, panel reactive antibodies (PRA), proteinuria, and the donor's age. In conclusion, CAN is a frequent finding in protocol kidney graft biopsies 12 months after transplantation. TGF-beta1 tissue expression is linked with chronic vasculopathy.     

Depressed cardiac myofilament function in human diabetes mellitus

Diabetes mellitus is associated with a distinct cardiomyopathy. Whether cardiac myofilament function is altered in human diabetes mellitus is unknown. Myocardial biopsies were obtained from seven diabetic patients and five control, nondiabetic patients undergoing coronary artery bypass surgery. Myofilament function was assessed by determination of the developed force-Ca2+ concentration relation in skinned cardiac cells from flash-frozen human biopsies. Separate control experiments revealed that flash freezing of biopsy specimens did not affect myofilament function. All patients in the diabetes mellitus cohort were classified as Type 2 diabetes mellitus patients, and most showed signs of diastolic dysfunction. Diabetes mellitus was associated with depressed myofilament function, that is, decreased Ca2+ sensitivity (29%, P < 0.05 vs. control) and a trend toward reduction of maximum Ca2+-saturated force (29%, P = 0.08 vs. control). The slope of the force-Ca2+ concentration relation (Hill coefficient) was not affected by diabetes, however. We conclude that human diabetes mellitus is associated with decreased cardiac myofilament function. Depressed cardiac myofilament Ca2+ responsiveness may underlie the decreased ventricular function characteristic of human diabetic cardiomyopathy.     

HLA-DRw6 and renal allograft rejection.

HLA-DRw6-positive patients are "high responders" to certain renal allograft antigens. A study was therefore conducted of the outcome of 247 first renal allografts in 74 DRw6-positive and 173 DRw6-negative recipients. The effectiveness of matching for HLA-DR determinants in both groups was also analysed. The one-year graft survival in DRw6-positive patients was 59% as compared with 75% in DRw6-negative recipients (p = 0.012). A striking difference between the two groups was that HLA-DR matching significantly improved renal allograft survival only in the DRw6-positive patients. In those patients the one-year survival of HLA-DR-identical grafts was 95% as compared with only 38% for 2-DR mismatched grafts (p = 0.009). In DRw6-negative patients only a slight beneficial effect of HLA-DR matching was observed (83% versus 72% at one year for the 0-DR and 2-DR mismatched grafts, respectively) (p greater than 0.05). These findings are clear evidence that DRw6-positive patients (about a quarter of the patients on the waiting list of Eurotransplant) should be given HLA-DR-identical kidney transplants only.     

Increased hexokinase/glucose-6-phosphatase ratio in the diabetic kidney as index of glucose overutilization

In mice with streptozotocin-induced diabetes of 3 days' duration, the hexokinase/glucose-6-phosphatase (HK/G6Pase) ratio in the kidney was enhanced by 52% (mean +/- SEM: 0.40 +/- 0.04 vs. 0.26 +/- 0.03; p less than 0.02) compared to control mice as a result of a 25% increase of HK (16.68 +/- 0.93 vs. 13.31 +/- 1.04 nmol/min/mg protein; p = 0.05) and a 17% decrease of G6Pase (42.51 +/- 2.75 vs. 51.25 +/- 1.89; p less than 0.05). In contrast, as expected, the corresponding ratio (HK + glucokinase/G6Pase) was strikingly reduced in the liver. In 9-day diabetic mice, the kidney enzyme changes were much smaller; however, in a chronic disease such as diabetes, even minimal deviations from the normal may lead to significant metabolic changes with time. The enhanced HK/G6Pase ratio in the diabetic kidney suggests an increase in glucose utilization. This may contribute to the increased synthesis of glycogen, glycoproteins (including basement membrane) and RNA (via provision of ribose-phosphate) occurring in the diabetic kidney and supports the view that the kidney (as opposed to other tissues) shows an 'anabolic response' to diabetes.     

Recognition and management of community-acquired acute kidney injury in low-resource settings in the ISN 0by25 trial: A multi-country feasibility study

BackgroundAcute kidney injury (AKI) is increasingly encountered in community settings and contributes to morbidity, mortality, and increased resource utilization worldwide. In low-resource settings, lack of awareness of and limited access to diagnostic and therapeutic interventions likely influence patient management. We evaluated the feasibility of the use of point-of-care (POC) serum creatinine and urine dipstick testing with an education and training program to optimize the identification and management of AKI in the community in 3 low-resource countries.Methods and findingsPatients presenting to healthcare centers (HCCs) from 1 October 2016 to 29 September 2017 in the cities Cochabamba, Bolivia; Dharan, Nepal; and Blantyre, Malawi, were assessed utilizing a symptom-based risk score to identify patients at moderate to high AKI risk. POC testing for serum creatinine and urine dipstick at enrollment were utilized to classify these patients as having chronic kidney disease (CKD), acute kidney disease (AKD), or no kidney disease (NKD). Patients were followed for a maximum of 6 months with repeat POC testing. AKI development was assessed at 7 days, kidney recovery at 1 month, and progression to CKD and mortality at 3 and 6 months. Following an observation phase to establish baseline data, care providers and physicians in the HCCs were trained with a standardized protocol utilizing POC tests to evaluate and manage patients, guided by physicians in referral hospitals connected via mobile digital technology. We evaluated 3,577 patients, and 2,101 were enrolled: 978 in the observation phase and 1,123 in the intervention phase. Due to the high number of patients attending the centers daily, it was not feasible to screen all patients to assess the actual incidence of AKI. Of enrolled patients, 1,825/2,101 (87%) were adults, 1,117/2,101 (53%) were females, 399/2,101 (19%) were from Bolivia, 813/2,101 (39%) were from Malawi, and 889/2,101 (42%) were from Nepal. The age of enrolled patients ranged from 1 month to 96 years, with a mean of 43 years (SD 21) and a median of 43 years (IQR 27–62). Hypertension was the most common comorbidity (418/2,101; 20%). At enrollment, 197/2,101 (9.4%) had CKD, and 1,199/2,101 (57%) had AKD. AKI developed in 30% within 7 days. By 1 month, 268/978 (27%) patients in the observation phase and 203/1,123 (18%) in the intervention phase were lost to follow-up. In the intervention phase, more patients received fluids (observation 714/978 [73%] versus intervention 874/1,123 [78%]; 95% CI 0.63, 0.94; p = 0.012), hospitalization was reduced (observation 578/978 [59%] versus intervention 548/1,123 [49%]; 95% CI 0.55, 0.79; p < 0.001), and admitted patients with severe AKI did not show a significantly lower mortality during follow-up (observation 27/135 [20%] versus intervention 21/178 [11.8%]; 95% CI 0.98, 3.52; p = 0.057). Of 504 patients with kidney function assessed during the 6-month follow-up, de novo CKD arose in 79/484 (16.3%), with no difference between the observation and intervention phase (95% CI 0.91, 2.47; p = 0.101). Overall mortality was 273/2,101 (13%) and was highest in those who had CKD (24/106; 23%), followed by those with AKD (128/760; 17%), AKI (85/628; 14%), and NKD (36/607; 6%). The main limitation of our study was the inability to determine the actual incidence of kidney dysfunction in the health centers as it was not feasible to screen all the patients due to the high numbers seen daily.ConclusionsThis multicenter, non-randomized feasibility study in low-resource settings demonstrates that it is feasible to implement a comprehensive program utilizing POC testing and protocol-based management to improve the recognition and management of AKI and AKD in high-risk patients in primary care.

Etienne Macedo and colleagues report on a point-of-care testing program for acute kidney injury and disease in high-risk primary care patients.     

Evaluation of gene panel mRNAs in urine samples of kidney transplant recipients as a non-invasive tool of graft function

Non-invasive monitoring may be useful after kidney transplantation (KT), particularly for predicting acute rejection (AR). It is less clear whether chronic allograft nephropathy (CAN) is also associated with changes in urine cells. To identify non-invasive markers of allograft function in kidney transplant patients (KTP), mRNA levels of AGT, TGF-beta1, EGFR, IFN-gamma, TSP-1, and IL-10 in urine (Ur) samples were studied using QRT-PCR. Ninety-five KTP and 111 Ur samples were evaluated. Patients (Pts) were divided as, within six months (N = 31), and with more than six months post-KT (N = 64). KTP with more than six months post-KT were classified as KTP with stable kidney function (SKF) (N = 32), KTP with SKF (creatinine < 2 mg/dL) and proteinuria > 500 mg/24 h (N = 18), and KTP with biopsy proven CAN (N = 14). F-test was used to test for equality of variances between groups. IL-10 mRNA was decreased in Ur samples from KTP with less than six months post-KT (P = 0.005). For KTR groups with more than six months post-KT, AGT and EGFR mRNA were statistically different among KTP with SKF, KTP with SKF and proteinuria, and CAN Pts (P = 0.003, and P = 0.01), with KTP with SKF having higher mean expression. TSP-1 mRNA levels also were significantly different among these three groups (P = 0.04), with higher expression observed in CAN Pts. Using the random forest algorithm, AGT, EGFR, and TGF-beta1 were identified as predictors of CAN, SKF, SKF with proteinuria. A characteristic pattern of mRNA levels in the different KTP groups was observed indicating that the mRNA levels in Ur cells might reflect allograft function.     

Higher incidence of death in multi-vessel coronary artery disease patients associated with polymorphisms in chromosome 9p21

ABSTRACT: OBJECTIVE: We investigated whether 9p21 polymorphisms are associated with cardiovascular events in a group of 611 patients enrolled in the Medical, Angioplasty or Surgery Study II (MASS II), a randomized trial comparing treatments for patients with coronary artery disease (CAD) and preserved left ventricular function. METHODS: The participants of the MASS II were genotyped for 9p21 polymorphisms (rs10757274, rs2383206, rs10757278 and rs1333049). Survival curves were calculated with the Kaplan-Meier method and compared with the log-rank statistic. We assessed the relationship between baseline variables and the composite end-point of death, death from cardiac causes and myocardial infarction using a Cox proportional hazards survival model. RESULTS: We observed significant differences between patients within each polymorphism genotype group for baseline characteristics. The frequency of diabetes was lower in patients carrying GG genotype for rs10757274, rs2383206 and rs10757278 (29.4%, 32.8%, 32.0%) compared to patients carrying AA or AG genotypes (49.1% and 39.2%, p= 0.01; 52.4% and 40.1%, p= 0.01; 47.8% and 37.9%, p= 0.04; respectively). Significant differences in genotype frequencies between double and triple vessel disease patients were observed for the rs10757274, rs10757278 and rs1333049. Finally, there was a higher incidence of overall mortality in patients with the GG genotype for rs2383206 compared to patients with AA and AG genotypes (19.5%, 11.9%, 11.0%, respectively; p= 0.04). Moreover, the rs2383206 was still significantly associated with a 1.75-fold increased risk of overall mortality (p= 0.02) even after adjustment of a Cox multivariate model for age, previous myocardial infarction, diabetes, smoking and type of coronary anatomy. CONCLUSION: Our data are in accordance to previous evidence that chromosome 9p21 genetic variation may constitute a genetic modulator in the cardiovascular system in different scenarios, including in patients with established CAD, by revealing an association between the rs2383206 and higher incidence of overall mortality and death from cardiac causes in patients with multi-vessel CAD.     

Duration of streptozotocin-induced diabetes differentially affects p38-mitogen-activated protein kinase (MAPK) phosphorylation in renal and vascular dysfunction

Background

In the present study we tested the hypothesis that progression of streptozotocin (STZ)-induced diabetes (14-days to 28-days) would produce renal and vascular dysfunction that correlate with altered p38- mitogen-activated protein kinase (p38-MAPK) phosphorylation in kidneys and thoracic aorta.

Methods

Male Sprague Dawley rats (350–400 g) were randomized into three groups: sham (N = 6), 14-days diabetic (N = 6) and 28-days diabetic rats (N = 6). Diabetes was induced using a single tail vein injection of STZ (60 mg/kg, I.V.) on the first day. Rats were monitored for 28 days and food, water intake and plasma glucose levels were noted. At both 14-days and 28-days post diabetes blood samples were collected and kidney cortex, medulla and aorta were harvested from each rat.

Results

The diabetic rats lost body weight at both 14-days (-10%) and 28-days (-13%) more significantly as compared to sham (+10%) group. Glucose levels were significantly elevated in the diabetic rats at both 14-days and 28-days post-STZ administration. Renal dysfunction as evidenced by renal hypertrophy, increased plasma creatinine concentration and reduced renal blood flow was observed in 14-days and 28-days diabetes. Vascular dysfunction as evidenced by decreased carotid blood flow was observed in 14-days and 28-days diabetes. We observed an up-regulation of inducible nitric oxide synthase (iNOS), prepro endothelin-1 (preproET-1) and phosphorylated p38-MAPK in thoracic aorta and kidney cortex but not in kidney medulla in 28-days diabetes group.

Conclusion

The study provides evidence that diabetes produces vascular and renal dysfunction with a profound effect on signaling mechanisms at later stage of diabetes.     

Involvement of interaction between viral VP466 and host tropomyosin proteins in virus infection in shrimp

The C3 component of complement has different roles in kidney disease and its local production in donor kidney may affect allograft function and rejection after organ transplantation. A single base substitution in c3 gene (rs2230199), defines two common allelic variants with different mobility on gel electrophoresis: S (Slow) and F (Fast). In order to evaluate the effect of this polymorphism on acute renal allograft rejection, one hundred samples of donor and recipients were collected and genotyping was done by PCR-RFLP method. The allelic frequencies were: C3S=0.791, C3F=0.209. There was no significant association between recipient's genotype and acute rejection (p value<0.05). No correlation between donor genotype and acute rejection was also present. Patients were divided into four groups, according to the recipient and donor genotypes: SS recipients and FS or FF donor, SS recipient and donor, FF or FS recipient and SS donor and FS or FF recipient and donor. There was no significant difference in rate of acute rejection between groups. Although the results didn't find any association between C3 complement polymorphisms and acute allograft rejection, there was no acute rejection in FS or FF donors and SS recipient group.