Cutaneous vascular structure and perfusion in patients with chronic plaque psoriasis.

BACKGROUND: Vascular dysfunction is a significant contributor to the pathophysiology of psoriasis. Some individuals have variation within the gene for vascular endothelial growth factor-A (VEGF-A), which confers an increased risk of developing psoriasis and having a severe disease phenotype, and may determine responsiveness to treatment. AIM: To determine whether patients with psoriasis have alterations in cutaneous microvascular anatomy and physiology due to expression of VEGF and whether laser Doppler imaging has utility in the assessment of this. METHODS: Twelve adult volunteers with Type 1 chronic plaque psoriasis underwent laser Doppler imaging of plaque and uninvolved skin. Skin biopsies were taken from the areas imaged for immunohistochemistry, including blood and lymphatic vessel markers, and VEGF-A isotype analysis (VEGF-A121, VEGF-A165 and VEGF-D). Venous blood was collected for DNA extraction, VEGF-A genotyping and peripheral blood mononuclear cell culture. RESULTS: Mean blood vessel area (P < 0·01), number of blood vessels (P < 0·001), number of lymphatic vessels (P < 0·001) and blood flow (P < 0·001) was significantly increased in psoriasis plaques, as was expression of VEGF-A121 (P < 0·01), VEGF-A165 (P < 0·04) and VEGF-D (P < 0·01). Blood flow within psoriasis plaques was independent of their increased vascularity (P < 0·01) and may be associated with baseline productivity of VEGF. The number of blood vessels within uninvolved skin in patients with psoriasis was associated with the VEGF-A (rs833061) genotype (P = 0·01), in a relationship suggesting an allele dosing effect. CONCLUSION: Noninvasive imaging of blood flow may help determine the cutaneous vascular signature for individual patients. This may be a useful prognostic indicator of psoriasis susceptibility and severity, and thus support selection of treatments.

Long-term outcomes of persistent disease and relapse in primary membranous nephropathy.

BACKGROUND: Primary membranous nephropathy is associated with variable clinical course ranging from spontaneous remission to slow progression to end stage renal failure. Achieving remission confers better renal survival in primary membranous nephropathy (PMN). Longer term outcomes such as patient survival and relapse of active disease remain poorly understood. METHODS: We performed a retrospective study of 128 consecutive adult patients diagnosed with biopsy proven PMN at a single UK centre between 1980 and 2010. These patients were followed prospectively over a median of 128 months. We assessed impact of persistent disease and relapse on Stage 5 chronic kidney disease (CKD-5) and patient survival and present longer term cumulative incidences of different end points. RESULTS: One hundred patients achieved partial remission (PartRem) and 28 patients did not achieve remission (NoRem). Nine per cent of patients achieving first remission developed CKD-5 and 75% of those with NoRem developed CKD-5 [hazard ratio (HR) 0.07, 95% confidence interval 0.03-0.19). Relapse following PartRem occurred in 31 patients (31%) during follow-up and was significantly associated with progression to CKD-5. Progression to CKD-5 was strongly associated with death (47 versus 6%, HR 23.4; P < 0.01). Cumulative incidence at 15 years following first presentation included: death, 14%; CKD-5, 28%; and relapse 40% (in patients who achieved first remission). CONCLUSIONS: Our data strongly suggest that mortality in PMN is seen in patients with disease progression to CKD-5. Achieving remission is strongly associated with improved renal survival after first presentation and following relapse. We suggest that patients who achieve remission should be followed up in longer term, and better strategies to help improve outcomes are needed in clinical practice.

rhErythropoietin-b as a tissue protective agent in kidney transplantation: a pilot randomized controlled trial.

BACKGROUND: Extended criteria donor (ECD) and donation after circulatory death (DCD) kidneys are at increased risk of delayed graft function (DGF). Experimental evidence suggests that erythropoietin (EPO) attenuates renal damage in acute kidney injury. This study piloted the administration of high dose recombinant human EPO-beta at implantation of ECD and DCD kidneys, and evaluated biomarkers of kidney injury post-transplant. METHODS: Forty patients were randomly assigned to receive either rhEPO-b (100,000 iu) (n = 19 in the intervention group, as 1 patient was un-transplantable post randomisation), or placebo (n = 20) in this, double blind, placebo-controlled trial at Manchester Royal Infirmary from August 2007 to June 2009. Participants received either an ECD (n = 17) or DCD (n = 22) kidney. Adverse events, renal function, haematopoietic markers, and rejections were recorded out to 90 days post-transplant. Biomarkers of kidney injury (neutrophil gelatinase-associated lipocalin, Kidney Injury Molecule-1 and IL-18) were measured in blood and urine during the first post-operative week. RESULTS: The incidence of DGF (53% vs 55%) (RR = 1.0; CI = 0.5-1.6; p = 0.93) and slow graft function (SGF) (32% vs 25%) (RR = 1.1; CI = 0.5-1.9; p = 0.73) respectively, serum creatinine, eGFR, haemoglobin and haematocrit, blood pressure, and acute rejection were similar in the 2 study arms. High dose rhEPO-b had little effect on the temporal profiles of the biomarkers. CONCLUSIONS: High dose rhEPO-b appears to be safe and well tolerated in the early post- transplant period in this study, but has little effect on delayed or slow graft function in recipients of kidneys from DCD and ECD donors. Comparing the profiles of biomarkers of kidney injury (NGAL, IL-18 and KIM-1) showed little difference between the rhEPO-b treated and placebo groups. A meta-analysis of five trials yielded an overall estimate of the RR for DGF of 0.89 (CI = 0.73; 1.07), a modest effect favouring EPO but not a significant difference. A definitive trial based on this estimate would require 1000-2500 patients per arm for populations with base DGF rates of 50-30% and 90% power. Such a trial is clearly unfeasible. TRIAL REGISTRATION: EudraCT Number 2006-005373-22 ISRCTN ISRCTN85447324 registered 19/08/09.

Anti-heparanase aptamers as potential diagnostic and therapeutic agents for oral cancer.

Heparanase is an endoglycosidase enzyme present in activated leucocytes, mast cells, placental tissue, neutrophils and macrophages, and is involved in tumour metastasis and tissue invasion. It presents a potential target for cancer therapies and various molecules have been developed in an attempt to inhibit the enzymatic action of heparanase. In an attempt to develop a novel therapeutic with an associated diagnostic assay, we have previously described high affinity aptamers selected against heparanase. In this work, we demonstrated that these anti-heparanase aptamers are capable of inhibiting tissue invasion of tumour cells associated with oral cancer and verified that such inhibition is due to inhibition of the enzyme and not due to other potentially cytotoxic effects of the aptamers. Furthermore, we have identified a short 30 bases aptamer as a potential candidate for further studies, as this showed a higher ability to inhibit tissue invasion than its longer counterpart, as well as a reduced potential for complex formation with other non-specific serum proteins. Finally, the aptamer was found to be stable and therefore suitable for use in human models, as it showed no degradation in the presence of human serum, making it a potential candidate for both diagnostic and therapeutic use.

Outcomes of peritoneal dialysis patients and switching to hemodialysis: a competing risks analysis.

BACKGROUND: We performed a review of a large incident peritoneal dialysis cohort to establish the impact of current practice and that of switching to hemodialysis. METHODS: Patients starting peritoneal dialysis between 2004 and 2010 were included and clinical data at start of dialysis recorded. Competing risk analysis and Cox proportional hazards model with time-varying covariate (technique failure) were used. RESULTS: Of 286 patients (median age 57 years) followed for a median of 24.2 months, 76 were transplanted and 102 died. Outcome probabilities at 3 and 5 years respectively were 0.69 and 0.53 for patient survival (or transplantation) and 0.33 and 0.42 for technique failure. Peritonitis caused technique failure in 42%, but ultrafiltration failure accounted only for 6.3%. Davies comorbidity grade, creatinine and obesity (but not residual renal function or age) predicted technique failure. Due to peritonitis deaths, technique failure was an independent predictor of death hazard. When successful switch to hemodialysis (surviving more than 60 days after technique failure) and its timing were analyzed, no adverse impact on survival in adjusted analysis was found. However, hemodialysis via central venous line was associated with an elevated death hazard as compared to staying on peritoneal dialysis, or hemodialysis through a fistula (adjusted analysis hazard ratio 1.97 (1.02 - 3.80)). CONCLUSIONS: Once the patients survive the first 60 days after technique failure, the switch to hemodialysis does not adversely affect patient outcomes. The nature of vascular access has a significant impact on outcome after peritoneal dialysis failure.

Pharmacology, efficacy and safety of oral phosphate binders.

The ideal serum level of phosphate in patients on dialysis, and the benefits of controlling levels of phosphate in serum remain unclear despite observational studies that associate phosphate levels with mortality. In the absence of robust data from trials, current guidelines are necessarily based on opinion. Oral phosphate binders are required by the majority of patients on dialysis, and all of these binders can control serum levels of phosphate to similar degrees. Patient preference and adherence to prescribed therapy is at least as important as the efficacy of the prescribed binder. Avoidance of calcium-containing binders has become accepted practice where the alternatives are affordable, but incontrovertible evidence in favor of this approach is lacking. Use of sevelamer and lanthanum avoids calcium loading, but at considerable financial cost and with no reliable patient outcome data to prove their value. Additional approaches to aid control of serum levels of phosphate include blockade of gastrointestinal phosphate absorption and possibly binding of salivary phosphate. Importantly, the role of phosphate control in determining patient outcomes must be quantified, which is likely to require a large randomized, controlled study of two levels of phosphate control. Without such a study we will continue to rely on observational data with all its uncertainties and potential to mislead.

Nutritional management of patients undergoing surgery following diagnosis with encapsulating peritoneal sclerosis.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of peritoneal dialysis (PD). Gastrointestinal (GI) symptoms affect appetite and dietary intake. Adequate nutrition is especially important if surgical interventions are required. AIM: To investigate the nutritional management of 23 EPS patients that underwent surgical intervention between 1999 and 2005 at Manchester Royal Infirmary, United Kingdom. METHODS: EPS was recognized by GI symptoms and diagnostically confirmed by laparotomy, computed tomographic scanning, or biopsy. RESULTS: Mean time on PD was 74 months (interquartile range 42-89 months). During the 12 months pre-diagnosis, 65% of the group showed significant weight loss (p = 0.0001), with 8 patients losing >10% of body weight; 74% of patients experienced significant albumin decrease (p = 0.001); and 56% of patients experienced GI symptoms during the 6 months pre-diagnosis. Nasogastric (NG) feeding was recommended for 8 patients but continued in only 1. 15 patients (mean albumin 27 g/L) commenced parenteral nutrition (PN); 9 patients recovered, with albumin increasing over the 6-month follow-up. Mean hospital time was 62 days for the group receiving neither NG nor PN, compared with 124.3 for the PN/NG group (p = 0.04). In patients that died of EPS, albumin continued to fall at 3 months post-diagnosis. CONCLUSION: There is currently little guidance for nutritional management of EPS. From this study we recommend (1) a high level of clinical suspicion for EPS, especially if PD patients have weight loss; (2) PN may be better than NG feeding but further studies into dual enteral nutrition and PN are needed; (3) aggressive nutritional supplementation pre- and postoperatively; and (4) dietitians need to recognize the high risk of refeeding syndrome.

VEGF polymorphisms are associated with severity of diabetic retinopathy.

PURPOSE: To determine whether single nucleotide polymorphisms (SNPs) in the vascular endothelial growth factor (VEGF) gene are associated with severity of diabetic retinopathy. METHODS: A case-control study was conducted in which 45 individuals with type 1 or 2 diabetes with proliferative diabetic retinopathy (PDR) and 61 individuals with type 1 or 2 diabetes without retinopathy (DWR) were genotyped for 14 SNPs in the VEGF promoter and gene. RESULTS: Three of the promoter SNP genotypes, -160C, -152A (rs13207351), and -116A (rs1570360), showed significant independent associations with PDR, as well as the minihaplotype CAA (P = 0.00017). Two promoter haplotypes were associated with severity of retinopathy: -460C, -417T, -172C, -165C, -160C, -152A, -141A, -116A, +405C was associated with PDR (OR [95% CI] = 29.92 [3.91, 228.78], P = 1.62 x 10(-5)) and -460C, -2417T, -172C, -165C, -160C, -152A, -141A, -116G, +405G was associated with DWR (OR = 0.05 [0.01, 0.35], P = 0.000373). Furthermore, two haplotype-tagged (ht) SNPs, +4618 (rs735286) and +5092 (rs2146323), and five htSNP haplotypes were associated with severity of retinopathy. When the nine promoter/5' untranslated region [UTR] and five htSNP genotypes were combined into a 14-SNP haplotype, a single haplotype, -460C, -417T, -172C, -165C, -160C, -152A, -141A, -116A, +405C, +674T, +4618C, +5092A, +9162C, +9512C was found to be significantly associated with the PDR group (OR = 18.45 [2.35, 144.67], P = 0.00622). CONCLUSIONS: A clear association was demonstrated between VEGF SNPs and severity of diabetic retinopathy. Furthermore, two of the htSNP haplotypes appear to be more generalized markers for angiogenesis, in that these have been found in prior work to be associated with neovascular age-related macular degeneration.

Encapsulating peritoneal sclerosis following renal transplantation despite tamoxifen and immunosuppressive therapy.

Encapsulating peritoneal sclerosis (EPS) is a rare disease in patients who have undergone peritoneal dialysis (PD). We report a case of EPS following renal transplantation that highlights important clinical issues. Initially, a presumptive diagnosis of EPS was made following surgical and pathological findings at the time of cholecystectomy. CT imaging at this time did not confirm the diagnosis. The patient continued PD and commenced tamoxifen. Prior to and immediately following transplantation, further CT imaging demonstrated no evidence of EPS. Acute bowel obstruction occurred 5 months post-transplantation and a diagnosis of EPS was made both clinically and on CT imaging, despite immunosuppression and tamoxifen. The role of these therapies in managing EPS post-transplant is discussed, in addition to the need for a high index of clinical suspicion to make the diagnosis.

TGF-beta1 in chronic allograft nephropathy following renal transplantation.

BACKGROUND: Evidence from experimental models and clinical studies supports a major role for transforming growth factor-beta1 (TGF-beta1) in renal fibrosis. The aim of this study was to use repeated measurement of plasma TGF-beta1 as an indicator of persistent expression in a cohort of patients during the first 2 years post-renal transplantation and to correlate the findings with the development of chronic allograft nephropathy (CAN). METHODS: Active plasma TGF-beta1 was quantified in 100 consecutive renal allograft recipients (samples/patient = 35.6 +/- 12.9) under standard clinical management for a mean of 23 months (range 3.4-45 months). All patients were followed up for a minimum of 5 years. RESULTS: By 5 years, 23 patients had developed biopsy-proven CAN (CAN+), all of whom had been positive for plasma TGF-beta1. Demographic data were compared between patients who were CAN+ and CAN-negative (CAN-) and were not significantly different. TGF-beta1 exposure expressed as area under the curve / day (AUC/day) was correlated with the incidence of CAN. A Cox regression model was used to investigate the interrelationship of CAN, acute cellular rejection (ACR) and TGF-beta1 levels. ACR episodes were predictive of the development of CAN (log-rank test, p=0.003). After allowing for the effect of ACR (hazard ratio [HR]=3.6; 95% confidence ratio [95% CI], 1.5-8.7) between patients with and without ACR episodes, p=0.003), the independent effect of TGF-beta1 was confirmed (HR=1.7; 95% CI, 1.1-2.6; per quartile; p=0.008). CONCLUSION: The results demonstrate that episodes of ACR are highly predictive of chronic damage in the graft. Cumulative exposure to TGF-beta1 is identified as an independent predictor of CAN in the first 2 years posttransplantation.

Heparanase gene haplotype (CGC) is associated with stage of disease in patients with ovarian carcinoma.

Heparanase (HSPE-1) and vascular endothelial growth factor (VEGF), proangiogenic growth factors, play important roles in the metastatic biology of ovarian cancer. The aim of the present study was to test for association between single nucleotide polymorphisms (SNPs) in HSPE-1 and VEGF and outcome in ovarian cancer. A mutational analysis was performed on the coding sequence of the HSPE-1 gene to define high-frequency SNPs. HSPE-1 polymorphisms, together with two SNPs in the VEGF gene, were studied in 136 patients with ovarian cancer. Patients were categorized into two groups, those with FIGO stages 1 and 2 (group 1) and those with stages 3 and 4 (group 2). We identified 10 polymorphisms in the HSPE-1 gene, those in introns 2, 3 and 5b, and exons 8, 13a and 13b occurring at a minor allele frequency of >/=10%. There was an increase in frequency of those individuals with a genotype that carried at least one copy of the intron 2 (C), exon 8 (G), exon 13a (C) haplotype (CGC) in group 2. Specifically there were 24% with this haplotype in group 2 versus 5% in group 1 (P = 0.0184, odds ratio 5.986, 95% confidence interval 1.340-26.752). Most of this association was captured by the intron 2 genotype, where carriage of the C allele was associated with stage (P = 0.0148, odds ratio 6.524, 95% confidence interval 1.401-27.921). There was no association between VEGF SNPs and stage of disease. The CGC HSPE-1 haplotype associates with stage in ovarian cancer. This haplotype may affect splicing of the HSPE-1 gene, as in silico it alters the presence of a splicing motif.

Paraoxonase gene polymorphism and serum activity in progressive IgA nephropathy.

BACKGROUND: HDL-associated paraoxonase (PON1) reduces oxidation of lipids in LDL, and activity is inversely related to coronary heart disease risk with a beneficial effect on the development of atherosclerosis. Risk factors associated with atherosclerosis, such as hypertension, dyslipidemia and smoking, also promote the progression of chronic glomerulonephritides which may therefore be associated with perturbations in PON1 activity. METHODS: We performed a genetic association study in patients with IgA nephropathy (IgAN) (n=115) compared with control subjects (n=118). The aim was to test whether polymorphisms in the PON1 coding region (Q192R and L55M) and its promoter (-108C/T and -162A/G) are associated with either IgAN or with the progression. We measured serum paraoxonase activity in 60 out of 115 patients. All patients had been followed up for more than 4 years. RESULTS: There were no differences in the genotype frequency at 3 of the polymorphic sites (Q192R, L55M and -108C/T) between the patients and controls. However, the frequency distribution at -162 position (A/G) was significantly diffe-rent in IgAN (p=0.028, chi-square test) with a higher frequency of the heterozygote (0.017, Fisher exact test [FE]; odds ratio [OR] = 1.99; 95% confidence interval [95% CI], 1.14-3.47). Although there were no differences in the genotype frequency at 3 of the polymorphic sites (Q192R, L55M and -162C/T) between the patients with progressive IgA and the nonprogressive patients, we found that the frequency of the C allele for the -108C/T polymorphism was elevated in those patients with nonprogressive disease (n=85) compared with those with progressive disease (n=30) (61% vs. 47%; p=0.070, FE; OR=1.75, 95% CI, 0.97-3.18). Furthermore, PON1 activity was significantly higher in nonprogressive patients compared with progressors (206 +/- 71 vs. 136 +/- 48; p<0.001), and activity significantly correlated with 1/serum creatinine (SCr) (p<0.001; r=0.38). CONCLUSIONS: The results of this study suggest that in IgAN, lower PON1 activity may be associated with the deterioration of kidney function. This could be due to variable expression of the PON1 gene, or a functional effect of the gene product.

Activation of transforming growth factor-beta1 and early atherosclerosis in systemic lupus erythematosus.

The efficiency of activating latent transforming growth factor (TGF)-beta1 in systemic lupus erythematosus (SLE) may control the balance between inflammation and fibrosis, modulating the disease phenotype. To test this hypothesis we studied the ability to activate TGF-beta1 in SLE patients and control individuals within the context of inflammatory disease activity, cumulative organ damage and early atherosclerosis. An Activation Index (AI) for TGF-beta1 was determined for 32 patients with SLE and 33 age-matched and sex-matched control individuals by quantifying the increase in active TGF-beta1 under controlled standard conditions. Apoptosis in peripheral blood mononuclear cells was determined by fluorescence-activated cell sorting. Carotid artery intima-media thickness was measured using standard Doppler ultrasound. These measures were compared between patients and control individuals. In an analysis conducted in patients, we assessed the associations of these measures with SLE phenotype, including early atherosclerosis. Both intima-media thickness and TGF-beta1 AI for SLE patients were within the normal range. There was a significant inverse association between TGF-beta1 AI and levels of apoptosis in peripheral blood mononuclear cells after 24 hours in culture for both SLE patients and control individuals. Only in SLE patients was there a significant negative correlation between TGF-beta1 AI and low-density lipoprotein cholesterol (r = -0.404; P = 0.022) and between TGF-beta1 AI and carotid artery intima-media thickness (r = -0.587; P = 0.0004). A low AI was associated with irreversible damage (SLICC [Systemic Lupus International Collaborating Clinics] Damage Index > or = 1) and was inversely correlated with disease duration. Intima-media thickness was significantly linked to total cholesterol (r = 0.371; P = 0.037). To conclude, in SLE low normal TGF-beta1 activation was linked with increased lymphocyte apoptosis, irreversible organ damage, disease duration, calculated low-density lipoprotein levels and increased carotid IMT, and may contribute to the development of early atherosclerosis.

Interaction between genetic control of vascular endothelial growth factor production and retinoid responsiveness in psoriasis.

Vascular endothelial growth factor (VEGF) promotes angiogenesis, and elevated levels are found in plaques of psoriasis. Two VEGF polymorphisms, +405 and -460, are associated with early-onset psoriasis and are close to the functional activator protein-1 site (+419) through which retinoids, an established systemic therapy for psoriasis, can block production of VEGF. We report that peripheral blood mononuclear cells (PBMCs) and epidermal keratinocytes (KC) from patients with psoriasis demonstrate differential, genotype-dependent, regulation of VEGF. For PBMCs, VEGF genotype distinguishes two groups of patients with psoriasis - "high and low VEGF producers" (P < 0.001). In contrast, KC production of VEGF is not genotype dependent. However, the effects of all-trans retinoic acid (RA) on cellular expression of VEGF are determined by both cell type and genotype. RA inhibits KC production of VEGF in a genotype-dependent manner (P < 0.005) whereas RA stimulates PBMCs production irrespective of VEGF genotype (P < 0.001). We also report that the -460 VEGF polymorphism appears to have a clinical pharmacogenetic role in predicting response or non-response of psoriasis to acitretin (P = 0.01). In future, determination of VEGF gene polymorphisms and thus individual patient VEGF "signatures" may be used as a prognostic factor for psoriasis susceptibility/severity and as a means for optimizing treatment response.

Single-center experience of encapsulating peritoneal sclerosis in patients on peritoneal dialysis for end-stage renal failure.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) or automated peritoneal dialysis (APD). It is characterized by a progressive, intra-abdominal, inflammatory process resulting in sheets of fibrous tissue that cover, bind, and constrict the viscera, thereby compromising the motility and function of the bowel. Although recent therapeutic approaches have been reported with variable success, the ability to detect reliably at an early stage patients at risk for EPS would be beneficial and allow treatment standardization. The aim of this study was to evaluate the clinical features of EPS and identify possible risk factors for its development in CAPD and APD patients. METHODS: This was a review of all cases of EPS in a single center over the last 5 years. RESULTS: There were 810 CAPD and APD patients, managed in our program over this period. We identified 27 cases of EPS, giving an overall of 3.3% in this population. The mean duration of CAPD before diagnosis of EPS was 72.6 +/- 39.7 months (range 16-172). Sixteen cases required surgical treatment and were classified as severe; others were treated conservatively (mild to moderate group). Ten patients received tamoxifen treatment with apparent benefit. The overall mortality rate was 29.6%. Eight patients from the severe group and the entire moderate group survived on hemodialysis or transplantation at 48.71 and 27.63 months follow-up, respectively. Peritonitis rates were not different between the 2 groups and peritoneal history was unremarkable compared to overall peritonitis rates in the unit. Data on small solute transport were not available in all patients in this retrospective analysis. CONCLUSION: EPS is a serious, life-threatening complication of CAPD. Most cases had PD duration of more than 4 years. Careful monitoring by CT scans of the peritoneal membrane in patients beyond 5 years, and early catheter removal in patients with peritoneal thickening should be considered for long-term CAPD patients. Treatment with tamoxifen may be of benefit in these patients.

VEGF -460 genotype plays an important role in progression to chronic kidney disease stage 5.

BACKGROUND: Changes in renal vasculature, with vascular and interstitial fibrosis, are hallmarks of progression to chronic kidney disease (CKD) stage 5. Vascular endothelial growth factor (VEGF) is a potent angiogenic and vascular permeability factor. Transforming growth factor-beta1 (TGF-beta1) plays a critical role in promoting extracellular matrix (ECM) deposition and fibrosis. This study investigates whether genetic polymorphisms of VEGF or TGF-beta1 are associated with (i) progressive decline in renal function in patients with glomerular disorders (cohort 1) and (ii) predisposition to CKD stage 5 in a separate group of renal transplant recipients with various primary diseases (cohort 2). METHODS: Two patient groups were studied. Cohort 1 comprised 91 patients with biopsy-proven glomerular disease who were followed-up for 5 years before categorization as either non-progressors (with stable serum creatinine or < or =30% increase over 5 years, n = 39) or progressors (requiring dialysis, transplantation or whose serum creatinine increased by >30% over 5 years, n = 52). Cohort 2 comprised 107 patients with various primary renal diseases, who had reached CKD stage 5 and undergone renal transplantation at the time of study. All patients were genotyped for the VEGF polymorphisms at positions -460 (C/T) and +405 (G/C). Linkage disequilibrium (LD) was established using EHplus. SNPHAP was used to estimate haplotype frequency and to infer haplotypes to all patients. Cohort 1 patients were genotyped for the TGF-beta1 polymorphisms at positions -800, -509, codons 10 and 25. Genotyping was performed by polymerase chain reaction-restriction length polymorphism (PCR-RFLP). RESULTS: In cohort 1, there was a significant increase in frequency of the -460 VEGF CC genotype 30.8 vs 5.1%, P = 0.008; odds ratio (OR), CC vs TT 10.67, 95% confidence interval (CI), 1.94-58.72 and C allele 56.7 vs 37.2%, P = 0.009; OR 2.22, 95% CI, 1.21-4.04, in the progressor patients when compared with the non-progressors. In cohort 2, there was a significant increase in the VEGF -460 CC genotype when compared with healthy volunteers 37 vs 20.8%, P = 0.011; OR CC vs TT 1.59, 95% CI, 0.72-3.51. The -460 and +405 polymorphisms were in LD P < 0.00007. There were significant differences in diplotype (haplotype pair) frequencies in cohort 1 and 2, P = 0.018, which confirmed the importance of the -460C allele. There were no associations between the VEGF +405 or TGF-beta1 polymorphisms and progressive renal disease. CONCLUSION: In this study, we have demonstrated an association between the VEGF -460 polymorphism and progression to CKD stage 5. The function of this polymorphism remains unclear although previous evidence suggests that promoter constructs containing this single nucleotide polymorphism (SNP) have been associated with increased activity. Clearly there is a role for TGF-beta1 in chronic kidney disease. However, this study found no associations with four TGF-beta1 polymorphisms in this cohort.