Search

Background Previous clinical studies of autosomal dominant polycystic kidney disease (ADPKD) reported that loss of kidney function usually follows a steep and relentless course. A detailed examination of individual patterns of decline in estimated glomerular filtration rate (eGFR) has not been performed. Study Design Longitudinal post hoc analysis of data collected during the Halt Progression of Polycystic Kidney Disease (HALT-PKD) trials. Setting & Participants 494 HALT-PKD Study A participants (younger; preserved eGFR) and 435 Study B participants (older; reduced eGFR) who had more than 3 years of follow-up and 7 or more eGFR assessments. Measurements Longitudinal eGFR assessments using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) creatinine equation. Predictors Demographic, clinical, laboratory, and imaging features of participants. Outcomes Probability of linear and nonlinear decline patterns or of stable eGFR calculated for each participant from a Bayesian model of individual eGFR trajectories. Results Most (62.5% in Study A and 81% in Study B) participants had a linear decline in eGFR during up to 8 years of follow-up. A proportion (22% in Study A and 13% in Study B) of progressors had a nonlinear pattern. 15.5% of participants in Study A and 6% in Study B had a prolonged (≥4.5 years) period of stable eGFRs. These individuals (Study A) had significantly smaller total kidney volumes, higher renal blood flows, lower urinary albumin excretion, and lower body mass index at baseline and study end. In Study B, participants with reduced but stable eGFRs were older than the progressors. Two-thirds of nonprogressors in both studies had PKD1 mutations, with enrichment for weak nontruncating mutations. Limitations Relatively short follow-up of a clinical trial population. Conclusions Although many individuals with ADPKD have a linear decline in eGFR, prolonged intervals of stable GFRs occur in a substantial fraction. Lower body mass index was associated with more stable kidney function in early ADPKD.

Objective:To investigate whether creatine administration could slow progressive functional decline in adults with early symptoms of Huntington disease.Methods:We conducted a multicenter, randomized, double-blind, placebo-controlled study of up to 40 g daily of creatine monohydrate in participants with stage I and II HD treated for up to 48 months. The primary outcome measure was the rate of change in total functional capacity (TFC) between baseline and end of follow-up. Secondary outcome measures included changes in additional clinical scores, tolerability, and quality of life. Safety was assessed by adverse events and laboratory studies.Results:At 46 sites in North America, Australia, and New Zealand, 553 participants were randomized to creatine (275) or placebo (278). The trial was designed to enroll 650 patients, but was halted for futility after the first interim analysis. The estimated rates of decline in the primary outcome measure (TFC) were 0.82 points per year for participants on creatine, 0.70 points per year for participants on placebo, favoring placebo (nominal 95% confidence limits −0.11 to 0.35). Adverse events, mainly gastrointestinal, were significantly more common in participants on creatine. Serious adverse events, including deaths, were more frequent in the placebo group. Subgroup analysis suggested that men and women may respond differently to creatine treatment.Conclusions:Our data do not support the use of creatine treatment for delaying functional decline in early manifest HD.Clinicaltrials.gov identifier:NCT00712426.Classification of evidence:This study provides Class II evidence that for patients with early symptomatic HD, creatine monohydrate is not beneficial for slowing functional decline.

Controlled trials provide the most valid determination of the efficacy and safety of an intervention, but large cardiovascular clinical trials have become extremely costly and complex, making it difficult to study many important clinical questions. A critical question, and the main objective of this review, is how trials might be simplified while maintaining randomisation to preserve scientific integrity and unbiased efficacy assessments. Experience with alternative approaches is accumulating, specifically with registry-based randomised controlled trials that make use of data already collected. This approach addresses bias concerns while still capitalising on the benefits and efficiencies of a registry. Several completed or ongoing trials illustrate the feasibility of using registry-based controlled trials to answer important questions relevant to daily clinical practice. Randomised trials within healthcare organisation databases may also represent streamlined solutions for some types of investigations, although data quality (endpoint assessment) is likely to be a greater concern in those settings. These approaches are not without challenges, and issues pertaining to informed consent, blinding, data quality and regulatory standards remain to be fully explored. Collaboration among stakeholders is necessary to achieve standards for data management and analysis, to validate large data sources for use in randomised trials, and to re-evaluate ethical standards to encourage research while also ensuring that patients are protected. The rapidly evolving efforts to streamline cardiovascular clinical trials have the potential to lead to major advances in promoting better care and outcomes for patients with cardiovascular disease.

While conducting a set of large-scale multi-site pragmatic clinical trials involving high-impact public health issues such as end-stage renal disease, opioid use, and colorectal cancer, there were substantial changes to both policies and guidelines relevant to the trials. These external changes gave rise to unexpected challenges for the trials, including decisions regarding how to respond to new clinical practice guidelines, increased difficulty in implementing trial interventions, achieving separation between treatment groups, and differential responses across sites. In this article, we describe these challenges and the approaches used to address them. When deliberating appropriate action in the face of external changes during a pragmatic clinical trial, we recommend considering the well-being of the participants, clinical equipoise, and the strength and quality of the evidence associated with the change; involving those charged with data and safety monitoring; and where possible, planning for potential external changes as the trial is being designed. Any solution must balance the primary obligation to protect the well-being of participants with the secondary obligation to protect the integrity of the trial in order to gain meaningful answers to important public health questions.

The National Institutes of Health (NIH) Health Care Systems (HCS) Research Collaboratory hosted a workshop to explore challenges and strategies for the dissemination, implementation, and sustainability of findings from pragmatic clinical trials (PCTs) embedded in HCS. PCTs are designed to assess the impact of interventions delivered in usual or real-world conditions and leverage existing infrastructure to answer important clinical questions. The goal of the workshop was to discuss strategies for conducting impactful future PCTs that bridge the gap between evidence, practice, and policy. This paper summarizes presentations about how to design and conduct PCTs embedded in HCS and use dissemination and implementation strategies during the planning and conduct of projects, emphasizing the ever-changing world of care delivery and the need for pragmatic trial operations to adapt at various levels of operation.

Extracts of the saw palmetto berry are used by many men in the United States as self-treatment for lower urinary tract symptoms due to benign prostatic hyperplasia. While the most recent data from double-blind clinical trials do not support efficacy superior to that of placebo, there are sparse data on saw palmetto toxicity.A total of 369 patients were randomized in the CAMUS (Complementary and Alternative Medicine for Urological Symptoms) trial, of whom 357 were included in this modified intent to treat analysis. Participants were randomized to 320, 640 and 960 mg daily of an ethanolic saw palmetto extract or to an identical-appearing placebo in an escalating manner at 6-month intervals for a total of 18 months of followup. Adverse event assessments, vital signs, and blood and urine laboratory tests were obtained at regular intervals.There were no statistically significant differences between the groups in the rates of serious or nonserious adverse events, changes in vital signs, digital prostate examination findings or study withdrawal rates. Overall, there were no significant intergroup differences in laboratory test abnormalities, while differences in individual laboratory tests were rare and small in magnitude. No evidence of significant dose-response phenomena was identified.The saw palmetto extract used in the CAMUS trial showed no evidence of toxicity at doses up to 3 times the usual clinical dose during an 18-month period.

Background Chronic hepatitis C is associated with significant morbidity and mortality as a consequence of progression to cirrhosis, hepatocellular carcinoma, and liver failure. Current treatment for chronic hepatitis C with pegylated interferon (IFN) and ribavirin is associated with suboptimal responses and numerous adverse effects. A number of botanical products have been used to treat hepatic disorders. Silymarin, extracted from the milk thistle plant, Silybum marianum (L) Gaertn. (Asteraceae), has been most widely used for various liver disorders, including chronic hepatitis C, B, and alcoholic liver disease. However, the safety and efficacy of silymarin have not been studied systematically in chronic hepatitis C. Purpose We describe our strategy for a phased approach for studying the impact of silymarin in hepatitis C, in the context of the unique challenges of botanical product clinical trials and the development of specific and curative antiviral therapy. Methods This multicenter, randomized, double-masked, placebo-controlled trial was conducted with four clinical centers and a data-coordinating center in the United States, to assess the impact of silymarin therapy in patients with chronic hepatitis C who failed conventional antiviral therapy. Results Key aspects relevant to performing clinical trials of botanical products include early identification of an appropriate product with standard product chemistry, acquisition of pharmacokinetic and dosing information, selection of the appropriate study group, and choosing rigorous outcome variables. Potential limitations Trial participants were chronic hepatitis C patients who were nonsustained virologic responders to IFN-based therapy; therefore, the findings are not generalizable to all hepatitis C populations. Further, alanine aminotransferase, a biochemical liver test, rather than hepatitis viral RNA or liver histology was the primary end point. Conclusions The challenges identified and addressed during development of this United States multicenter Phase II trial to evaluate silymarin for treatment of patients with chronic hepatitis C infection who had failed to respond successfully to previous IFN-based therapy are common and must be addressed to conduct rigorous trials of botanical products.

Autosomal dominant polycystic kidney disease (ADPKD) is associated with a substantial cardiovascular disease burden including early onset hypertension, intracranial aneurysms, and left ventricular hypertrophy (LVH). A 41% prevalence of LVH has been reported in ADPKD, using echocardiographic assessment of LV mass (LVM). The HALT PKD study was designed to assess the effect of intensive angiotensin blockade on progression of total kidney volume and LVM. Measurements of LVM were performed using cardiac magnetic resonance (MR).Five hundred forty-three hypertensive patients with GFR60 ml/min per 1.73 m(2) underwent MR assessment of LVM at baseline. LVM was adjusted for body surface area and expressed as LVM index (LVMI; g/m(2)).Baseline BP was 125.1 ± 14.5/79.3 ± 11.6 mmHg. Average duration of hypertension was 5.79 years. Prior use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers was present in 59.5% of patients. The prevalence of LVH assessed using nonindexed LVM (g) was 3.9% (n = 21, eight men and 13 women) and 0.93% (n = 5, one man and four women) using LVMI (g/m(2)). In exploratory analyses, the prevalence of LVH using LVM indexed to H(2.7), and the allometric index ppLVmass(HW), ranged from 0.74% to 2.23% (n = 4 to 12). Multivariate regression showed significant direct associations of LVMI with systolic BP, serum creatinine, and albuminuria; significant inverse associations with LVMI were found with age and female gender.The prevalence of LVH in hypertensive ADPKD patients50 years of age with short duration of hypertension, and prior use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers is low. Early BP intervention in ADPKD may have decreased LVH and may potentially decrease cardiovascular mortality.

Background and objectives: Two HALT PKD trials will investigate interventions that potentially slow kidney disease progression in hypertensive autosomal dominant polycystic kidney disease (ADPKD) patients. Studies were designed in early and later stages of ADPKD to assess the impact of intensive blockade of the renin-angiotensin-aldosterone system and level of BP control on progressive renal disease. Design, settings, participants, and measurements: PKD-HALT trials are multicenter, randomized, double-blind, placebocontrolled trials studying 1018 hypertensive ADPKD patients enrolled over 3 yr with 4 to 8 yr of follow-up. In study A, 548 participants, estimated GFR (eGFR) of >60 ml/min per 1.73 m 2 were randomized to one of four arms in a 2-by-2 design: combination angiotensin converting enzyme inhibitor (ACEi) and angiotensin receptor blocker (ARB) therapy versus ACEi monotherapy at two levels of BP control. In study B, 470 participants, eGFR of 25 to 60 ml/min per 1.73 m 2 compared ACEi/ARB therapy versus ACEi monotherapy, with BP control of 120 to 130/70 to 80 mmHg. Primary outcomes of studies A and B are MR-based percent change kidney volume and a composite endpoint of time to 50% reduction of baseline estimated eGFR, ESRD, or death, respectively. Results: This report describes design issues related to (1) novel endpoints such as kidney volume, (2) home versus office BP measures, and (3) the impact of RAAS inhibition on kidney and patient outcomes, safety, and quality of life. Conclusions: HALT PKD will evaluate potential benefits of rigorous BP control and inhibition of the renin-angiotensinaldosterone system on kidney disease progression in ADPKD. Clin J Am Soc Nephrol 5: 102–109, 2010. doi: 10.2215/CJN.04310709

Arteriovenous graft stenosis leading to thrombosis is a major cause of complications in patients undergoing hemodialysis. Procedural interventions may restore patency but are costly. Although there is no proven pharmacologic therapy, dipyridamole may be promising because of its known vascular antiproliferative activity.We conducted a randomized, double-blind, placebo-controlled trial of extended-release dipyridamole, at a dose of 200 mg, and aspirin, at a dose of 25 mg, given twice daily after the placement of a new arteriovenous graft until the primary outcome, loss of primary unassisted patency (i.e., patency without thrombosis or requirement for intervention), was reached. Secondary outcomes were cumulative graft failure and death. Primary and secondary outcomes were analyzed with the use of a Cox proportional-hazards regression with adjustment for prespecified covariates.At 13 centers in the United States, 649 patients were randomly assigned to receive dipyridamole plus aspirin (321 patients) or placebo (328 patients) over a period of 4.5 years, with 6 additional months of follow-up. The incidence of primary unassisted patency at 1 year was 23% (95% confidence interval [CI], 18 to 28) in the placebo group and 28% (95% CI, 23 to 34) in the dipyridamole-aspirin group, an absolute difference of 5 percentage points. Treatment with dipyridamole plus aspirin significantly prolonged the duration of primary unassisted patency (hazard ratio, 0.82; 95% CI, 0.68 to 0.98; P=0.03) and inhibited stenosis. The incidences of cumulative graft failure, death, the composite of graft failure or death, and serious adverse events (including bleeding) did not differ significantly between study groups.Treatment with dipyridamole plus aspirin had a significant but modest effect in reducing the risk of stenosis and improving the duration of primary unassisted patency of newly created grafts. (ClinicalTrials.gov number, NCT00067119.)

Background and objectives: To evaluate the inter- and intrareader reliability and the effect of gadolinium enhancement on kidney volume measurements obtained from pre- and postgadolinium T1 MR images in patients with autosomal dominant polycystic kidney disease (ADPKD). Design, setting, participants, & measurements: Twenty subjects were randomly selected with approximately equal frequency from three kidney-size groups. Pre- and postgadolinium 3D T1 (pre-T1, post-T1) MR images were obtained. The stereology method was applied to segment and measure kidney volumes. The measurement process was repeated at two-wk intervals by two radiologists. Reliability was assessed with correlation coefficients. Intra- and inter-reader bias and measure differences were assessed with paired T-tests. The size effect on the pre- and post-T1 measurements was evaluated with one-way ANOVA. Results: The intra- and inter-reader reliability was extremely high in all measurements. No systematic intrareader bias but a small inter-reader bias for the post-T1 measurements was observed. All kidney volumes measured on the pre- and post-T1 images were highly correlated with each other for both readers. The post-T1 volumes were significantly higher than pre-T1 volumes. While the post-pre volume differences were relatively constant across the three kidney-size groups, the post-pre percent volume differences were significantly smaller as the size of the kidney increased. Conclusions: Kidney volume measurements can be made with minimum intra- and inter-reader variability on both pre- and post-T1 MR images. Kidney volumes measured on the pre-T1 were smaller than those on post-T1, and percent differences between pre-T1 and post-T1 kidney volumes decreased with increasing kidney size.

Mutation-based molecular diagnostics of autosomal dominant polycystic kidney disease (ADPKD) is complicated by genetic and allelic heterogeneity, large multi-exon genes, duplication of PKD1, and a high level of unclassified variants (UCV). Present mutation detection levels are 60 to 70%, and PKD1 and PKD2 UCV have not been systematically classified. This study analyzed the uniquely characterized Consortium for Radiologic Imaging Study of PKD (CRISP) ADPKD population by molecular analysis. A cohort of 202 probands was screened by denaturing HPLC, followed by direct sequencing using a clinical test of 121 with no definite mutation (plus controls). A subset was also screened for larger deletions, and reverse transcription-PCR was used to test abnormal splicing. Definite mutations were identified in 127 (62.9%) probands, and all UCV were assessed for their potential pathogenicity. The Grantham Matrix Score was used to score the significance of the substitution and the conservation of the residue in orthologs and defined domains. The likelihood for aberrant splicing and contextual information about the UCV within the patient (including segregation analysis) was used in combination to define a variant score. From this analysis, 44 missense plus two atypical splicing and seven small in-frame changes were defined as probably pathogenic and assigned to a mutation group. Mutations were thus defined in 180 (89.1%) probands: 153 (85.0%) PKD1 and 27 (15.0%) PKD2. The majority were unique to a single family, but recurrent mutations accounted for 30.0% of the total. A total of 190 polymorphic variants were identified in PKD1 (average of 10.1 per patient) and eight in PKD2. Although nondefinite mutation data must be treated with care in the clinical setting, this study shows the potential for molecular diagnostics in ADPKD that is likely to become increasingly important as therapies become available.

The arteriovenous graft (AVG) is most often used in hemodialysis patients when an autogenous fistula is not feasible. The optimal location (forearm or upper arm) and configuration (loop or straight) of AVGs are not known. To evaluate relationships of AVG location and configuration with patency, we conducted a secondary analysis using data from a randomized, placebo-controlled trial of dipyridamole plus aspirin for newly placed AVG.Participants of the Dialysis Access Consortium (DAC) Graft Study with newly placed upper extremity prosthetic grafts involving the brachial artery were studied. Multivariable analyses adjusting for trial treatment group, center, gender, race, body mass index, diabetes, current treatment with chronic dialysis, and prior arteriovenous vascular access or central venous catheter were performed to compare outcomes of forearm (fAVG) and upper arm (uAVG) grafts, including loss of primary unassisted patency (LPUP) and cumulative primary graft failure (CGF). Subgroup analyses of graft configuration and outflow vein used were also conducted.A total of 508 of the 649 participants (78%) enrolled in the trial had an upper extremity brachial artery graft placed, 255 with fAVG and 253 with uAVG. Participants with fAVG were less often male (33% vs 43%; P = .03), African American (62% vs 78%; P .001), and receiving dialysis at the time of surgery (62% vs 80%; P .001). Participants with fAVG had a higher mean body mass index (33 vs 29; P .001). The LPUP (fAVG 70% vs uAVG 78%; P = .07) and CGF (33% vs 36%; P = .91) were similar between fAVG and uAVG at 1-year follow-up. In multivariable analysis, AVG location (uAVG vs fAVG) was not associated with LPUP (hazard ratio, 1.21; 95% confidence interval, 0.90-1.63; P = .20) or CGF (hazard ratio, 1.36; 95% confidence interval, 0.94-1.97; P = .10). LPUP did not differ significantly between fAVG and uAVG among subgroups based on AVG configuration (P = 1.00) or outflow vein used (P = .16).Patency was comparable between fAVG and uAVG despite the larger caliber veins often encountered in the upper arm in carefully selected patients. Our findings support the traditional view that, in order to preserve a maximal number of access sites, the forearm location should be considered first before resorting to an upper arm graft.

Data from serial renal magnetic resonance imaging of the Consortium of Radiologic Imaging Study of PKD (CRISP) autosomal dominant polycystic kidney disease (PKD) population showed that cystic expansion occurs at a consistent rate per individual, although it is heterogeneous in the population, and that larger kidneys are associated with more rapid disease progression. The significance of gene type to disease progression is analyzed in this study of the CRISP cohort. Gene type was determined in 183 families (219 cases); 156 (85.2%) had PKD1, and 27 (14.8%) had PKD2. PKD1 kidneys were significantly larger, but the rate of cystic growth (PKD1 5.68%/yr; PKD2 4.82%/yr) was not different (P = 0.24). Cyst number increased with age, and more cysts were detected in PKD1 kidneys (P < 0.0001). PKD1 is more severe because more cysts develop earlier, not because they grow faster, implicating the disease gene in cyst initiation but not expansion. These insights will inform the development of targeted therapies in autosomal dominant PKD.

Recent observations regarding intrinsic glomerular cell biology, particularly in the podocyte, have provided exciting new insights into potential pathogenic mechanisms of human glomerular disease. Although both immune and nonimmune mechanisms of glomerular injury have been studied previously, experimental models of disease and recent techniques that provide tools for molecular profiling show great promise for identifying glomerular disease biomarkers. Despite these recent advances, additional work in both basic and clinical studies of glomerular disease is needed to advance the field. Standardization of animal models of distinct forms of glomerular disease would likely facilitate the search for biomarkers. Several factors limit current efforts to implement clinical trials of glomerular disease. Identification of disease biomarkers, development of disease-specific end points, and organization of collaborative clinical groups are critical for ultimately designing and implementing appropriately powered trials of glomerular disease.

Background Surgically created arteriovenous (AV) grafts are the most common type of hemodialysis vascular access in the United States, but fail frequently due to the development of venous stenosis. The Dialysis Access Consortium (DAC) Aggrenox Prevention of Access Stenosis Trial tests the hypothesis that Aggrenox (containing dipyridamole and aspirin) can prevent stenosis and prolong survival of arteriovenous grafts.Methods This is a multicenter, randomized, double-blind, placebo-controlled trial that will enroll 1056 subjects over four years with one-half year follow-up. Subjects undergoing placement of a new AV graft for hemodialysis are randomized to treatment with Aggrenox or placebo immediately following access surgery. The primary outcome is primary unassisted patency defined as the time from access placement until thrombosis or an access procedure carried out to maintain or restore patency. The major secondary outcome is cumulative access patency. Monthly access flow monitoring is incorporated in the study design to enhance detection of a hemodynamically significant access stenosis before it leads to thrombosis.Results This paper describes the key issues in trial design, broadly including: 1) ethical issues surrounding the study of a clinical procedure that, although common, is no longer the clinical intervention of choice; 2) acceptable risk (bleeding) from the primary intervention; 3) inclusion of subjects already receiving a portion of the study intervention; 4) inclusion of subjects with incident rather than prevalent qualifying clinical conditions; 5) timing of the study intervention to balance safety and efficacy concerns; and 6) the selection of primary and secondary study endpoints.Conclusions This is the first, large, multicenter trial evaluating a pharmacologic approach to prevent AV graft stenosis and failure, an important and costly problem in this patient population. Numerous design issues were addressed in implementing the trial and these will form a roadmap for future trials in this area.

Hepatitis C is both a cause and a complication of chronic renal disease. Chronic infection with hepatitis C virus (HCV) can lead to the immune complex syndromes of cryoglobulinemia and membranoproliferative glomerulonephritis (MPGN). The pathogenetic mechanisms for these conditions have not been defined, although they are clearly caused by the chronic viral infection. Management of HCV-related cryoglobulinemia and MPGN is difficult; antiviral therapy is effective in clearing HCV infection in a proportion of patients, but these conditions can be severe and resistant to antiviral therapy. Hepatitis C also is a complicating factor among patients with end-stage renal disease and renal transplants. The source of HCV infection in these patients can be nosocomial. Screening and careful attention to infection control precautions are mandatory for dialysis units to prevent the spread of hepatitis C. Prevention of spread is particularly important in these patients because HCV infection is associated with significant worsening of survival on dialysis therapy, as well as after kidney transplantation. Furthermore, therapy for hepatitis C is problematic, only partially effective, and associated with significant side effects in this population. There are significant needs in both basic and clinical research in the pathogenesis, natural history, prevention, and therapy for hepatitis C in patients with renal disease.

As reports of mice genetically deficient for TGF-beta1 demonstrated aberrant renal class II MHC expression, we investigated inducible class II MHC expression on renal tubular epithelial cells derived from TGF-beta1 knockout (-/-) and wild-type (+/+) mice. IFN-gamma markedly upregulated class II MHC (I-A(b)) expression in both (-/-) and (+/+) tubular epithelial cells. Coincubation studies of (+/+) and (-/-) tubular epithelial cells with IFN-gamma+LPS, or pretreatment of these cells with TGF-beta1, revealed inhibition of IFN-gamma-induced I-A(b) mRNA and cell surface expression that occurred via a decrease in class II transactivator gene expression in both (+/+) and (-/-) tubular epithelial cells. In addition, ICAM-1 was constitutively expressed on both (+/+) and (-/-) tubular epithelial cells and was upregulated by IFN-gamma or IFN-gamma+LPS. ICAM-1 expression in (+/+) and (-/-) tubular epithelial cells, however, was decreased by TGF-beta1. Parallel analysis evaluating B7-1 expression detected low levels of B7-1 in unstimulated (+/+) and (-/-) tubular epithelial cells that were increased by IFN-gamma, LPS, and IFN-gamma+LPS. IFN-gamma+LPS-mediated upregulation of B7-1 was also blocked by pretreatment with TGF-beta1. Cytokine analysis detected significantly higher levels of TNF-alpha and MIP-1alpha mRNA in all treated (-/-) preparations than in (+/+) tubular epithelial cell controls. These studies demonstrate normal patterns of class II MHC, ICAM-1, and B7 expression in TGF-beta1 (-/-) tubular epithelial cells in response to IFN-gamma, LPS, and TGF-beta1. Upregulated cytokine expression at baseline and in response to proinflammatory mediators is apparent in (-/-) tubular epithelial cells, however, and suggests that dysregulation of cytokine expression in inflammatory responses may be a primary event in multifocal inflammation observed in TGF-beta1-deficient animals.

IFN-γ and LPS differentially modulate class II MHC and B7-1 expression on murine renal tubular epithelial cells. Background We have investigated inducible class II major histocompatibility complex (MHC) and B7 expression on primary murine renal tubular epithelial cells, called F1K cells, and examined their role in activating nephritogenic T cells derived from kidneys of animals with autoimmune glomerulonephritis. Methods Class II MHC, class II transactivator, and costimulatory molecule expression were evaluated in untreated and cytokine-treated F1K cells by Northern hybridization and flow cytometry. Cell-surface B7-1 expression was evaluated in vitro by immunoprecipitation and in vivo by immunohistochemistry. T-cell activation studies were then performed to assess the functional significance of B7-1 expression on F1K cells. Results Coincubation of F1K cells with interferon (IFN)-γ and lipopolysaccharide (LPS) significantly decreased IFN-γ–induced class II MHC expression, by both fluorescence-activated cell sorting and Northern analyses. LPS-mediated inhibition of class II MHC in this setting was effected through a decrease in class II transactivator mRNA levels in treated F1K cells. By contrast, IFN-γ and LPS coincubation induced B7-1 but not B7-2 expression in F1K cells, as detected by Northern analysis, flow cytometry, and immunoprecipitation. In addition, renal tubular staining for B7-1 was apparent in kidneys isolated from IFN-γ+LPS-treated recipient mice, as well as mice with autoimmune glomerulonephritis. Further studies evaluated the interaction of F1K cells and MR1.3, a nephritogenic CD4+ Th2 clone derived from kidneys of animals with autoimmune glomerulonephritis. Cytokine production assays revealed that F1K cells activated MR1.3 cells if they were pretreated with both IFN-γ and LPS 48hours prior to exposure to nephritogenic T cells. Conclusions These studies are the first description of a differential regulation of class II MHC and B7-1 expression in renal tubular epithelial cells mediated by IFN-γ and LPS. Such findings indicate that discrete proinflammatory stimuli could potentiate antigen-presenting capabilities of renal tubular epithelial cells in vivo and further suggest a direct role of such nonprofessional antigen-presenting cells in modulating renal immune responses.

Emerging data on the role of interstitial inflammation in progressive renal disease are redefining our understanding of the pathogenic mechanisms of chronic kidney damage. Recent experimental evidence emphasizes the role for both immune and non-immune mechanisms in interstitial nephritis. New observations regarding maneuvers that downregulate such injurious renal responses may direct further studies that develop new therapeutic modalities.

Immunomodulatory effects of interferon- γ on autoreactive nephritogenic T-cell clones. Background We examined the immunomodulatory effects of interferon- γ (IFN- γ ) on renal-derived CD4 + α/β + T cells, called mouse renal (MR) cells, isolated from animals with murine chronic graft-versus-host disease, a model of autoimmune glomerulonephritis. MR T cells express a Th2 cytokine profile, although IFN- γ expression is also detected in a subset of clones that adoptively transfers renal disease to naive recipients. In view of disparate patterns of IFN- γ expression, we evaluated the effects of exogenous IFN- γ on nephritogenic (MR1.3) and nonnephritogenic (MR1.6) clonal activity. Methods These studies examined IFN- γ –mediated effects on clonal proliferation, cytokine production, nephritogenic potential, and IFN- γ receptor expression. Results IFN- γ mediated dose-dependent inhibition of MR1.3 and MR1.6 proliferation. This cytostatic effect was not mediated by inhibiting cytokine genes, as expression of interleukin (IL)-4, IL-10, IL-13, and IFN- γ after IFN- γ treatment was not markedly altered in either clone, although baseline IL-13 expression was enhanced in MR1.6. IFN- γ markedly altered the functional phenotype of MR1.6, as pretreated recipients developed severe mononuclear cell infiltrates and tubular damage following adoptive transfer of MR1.6. Neutralizing anti–IFN- γ antibodies did not inhibit MR1.3 nephritogenicity, but did block MR1.6-induced disease in IFN- γ –treated mice. Although both clones constitutively expressed the IFN- γ receptor β chain, IFN- γ exposure decreased its expression in MR1.3 cells, but did not markedly change its expression in MR1.6 cells. Conclusion These studies describe an unusual permissive role for IFN- γ in modulating nephritogenic Th2 activity in vivo , which facilitates the initiation of cell-mediated autoimmune renal injury. Apparent differential effects of IFN- γ on distinct T-cell clones may be mediated in part by alterations in cytokine receptor expression.

To investigate mechanisms of cell-mediated events in chronic glomerulonephritis, T cell clones were isolated from kidneys of animals with murine chronic graft-vs-host disease. This systemic disorder is induced in normal (C57BL/6 × DBA/2)F1 recipients (H-2b/d) following transfer of parental (DBA/2) T cells (H-2d). These studies demonstrate that mouse renal (MR) T cells isolated from nephritic kidneys of diseased recipients are host-derived CD4+ α/β+ T cells. Adoptive transfer of a panel of MR clones to naive (C57BL/6 × DBA/2)F1 recipients reveals distinct functional subsets. One subset does not transfer renal disease, and one induces severe renal inflammation and damage. In vitro proliferative responses of nephritogenic MR clones reveal predominant reactivity toward autologous class II MHC (I-Ed/I-Ad) determinants, and selected nephritogenic MR clones preferentially recognize renal Ag preparations derived from normal (C57BL/6 × DBA/2)F1 kidneys. In addition, cytokine profile analysis of MR clones indicates a Th2 pattern with IL-4 and IL-10 expression, although nephritogenic T cell clones also express IFN-γ. These data suggest that the nephritogenic T cell response in chronic graft-vs-host disease is autoreactive in nature and may be restricted by determinants shared by both graft and host (Iad).

Cyclosporine A regulates T cell-epithelial cell adhesion by altering LFA-1 and ICAM-1 expression. In contrast to the well characterized suppressive effect of cyclosporine A (CsA) on IL-2 gene transcription in T cells, other immunosuppressive effects of CsA have received less attention. We have examined the effect of CsA on the expression of the β 2 integrin, LFA-1, and its counter receptor, ICAM-1, on a renal Ag-specific murine T cell clone and Ag-expressing renal tubular epithelial cells. We have found that CsA has a concentration dependent effect on the expression of both ICAM-1 mRNA and gene product on renal tubular cells. At 0.1 μ g/ml, CsA exhibits a costimulatory effect, with TNF α , on ICAM-1 expression. CsA at 1 to 5 μ g/ml exhibits concentration dependent inhibition of ICAM-1 cell surface expression by the tubular cells. Although CsA does not inhibit ICAM-1 on T cells, it does inhibit surface expression of LFA-1. The concentration dependent effects of CsA on ICAM-1 expression correlate well with ICAM-1 dependent T cell adhesion to TNFα stimulated tubular epithelial cells. TGF- β 1 has similar effects on ICAM-1 and LFA-1 expression as high dose CsA, but the CsA effects are not mediated through induced TGF- β 1 expression. Our studies support the conclusion that CsA may bidirectionally alter ICAM-1 dependent cellular adhesive interactions. The inhibition of cytokine stimulated ICAM-1 expression at higher CsA concentrations would contribute to the overall immunosuppressive effect of the drug.

Advances in basic immunology have markedly enhanced our understanding of immune-mediated renal disease, particularly in view of the growing recognition of the importance of T-cells in mediating renal injury. Recent milestones in investigative technology, including cell-culture techniques supporting T-cell clones and renal-derived cell populations, and genetic inbreeding of both recombinant and transgenic mice, provide a unique opportunity to study specific mechanisms of cell-mediated responses that target the kidney. In the past year the role of major histocompatibility complex molecule expression and T-cell repertoire selection has been better defined in some models of autoimmune renal disease. In addition, new observations regarding mechanisms that down regulate injurious T-cell-mediated responses may direct further studies that develop new therapeutic modalities.

Immunoregulation and TGF-β 1 . Suppression of a nephritogenic murine T cell clone. Transforming growth factor beta (TGF-β) has been clearly linked in several model systems to the development of pathologic extracellular matrix deposition in the glomerulus and interstitium. TGF-β additionally exerts multiple immunomodulatory effects on T and B lymphocytes, including growth inhibition. Such pleiotropic effects make it difficult to predict how TGF-β might directionally affect the expression of T cell mediated kidney disease. We have examined the effects of TGF-β 1 on the activity of effector T cells in a model of autoimmune interstitial nephritis. M52.26 is an antigen-specific, nephritogenic, cytotoxic T cell clone. TGF-β 1 mediates a concentration-dependent inhibition of M52.26-directed cytotoxicity of tubular epithelial cells in culture, and also of M52.26-mediated transfer of interstitial nephritis to syngeneic recipients. The loss of these functional activities is associated with distinct changes in cytokine gene expression in M52.26. These cytokine alterations consist of a loss of IFN-γ and perforin expression, and an up-regulation of TGF-β expression, which is likely relevant to the observed effector T cell inactivation.

The Office of Dietary Supplements (ODS) and the National Center for Complementary and Alternative Medicine (NCCAM) were both established by Congress in the 1990’s. ODS aims to strengthen knowledge and understanding of dietary supplements (DS). NCCAM promotes exploration of complementary and alternative medicine in the context of rigorous science. Together, they developed the Botanical Research Centers Program to promote interdisciplinary study of botanicals, particularly those found in DS, by supporting research activities ranging from plant and characterization to preclinical and early-phase clinical studies. These Centers are part of the coordinated efforts of ODS and NCCAM to enhance botanical research.

To further investigate mechanisms of cell-mediated tissue destruction in an organ-specific autoimmune disease, we have established and characterized a nephritogenic CD8+ T cell line. This target antigen-specific effector T cell line, M52, was derived from bulk populations of CD8+ T cells isolated from susceptible animals immunized to produce anti-tubular basement membrane (alpha TBM) disease. Our studies show that M52 retains the phenotypic and functional characteristics of nephritogenic T cells induced in vivo. M52 mediates antigen-specific delayed-type hypersensitivity (DTH) responses to the target antigen 3M-1, it is cytotoxic to 3M-1-expressing renal tubular epithelial cells in vitro, and it adoptively transfers interstitial nephritis to naive syngeneic recipients. Clonal analysis of these nephritogenic CD8+ T cells reveals distinct functional phenotypes within the M52 cell line. We have isolated a cytotoxic CD8+ clone, M52.26, which is not DTH-reactive to 3M-1, and multiple DTH-reactive clones which mediate less efficient cytotoxicity to 3M-1-expressing target cells. Cytofluorographic analysis of four randomly selected clones reveals alpha beta T cell receptor expression. Further characterization of these functionally distinct CD8+ T cell clones will help to define their respective roles in mediating tubular epithelial cell injury and the inflammatory lesion of autoimmune interstitial nephritis.

Context The arteriovenous fistula is the preferred type of vascular access for hemodialysis because of lower thrombosis and infection rates and lower health care expenditures compared with synthetic grafts or central venous catheters. Early failure of fistulas due to thrombosis or inadequate maturation is a barrier to increasing the prevalence of fistulas among patients treated with hemodialysis. Small, inconclusive trials have suggested that antiplatelet agents may reduce thrombosis of new fistulas. Objective To determine whether clopidogrel reduces early failure of hemodialysis fistulas. Design, Setting, and Participants Randomized, double-blind, placebo-controlled trial conducted at 9 US centers composed of academic and community nephrology practices in 2003-2007. Eight hundred seventy-seven participants with end-stage renal disease or advanced chronic kidney disease were followed up until 150 to 180 days after fistula creation or 30 days after initiation of dialysis, whichever occurred later. Intervention Participants were randomly assigned to receive clopidogrel (300-mg loading dose followed by daily dose of 75 mg; n = 441) or placebo (n = 436) for 6 weeks starting within 1 day after fistula creation. Main Outcome Measures The primary outcome was fistula thrombosis, determined by physical examination at 6 weeks. The secondary outcome was failure of the fistula to become suitable for dialysis. Suitability was defined as use of the fistula at a dialysis machine blood pump rate of 300 mL/min or more during 8 of 12 dialysis sessions. Results Enrollment was stopped after 877 participants were randomized based on a stopping rule for intervention efficacy. Fistula thrombosis occurred in 53 (12.2%) participants assigned to clopidogrel compared with 84 (19.5%) participants assigned to placebo (relative risk, 0.63; 95% confidence interval, 0.46-0.97; P = .018). Failure to attain suitability for dialysis did not differ between the clopidogrel and placebo groups (61.8% vs 59.5%, respectively; relative risk, 1.05; 95% confidence interval, 0.94-1.17; P = .40). Conclusion Clopidogrel reduces the frequency of early thrombosis of new arteriovenous fistulas but does not increase the proportion of fistulas that become suitable for dialysis. Trial Registration clinicaltrials.gov Identifier: NCT00067119

For segmentation and volume measurement of renal cysts and parenchyma from kidney MR images in subjects with autosomal dominant polycystic kidney disease (ADPKD), a semi-automated, multi-spectral anaylsis (MSA) method was developed and applied to T1- and T2-weighted MR images. In this method, renal cysts and parenchyma were characterized and segmented for their characteristic T1 and T2 signal intensity differences. The performance of the MSA segmentation method was tested on ADPKD phantoms and patients. Segmented renal cysts and parenchyma volumes were measured and compared with reference standard measurements by fluid displacement method in the phantoms and stereology and region-based thresholding methods in patients, respectively. As results, renal cysts and parenchyma were segmented successfully with the MSA method. The volume measurements obtained with MSA were in good agreement with the measurements by other segmentation methods for both phantoms and subjects. The MSA method, however, was more time-consuming than the other segmentation methods because it required pre-segmentation, image registration and tissue classification-determination steps.

Whether changes in renal blood flow (RBF) are associated with and possibly contribute to cystic disease progression in autosomal dominant polycystic kidney disease (ADPKD) has not been ascertained. The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP) was created to develop imaging techniques and analyses to evaluate progression. A total of 131 participants with early ADPKD had measurements of RBF and total kidney (TKV) and cyst (TCV) volumes by magnetic resonance and of GFR by iothalamate clearance at baseline and 1, 2, and 3 yr. The effects of age, gender, body mass index, hypertension status, mean arterial pressure (MAP), TKV, TCV, RBF, renal vascular resistance (RVR), GFR, serum uric acid, HDL and LDL cholesterol, 24-h urine volume, sodium (UNaE) and albumin (UAE) excretions, and estimated protein intake were examined at baseline on TKV, TCV, and GFR slopes. TKV and TCV increased, RBF decreased, and GFR remained stable. TKV, TCV, RVR, serum uric acid, UAE, UNaE, age, body mass index, MAP, and estimated protein intake were positively and RBF and GFR negatively correlated with TKV and TCV slopes. TKV, RBF, UNaE, and UAE were independent predictors of TKV and TCV slopes (structural disease progression). TKV, TCV, RVR, and MAP were negatively and RBF positively correlated with GFR slopes. Regression to the mean confounded the analysis of GFR slopes. TKV and RBF were independent predictors of GFR decline (functional disease progression). In ADPKD, RBF reduction (1) parallels TKV increase, (2) precedes GFR decline, and (3) predicts structural and functional disease progression.

The objective of this study was to investigate the prevalence of hepatic cysts by age and gender in patients with early autosomal-dominant polycystic kidney disease (ADPKD) and to determine whether hepatic cyst volume is related to renal and renal cyst volumes by using magnetic resonance imaging (MRI). A total of 230 patients with ADPKD (94 men and 136 women) who were aged 15 to 46 yr and had relatively preserved renal function were studied. MRI images of the kidney and liver were obtained to measure renal, renal cyst, and hepatic cyst volumes. These volume measurements and hepatic cyst prevalence were compared in all patients and in subgroups on the basis of gender and age (15 to 24, 25 to 34, and 35 to 46 yr). The overall prevalence of hepatic cysts was 83%; the prevalence was 58, 85, and 94% in the sequential age groups and 85% in women and 79% in men. The prevalence was related directly to renal volume (chi2 = 4.30, P = 0.04) and to renal cyst volume (chi2 = 5.59, P = 0.02). The total hepatic cyst volume was significantly greater in women than in men (a logarithmic transformation mean of 5.27 versus 1.94 ml; P = 0.003). The average hepatic cyst volume was 0.25, 5.75, and 22.78 ml in sequential age groups. Hepatic cysts are evident in 94% of patients who are older than 35 yr and in 55% of individuals who are younger than 25 yr. Hepatic cysts are more prevalent and larger in total cyst volume in women than in men. Hepatic cyst prevalence and aggregate total hepatic cyst volume increased with age.

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive enlargement of cyst-filled kidneys.In a three-year study, we measured the rates of change in total kidney volume, total cyst volume, and iothalamate clearance in patients with ADPKD. Of a total of 241 patients, in 232 patients without azotemia who were 15 to 46 years old at baseline we used magnetic-resonance imaging to correlate the total kidney volume and total cyst volume with iothalamate clearance. Statistical methods included analysis of variance, Pearson correlation, and multivariate regression analysis.Total kidney volume and total cyst volume increased exponentially, a result consistent with an expansion process dependent on growth. The mean (+/-SD) total kidney volume was 1060+/-642 ml at baseline and increased by a mean of 204+/-246 ml (5.27+/-3.92 percent per year, P0.001) over a three-year period among 214 patients. Total cyst volume increased by 218+/-263 ml (P0.001) during the same period among 210 patients. The baseline total kidney volume predicted the subsequent rate of increase in volume, independently of age. A baseline total kidney volume above 1500 ml in 51 patients was associated with a declining glomerular filtration rate (by 4.33+/-8.07 ml per minute per year, P0.001). Total kidney volume increased more in 135 patients with PKD1 mutations (by 245+/-268 ml) than in 28 patients with PKD2 mutations (by 136+/-100 ml, P=0.03).Kidney enlargement resulting from the expansion of cysts in patients with ADPKD is continuous and quantifiable and is associated with the decline of renal function. Higher rates of kidney enlargement are associated with a more rapid decrease in renal function.

A decline in renal function suggests progression of chronic kidney disease. This can be determined by measured GFR (e.g., iothalamate clearance), serum creatinine (SCr)-based GFR estimates, or creatinine clearance. A cohort of 234 patients with autosomal dominant polycystic kidney disease and baseline creatinine clearance >70 ml/min were followed annually for four visits. Iothalamate clearance, SCr, and creatinine clearance were obtained at each visit. Estimated GFR (eGFR) was determined with the Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault equations. Renal function slopes had a mean residual SD of 10.7% by iothalamate clearance, 8.2% by MDRD equation, 7.7% by Cockcroft-Gault equation, and 14.8% by creatinine clearance. By each method, a decline in renal function (lowest quintile slope) was compared among baseline predictors. Hypertension was associated with a decline in iothalamate clearance (odds ratio [OR] 5.8; 95% confidence interval [CI] 2.3 to 14), eGFR (OR [MDRD] 2.0 [95% CI 1.0 to 4.2] or OR [Cockcroft-Gault] 1.9 [95% CI 0.9 to 3.9]), and creatinine clearance (OR 2.0; 95% CI 1.0 to 4.2). Each doubling of kidney volume at baseline was associated with a decline in iothalamate clearance (OR 2.4; 95% CI 1.5 to 3.7), eGFR (OR 1.7 [95% CI 1.1 to 2.6] or 2.1 [95% CI 1.4 to 3.3]), and creatinine clearance (OR 1.7; 95% CI 1.1 to 2.5). Predictor associations were strongest with measured GFR. Misclassification from changes in non-GFR factors (e.g., creatinine production, tubular secretion) conservatively biased associations with eGFR. Misclassification from method imprecision attenuated associations with creatinine clearance.

Despite continued improvement in incidence of acute immune injury and short-term graft survival, late allograft dysfunction remains a significant problem in the renal transplant population. Recent reports suggest that rates of renal function decline are quite varied in the overall recipient population, and that individual rates for many recipients may not change substantially over time. Moreover, analyses also reveal distinct predictive factors for both early and late functional decline. Long-term outcome studies for renal transplantation, however, might be significantly limited by incomplete data sets for assessing clinical endpoints. In view of the heterogeneous factors that may cause progressive allograft injury, more routine biopsy sampling would allow a more complete characterization of induced injuries. Elucidating mechanisms of renal fibrosis in response to injury, in experimental systems and humans, is also an important goal in better understanding chronic allograft damage. Regulation of cell senescence genes and epithelial to mesenchymal transition, studied in other models of renal fibrosis, are likely relevant to studies of renal allograft dysfunction. Recent technical advances in analyzing biological samples may play a pivotal role in identifying and validating surrogate markers of allograft function for future interventional trials in transplantation.

TGF-β1 down-regulates induced expression of both class II MHC and B7-1 on primary murine renal tubular epithelial cells. Background We examined the immunomodulatory effects of transforming growth factor-β1 (TGF-β1) on the regulation of class II MHC and costimulatory molecule expression in a primary renal tubular epithelial cell line, called F1K. Methods Class II major histocompatibility complex (MHC), class II transactivator, B7-1, intercellular adhesion molecule-1 (ICAM-1) and interferon-γ (IFN-γ) receptor β chain were evaluated in untreated and cytokine-treated F1K by Northern hybridization analysis and flow cytometry. T cell activation studies were performed to assess TGF-β1-mediated effects on antigen presenting cell function of F1K. Results Pretreatment of F1K with TGF-β1 markedly inhibited IFN-γ-induced class II MHC expression, by both FACS and Northern analysis. Total class II transactivator mRNA levels were also diminished by TGF-β1, indicating that class II MHC modulation in F1K results from inhibition of this intermediate protein. As previous studies demonstrated that cotreatment of F1K cells with IFN-γ+ lipopolysaccharide (LPS) induces B7-1, we evaluated the potential regulatory effects of TGF-β1 exposure on B7-1 expression. Our studies revealed that B7-1 mRNA and cell-surface expression in IFN-γ+ LPS-treated F1K were decreased by TGF-β1 pretreatment. Functional studies evaluating TGF-β1-mediated effects were performed with IFN-γ+ LPS-treated F1K and MR1.3, a nephritogenic CD4+ Th2 clone derived from kidneys of animals with autoimmune glomerulonephritis. Interleukin (IL)-4 production assays demonstrated activation of MR1.3 by IFN-γ+ LPS-treated cells, but not by IFN-γ+ LPS-treated cells previously exposed to TGF-β1, indicating that TGF-β1-mediated inhibition of class II MHC and B7-1 expression alters the antigen presenting cell function of F1K. Conclusions These studies describe the proscriptive influence of TGF-β1 on class II MHC and B7-1 expression in renal tubular epithelial cells. Such findings indicate that TGF-β1 alters the antigen presenting cell function of renal tubular epithelial cells in vitro, and suggest a potential mechanism for immunosuppression of T cell-mediated renal immune responses in vivo.

To investigate the role of costimulation in autoimmune glomerulonephritis that develops in the setting of murine chronic graft-vs-host disease (cGVHD), we examined the effects of blocking CD40L, a costimulatory marker expressed on activated CD4+ T cells, in recipient mice. These studies addressed the potential role of CD40L blockade in preventing disease and in downregulating its expression in animals with evidence of autoreactivity. Animals treated acutely with anti-CD40L antibody at disease induction do not develop circulating anti-DNA antibodies, proteinuria, or histologic evidence of renal disease. If treatment is delayed for two weeks, after circulating anti-DNA antibodies are apparent, all animals develop massive proteinuria by 14 weeks after disease induction. Renal histology of kidneys from the delayed treatment and control groups reveal similar glomerular immune deposits, and intense staining for CD4, ICAM-1, and I-A(b) in areas of mononuclear cell infiltration. Long-term treatment studies begun two weeks after disease induction is not disease-protective, as all animals develop massive proteinuria and renal disease by 14 weeks. These studies suggest that early CD40L signaling events are critical to induction of allogeneic interactions and autoreactivity in cGVHD, but that short-term or chronic CD40L blockade, once autoreactivity is evident, does not abrogate systemic autoreactivity and renal involvement.

Context The botanical product silymarin, an extract of milk thistle, is commonly used by patients to treat chronic liver disease, despite scant and conflicting evidence of its efficacy. Objective To determine the effect of silymarin on liver disease activity in patients with chronic hepatitis C virus (HCV) infection unsuccessfully treated with interferon-based therapy. Design, Setting, and Participants Multicenter, double-blind, placebo-controlled trial conducted at 4 medical centers in the United States. Participants included 154 persons with chronic HCV infection and serum alanine aminotransferase (ALT) levels of 65 U/L or greater who were previously unsuccessfully treated with interferon-based therapy. Enrollment began in May 2008 and was completed in May 2010, with the last follow-up visit completed in March 2011. Intervention Participants were randomly assigned to receive 420-mg silymarin, 700-mg silymarin, or matching placebo administered 3 times per day for 24 weeks. Main Outcome Measures The primary outcome measure was serum ALT level of 45 U/L or less (considered within the normal range) or less than 65 U/L, provided this was at least a 50% decline from baseline values. Secondary outcomes included changes in ALT levels, HCV RNA levels, and quality-of-life measures. Results After 24 weeks of treatment, only 2 participants in each treatment group (P ≥ .99) met the primary outcome measure (3.8% [95% CI, 0.5% to 13.2%] for placebo, 4.0% [95% CI, 0.5% to 13.7%] for 420-mg silymarin, and 3.8% [95% CI, 0.5% to 13.2%] for 700-mg silymarin). The mean decline in serum ALT activity at the end of treatment did not differ significantly (P = .75) across the 3 treatment groups (mean decline, −4.3 [95% CI, −17.3 to 8.7] U/L for placebo, −14.4 [95% CI, −41.6 to 12.7] U/L for 420-mg silymarin, −11.3 [95% CI, −27.9 to 5.4] U/L for 700-mg silymarin); there likewise were no significant differences in HCV RNA levels (mean change, 0.07 [95% CI, −0.05 to 0.18] log 10 IU/mL for placebo, −0.03 [95% CI, −0.18 to 0.12] log 10 IU/mL for 420-mg silymarin, 0.04 [95% CI, −0.08 to 0.16] log 10 IU/mL for 700-mg silymarin; P = .54) or quality-of-life measures. The adverse event profile of silymarin was comparable with that of placebo. Conclusion Higher than customary doses of silymarin did not significantly reduce serum ALT levels more than placebo in participants with chronic HCV infection unsuccessfully treated with interferon-based therapy. Trial Registration clinicaltrials.gov Identifier: NCT00680342

We have used a murine model of organ-specific autoimmunity to characterize therapeutic modalities capable of down-regulating the cellular limb of the autoimmune response. Murine interstitial nephritis is an autoimmune disease mediated by tubular antigen-specific CD8+ nephritogenic effector T cells which are delayed-type hypersensitivity (DTH) reactive and cytotoxic to renal epithelial cells. Previous studies have demonstrated that disease can be suppressed with experimentally induced populations of T cells (Ts1 and Ts2 cells) obtained after injection of tubular antigen-coupled splenocytes into syngeneic mice. As the target of Ts2 is the CD8+ effector T cell, we have evaluated its effects on nephritogenic effector T cell clones isolated from diseased animals. Our studies demonstrate that soluble proteins expressed by Ts2 cells (TsF2) specifically abrogate the DTH, cytotoxic, and nephritogenic potential of M52 cells, although T cell receptor and IL-2 receptor expression are unchanged in these unresponsive M52 clones. TsF2-induced inhibition is dependent on new mRNA and protein synthesis. In a cytotoxic clone, M52.26, exposure to TsF2 induces expression of TGF-beta 1 which is, in turn, required for inhibition of cytotoxicity and nephritogenicity. Our studies are consistent with TGF-beta 1 behaving, at least in some T cells, as a nonspecific final effector of clone-specific suppression.

Context Saw palmetto fruit extracts are widely used for treating lower urinary tract symptoms attributed to benign prostatic hyperplasia (BPH); however, recent clinical trials have questioned their efficacy, at least at standard doses (320 mg/d). Objective To determine the effect of saw palmetto extract (Serenoa repens, from saw palmetto berries) at up to 3 times the standard dose on lower urinary tract symptoms attributed to BPH. Design, setting, and participants A double-blind, multicenter, placebo-controlled randomized trial at 11 North American clinical sites conducted between June 5, 2008, and October 10, 2010, of 369 men aged 45 years or older, with a peak urinary flow rate of at least 4 mL/s, an American Urological Association Symptom Index (AUASI) score of between 8 and 24 at 2 screening visits, and no exclusions. Interventions One, 2, and then 3 doses (320 mg/d) of saw palmetto extract or placebo, with dose increases at 24 and 48 weeks. Main outcome measures Difference in AUASI score between baseline and 72 weeks. Secondary outcomes included measures of urinary bother, nocturia, peak uroflow, postvoid residual volume, prostate-specific antigen level, participants' global assessments, and indices of sexual function, continence, sleep quality, and prostatitis symptoms. Results Between baseline and 72 weeks, mean AUASI scores decreased from 14.42 to 12.22 points (-2.20 points; 95% CI, -3.04 to -1.36) [corrected]with saw palmetto extract and from 14.69 to 11.70 points (-2.99 points; 95% CI, -3.81 to -2.17) with placebo. The group mean difference in AUASI score change from baseline to 72 weeks between the saw palmetto extract and placebo groups was 0.79 points favoring placebo (upper bound of the 1-sided 95% CI most favorable to saw palmetto extract was 1.77 points, 1-sided P = .91). Saw palmetto extract was no more effective than placebo for any secondary outcome. No clearly attributable adverse effects were identified. Conclusion Increasing doses of a saw palmetto fruit extract did not reduce lower urinary tract symptoms more than placebo. Trial registration clinicaltrials.gov Identifier: NCT00603304.