Randomized clinical trial to determine the effectiveness of CO-oximetry and anti-smoking brief advice in a cohort of kidney transplant patients who smoke.

Background: measure the efficacy of exhaled carbon monoxide (CO) measurement plus brief advisory sessions to reduce smoking exposure and smoking behaviour in kidney transplant recipients. Methods: Randomized, controlled, open-label clinical trial at a Spanish hospital.Smoking kidney transplant recipients giving their consent to participate were randomized to control (brief advice, n=63) or intervention group (brief advisory session plus measuring exhaled CO, n=59). Measurements: Sociodemographic characteristics, cardiovascular risk factors, treatment, rejection episodes, infections, self-reported smoking, drug use, level of dependence and motivation to stop smoking (Fagerström's and Richmond's test) and stage of change (Prochaska and DiClemente's Stages). Efficacy was assessed at 3, 6, 9 and 12 months as: cotinine test, CO levels in exhaled air, nicotine dependence, motivational stages of change, motivation to stop smoking, pattern of tobacco use and smoking cessation rates. Logistic regression models were computed. Results: At 12 months of follow-up, differences were found in exhaled CO between the intervention and control group(6.1±6.8vs.10.2±9.7ppm;p=0.028). Carboxyhemoglobin levels were lower in the intervention group as well as the positive cotinine test (1.2±1.2%vs.2.0±2.4%;p=0.039),(53.4%vs.74.2%). At 12 months, intervention reduces the probability of a positive urine test by 28%. Conclusions: Co-oximetry is a clinically relevant intervention for reduction of tobacco exposure in kidney transplant recipients.

Eculizumab Modifies Outcomes in Adults with Atypical Hemolytic Uremic Syndrome with Acute Kidney Injury.

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a rare disease associated with congenital or acquired genetic abnormalities that result in uncontrolled complement activation, leading to thrombotic microangiopathy and kidney failure. Until recently, the only treatment was plasma exchange or plasma infusion (PE/PI), but 60% of patients died or had permanent kidney damage despite treatment. Eculizumab, a complement inhibitor, has shown promising results in aHUS. However, data are mainly extracted from case reports or studies of heterogeneous cohorts, and no direct comparison with PE/PI is available. METHODS: An observational retrospective study of adult, dialysis-dependent aHUS patients with acute kidney injury (AKI) who were treated with either PE/PI alone or with second-line eculizumab in our center. We compared the effect of PE/PI and eculizumab on kidney function, hypertension, proteinuria, hematologic values, relapse, and death. RESULTS: Thirty-one patients were included (females, 18; sporadic aHUS, 29; mean age, 46 ± 20 years). Twenty-six patients were treated with PE/PI alone, and 5 were deemed to be plasma-resistant and received eculizumab after stopping PE/PI. Among patients receiving eculizumab, 80% attained complete recovery of kidney function, 100% stopped dialysis, 20% had decreased proteinuria, and no patient relapsed (vs. 38.5, 50, 15.4, and 11.5%, respectively, of patients receiving only PE/PI). At 1-year of follow-up, no deaths had occurred in either group. CONCLUSION: Eculizumab shows greater efficacy than PE/PI alone for the treatment of adult aHUS patients with AKI. Prospective studies and meta-analyses are warranted to confirm our findings and set guidelines for treatment, monitoring, and maintenance.

Incidence of cardiovascular events and associated risk factors in kidney transplant patients: a competing risks survival analysis.

BACKGROUND: The high prevalence of cardiovascular risk factors among the renal transplant population accounts for increased mortality. The aim of this study is to determine the incidence of cardiovascular events and factors associated with cardiovascular events in these patients. METHODS: An observational ambispective follow-up study of renal transplant recipients (n = 2029) in the health district of A Coruña (Spain) during the period 1981-2011 was completed. Competing risk survival analysis methods were applied to estimate the cumulative incidence of developing cardiovascular events over time and to identify which characteristics were associated with the risk of these events. Post-transplant cardiovascular events are defined as the presence of myocardial infarction, invasive coronary artery therapy, cerebral vascular events, new-onset angina, congestive heart failure, rhythm disturbances, peripheral vascular disease and cardiovascular disease and death. The cause of death was identified through the medical history and death certificate using ICD9 (390-459, except: 427.5, 435, 446, 459.0). RESULTS: The mean age of patients at the time of transplantation was 47.0 ± 14.2 years; 62% were male. 16.5% had suffered some cardiovascular disease prior to transplantation and 9.7% had suffered a cardiovascular event. The mean follow-up period for the patients with cardiovascular event was 3.5 ± 4.3 years. Applying competing risk methodology, it was observed that the accumulated incidence of the event was 5.0% one year after transplantation, 8.1% after five years, and 11.9% after ten years. After applying multivariate models, the variables with an independent effect for predicting cardiovascular events are: male sex, age of recipient, previous cardiovascular disorders, pre-transplant smoking and post-transplant diabetes. CONCLUSIONS: This study makes it possible to determine in kidney transplant patients, taking into account competitive events, the incidence of post-transplant cardiovascular events and the risk factors of these events. Modifiable risk factors are identified, owing to which, changes in said factors would have a bearing of the incidence of events.

A randomized clinical trial to determine the effectiveness of CO-oximetry and anti-smoking brief advice in a cohort of kidney transplant patients who smoke: study protocol for a randomized controlled trial.

BACKGROUND: The cardiovascular risk in renal transplant patients is increased in patients who continue to smoke after transplantation. The aim of the study is to measure the effectiveness of exhaled carbon monoxide (CO) measurement plus brief advisory sessions, in comparison to brief advice, to reduce smoking exposure and smoking behavior in kidney transplant recipients who smoke. The effectiveness will be measured by: (1) abandonment of smoking, (2) increase in motivation to stop smoking, and (3) reduction in the number of cigarettes smoked per day. DESIGN: a randomized, controlled, open clinical trial with blinded evaluation. SCOPE: A Coruña Hospital (Spain), reference to renal transplantation in the period 2012-2015. INCLUSION CRITERIA: renal transplant patients who smoke in the precontemplation, contemplation or preparation stages according to the Prochaska and DiClemente's Stages of Change model, and who give their consent to participate. EXCLUSION CRITERIA: smokers attempting to stop smoking, patients with terminal illness or mental disability that prevents them from participating. RANDOMIZATION: patients will be randomized to the control group (brief advisory session) or the intervention group (brief advisory session plus measuring exhaled CO). The sample target size is n = 112, with 56 patients in each group. Allowing for up to 10 % loss to follow-up, this would provide 80 % power to detect a 13 % difference in attempting to give up smoking outcomes at a two-tailed significance level of 5 %. MEASUREMENTS: sociodemographic characteristics, cardiovascular risk factors, treatment, rejection episodes, infections, self-reported smoking habit, drug use, level of dependence (the Fagerström test), stage of change (Prochaska and DiClemente's Stages of Change model), and motivation to giving up smoking (the Richmond test). RESPONSE: the effectiveness will be evaluated every 3, 6, 9 and 12 months as: pattern of tobacco use (self-reported tobacco use), smoking cessation rates, carbon monoxide (CO) levels in exhaled air measured by CO-oximetry, urinary cotinine tests, nicotine dependence (Fagerström test), motivational stages of change (Prochaska and DiClemente's stages) and motivation to stop smoking (the Richmond test). ANALYSIS: descriptive statistics and linear/logistic multiple regression models will be performed. Clinical relevance will be measured as relative risk reduction, absolute risk reduction and the number needed to treat. ETHICS: informed consent of the patients and Ethical Review Board was obtained (code 2011/061). DISCUSSION: Tobacco is a modifiable risk factor that increase the risk of morbidity and mortality in kidney transplant recipients. If effectiveness of CO-oximetry is confirmed to reduce tobacco exposure, we would have an intervention that is easy to use, low cost and with great implications about cardiovascular risk prevention in these patients. TRIAL REGISTRATION: Current Controlled Trials ISRCTN16615772 . EudraCT number: 2015-002009-12.

Incidence of cardiovascular events after kidney transplantation and cardiovascular risk scores: study protocol.

BACKGROUND: Cardiovascular disease (CVD) is the major cause of death after renal transplantation. Not only conventional CVD risk factors, but also transplant-specific risk factors can influence the development of CVD in kidney transplant recipients. The main objective of this study will be to determine the incidence of post-transplant CVD after renal transplantation and related factors. A secondary objective will be to examine the ability of standard cardiovascular risk scores (Framingham, REGICOR, SCORE, and DORICA) to predict post-transplantation cardiovascular events in renal transplant recipients, and to develop a new score for predicting the risk of CVD after kidney transplantation. METHODS/DESIGN: Observational prospective cohort study of all kidney transplant recipients in the A Coruna Hospital (Spain) in the period 1981-2008 (2059 transplants corresponding to 1794 patients). The variables included will be: donor and recipient characteristics, chronic kidney disease-related risk factors, pre-transplant and post-transplant cardiovascular risk factors, routine biochemistry, and immunosuppressive, antihypertensive and lipid-lowering treatment. The events studied in the follow-up will be: patient and graft survival, acute rejection episodes and cardiovascular events (myocardial infarction, invasive coronary artery therapy, cerebral vascular events, new-onset angina, congestive heart failure, rhythm disturbances and peripheral vascular disease). Four cardiovascular risk scores were calculated at the time of transplantation: the Framingham score, the European Systematic Coronary Risk Evaluation (SCORE) equation, and the REGICOR (Registre Gironi del COR (Gerona Heart Registry)), and DORICA (Dyslipidemia, Obesity, and Cardiovascular Risk) functions. The cumulative incidence of cardiovascular events will be analyzed by competing risk survival methods. The clinical relevance of different variables will be calculated using the ARR (Absolute Risk Reduction), RRR (Relative Risk Reduction) and NNT (Number Needed to Treat). The ability of different cardiovascular risk scores to predict cardiovascular events will be analyzed by using the c index and the area under ROC curves. Based on the competing risks analysis, a nomogram to predict the probability of cardiovascular events after kidney transplantation will be developed. DISCUSSION: This study will make it possible to determine the post-transplant incidence of cardiovascular events in a large cohort of renal transplant recipients in Spain, to confirm the relationship between traditional and transplant-specific cardiovascular risk factors and CVD, and to develop a score to predict the risk of CVD in these patients.

Human C3 mutation reveals a mechanism of dense deposit disease pathogenesis and provides insights into complement activation and regulation.

Dense deposit disease (DDD) is a severe renal disease characterized by accumulation of electron-dense material in the mesangium and glomerular basement membrane. Previously, DDD has been associated with deficiency of factor H (fH), a plasma regulator of the alternative pathway (AP) of complement activation, and studies in animal models have linked pathogenesis to the massive complement factor 3 (C3) activation caused by this deficiency. Here, we identified a unique DDD pedigree that associates disease with a mutation in the C3 gene. Mutant C(3923ΔDG), which lacks 2 amino acids, could not be cleaved to C3b by the AP C3-convertase and was therefore the predominant circulating C3 protein in the patients. However, upon activation to C3b by proteases, or to C3(H2O) by spontaneous thioester hydrolysis, C(3923ΔDG) generated an active AP C3-convertase that was regulated normally by decay accelerating factor (DAF) but was resistant to decay by fH. Moreover, activated C(3b923ΔDG) and C3(H2O)(923ΔDG) were resistant to proteolysis by factor I (fI) in the presence of fH, but were efficiently inactivated in the presence of membrane cofactor protein (MCP). These characteristics cause a fluid phase-restricted AP dysregulation in the patients that continuously activated and consumed C3 produced by the normal C3 allele. These findings expose structural requirements in C3 that are critical for recognition of the substrate C3 by the AP C3-convertase and for the regulatory activities of fH, DAF, and MCP, all of which have implications for therapeutic developments.

Cancer incidence in kidney transplant recipients: a study protocol.

BACKGROUND: Different publications show an increased incidence of neoplasms in renal transplant patients. The objective of this study is to determine the incidence of cancer in the recipients of renal transplants performed in the A Coruña Hospital (Spain) during the period 1981-2007. METHODS/DESIGN: During the study period 1967 kidney transplants were performed, corresponding to 1710 patients. Patients with neoplasms prior to the transplant will be excluded (n = 38). A follow-up study was carried out in order to estimate cancer incidence after transplantation.For each patient, information included donor and recipient characteristics, patients and graft survival and cancer incidence after transplantation. Incident cancer is considered as new cases of cancer after the transplant with anatomopathological confirmation. Their location will be classified according to the ICD-9.The analysis will be calculated using the indirect standardisation method. Age-adjusted cancer incidence rates in the Spanish general population will be obtained from the Carlos III Health Institute, the National Epidemiology Centre of the Ministry of Science and Technology. Crude first, second and third-year post-transplantation cancer incidence rates will be calculated for male and female recipients. The number of cases of cancer at each site will be calculated from data in the clinical records. The expected number of cancers will be calculated from data supplied by the Carlos III Health Institute. For each tumour location we will estimate the standardized incidence ratios (SIRs), using sex-specific cancer incidence rates, by dividing the incidence rate for the transplant patients by the rate of the general population. The 95% confidence intervals of the SIRs and their associated p-values will be calculated by assuming that the observed cancers follow a Poisson distribution. Stratified analysis will be performed to examine the variation in the SIRs with sex and length of follow-up.Competing risk survival analysis methods will be applied to estimate the cumulative incidence of cancer and to identify variables associated to its occurrence. DISCUSSION: Information about cancer incidence in kidney transplant patients could be useful to adapt the guidelines on post-kidney transplant follow-up on tumour screening, and evaluate the impact of intervention measures for the prevention of cancer in these patients.

Validity and reliability of the SF-36 questionnaire in patients on the waiting list for a kidney transplant and transplant patients.

BACKGROUND/AIMS: The aim of this study is to explore the validity and reliability of the health-related quality of life SF-36 questionnaire in patients undergoing renal replacement therapy. METHODS: A multicenter descriptive transversal study was carried out in Galicia, Spain, with patients undergoing renal replacement therapy. The tool used to measure the health-related quality of life was the authorized Spanish version of the 'SF-36' generic health questionnaire. The internal consistency of this survey was determined by means of interscale correlations and Cronbach's alpha statistic. Validity was examined with a principal component exploratory factor analysis with Varimax rotation. RESULTS: A total of 213 patients waiting for a kidney transplant and 72 recipients with a functioning renal transplant were studied. All the interscale correlations were positive and significant. The overall statistical value for Cronbach's alpha was equal to 0.91 (95% CI: 0.91-0.94) and in all domains this value ranged from 0.7 to 0.92. The factor analysis identified 8 factors that explain 66.6% of the variance, 5 of which consisted of the same structure as 5 factors (domains) of the theoretical model. CONCLUSION: The SF-36 questionnaire is also a reliable and valid tool when used to measure the quality of life of patients undergoing renal replacement therapy.

Cross-reactivity between swine leukocyte antigen and human anti-HLA-specific antibodies in sensitized patients awaiting renal transplantation.

Xenotransplantation is increasingly viewed as a promising way to alleviate the problem of patients who have alloreactive lymphocytotoxic antibodies and therefore tend to accumulate on the waiting list for renal transplantation. One barrier to xenotransplantation in these patients could be the hyperacute or acute vascular rejection as a result of preexisting anti-HLA antibodies that recognize swine leukocyte antigens. The cross-reactivity of sera from 98 patients with pig lymphocytes was studied by flow cytometry. After absorption of xenoreactive natural antibodies (XNA), isotype, class, and antibody specificity causing a positive cross-match (XM) were determined. For nonsensitized patients, all of the antibody binding to pig lymphocytes was due to XNA, which were removed by pig red blood cells absorption. In contrast, in sensitized patients, after removal of XNA, pig lymphocyte XM remained positive. There was no correlation between antibody binding to pig lymphocytes and Ig isotype (IgG or IgM) or HLA class-specific antibodies. For testing evidence that class II-specific antibodies were responsible for antibody binding to pig lymphocytes, HLA class I-specific antibodies were absorbed with pooled human platelets. It was confirmed that HLA class II-specific antibodies were responsible for the positive pig XM, but the strength of the positive XM was weaker than the strength caused by HLA class I-specific antibodies. Sera with multiple specificities (plurispecific sera) displayed a greater frequency of cross-reactivity with swine leukocyte antigens (P < 0.05). Seven of 11 highly immunized patients without cross-reactivity IgG with porcine lymphocytes showed positive XM before an IgM was used. The results demonstrate the cross-reactive nature of HLA antibodies and therefore point out the need to perform a prospective XM after absorption of XNA in presensitized individuals.

Progression of renal disease measured by the reciprocal of serum creatinine.

BACKGROUND: This study aims to quantify the decrease in the reciprocal of serum creatinine during the two years prior to the start of dialysis and to identify the factors associated with the progression of renal disease. METHODS: The study included 76 patients who were monitored for an average of 26.27 months. During the study 52 patients began dialysis treatments. The clinical and analytical variables were analyzed using the t-student test, ANOVA or the Kruskall-Wallis test. A multiple regression analysis was carried out with the decrease in the reciprocal of serum creatinine as the dependent variable. RESULTS: There was a decrease between the mean value during the two years prior to dialysis, the mean value during the previous year and the value at the start of dialysis treatments of 0.29, 0.21 and 0.17 respectively. The nephropathy having the sharpest drop in the reciprocal of serum creatinine, expressed as a percentage of the initial value, was found to be nephroangiosclerosis (46.29%). A greater decline in the reciprocal of serum creatinine was exhibited by low albumin values and adjusted by means of different variables with LDL levels (p = 0.141). For different levels of haemoglobin, proteinuria and cholesterol, the drop in the reciprocal of serum creatinine was greater in patients having a diastolic blood pressure reading of 90 or greater. CONCLUSIONS: The decrease in the reciprocal of serum creatinine was associated with different variables in patients who required dialysis.