Teresa Ortega

Efficacy of peritoneal ultrafiltration in the treatment of refractory congestive heart failure

BACKGROUND Heart failure (HF) is a major health problem in developed countries. HF is a progressive, lethal disorder, even with adequate treatment. There exists a vicious circle in the pathophysiology of HF that perpetuates and magnifies the problem. Concomitant fluid accumulation may worsen the congestive HF, it is responsible for numerous hospitalizations and it is an important cause of mortality. In this situation, any means of fluid removal may aid in the management of these patients. The objective of this study was to evaluate the efficacy of peritoneal dialysis (PD) in the treatment of refractory HF in terms of functional status, hospitalization and mortality. We also determined the improvement in health-related quality of life with the use of PD, and examined the economic consequences of its use. METHODS We conducted a single centre, prospective, non-randomized study involving patients showing symptoms and signs of congestive HF refractory to maximum tolerable drug treatment. All of them were treated with PD. We analysed physical and biochemical determinations, functional status (according to the NYHA classification) and echocardiogram parameters. Also, to determine the efficacy of the technique we compared the perceived state of health (measured by the EQ5D) to PD patients respect to those reported with conservative therapies. Finally, we carried out a cost-utility evaluation measured by the incremental cost-utility ratio between these two options. RESULTS Seventeen patients (65% men, 64 +/- 9 years) were included in the study, and 12 were still undergoing PD treatment at the end of the follow-up period (15 +/- 9 months). All patients improved their NYHA functional status (65% two classes; the rest, one; P < 0.001), with an important improvement in their pulmonary artery systolic pressure (44 +/- 12 versus 27 +/- 9 mmHg; P = 0.007), but no changes in left ventricular ejection fraction. Hospitalization rates underwent a dramatic reduction (from 62 +/- 16 to 11 +/- 5 days/patient/year; P = 0.003) before and after PD treatment. PD treatment raised life expectancy of 82% after 12 months of treatment, and 70% and 56% after 18 and 24 months, respectively, much better outcomes than those reported about conservative therapies, which only use diverse diuretic regimens. PD was associated with a higher perception state of health than the conservative therapy (0.6727 versus 0.4305; P < 0.01). Finally, we found that PD is cost-effective compared with the conservative therapy. CONCLUSIONS We demonstrate that congestive HF programmes should consider offering PD in hope of seeing better functional status, reduced morbidity and mortality, better quality of life as well as reduced health care costs.

Spanish validation of the "Kidney Transplant Questionnaire": a useful instrument for assessing health related quality of life in kidney transplant patients

BackgroundThere is a growing interest in the evaluation of Health Related Quality of Life (HRQoL) among patients undergoing Renal Replacement Therapy. In Spain, no specific questionnaire exists for kidney transplant patients. Here we present the Spanish validation of the first specific HRQoL assessment tool: the kidney transplant questionnaire (KTQ).MethodsProspective study of 31 patients on transplant waiting list who received the first kidney. Patients were evaluated before transplant and after 1, 3, 6 and 12 months, using the KTQ and the SF-36 Health Survey. Feasibility, validity, reliability, and sensibility to change were evaluated.ResultsMean time of administration of the KTQ was 12 minutes. Correlation coefficients among KTQ dimensions range between 0.32 and 0.72. Correlation coefficients of KTQ dimensions with SF-36 PCS were low (r<0.4), and with SF-36 MCS were moderate-high (r>0.4) except for Physical Symptom dimension (r = 0.33). Cronbachs Alpha was satisfactory for all KTQ dimensions (Physical Symptoms = 0.80; Fatigue = 0.93; Uncertainty/Fear = 0.81; Emotional= 0.90) except Appearance (0.69). Intraclass correlation coefficients ranged between 0.63 and 0.85, similar to those of the original KTQ version.ConclusionsResults of validation study show that feasibility, validity, reliability and sensibility to change of the Spanish version of the KTQ are similar to those of the original version.

Identification of Epitopes and Immunodominant Regions on the MICA Protein Defined by Alloantibodies From Kidney Transplant Patients

Background. Several reports showed a contribution of anti-MICA (major histocompatibility complex class I chain-related molecule A) antibodies (Abs) to the development of acute and chronic rejection. Identification of the epitopes to which the Abs bind may help to determine immunoreactive regions essential for the major histocompatibility complex compatibility between donor and recipients, leading to the best outcome of the transplant. Methods. Sera from 284 kidney transplant patients were screened for anti-MICA Abs by Luminex assay. MICA allele typing of the recipients was determined. The epitopes of MICA were mapped by screening a synthesized library of overlapping peptides from the extracellular domains of the protein against the sera from kidney transplant patients with anti-MICA Abs. Results. Antibodies against MICA were detected in 50 of 284 patients (17.6%) and correlated with the development of acute rejection. Nine antigenic regions were immunoreactive with anti-MICA Abs in the sera samples. Four of these continuous epitopes mapped to polymorphic amino acids (aa). Five antigenic regions were shared epitopes found in all the MICA alleles. The polymorphic residues, 173 (E/K), 175 (S/G), and 181 (R/T), had determined allele-specific epitopes (reactivity patterns 1 and 2). In contrast, the aa 208Y and 213T were implicated in the cross-reactivity among alleles. Conclusions. The presence of anti-MICA Abs could be an important marker for diagnosis because of their contribution to the outcome of the graft, regardless of presence of anti-HLA Abs. Additionally, the identification of epitopes revealed the in vivo antigens of the transplant and is spurring the development of new matching strategies to reduce the incidence of acute and chronic rejection.

The utility of a specific measure for heart transplant patients: reliability and validity of the Kansas City Cardiomyopathy Questionnaire.

Background. Health-Related Quality of Life of patients with heart transplantation is an important variable; however, it has received little attention so far, and only two Spanish validated measurement instruments are available. The aim of our study was to validate the Spanish version of the Kansas City Cardiomyopathy Questionnaire (KCCQ) in heart transplant patients. Methods. A prospective study was performed in 186 patients awaiting heart transplantation in nine transplant hospitals. Hundred transplant recipients filled out the KCCQ, the Euroqol 5-D (EQ5D), and the Short Form-36 (SF-36) Health Survey at pretransplant, after 3 months, 6 months, and 1 year of follow-up. A complete set of sociodemographic and clinical data were also collected. The validity, reliability, sensitivity to change, and effect size were studied. Two questionnaires, the SF-36 and EQ5D, were used to evaluate the validity. Results. Mean age of patients was 56.0 years, and 80.5% were men. Twenty-six percent had acute rejection. A five-dimensional factorial structure could be discerned. The questionnaire presented a Cronbachs α coefficient of more than 0.7. Correlations between the KCCQ and the other questionnaires and clinical variables were satisfactory. Conclusions. The KCCQ features adequate psychometric properties. The KCCQ offers several advantages over other questionnaires because it quantifies symptoms (frequency, severity, and stability) and it is much more sensitive to change, even when compared with the SF-36. The specific questionnaire for heart transplant patients is a useful and user-friendly instrument for measuring the Health-Related Quality of Life related to functional status, quality of life, and social limitation more accurately.

CD127low Expression in CD4 + CD25high T Cells as Immune Biomarker of Renal Function in Transplant Patients

Background. Noninvasive tests measuring cellular immunity could help predict immunologic risk and subsequent allograft dysfunction in transplant patients. CD25 is a promising marker of activation. Recent descriptions of CD127 expression as a discriminating factor between regulatory and activated T cells suggest its potential utility. Methods. Expression of CD127 in CD4+CD25high T cells was analyzed by flow cytometry in peripheral blood from 62 renal transplanted patients and 30 healthy controls. Forty patients presented stable graft function and 22 suffered renal failure. Results. Renal transplant patients showed higher levels of CD127high and a lower frequency of CD127low than healthy controls (0.63% vs. 0.29% [P<0.001] and 1.4% vs. 2.4% [P<0.001], respectively). However, high frequencies of not only CD127high but also CD127low showed a significant correlation with serum creatinine levels (P=0.012 and P=0.003, respectively). Allogenic stimulation in vitro increased the frequency of CD127low subset in a dose dependent manner. Furthermore, in patients with a high frequency of CD127low subset, this consisted mostly of FoxP3 negative cells, discarding their regulatory origin. Median frequency of CD127low, but not CD127high, cells showed significant differences between patients with stable function and with renal failure (P<0.005), with 16.7% and 53.1% of individuals above the median CD127low value (1.4%), respectively. Conclusion. Quantification of CD127low subset through staining of CD4+ T cells with the combined markers CD127/CD25/CD45RO has been demonstrated to be a significant tool for monitoring the outcome course of renal transplant patients.

Estimación de un índice de utilidad mediante el uso de la versión española del Cuestionario de Salud SF-36: validez del índice SF-6D frente al EQ-5D

BACKGROUND AND OBJECTIVE: A new utility index derived of the SF-36, the SF-6D, was recently developed and has been compared with other utility measures. The objective was to validate this index in the Spanish version of SF-36 with respect to the EQ-5D. METHOD: 1,843 complete measures of the SF-36 and the EQ-5D from 1,283 patients who received a solid organ transplant were collected. SF-6D values were calculated using the model proposed by its creator and without tariff values (not weighted). EQ-5D values were calculated using Spanish visual analog scale tariff (VAS-t), the time-trade off tariff (TTO-t) and also without tariff values (not weighted). Spearman correlation coefficients were calculated between SF-6D and EQ-5D values. RESULTS: Mean value (standard deviation) of SF-6D was 0.67 (0.15), of VAS-t, 0.69 (0.24) and of TTO-t, 0.70 (0.32). SF-6D values had moderate correlation with VAS-t (r = 0.734) and TTO-t (r = 0.731) (both p < 0.001). The not weighted SF-6D had a high correlation with the weighted version (r = 0.969, p < 0.001), and moderate with the VAS-t (r = 0.754), TTO-t (r = 0.750) and no weighted EQ-5D (r = 0.784) (p < 0.001). CONCLUSIONS: The SF-6D index derived from the Spanish version of SF-36 seem to be a valid utility index to be used with the SF-36 databases from studies made in Spain.

Evaluation of reliability and validity of Spanish version of the end-stage renal disease symptom checklist-transplantation module.

Background. Although health-related quality of life (HRQoL) of patients with a renal transplantation is an important variable, it has received little attention and only a few Spanish validated measurement instruments are available. The aim of this study was to assess the psychometric properties of the Spanish version of the End Stage Renal Disease Symptom Checklist–Transplantation Module (ESRD-SCL), a specific questionnaire for measuring HRQoL of kidney transplant patients. Methods. This prospective study to validate the ESRD-SCL included 307 patients who received a first kidney transplant. Patients filled out the ESRD-SCL, the EuroQol-5D and the Short Form-36 Health Survey at pretransplant, after 3 months, 6 months, and 1 year of follow-up. A complete set of sociodemographic and clinical data was also collected. Results. Mean age of patients was 51.6 years (SD±12) and 59.2% were men. A total of 24% had suffered initial allograft dysfunction and 18% had acute rejection. A six-dimensional factorial structure could be discerned. These dimensions were different from the original questionnaire and explained 56.07% of the variance. Internal consistency was good (Cronbach &agr; = 0.91 for the overall score and 0.60–0.86 for dimensions). A statistically significant moderate correlation was observed between the Short Form-36 and EuroQol-5D with the ESRD-SCL dimensions and with some of the clinical and sociodemographic variables. Conclusions. The Spanish version of the ESRD-SCL is a useful, user-friendly instrument for measuring the HRQoL related to the side effects on immunosuppression treatment of renal transplant patients more accurately.