Alpha-klotho and peritoneal membrane status: A hypothesis generating study.

BACKGROUND: Long-term success of peritoneal dialysis relies on the integrity of the peritoneal membrane. This proof-of-concept study addressed the hypothesis that fibrosis is already present in the membrane at pre-dialysis and that the membrane status is related to the individual's uraemic fingerprint. METHODS: A clinical-mechanistic, transversal, single-centre study was conducted. Pre-dialysis peritoneal biopsies were scored considering the submesothelial compact zone thickness (STM), vasculopathy and inflammation. We investigated if the membrane status could be inferred from a panel of proteins (α-Klotho, Galectin-3, FGF21, FGF23, Tweak, TNFα and hsPCR) in blood. RESULTS: A total 58 incident patients aged 56 ± 15 years old were included, 31% female, 55% hypertension, 29% diabetic and 24% obese. Person-to-person STM was found to be highly variable and 38% of patients were fibrosis positive. Both α-Klotho (Spearman r = -.7491, p < 0.001) and FGF21 (Spearman r = -.5102, p < 0.001) were negatively associated with STM. α-Klotho, but not FGF21, was able to discriminate fibrosis from nonfibrosis with/without inflammation and vasculopathy. PLS models identified α-Klotho as the protein most relevant for fibrosis. α-Klotho was independently associated with fibrosis of the peritoneal membrane (OR = .991 (.896-.997), p = 0.002). CONCLUSION: Before the start of dialysis in incident patients, some patients already present fibrosis of the peritoneal membrane and other patients do not. Our findings suggest that α-Klotho may be implicated in fibrosis of the peritoneal membrane.

Validation of the Portuguese version of the Functional Index for Hand Osteoarthritis (FIHOA).

INTRODUCTION: Hand osteoarthritis (HOA) is a prevalent rheumatic disease that may cause significant disability. The Functional index for HOA (FIHOA) is a validated questionnaire to evaluate loss of function in patients with HOA. OBJECTIVE: To undertake a cross-cultural adaptation and validation of FIHOA into Portuguese. PATIENTS AND METHODS: First, the original French version of FIHOA had been forward-backward translated into Portuguese, according to the guidelines for cross-cultural adaptation. Secondly, patients with primary HOA were consecutively recruited in three Portuguese rheumatology outpatient clinics between May 2016 and April 2018. The final consensual Portuguese version of FIHOA was administered to 52 patients. A numerical rating scale (NRS - 0 to 100mm) for hand pain and for perceived hand dysfunction was also registered. Ten randomly selected patients were re-administered the same tools 5 to 15 days later. Internal consistency, test-retest reliability, internal construct validity and external validity related to dysfunction NRS were evaluated. RESULTS: Fifty-two patients were evaluated: all right-handed, 96% women, mean age of 63 (10) years and 8 (6) years of disease duration. Mean (SD) pain and dysfunction were 47 (25) and 46 (25), respectively, with 68% patients being symptomatic. Mean (SD) FIHOA was 7 (5). Cronbach's alpha for internal consistency was high and adequate (0.87) and corrected item-total correlation revealed adequate performance. For reliability, Spearman's rho coefficient was 0.88 and total intraclass correlation coefficient (ICC) between test and retest was 0.87, showing good reliability. Factor analysis revealed three factors accounting for 71% of the variance of the score, with the first one (including questions 1, 2, 3 and 10) being responsible for 47% of the variance. Spearman's rho between FIHOA and dysfunction NRS was 0.5, showing a moderate but significant correlation and moderate external validity. CONCLUSION: The Portuguese version of FIHOA is a consistent, reliable, and valid instrument to measure loss of function in HOA Portuguese patients.