#2674 ASSOCIATION BETWEEN SARCOPENIA, BODY COMPOSITION AND FRAILTY IN PERITONEAL DIALYSIS PATIENTS: A MULTI-CENTRIC STUDY Miguel Nuno Petrucci Mauricio 1 , Jaime Hernán Merino 1 , Andreia Carnevale 2 , Sofia Azeredo Pereira 3 , Ana Rita Martins 2 , Rita Calça 2 , Patricia Matias 2 , Barbara Cancho Castellano 1 , Nicolas-Roberto Robles Perez-Monteoliva 1 and Patricia Branco 2 1 Hospital Universitario de Badajoz, Badajoz, Spain, 2 Hospital Santa Cruz, Carnaxide, Portugal and 3 Nova Medical School, Lisboa, Portugal Background and Aims: Patients with chronic kidney disease (CKD) have an increased risk of mortality due to many causes. One of them is sarcopenia, a progressive skeletal muscle disorder that increases adverse outcomes such as fractures, falls, and physical disability, and has been considered an independent risk factor for mortality. Sarcopenia could be defined as a muscle failure in which muscle strength is the most solid measure of muscle function and a better predictor of adverse events rather than muscle mass. Grip strength is considered a reliable surrogate for measures of arm and leg strength. The aim of this study was to evaluate the prevalence of probable sarcopenia in peritoneal dialysis (PD) patients and its association with body composition and several clinical variables. Method: This retrospective multi-centric descriptive study was conducted at the Hospital de Santa Cruz (Lisboa) and Hospital Universitario de Badajoz (Badajoz). We performed a single evaluation of 62 patients on peritoneal dialysis from at least 3 months, aged >18 years in whom we measured muscle strength by handgrip strength using a dynamometer. We divided patients into two groups, using cut-off points to consider probable sarcopenia for men and women less than 27 kg and 16 kg, respectively. Patients with acute infection, amputated limbs, and implantable cardiac devices were excluded. The following data were analyzed: age, anthropometric variables, gender, duration, modality of PD, presence of hypertension, diabetes, and cardiovascular disease, obtained from electronic medical records. We also analyze data from body composition using a bioelectrical impedance device (overhydration, extracellular intracellular water ratio (E/I), lean and fat tissue index and phase angle), PD parameters (weekly urea Kt/v, nGFR, D/P Cr, nPCR, residual urine output) and measured serum concentrations of hemoglobin, PCR, NT-ProBNP, PTH, Ca-125, calcium, and phosphorus. We assessed patients for the Clinical Fragility Scale (CFS) and measured performance in activities of daily living using the Barthel Scale. Results: Records of 62 patients, 61% male, mean age 57 ± 22 years, and body mass index 27.5 ± 5.1 kg/m 2 were reviewed, with 15 (18.8%) classified as probable sarcopenic. Old age (p = 0.005), high CFS score (p = 0.005), E/I ratio (p < 0,001), and low values of lean tissue index (p < 0.031), mean phase angle (p < 0.001) and residual urine output (p < 0,018) were correlated with the presence of probable sarcopenia. In the multivariable analysis, age (HR 1.135; CI 95% 1.015 - 1.269), CFS score (HR 2.637; CI 1,008 - 6,900), and urine output (HR 0,996; CI 95% 0.993 - 0.999) were also related to probable sarcopenia. There was no association between the presence of anemia, cardiovascular disease, type of peritoneal transport, and clearance of small solutes. Conclusion: This study reported a low prevalence of probable sarcopenia in PD patients. We corroborate the association between age and frailty in the sarcopenic group. The percentage of extracellular water, muscle mass, and phase angle measured by bioimpedance could be useful variables to identify sarcopenic or at-risk patients. In multivariate analysis, age, higher CFS score, and urine output have been associated with sarcopenia. Preservation of residual renal function seems to be associated with less sarcopenia, which reinforces the importance of preserving residual renal function in PD patients. It’s also important to identify sarcopenic or at-risk patients in order to promote early detection and treatment. KIDNEY TRANSPLANTATION E1 - EXPERIMENTAL, IMMUNE-TOLERANCE & XENOGENIC TRANSPLANTS #4917 AN EXOME-WIDE STUDY OF RENAL OPERATIONAL TOLERANCE Annick Massart 1 ,2,3 , Richard Danger 4 , Catharina Olsen 5 , Mary Emond 6,7 , Ondrej Viklicky 8 , Valérie Jacquemin 2 , Julie Soblet 9 , Sarah Duerinckx 2 , Didier Croes 10 , Camille Perazzolo 2 , Petra Hruba 8 , Dorien Daneels 11 , Ben Caljon 11 , Mehmet Sukru Sever 12 , Julio Pascual 13 , Isabelle Pirson 2 , Lidia Ghisdal 14 , Guillaume Smits 9 , Magali Giral 15 , Daniel Abramowicz 1 , Marc Abramowicz 2,16 and Sophie Brouard 15 1 Department of Nephrology, Antwerp University Hospital and Laboratory of Experimental Medicine, University of Antwerp, Belgium, 2 Institut de Recherche Interdisciplinaire en Biologie Humaine et mole´ culaire (IRIBHM), Human Genetics unit, Universite´Libre de Bruxelles (ULB), Belgium, 3 Interuniversity Institute of Bioinformatics in Brussels (IB2), ULB-VUB, Belgium, 4 Nantes Université, INSERM, Center for Research in Transplantation and Translational Immunology, CRT2I, France, 5 Center for Medical Genetics, Reproduction and Genetics, Reproduction Genetics and Regenerative Medicine, Vrije Universiteit Brussel, UZ Brussel, Belgium, 6 United States of America, 7 Department of Biostatistics, University of Washington, United States of America, 8 Transplant Laboratory, Institute for Clinical and Experimental Medicine, Czech Republic, 9 Department of Genetics, Hoˆ pital Erasme, ULB Center of Human Genetics, Universite´Libre de Bruxelles, Belgium, 10 Center for Human Genetics, Clinique Universitaires Saint Luc, Belgium, 11 Brussels Interuniversity Genomics High Throughput core (BRIGHTcore), VUB-ULB, Belgium, 12 Istanbul School of Medicine, Internal Medicine, Nephrology, Istanbul Tıp faku¨ltesi, Turkey, 13 Department of Nephrology, Hospital Universitario 12 de Octubre, Spain , 14 Department of Nephrology, Hospital Centre EpiCURA, Belgium, 15 CHU Nantes and Nantes Université, INSERM, Center for Research in Transplantation and Translational Immunology, CRT2I, France and 16 Department of Genetic Medicine and Development, Faculty of Medicine, Universite´de Gene` ve, Switzerland Background and Aims: Renal operational tolerance is a rare and beneficial state of prolonged renal allograft function in the absence of immunosup- pression. The underlying mechanisms are unknown. We hypothesized that tolerance might be driven by inherited protein coding genetic variants with large effect, at least in some patients. Method: We set up a European survey of over 218,000 renal transplant recipients and collected DNAs from 40 recipients of an allogeneic kidney trans- plant who maintained good graft function (serum creatinine <1.7 mg/dL and proteinuria ≤1g/day or /g creatinine) in the absence of immunosuppression for at least one year. We performed an exome-wide association study comparing the distribution of moderate to high impact variants in 36 tolerant patients, selected for genetic homogeneity using principal component analysis, and 192 controls, using an optimal sequence-kernel association test adjusted for small samples. Results: We identified rare variants (allele frequency < 1%) of HOMER2 (3/36, FDR 0.0387), IQCH (5/36, FDR 0.0362), and LCN2 (3/36, FDR 0.102) in 10 tolerant patients vs 0 controls. One patient carried a variant in both HOMER2 and LCN2. Furthermore, the three genes showed an identical variant in two patients each. The three genes are expressed at the primary cilium (p 0 = 0.01), a key structure in immune responses. Both LCN2 variants were located 9 base pairs apart, in the 20 amino-acid long signal peptide of the encoded NGAL protein, suggesting the possibility of a shared functional effect Conclusion: Rare protein coding variants in a small set of primary cilium genes are associated with operational tolerance in a sizable portion of patients. Our findings have important implications for a better understanding of immune tolerance in transplantation and other fields of medicine. ClinicalTrials.gov Identifier NCT05124444. Abstracts i165 Downloaded from https://academic.oup.com/ndt/article/38/Supplement_1/gfad063b_2674/7195496 by guest on 15 June 2023