Effects of rare kidney diseases on kidney failure: a longitudinal analysis of the UK National Registry of Rare Kidney Diseases (RaDaR) cohort
Katie Wong, David Pitcher, Fiona Braddon, Lewis Downward, Retha Steenkamp, Nicholas M. P. Annear, Jonathan Barratt, Coralie Bingham, Constantina Chrysochou, Richard J. Coward, David Game, Siân Griffin, Matt Hall, Sally Johnson, Durga Kanigicherla, Fiona Karet Frankl, David Kavanagh, Larissa Kerecuk, Eamonn R. Maher, Shabbir H. Moochhala, Jenny Pinney, John A Sayer, Roslyn Simms, Smeeta Sinha, Shalabh Srivastava, Frederick W.K. Tam, Andrew Neil Turner, Stephen B Walsh, Aoife Waters, Patricia D. Wilson, Edwin Wong, C. Mark Taylor, Dorothea Nitsch, Moin A. Saleem, Detlef Böckenhauer, Kate Bramham, Daniel P. Gale, Sharirose Abat, Shazia Adalat, Joy O. Agbonmwandolor, Zubaidah Ahmad, Abdulfattah Alejmi, Rashid Almasarwah, Nicholas Annear, Ellie Asgari, Amanda Ayers, Jyoti Baharani, Gowrie Balasubramaniam, Felix Kpodo, Tarun Bansal, Alison Barratt, Jonathan Barratt, Megan Bates, Natalie Bayne, Janet Bendle, Sarah Benyon, Carsten Bergmann, Sunil Bhandari, Coralie Bingham, Preetham Boddana, Sally L. Bond, Fiona Braddon, Kate Bramham, Angela Branson, Stephen Brearey, Vicky Brocklebank, Sharanjit Budwal, Conor Byrne, Hugh Cairns, Brian Camilleri, Gary Campbell, A. Capell, Margaret Carmody, Marion Carson, Tracy Cathcart, Christine Catley, Karine Cesar, Melanie Chan, Houda Chea, James Chess, Chee Kay Cheung, Katy-Jane Chick, Nihil Chitalia, Martin Christian, Constantina Chrysochou, Katherine Clark, Christopher L. Clayton, Rhian Clissold, Helen Cockerill, Joshua Coelho, Elizabeth Colby, Viv Colclough, Eileen Conway, H. Terence Cook, Wendy L. Cook, Theresa Cooper, Richard J. Coward, Sarah Crosbie, Gabor Cserep, Anjali Date
Abstract
Background Individuals with rare kidney diseases account for 5–10% of people with chronic kidney disease, but constitute more than 25% of patients receiving kidney replacement therapy. The National Registry of Rare Kidney Diseases (RaDaR) gathers longitudinal data from patients with these conditions, which we used to study disease progression and outcomes of death and kidney failure. Methods People aged 0–96 years living with 28 types of rare kidney diseases were recruited from 108 UK renal care facilities. The primary outcomes were cumulative incidence of mortality and kidney failure in individuals with rare kidney diseases, which were calculated and compared with that of unselected patients with chronic kidney disease. Cumulative incidence and Kaplan–Meier survival estimates were calculated for the following outcomes: median age at kidney failure; median age at death; time from start of dialysis to death; and time from diagnosis to estimated glomerular filtration rate (eGFR) thresholds, allowing calculation of time from last eGFR of 75 mL/min per 1·73 m 2 or more to first eGFR of less than 30 mL/min per 1·73 m 2 (the therapeutic trial window). Findings Between Jan 18, 2010, and July 25, 2022, 27 285 participants were recruited to RaDaR. Median follow-up time from diagnosis was 9·6 years (IQR 5·9–16·7). RaDaR participants had significantly higher 5-year cumulative incidence of kidney failure than 2·81 million UK patients with all-cause chronic kidney disease (28% vs 1%; p<0·0001), but better survival rates (standardised mortality ratio 0·42 [95% CI 0·32–0·52]; p<0·0001). Median age at kidney failure, median age at death, time from start of dialysis to death, time from diagnosis to eGFR thresholds, and therapeutic trial window all varied substantially between rare diseases. Interpretation Patients with rare kidney diseases differ from the general population of individuals with chronic kidney disease: they have higher 5-year rates of kidney failure but higher survival than other patients with chronic kidney disease stages 3–5, and so are over-represented in the cohort of patients requiring kidney replacement therapy. Addressing unmet therapeutic need for patients with rare kidney diseases could have a large beneficial effect on long-term kidney replacement therapy demand. Funding RaDaR is funded by the Medical Research Council, Kidney Research UK, Kidney Care UK, and the Polycystic Kidney Disease Charity.