Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: A proposal for identifying the low renal uric acid clearance phenotype. | Indraratna et al. Arthritis Research Therapy 2010 12 149 http content 12 6 149 COMMENTARY A proposal for identifying the low renal uric acid clearance phenotype Praveen L Indraratna1 2 Sophie L Stocker3 4 Kenneth M Williams1 2 Garry G Graham1 2 Graham Jones5 and Richard O Day 1 2 Abstract Investigation of the genetic basis of hyperuricaemia is a subject of intense interest. However clinical studies commonly include hyperuricaemic patients without distinguishing between over-producers or under-excretors of urate. The statistical power of studies of genetic polymorphisms of genes encoding renal urate transporters is diluted if over-producers of uric acid are included. We propose that lower than normal fractional renal clearance of urate is a better inclusion criterion for these studies. We also propose that a single daytime spot urine sample for calculation of fractional renal clearance of urate should be preferred to calculation from 24-hour urine collections. Introduction Hyperuricaemia defined as a plasma concentration of urate used interchangeably with uric acid greater than mmol L mg dL 1 is the major risk factor for gout. Impaired renal clearance of urate or underexcretion accounts for up to 90 of hyperuricaemia cases. In the remainder the mechanism is excessive production of urate due to purine synthetic enzymatic abnormalities haematological malignancies 2 or dietary excess. Underexcretion and over-production of urate can co-exist 3 . Investigation of the molecular basis of low renal urate clearance ought to be conducted in individuals where low clearance has been proven but most studies have used hyperuricaemia alone as the inclusion criterion thereby reducing the power of the study 4-7 . Simkin and colleagues proposed a spot morning urine test of urate excretion normalised to glomerular filtration rate GFR to identify over-producers of urate 8 . We Correspondence 2Department of Clinical Pharmacology and .
