Randall’s Plaque

Background Overgrowth of calcium oxalate on Randall’s plaque is a mechanism of stone formation among idiopathic calcium oxalate stone-formers (ICSFs). It is less clear how stones formwhen there is little or no plaque. Design, setting, participants, & measurements Participants were a consecutive cohort of ICSFs who underwent percutaneous nephroscopic papillary mapping in the kidney or kidneys containing symptomatic stones and a papillary tip biopsy from a representative calyx during a stone removal procedure between 2009 and 2013. The distribution of Randall’s plaque coverage was analyzed and used to divide ICSFs into those with a high ($5%; mean, 10.5%; n=10) versus low (,5%; mean, 1.5%; n=32) amount of plaque coverage per papilla. Demographic and laboratory features were compared between these two groups. ResultsLow-plaque stone formers tended to be obese (50%versus 10%; P=0.03) and have a history of urinary tract infection (34 % versus 0%; P=0.04). They were less likely to have multiple prior stone events (22 % versus 80%