Mp58-04 Discovery and Implications of Inappropriately Alkaline Microenvironments Within the Functioning Human Kidney
Year: 2016
Type: article
Study design: Case Report
Abstract: You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology I1 Apr 2016MP58-04 DISCOVERY AND IMPLICATIONS OF INAPPROPRIATELY ALKALINE MICROENVIRONMENTS WITHIN THE FUNCTIONING HUMAN KIDNEY Michael S Borofsky, Andrew P Evan, James C Williams, Rajash K Handa, Casey A Dauw, Sharon Bledsoe, Fredric L Coe, Elaine M Worcester, and James E Lingeman Michael S BorofskyMichael S Borofsky More articles by this author , Andrew P EvanAndrew P Evan More articles by this author , James C WilliamsJames C Williams More articles by this author , Rajash K HandaRajash K Handa More articles by this author , Casey A DauwCasey A Dauw More articles by this author , Sharon BledsoeSharon Bledsoe More articles by this author , Fredric L CoeFredric L Coe More articles by this author , Elaine M WorcesterElaine M Worcester More articles by this author , and James E LingemanJames E Lingeman More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.802AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES One hypothesis for the rise in calcium phosphate (CaP) stones over the past several decades is focal damage to renal acidification mechanisms within Bellini ducts that subsequently raise pH and favor CaP formation. These injured ducts are manifest grossly via dilation and tubular plugging, most often with CaP deposits. To date this theory remains speculative with no prior research analyzing regional pH within the working human kidney. Using a fiber-optic pH microsensor, only 140 microns wide (PreSens, Regensburg, Germany), we sought to measure the intraluminal pH within these dilated ducts, specifically among patients with short bowel syndrome or ileostomy as these patients have known evidence of diffuse CaP plugging despite acidic bulk urine that should not allow for CaP crystallization. METHODS After IRB approval, four patients with acidic urine secondary to short gut syndrome/ileostomy undergoing percutaneous nephrolithotomy consented for study participation. In each case, the fiber-optic pH microsensor was preconditioned and tested for validity in a variety of physiologic buffers. At the beginning of the procedure, pH measurements were taken from bladder urine and saline irrigant. Upon completion of stone removal, renal papillae were inspected to identify dilated Bellini ducts. The pH microsensor was then introduced into the dilated duct and intraluminal urine pH was measured. (Figure 1). RESULTS All patients had acidic bladder urine (pH range: 4.83-5.58). Saline irrigant was similarly acidic in all cases (pH range 5.17-5.75). Intraluminal Bellini duct pH measurements were successfully obtained in all four patients (12 ducts total). Intraductal urine pH was greater than 1 pH unit higher compared to bladder urine pH in 11/12 cases. Mean ductal pH was 6.50 compared to mean bladder pH of 5.22 (p<0.001). CONCLUSIONS This is the first evidence for the presence of inappropriately alkaline microenvironments within injured/dilated Bellini ducts in a functioning human kidney. These findings help explain the paradoxical presence of CaP plugs in dilated Bellini ducts of patients with stone forming diseases characterized by highly acidic urine. They also suggest the potential for heterogeneous acidification within the working kidney and strengthen the hypothesis that focal renal tubular injury may have a role in the increasing prevalence of CaP stone formation via urinary alkalization. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e776-e777 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Michael S Borofsky More articles by this author Andrew P Evan More articles by this author James C Williams More articles by this author Rajash K Handa More articles by this author Casey A Dauw More articles by this author Sharon Bledsoe More articles by this author Fredric L Coe More articles by this author Elaine M Worcester More articles by this author James E Lingeman More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...
Source: The Journal of Urology
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2329459143