Fahmy N et al, 2013: Urinary Expression of Novel Tissue Markers of Kidney Injury Following Ureteroscopy, Shock Wave Lithotripsy and in Normal Healthy Controls
Fahmy N, Sener A, Sabbisetti V, Nott L, Lang RM, Welk B, Mendez-Probst CE, Macphee RA, Vaneerdewijk S, Cadieux PA, Bonventre J, Razvi H
London, Ontario, Canada, University of Western Ontario, Surgery, Division of Urology, 339 Windermere Road, LHSC-UH, C4-208, London, Ontario, Canada, N6A 5A5, 519-685-8500x 33353
BACKGROUND AND PURPOSE: Shockwave lithotripsy (SWL) and Ureteroscopy (URS) are minimally invasive treatment alternatives for kidney stones. Although less invasive, SWL subjects the renal parenchyma to a high level of energy and the potential to cause renal injury. The ability to detect renal injury post-SWL in a reliable and non-invasive way would be clinically beneficial. KIM-1 and NAG are 2 proteins secreted by the kidney into the urine and have been found to be sensitive markers of acute kidney injury in transplant patients. The aim of this work was to measure urinary levels of KIM-1 and NAG in kidney stone patients treated by SWL, URS and in non-stone volunteers.
PATIENTS AND METHODS: Kidney stone patients treated by SWL (n=50) and URS (n=10) were recruited. Voided urine samples were collected before and 2-3 hours following URS and SWL. Additionally, further urinary specimens were collected 2 days and 2 weeks post SWL treatment. Voided urine samples from healthy volunteers were also collected.
RESULTS: Mean KIM-1 values were increased in kidney stone patients when compared to volunteers. KIM-1 and NAG levels significantly increased post SWL and returned to baseline within 2 weeks post SWL. Poor kidney function was significantly associated with increased biomarker activity both in baseline and post SWL measurements. There was no significant change in urinary KIM-1 and NAG concentrations before and after ureteroscopy.
CONCLUSIONS: Kim-1 and NAG levels significantly increased post SWL treatment suggesting a potential role for these urinary markers in identifying patients at higher risk of tissue injury.
J Endourol. 2013 Sep 4. [Epub ahead of print]
PMID:24004191 [PubMed - as supplied by publisher]
This is the second report on urinary KIM-1 levels in controls and stone patients before and after SWL in this review series. What Tiselius has discussed on the paper by Hatipoğlu et al. also applies to this publication. Hatipoğlu et al. processed the urine specimens different, used a different assay, expressed the results in different dimensions and their stone patients had normal kidney function. Controls had identical KIM-1 values as stone patients.
In the current series some stone patients had reduced GFR of different degree, detailed information on comorbidities and medications that could influence the KIM-1 results are given.
The comparative table below is deliberately given without dimensions to guide the view on the relative differences only.
Obviously the use of KIM-1 needs further refinement before a more representative use to determine SWL effects on the kidney.