Basic Science: Stones

Moderated Poster Session

MP2-6 - Quantitative and qualitative evaluation of heavy metals and trace elements in the urinary stones: a multi-center global study

Presenting Author(s)

• 

  Mahmoud Abdel-Gawad, MD

  Consultant Urologist
  Elnagar Urology Center

Author(s)

• EE

  Emad Elsobky

  Consultant Urologist
  Al-Noor Hospital
• NA

  Naemat Alsayegh

  Cosultant
  Alwaha Hospital
• MK

  Mustafa Kura

  Consultant Urologist
• SM

  Sanjeev Mehta
• 

  Guido Kamphuis

  Consultant Urologist
  AMC Hospital Amsterdam
• BA

  Bedeir Ali-El-Dein

  Consultant Urologist
  Mansoura Urology Center

Introduction & Objective : Many heavy metals and trace elements (HMTE) have been reported as important components during the process of lithogenesis. Ordinary analysis techniques can only define the crystalline composition and the major elements within the urinary stones. These techniques cannot determine the micro-elements of the urinary stones. The aim of this study was to identify the types and evaluate the concentration of heavy metals and trace elements within the urinary stones from patients living in diverse geographical regions (10 countries).

Methods : A total of 1177urinary stones were collected from the patients after either open or endoscopic stone retrieval procedures. The stones underwent macro-analysis of the chemical structure by using Fourier Transform Infrared Spectroscopy (FT-IR). The heavy metals and trace elements (22 elements/stone) concentrations were determined by using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES).

Results : There were 794 (67.5%) males and 383 (32.5%) females. The mean age was 46.1 ± 12.5 years. The mineralogical structures of the stones were; 650 Ca oxalate (55.2%), 317 Ca phosphate (26.9%) and 210 uric acid and cystine stones (17.8 %). Many HMTE have been detected in all the analyzed stones with variable concentrations. However, there were significantly higher concentrations of 17 elements (Al, As, Ba, B, Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, S, Se, Sr and Zn) in the examined stones. Calcium-based stones contained a higher concentration of 7 elements (Al, As, Se, Sr, Fe, Zn and Ni). Phosphate-based stones had a higher concentration of 8 elements (Mg, B, Ba, Cd, Se, Pb, Sr and Zn). Uricites and Cystine had a higher concentration of S. The types and concentrations of HMTE within the stones differ from country to country. Calculi from developed countries contained a higher concentration of 13 HMTE compared to those from developing countries. The urinary stones were more common in younger patients from south countries (developing), while the stones affected older patients in northern countries (developed). Phosphate urinary calculi exhibited higher concentration of heavy metals compared to calcium oxalate and uric acid stones.

Conclusions :

These results indicate the involvement of many heavy metals and trace elements in the pathogenesis of urinary stones. Therefore, routine stone analysis techniques in addition to ICP-OES can be used for comprehensive stone analysis and evaluation of different HMTE concentrations. Consequently, the urinary stones management strategy could be changed in the future toward the early prevention and reduction of stone recurrence rate.