Hyaluronan as a predictive biomarker in recurrent renal stone formers

Abstract

Recurrence of renal calculi after treatments such as extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and surgeries, remains high. A viable diagnostic biomarker is needed to alert the patient and the clinician to monitor for stone recurrences. This study concentrates on idiopathic stone-formers (SF) and 6 groups of subjects were recruited with Active-SF (pre- and post- treatments), Non-SF (with and without infection) for comparisons. Urine and blood samples were collected from the patients (with inclusion and exclusion criteria) from the hospital clinic and processed at the laboratory with ELISA and biochemical methods (electrophoresis and HPLC). 120 samples were collected amongst the 3 groups. The following demographics were obtained: Age-range (32 – 63 years old); Male: Female ratio (58: 42); Mean urinary pH 6.33 ± 0.23 (though in each group there are differential mean pH) and urinalysis done for all samples to verify the integrity of the samples. The first biomarker studied was the excretion of urinary glycosaminoglycans (GAGs). Chondroitin sulphate A/C (CS), dermatan sulphate (DS), heparin sulphate (HS) and hyaluronan (HA) were extracted and quantified. Active SF (prior treatment) had 70% positive indicator for GAGs and those SF (post treatment) had over 90% compared to the Normals. Other biomarkers (not reported here) under investigations are cytokines including NAG and MIP-1α. This study combines majority of the biomarkers in our study under a case-control investigation to suggest a potential and sensitive marker for recurrent SFs. Hyaluronan is one such candidate biomarker. Keywords: Biomarkers; Glycosaminoglycans; Hyaluronan; Recurrence; Urolithiasis