THE ASSOCIATION OF ELEVATED URINARY TOTAL TO SULFATED GLYCOSAMINOGLYCAN RATIO AND HIGH MOLECULAR MASS HYALURONIC ACID WITH INTERSTITIAL CYSTITIS

Abstract

A decrease in the glycosaminoglycan (GAG) layer on the urothelium is believed to be one of the possible causes of interstitial cystitis. Consequently, GAG-like substances and hyaluronic acid (HA) have been prescribed for treating this condition. To delineate the possible role of GAG and HA in the interstitial cystitis disease process, we compared the urinary levels of total GAGs (sulfated + non-sulfated), sulfated GAGs and HA in interstitial cystitis patients and normal controls. We also examined different HA species present in the urine of interstitial cystitis patients. The total GAG and sulfated GAG levels in urine specimens of normal individuals (n = 20) and interstitial cystitis patients (n = 25) were determined by utilizing the carbazole reaction assay and the Farndale method, respectively, and were expressed as microg./mg. creatinine. Urinary HA levels were measured by applying the HA test and were expressed as ng./mg. creatinine. Gel filtration column chromatography was used to examine the profile of urinary GAGs and HA species. Total urinary GAGs were 2.5 to 4-fold elevated in interstitial cystitis patients with moderate to severe symptoms (Group 2; 76.2 +/- 24.8) when compared with those in normal individuals (19.9 +/- 2.5) and patients with mild symptoms (Group 1; 30.4 +/- 5.1) (p <0.001). Three urinary GAG peaks were detected in both normal and interstitial patients. However, each GAG peak from interstitial cystitis patient urine was 3 to 5-fold higher than that from normal patient urine. The sulfated GAG levels, however, remained unchanged among normal individuals (1.4 +/- 0.22), Group 1 (2.2 +/- 0.96) and Group 2 (1.6 +/- 0.38) patients (p >0.05). Consequently, the ratio of total GAGs to sulfated GAGs was elevated 3 to 3.5-fold in Group 2 patients (49.9 +/- 13.9) in comparison to that in normal individuals (16.7 +/- 2.5) and group 1 patients (14.4 +/- 4.6) (p <0.001). Urinary HA levels were marginally elevated in Group 2 patients (821. 4 +/- 247.9) when compared with those in the normal group (337.3 +/- 106.1) and Group 1 patients (540.9 +/- 166.5). In addition, a distinct high molecular mass HA species was present only in Group 2 patients. The increased ratio of total GAGs to sulfated GAGs and marginally elevated HA levels in urine indicate that the GAG layer is altered in interstitial cystitis patients. However, these results are in contrast to the accepted concept that a reduction in urothelial GAGs causes interstitial cystitis. The high molecular mass HA species detected in patients with severe symptoms may play a role in the pathophysiology of this disease.