Correlations between related-purine derivatives and renal disorders in patients with psoriasis vulgaris

Recent data suggest that severe psoriasis is an independent risk factor for chronic renal disease. In the present study, we investigated the role of related-purine derivatives as predictors of renal dysfunctions in patients with psoriasis. A prospective study was conducted on a group of 45 patients with psoriasis vulgaris and 45 control cases, monitored over a 5-year period. Alterations of renal function, albumin/creatinine ratio (ACR, mg/g) and UA/creatinine ratio (UACR, mg/mg) were determined in spontaneous urine samples. The status of related-purine derivatives was evaluated by quantification of uric acid (UA, mg/dl), adenosine deaminase (ADA, UI/mg protein), xanthine oxidase (XO, UI/mg protein) and 8-hydroxy-deoxy-guanosine levels (8-OHdG, ng/ml) in serum samples. Compared to the controls, in patients with psoriasis there was an increase in related-purine derivatives levels, which was demonstrated by the elevated serum levels of UA (5.1±0.4 vs. 5.4±1.0, P=0.066), ADA (0.14±0.08 vs. 0.29±0.12, P=0.052), XO (0.22±0.11 vs. 0.42±0.21, P=0.011) and 8-OHdG (3.1±0.05 vs. 8.3±4.7, P=0.002). The serum levels of related-purine derivatives were associated with the severity of psoriasis. In addition, there was a link between the serum levels of related-purine derivatives and markers of renal impairment. There were positive correlations between 8-OHdG and ACR (r=0.452, P=0.028) and between ADA, XO, UA, 8-OHdG and UACR (r=0.297 and P=0.032, r=0.301 and P=0.002, r=0.431 and P=0.027, r=0.508 and P=0.002) and negative correlations between UA, 8-OHdG and the estimated glomerular filtration rate (r=-0.301 and P=0.036, r=-0.384 and P=0.002). Thus, severe psoriasis is a risk factor for the development of renal disease.