Effect of treatment with allopurinol on blood pressure, creatinine clearance, and proteinuria in adult renal allograft recipients

Aim: Hyperuricemia has been associated with the development of hypertension, cardiovascular, and renal disease. However, there is no data about the effect of lowering uric acid level on hypertension, renal function, and proteinuria in renal transplant patients. We therefore conducted a retrospective study to investigate the benefits of allopurinol treatment in renal transplant patients and to investigate indirectly its effect on graft survival. Materials and methods: A total of 105 RTRs were included in this study, 54 patients who have taken allopurinol for the past 6 months and 51 patients who have not taken allopurinol. We have examined uric acide, urinary protein/Cr ratio, MDRD, CRP and blood pressure before and 6 months later after treatment in both group. Results: In the allopurinol group, the mean serum uric acid levels, GFR, creatinine urinary protein/Cr ratio significantly improved (p < 0.001). However ,blood pressure, CRP not statistically significant (p > 0.05). No correlation was observed between changes in uric acide and changes in CRP, or blood pressure in the allopurinol group. No significant changes were observed in the control group (p > 0.05), only statistically significant increase in CRP level was observed(p<0,05). Multivariable regression analysis showed that uric acide was positively correlated with urinary Protein/Cr ratio (r= 0,473, β = 0.021, p = 0.002) and negatively correlated with MDRD ( r= -0554 β = 0.016, P = 0.001) in RTR. Conclusion: We bring indirect evidence that hyperuricemia increases urinary protein/Cr ratio, and decreases MDRD. Hence, treatment of hyperuricemia suggests that it can also prevent the progression of kidney disease in patients with normal kidney function, which suggests that early treatment with allopurinol is an important part of the management of kidney transplant recipients. Long-term follow-up studies are required to identify the benefits of uric acid management on renal function and proteinuria.