Background: Studies to date regarding hyperuricemia and gout in the postrenal transplant (RT) setting do not distinguish neither if patients with gout after the allograft had or did not have hyperuricemia before been transplanted nor if data concerning to hyperuricemia correspond to prevalent or incident cases. Among RT patients, we assessed (1) the incidence of gout in recipients with and without hyperuricemia pre-RT and (2) the incidence of hyperuricemia during the follow-up.
Methods: We selected from our RT registry (1989-2003) 236 subjects who were transplanted in our institution, with at least 1 year follow-up, without gout pre-RT, with at least one measurement of serum uric acid pre-RT and two post-RT. Immunosuppressants, demographic, and clinical features were registered. Survival curves for hyperuricemia and gout were derived using the Kaplan-Meier method and were statistically tested by log rank test.
Results: The median follow-up was 4.8 years (1.0-14.9), 43% were women, with a mean body mass index of 22.7+/-3.7 kg/m2 and a mean age at the moment of transplant of 32.4+/-11 years. The incidence of hyperuricemia was 315.2 x 1000 patient-years. Hyperuricemia was diagnosed in half of the subjects during the first year of follow-up. The incidence of gout was 19.7 x 1000 and 2.67 x 1000 patient-years in the groups with and without hyperuricemia pretransplant, respectively (Log rank 9.44, P<0.002). The group with hyperuricemia pre-RT also had earlier and more aggressive gout.
Conclusions: Hyperuricemia was a common complication among RT recipients. However, gout incidence varied according to the pretransplant hyperuricemic status.