Urinary prostacyclin metabolites in patients with IgA nephropathy

Abstract

Background. Urinary 6-keto-prostaglandin F 1α (6kPGF) is an index of renal prostacyclin (PGI 2 ) synthesis, while urinary 2,3-dinor-6-keto-prostaglandin F 1α (23d6kPGF) reflects extrarenal PGI 2 synthesis. We therefore examined the relationship between the urinary excretion of PGI 2 metabolites and the deterioration of renal function and histopathological findings. Methods. We measured these PGI 2 metabolites in 24-h collected urine from 32 patients with IgA nephropathy (IgAN) and 24 normal controls. Results. The urinary 6kPGF excretion in all patients (790 Ϯ 395 pg/mg creatinine [Cr]) did not differ significantly from that in the normal controls (896 Ϯ 351 pg/mgCr), but it was decreased in the patients with histopathological deterioration (661 Ϯ 281 pg/mgCr). There were no such findings for 23d6kPGF. In the IgAN patients, the urinary 6kPGF excretion demonstrated a positive correlation to the 1/creatinine slope, which indicated deterioration of renal function (r ϭ 0.43; P Ͻ 0.03). Conclusions. Renal PGI 2 production is reduced in IgAN patients with histopathological deterioration, and 24-h urinary 6kPGF excretion may be an effective marker to evaluate the renal injury.