Urinary Hypoxia-Inducible Factor-1alpha Levels Are Associated with Histologic Chronicity Changes and Renal Function in Patients with Lupus Nephritis

ABSTRACT

PURPOSE: Tubulointerstitial hypoxia in the kidney is considered a hallmark of injury and a mediator of the progression of tubulointerstitial fibrosis. Hypoxia-inducible factor-1alpha (HIF-1alpha), a master transcription factor in cellular adaptation to hypoxia, regulates a wide variety of genes, some of which are closely associated with tissue fibrosis. The present study set out to characterize urinary HIF-1alpha expressions in patients with lupus nephritis (LN) and to explore whether urinary HIF-1alpha expressions are associated with histologic chronicity changes and renal function. MATERIALS AND METHODS: Urinary HIF-1alpha levels were measured by enzyme-linked immunosorbent assays in 42 patients with LN and in 30 healthy controls. Activity and chronicity indexes as well as tubular HIF-1alpha expressions were analyzed for each specimen. RESULTS: Urinary HIF-1alpha levels were higher in LN patients than in healthy controls (3.977+/-1.696 vs. 2.153+/-0.554 ng/mL, p0.05). CONCLUSION: Urinary HIF-1alpha levels were elevated in LN patients and were associated with histologic chronicity changes and renal function, indicating that HIF-1alpha might contribute to histologic chronicity in LN.