Early Kidney Injury in Immunoglobulin A Vasculitis: Role of Renal Biomarkers.

Background We aimed to determine whether urine Kidney Injury Molecule-1 (KIM-1) and Neutrophil Gelatinase Associated Lipocalin (NGAL) can be used as early noninvasive biomarkers of kidney injury in Immunoglobulin A vasculitis. Methods Patients who were diagnosed with Immunoglobulin A vasculitis were included in the study. Urine samples were collected for determination of urine KIM-1and NGAL levels. The control group was comprised of age-matched healthy children. Results 61 patients who diagnosed with Immunoglobulin A vasculitis were included in the study. 37.7% of these patients were determined to have renal involvement. Median KIM-1 was found to be statistically significantly higher in the patient group (69.59 pg/ml) compared to the control group (40.84 pg/ml) (p= 0.001). Median NGAL was determined to be statistically significantly higher in the patient group (59.87 ng/ml) compared to the control group (44.87 ng/ml) (p=0.013). In 23.6% of the patients without renal involvement at admission were found to develop renal involvement within following six months. When median KIM-1 and NGAL at admission of these patients were compared with the control group, they were determined to be statistically significantly higher (p= 0.001, p= 0.003). Conclusions The fact that our patients with late-term nephropathy had no hematuria and/or proteinuria and that KIM-1and NGAL levels, however, were determined to be high indicates that these biomarkers might be potentially reliable, noninvasive and early determinants of kidney injury.