DETECTION OF KIDNEY INJURY BY USING THE CORRELATION OF PERIOSTIN AND RENAL PATHOLOGY IN PATIENTS WITH LUPUS NEPHRITIS AND IgA NEPHROPATHY

Abstract

The objective of this study was to examine the correlation between periostin level in kidney tissue, urine and serum samples and renal pathology as well as renal functions in patients with lupus nephritis and IgA nephropathy and to investigate the periostin levels of patients compared with controls. The prediction of clinical response from periostin measurement was also assessed. This study was conducted from April 2013 to February 2015 at the Department of Medicine, Phramongkutklao Hospital, Bangkok, Thailand. Fifty patients and 50 healthy controls were included in this study. There were 37 and 13 patients diagnosed with lupus nephritis and IgA nephropathy, respectively. Five normal kidney tissue sections from renal cell carcinoma patients were used as control kidney tissues. The results from periostin immunohistochemistry found that periostin was not detected from control kidney tissue. In contrast, the most common area with positive periostin from patients’ kidney tissue was tubular. Periglomeruli, sclerosed glomeruli, interstitial fibrosis and vascular fibrosis were also positive for periostin. The periostin staining was significant correlated with chronicity index and renal functions (p<0.05). In addition, worsening renal function was observed in patients with high periostin staining scores compared with low periostin staining scores among patients with low active and low chronic disease. The results from urine periostin analysis reported a significantly higher level of urine periostin in patients than in healthy controls (p<0.05). There was a significant correlation between urine periostin level and renal functions (p<0.05). Urine periostin was detected in 23 out of 50 patients and 11 out of 50 healthy controls. Worsening renal function was found in patients with urine periostin detection. In contrast, there was no significant difference in serum periostin level between patients and healthy controls. No correlation was found between serum periostin level and urine periostin level. After 6 months of treatment, there was no statistical difference in baseline renal pathology, characteristic data, renal parameters, treatment, urine periostin level and serum periostin level between patients with response and non-response to therapy. However, there was a significant decrease in urine periostin level after 6 months of treatment in patients with response to therapy (p<0.05). In conclusion, periostin may be a promising tissue biomarker in lupus nephritis and IgA nephropathy patients that is related to chronic kidney disease progression and kidney functions. Periostin staining may be used for predicting worsening kidney disease progression rather than routine staining, especially in patients with low active disease or low chronic disease. Urine periostin measurement may be used for the prognosis of disease progression in lupus nephritis and IgA nephropathy patients. It may be possible to use urine periostin measurement for monitoring response to therapy after 6 months of treatment.