[Tubulointerstitial nephritis antigen expression in chronic kidney disease and its clinical significance].

Abstract

To explore tubulointerstitial nephritis antigen (TIN-ag) expression of chronic kidney disease (CKD) patients' renal tissue and the correlation to clinical phenotype. Through digital drawing lots, a total of 77 CKD patients from October 2012 to February 2013 at our department were randomly selected. All of them underwent biopsy. Based upon their pathological findings, they were divided into 2 groups of minimal change disease (MCD) and non-minimal change disease (NMCD). The stains of hematoxylin and eosin and Masson were used to observe renal pathological changes and immunofluorescence for detecting the TIN-ag expression of kidney tissue. The serum levels of creatinine, blood urea nitrogen, estimated glomerular filtration rate (eGFR), 24-hour urine output, 24-hour urine protein, α1-microglobulin, β2-microglobulin, pathological casts, N-acetyl-beta-glucosaminidase (NAG), specific gravity and other clinical parameters were monitored to examine their relationship between renal tissue TIN-ag expression. TIN-ag expression was distinct in renal tubular basement membrane of MCD patients while weak in primary focal segmental glomerulosclerosis (FSGS)(n = 16), IgA nephropathy (n = 23), MN (n = 14) and LN (n = 15) renal tissue. Immunofluorescence quantitative analysis showed that tubular TIN-ag fluorescence intensity of NMCD group was significantly lower than that of MCD group (4.84(3.02, 10.73) vs 20.79(8.19, 37.00), P < 0.01). In addition, TIN-ag expression in renal interstitial collagen area deposition of 0 grade group was higher than that of collagen area deposition 1-3 grades group (all P < 0.05). Serum α1-microglobulin and pathological urine cast, 24-hour urine protein of CKD patients were negatively correlated with kidney tubules TIN-ag expression (r = -0.312, -0.298, -0.214, all P < 0.05). Serum creatinine, blood urea nitrogen, serum β2-microglobulin and eGFR of CKD patients had no significant correlations with TIN-ag expression (P > 0.05). TIN-ag expression of CKD patients with lower expression levels of NAG was significantly higher than that of normal levels of NAG expression. TIN-ag expression of low urine specific gravity group was lower than that of normal urine specific gravity group (P < 0.05). TIN-ag expression of renal tissue tubule basement membrane in NMCD group is significantly lower than that in MCD group. TIN-ag expression is negatively correlated with renal tissue fibrosis. Expression of serum α1-microglobulin and concentrations of urinary pathology tube, 24-hour urine protein, NAG expression and urine specific gravity are negatively correlated with renal tissue TIN-ag expression in CKD patients.