[Toll-like receptor 4 deposition and its significance in hepatitis B virus associated nephropathy].

OBJECTIVE: To investigate the expression and distribution of Toll-like receptor 4 (TLR4) in renal tissue of HBV associated nephropathy (HBV-GN) and its role in the pathogenesis and clinical manifestations of HBV-GN.

METHODS: Renal tissues were sampled from 48 HBV-GN patients confirmed by renal biopsy and 154 non-HBV-GN patients. The distribution of TLR4 in renal tissue and the relationship between the distribution of TLR4 and HBsAg were detected by immunohistochemistry. Integrating case record, correlations between the expression of TLR4 with clinical parameters including pathology, glomeruli, kidney tubules lesions, renal interstitial inflammatory infiltration and blood serum HBV were analyzed.

RESULTS: TLR4 mainly distributed in the renal tubular epithelial cells and interstitial areas as brownish red and granular, which was in consistent with HBsAg distribution. The TLR4 positive rate and score in HBV-GN group were higher than those in non-HBV-GN group (P < 0.05). TLR4 positive score was slightly higher in mesangial proliferative glomerulonephritis group and focal segmental glomerulosclerosis group, which had no significant difference (P > 0.05). Kidney tubules lesions were strongly associated with TLR4 expression (r = 0.748, P < 0.001) which increased with aggravation of renal interstitial fibrosis (r = 0.569, P < 0.001), tubular atrophy (r = 0.577, P < 0.001) and inflammatory cell infiltration (r = 0.684, P < 0.001). No obvious correlation with glomeruli lesions was observed (r = 0.293, P = 0.053). Negative correlation could be seen between TLR4 and the renal function (R(2) = 0.784), systolic blood pressure (R(2) = 0.869), high sensitivity C-reactive protein (R(2) = 0.979) and urinary protein (R(2) = 0.615) by regression analysis. Other clinical parameters had no statistical significances.

CONCLUSIONS: The expression of TLR4 is abnormal in the renal tissue of HBV-GN patients, mainly in renal tubular epithelial cells and interstitial, which is consistent with the distribution of HBsAg. Its intensity is closely related with renal interstitial lesions, renal function changes and inflammatory cell infiltration. A speculation, that HBV can promote abnormal expression of TLR4 in renal tissues of HBV-GN which may be involved in the lesion progress of HBV-GN, is made upon our study.