Abstract: Ｏｂｊｅｃｔｉｖｅ：To investigate the clinicopathological features and prognosis of hypothyroidismrelated renal impairment (HRRI).
Ｍｅｔｈｏｄｏｌｏｇｙ：HRRI were diagnosed by renal biopsy from January 2009 to December 2020 in National Clinical Research Center of Kidney Diseases, Jinling Hospital. We reviewed the electronic medical records and summarized the clinical and pathological characteristics.
Ｒｅｓｕｌｔｓ：A total of eighteen cases of HRRI were included, with an average age of 404±109 years. Among these patients, 17 were male. The most frequent chief complaint was edema (13 cases, 722％), followed by increased serum creatinine (4 cases, 222％). Hypothyroidism diagnosed after renal injury was found in 611％ of patients. Baseline serum creatinine at renal biopsy was 1406±186 μmol／L. And serum cystatin C was 093±012 mg／L, which only one case was higher than the upper limit of normal. The proteinuria and hematuria were almost negative. NacetylβDglucosidase and retinolbinding protein in the urine were all in normal range. Renal lesions were mild, mainly mild acute tubulointerstitial lesions. The glomerular lesions under electron microscope were various, but most of them were mild and lacked characteristic ultrastructural changes. After thyroid hormone replacement therapy, eGFR of all patients increased by more than 30％ compared with baseline, and the median time of renal function improvement was 27 months.
Ｃｏｎｃｌｕｓｉｏｎ：For unexplained renal impairment, checking serum creatinine and cystatin C levels stimultaneously time and detecting thyroid function were helpful to identify HRRI. Thyroid hormone replacement therapy significantly improved renal function in HRRI patients. When HRRI was highly suspected, THRT can be performed first, and then reassessed for renal biopsy.

Key words: renal impairment, hypothyroidism, kidney pathology, prognosis