[Clinical characteristics, treatment and outcome of chronic mercury-related nephrotic syndrome].

Objective: To investigate the etiology, clinical features, treatment and outcome of nephrotic syndrome associated with chronic mercury poisoning. Methods: From June 2013 to April 2018, Beijing Chaoyang Hospital, Capital Medical University received 33 patients with chronic mercury-neutral nephrotic syndrome. The clinical manifestations, laboratory tests, treatment methods, and outcomes were analyzed. Results: Among the 33 patients, 27 patients had mercury exposure due to daily-life contact and the other 6 patients were caused by iatrogenic mercury. The symptom was characterized by typical nephrotic syndrome such as lower extremity edema and proteinuria at first onset. The treatment was based on mercury-removing treatment, 19 cases were treated with mercury removal alone, 16 cases were completely relieved; 10 cases were treated with mercury removal and glucocorticoids, all of which were completely relieved; 4 cases were treated with mercury removal, glucocorticoids and immunosuppressive agents, all complete remission; clinical complete remission rate is about 90.9% (30 cases in total) . Urinary mercury levels decreased the fastest between the first and second courses of mercury treatment, but the total amount of urine protein increased. As the amount of urinary mercury excreted increased, the total amount of urine protein decreased gradually (Z=2.86, P<0.01) . Conclusion: The clinical features of chronic mercury-induced nephrotic syndrome are non-specific, easy to be misdiagnosed and missed. The treatment is mainly treated with mercury removal treatment. The prognosis is good. In severe cases, glucocorticoid therapy can be supplemented.