RESUMO
OBJECTIVE: To compare the safety of low-dose cyclophosphamide and high-dose cyclophosphamide in the treatment of systemic lupus erythematosus (SLE). METHODS: A total of 1 022 patients with systemic lupus erythematosus from 24 hospitals in China between March 2017 to July 2018 were enrolled. Their clinical manifestations, laboratory tests, adverse events, reasons for stopping receiving intravenous cyclophosphamide and comorbidities were collected. Among them, 506 SLE patients received short-interval low-dose intravenous cyclophosphamide therapy (SILD IV-CYC, 400 mg every two weeks), and 256 patients underwent high-dose cyclophosphamide therapy (HD IV-CYC, 500 mg/m2 of body surface area every month), the side effects between the two groups were compared, the remaining 260 SLE patients were treated with IV-CYC irregularly. Moreover, a total of 377 patients in SILD IV-CYC group and 214 patients in HD IV-CYC group had medical records of the reasons for stopping recei-ving IV-CYC. The reasons for stopping receiving IV-CYC in these two groups were analyzed. RESULTS: In this study, only 40.27%(238/591)of the SLE patients stopped receiving intravenous cyclophosphamide for the causes of disease improvement, however, up to 33.67% (199/591) of the patients for the reason of drug-related side effects. There were 83 patients out of 214 (38.79%) with high-dose intravenous cyclophosphamide treatment who stopped receiving IV-CYC for the drug-related side effects, which was significantly higher than that in the low-dose cyclophosphamide group (30.77%, 116/337, P=0.048). Of theses 506 patients in SILD IV-CYC group, 88 (17.39%) patients experienced gastrointestinal reactions, 66 (13.04%) suffered from infections, 49 (9.68%) had myelosuppression and 68 (13.44%) had alopecia, respectively. Among the 256 patients in the HD IV-CYC group, 80 (31.25%) experienced gastrointestinal reactions, 57 (22.27%) suffered from infections, 51 (19.92%) had myelosuppression and 49 (19.14%) had alopecia. Moreover, 71 (25.18%) of 282 female patients with age between 16 to 45 years in SILD IV-CYC group had abnormal menstruation, while menstrual disorder occurred in 39.72% (56/141) patients of HD IV-CYC group. There was no difference of drug-induced hepatic injury, hemorrhagic cystitis and fatigue between the two groups. CONCLUSION: Low-dose cyclophosphamide showed a lower prevalence of adverse events than high-dose cyclophosphamide in systemic lupus erythematosus patients.