Objective
To evaluate the long-term effects of pulse intravenous methylprednisolone (IVMP) or intravenous immunoglobulin (IVIG) administered during the first year of diagnosis in dermatomyositis (DM) and polymyositis (PM) patients.
Methods
This is a retrospective single-center cohort study of patients with DM/PM followed for up to 4 years from 2001 to 2017. We used Cox regression models to estimate hazard ratios (HRs) and assess the effects of early pulse IVMP or IVIG on 3 outcomes: complete clinical response, corticosteroid discontinuation, and survival. Analysis was adjusted for clinical, laboratory, and treatment covariates.
Results
A total of 204 patients were included and categorized into 4 initial treatment groups: pulse IVMP (n = 46), pulse IVMP+IVIG (n = 55), IVIG (n = 10), and without IVMP or IVIG (n = 93). The groups of early pulse IVMP and pulse IVMP+IVIG had a higher HR for complete clinical response in the multivariate models (HR = 1.56, 95% CI = 1.05–2.33, p = 0.029; and HR = 1.58, 95% CI = 1.02–2.45, p = 0.041, respectively). Only the group of pulse IVMP+IVIG had a significant association with corticosteroid discontinuation in the multivariate analysis (HR = 1.65, 95% CI = 1.02–2.68, p = 0.043). Early pulse IVMP or IVIG had no impact on mortality.
Conclusion
Despite having a more severe disease profile, patients with DM/PM submitted to pulse IVMP or pulse IVMP+IVIG during the first year of diagnosis had a higher HR for complete clinical response, whereas the combination of pulse IVMP+IVIG had an association with corticosteroid discontinuation. Prospective long-term studies are warranted to confirm these benefits of early pulse IVMP and IVIG on patients with DM/PM.