Progressive multifocal leukoencephalopathy in dimethyl fumarate-treated multiple sclerosis patients.

Dimethyl fumarate (DMF), a fumaric acid with antioxidant and immunomodulatory properties, is among the most commonly used oral therapies for relapsing multiple sclerosis (MS). Progressive multifocal leukoencephalopathy (PML) has been associated with several disease-modifying therapies (DMTs), including DMF in treating MS. We present detailed clinical characteristics of nine PML cases and show that the PML incidence in DMF-treated patients is 0.02 per 1000 patients. In addition to persistent severe lymphopenia, older age appears to be a potential risk for PML. However, younger patients without lymphopenia were also observed to develop PML. DMF-associated PML has occurred in patients with absolute lymphocyte counts (ALCs) above the guideline threshold, suggesting that changes in specific subsets might be more important than total ALC. Furthermore, since DMF has been found to decrease immune cell migration by decreasing the expression of adhesive molecules, the cerebrospinal fluid (CSF) immune profile may also be useful for assessing PML risk in DMF-treated patients. This review provides an up-to-date assessment of PML cases occurring in DMF-treated patients and discusses other potential considerations in light of our current understanding of DMF's mechanism of action on the immune system in the periphery and in the central nervous system (CNS).

Reliability, construct validity and responsiveness to change of the PROMIS-29 in systemic sclerosis-associated interstitial lung disease.

OBJECTIVES: PROMIS-29 is a generic health-related quality of life instrument. Our objective was to assess the reliability, construct validity, and responsiveness to change of PROMIS-29 in systemic sclerosis-associated interstitial lung disease (SSc-ILD). METHODS: Seventy-three participants with SSc-ILD were administered patient reported outcomes (PROs) at baseline and follow-up visits which included PROMIS-29 and other measures of generic health, dyspnea, and cough instruments. We assessed internal consistency reliability using Cronbach's α, an alpha of ≥ 0.70 was considered satisfactory. We assessed the responsiveness to change using linear regression models. RESULTS: Mean age of the participants was 51.9 years and the mean disease duration was 7.9 years after first non-Raynaud's symptom. Of the 73 participants, 56.2% were classified as diffuse SSc and 26% limited SSc. The baseline (mean ± SD) FVC % predicted was 73.9±15.5 with a DLCO % predicted of 57.7±21.1; 95.9% had fibrotic NSIP pattern on HRCT. PROMIS-29 scores were 0.2 to 0.9 SD below the US population. Cronbach's α reliability was acceptable for all domains (ranged from 0.77 to 0.98). All scales showed statistically significant correlations with hypothesised PROMIS-29 domains (p≤0.05 for all comparisons). PROMIS-29 showed none-to-small discriminatory ability in comparison with physiologic measures (FVC and DLCO). There was no significant relationship between the change in FVC versus the change in PROMIS-29 measures over time. CONCLUSIONS: PROMIS-29 has adequate reliability and construct validity for evaluation in SSc-ILD. It has moderate-to-large correlations with other PROs. The PROMIS-29 domains were not found to change over time in this cohort, likely due to stable nature of the observational cohort.