Early predictive risk factors for dimethyl fumarate-associated lymphopenia in patients with multiple sclerosis.

BACKGROUND: Lymphopenia is a major concern in MS patients treated with dimethyl-fumarate (DMF) as it increases the risk of progressive multifocal leukoencephalopathy. A pronounced reduction in absolute lymphocyte counts (ALCs) early after treatment initiation has been suggested to be associated with the occurrence of lymphopenia thereafter. OBJECTIVES: To identify risk factors for DMF-induced lymphopenia and evaluate whether the degree of decrease in the ALCs three months after initiation of DMF treatment is a predictor of the subsequent development of lymphopenia. METHODS: In this real-world Spanish prospective multicenter study conducted in MS patients who started DMF between 2014 and 2019, we analyzed the association between DMF-related lymphopenia and the percentage of early ALCs decline using regression models, considering both, significant lymphopenia (grades 2 + 3) and severe lymphopenia (grade 3). The cutoff values of early ALCs declines were obtained using the ROC curve. RESULTS: Among 532 MS patients treated with DMF, 193 (36.3%) developed any grade of lymphopenia. Older age and lower ALCs at treatment onset predicted the risk for lymphopenia but the best predictive risk factor was the reduction of ALCs within the three first months of treatment. Specifically, a reduction in ALCs≥21.2% was associated with a 6.5-fold higher risk of developing significant lymphopenia, and a decrease in ALCs≥40.2% with a 12.7-fold higher risk of developing severe lymphopenia. CONCLUSIONS: A pronounced reduction in ALCs early after initiation of DMF in MS patients is the best predictive risk factor for the subsequent development of significant lymphopenia.

Risk and outcomes of COVID-19 in patients with multiple sclerosis.

BACKGROUND AND PURPOSE: Limited information is available on incidence and outcomes of COVID-19 in patients with multiple sclerosis (MS). This study investigated the risks of SARS-CoV-2 infection and COVID-19-related outcomes in patients with MS, and compared these with the general population. METHODS: A regional registry was created to collect data on incidence, hospitalization rates, intensive care unit admission, and death in patients with MS and COVID-19. National government outcomes and seroprevalence data were used for comparison. The study was conducted at 14 specialist MS treatment centers in Madrid, Spain, between February and May 2020. RESULTS: Two-hundred nineteen patients were included in the registry, 51 of whom were hospitalized with COVID-19. The mean age ± standard deviation was 45.3 ± 12.4 years, and the mean duration of MS was 11.9 ± 8.9 years. The infection incidence rate was lower in patients with MS than the general population (adjusted incidence rate ratio = 0.78, 95% confidence interval [CI] = 0.70-0.80), but hospitalization rates were higher (relative risk = 5.03, 95% CI = 3.76-6.62). Disease severity was generally low, with only one admission to an intensive care unit and five deaths. Males with MS had higher incidence rates and risk of hospitalization than females. No association was found between the use of any disease-modifying treatment and hospitalization risk. CONCLUSIONS: Patients with MS do not appear to have greater risks of SARS-CoV-2 infection or severe COVID-19 outcomes compared with the general population. The decision to start or continue disease-modifying treatment should be based on a careful risk-benefit assessment.

Cerebrospinal fluid mitochondrial DNA levels in patients with multiple sclerosis.

The role of cerebrospinal fluid (CSF) mitochondrial DNA (mtDNA) levels as biomarker in multiple sclerosis (MS) is unknown. We determined CSF mtDNA levels in a cohort of 237 individuals, including patients with MS and clinically isolated syndrome (CIS), inflammatory and non-inflammatory neurological controls, and cognitively healthy controls (HC). mtDNA concentration was measured by droplet digital polymerase chain reaction. CSF mtDNA levels were increased in all pathological conditions compared with HC, though no differences were observed between relapse-onset and progressive MS clinical forms, CIS patients and neurological controls. These findings do not support the determination of CSF mtDNA levels as a useful biomarker in MS clinical practice.