Author Of 1 Presentation
P0169 - The association between spontaneous MxA mRNA level and disease activity in multiple sclerosis (ID 1732)
Abstract
Background
Myxovirus resistance protein A (MxA) is one of the proteins upregulated by interferon-beta. MxA mRNA level is often used in clinical practice to determine bioactivity of interferon-beta treatment in patients with relapsing-remitting multiple sclerosis (RRMS). Lack of bioactivity is often due to the development of neutralizing antibodies against the drug. In 2010, we reported the association between spontaneous MxA mRNA level and clinical disease activity in multiple sclerosis (MS). Low levels of spontaneous MxA mRNA level were associated with contrast enhancing lesions (CELs) on baseline MRI, clinical relapses and a shorter time to first relapse. In the current study we assessed the long term data in the same cohort for the association between spontaneous MxA mRNA levels and clinical disease activity and disability.
Objectives
To investigate the association between spontaneous myxovirus resistance protein A (MxA) mRNA levels and disease activity in MS patients over a longer follow-up period.
Methods
Spontaneous MxA mRNA levels were determined in a previously described cohort of 116 patients diagnosed with a clinically isolated syndrome (CIS) or with a recent diagnosis of RRMS, and related to clinical scores (Expanded Disability Status Scale (EDSS), timed-25-foot walk (T25FW), 9-hole-peg test (9HPT)), and MS type over a long follow-up. MRI-imaging was performed at baseline and during follow-up to assess the development of new T2-lesions and CELs.
Results
116 patients where included in the analyses. 74 (63.8%) were female. At baseline, 67 patients (57.8%) were diagnosed with RRMS and 49 (42.2%) with a CIS. Median follow-up duration was 10.76 years (IQR 69.52-148.50 months). Median EDSS at follow-up was 3.0. Spontaneous MxA mRNA level was not associated with EDSS, T25FW and 9HPT, and MS subtype at follow-up. 89.7% of patients ever experienced MRI-activity during follow-up. Low spontaneous MxA mRNA levels were associated with the occurrence of more T2-lesions on MRI imaging during follow-up in patients with a small number of T2-lesions (<9 lesions) on baseline MRI (B=-1.595, p=0.029).
Conclusions
Baseline spontaneous MxA mRNA level is associated with the development of new T2-lesions on MRI during long-term follow-up and, if confirmed in other populations, has a potential value as a predictive biomarker for long-term inflammatory disease activity in MS.