Measles IgG antibody index correlates with T2 lesion load on MRI in patients with early multiple sclerosis

Abstract

Background: B cells and humoral immune responses play an important role in the pathogenesis and diagnosis of multiple sclerosis (MS). A characteristic finding in patients with MS is a polyspecific intrathecal B cell response against neurotropic viruses, specifically against measles virus, rubella virus, and varicella zoster virus, also known as an MRZ reaction (MRZR). Here, we correlated from the routine clinical diagnostics individual IgG antibody indices (AIs) of MRZR with magnetic resonance imaging (MRI) findings in patients with first MS diagnosis.

Methods/results: MRZR was determined in 68 patients with a clinically isolated syndrome (CIS) or early relapsing-remitting MS (RRMS). Absolute AI values for measles virus, rubella virus, and varicella zoster virus were correlated with T2 lesion load and gadolinium enhancing lesions on cerebral MRI (cMRI) and cMRI combined with spinal MRI (sMRI). Measles virus AI correlated significantly with T2 lesion load on cMRI (p = 0.0312, Mann-Whitney U test) and the sum of lesions on cMRI and sMRI (p = 0.0413). Varicella zoster virus AI also showed a correlation with T2 lesion load on cMRI but did not reach statistical significance (p = 0.2893).

Conclusion: The results confirm MRZR as part of the polyspecific immune reaction in MS with possible prognostic impact on MRI and clinical parameters. Furthermore, the data indicate that intrathecal measles virus IgG production correlates with disease activity on cMRI and sMRI in patients with early MS.

Figure 1. IgG antibody index of MRZR and MRI activity.

IgG antibody index (AI) results for measles virus (A), rubella virus (B) and varicella zoster virus (C) for patients with <6 lesions, ≥6 lesions, no Gd-enhancing lesions and Gd-enhancing lesions on cMRI are shown as box plot graphs. The boxes include values between the 25^th and 75^th percentile of the distribution, while the line within the box represents the median value. The whiskers above and below the box indicate the 90^th and 10^th percentile, respectively, and the black dots indicate the outliers, while the dotted line at AI 1.5 indicates the upper limit of the reference range. The number of patients in each group is shown in brackets above boxes.