BackgroundPregnancy is associated with reduced activity of multiple sclerosis (MS). However, the biological mechanisms underlying this pregnancy-related decrease in disease activity are poorly understood.MethodologyWe conducted a genome-wide transcription analysis in peripheral blood mononuclear cells (PBMCs) from 12 women (7 MS patients and 5 healthy controls) followed during their pregnancy. Samples were obtained before, during (i.e. at the third, sixth, and ninth month of gestation) and after pregnancy. A validation of the expression profiles has been conducted by using the same samples and an independent group of 25 MS patients and 11 healthy controls. Finally, considering the total group of 32 MS patients, we compared expression profiles of patients relapsing during pregnancy (n = 6) with those of relapse-free patients (n = 26).Principal FindingsResults showed an altered expression of 347 transcripts in non-pregnant MS patients with respect to non-pregnant healthy controls. Complementary changes in expression, occurring during pregnancy, reverted the previous imbalance particularly for seven inflammation-related transcripts, i.e. SOCS2, TNFAIP3, NR4A2, CXCR4, POLR2J, FAM49B, and STAG3L1. Longitudinal analysis showed that the overall deregulation of gene expression reverted to “normal” already within the third month of gestation, while in the post-partum gene expressions rebounded to pre-pregnancy levels. Six (18.7%) of the 32 MS patients had a relapse during pregnancy, mostly in the first trimester. The latter showed delayed expression profiles when compared to relapse-free patients: in these patients expression imbalance was reverted later in the pregnancy, i.e. at sixth month.ConclusionsSpecific changes in expression during pregnancy were associated with a decrease in disease activity assessed by occurrence of relapses during pregnancy. Findings might help in understanding the pathogenesis of MS and may provide basis for the development of novel therapeutic strategies.

ObjectiveTo evaluate the long-term effects of rituximab (RTX) on total and specific immunoglobulins (Igs) in patients with neuromyelitis optica spectrum disorders (NMOSDs).MethodsTotal IgG, IgA, and IgM levels were evaluated in 15 patients with NMOSDs treated with RTX (median follow-up 70 months). Anti-aquaporin 4 (AQP4)-IgG titration was performed on samples from 9 positive patients. Anti-tetanus (TET), anti-varicella-zoster virus (VZV), and anti-Epstein–Barr virus nuclear antigen (EBNA) IgGs were also tested in patients with NMOSDs and in 6 healthy controls (HCs).ResultsRTX reduced total IgG by 0.42 g/L per year, IgA by 0.08 g/L per year, and IgM by 0.07 g/L per year. Hypogammaglobulinemia (hypo-IgG) (IgG < 7 g/L) developed in 11/15 patients. Severe hypo-IgG (IgG < 4 g/L) was found in 3/15 patients, of whom 2 patients developed serious infectious complications. In group analysis, anti-AQP4 IgG titers were reduced by RTX over time, and a significant correlation between anti-AQP4 IgG titers and total IgG levels was found. The effects of RTX were observed on pathogen-specific IgGs as well. In particular, the levels of anti-TET IgG in patients were significantly lower than those in HCs. The half-life of anti-TET IgG was reduced by about 50% in patients compared with the general population.ConclusionsLong-term RTX treatment is associated with the risk of hypo-Ig and reduction of anti-TET protection in patients with NMOSDs. Results obtained in this study suggest the importance of monitoring total and specific Ig levels before and during treatment with anti-CD20 drugs to prevent hypo-Ig–related complications and to optimize clinical management.