Fingolimod induces BAFF and expands circulating transitional B cells without activating memory B cells and plasma cells in multiple sclerosis.

Patients with multiple sclerosis (MS) who are treated with fingolimod have an increased proportion of transitional B cells in the circulation, but the underlying mechanism is not known. We hypothesized that B cell-activating factor of the tumor necrosis factor family (BAFF) is involved in the process. Compared with healthy controls and untreated MS patients, fingolimod-treated MS patients had significantly higher serum concentrations of BAFF, which positively correlated with the proportions and the absolute numbers of transitional B cells in blood. Despite the elevated concentrations of BAFF in fingolimod-treated MS patients, serum levels of soluble transmembrane activator and calcium-modulating cyclophilin ligand interactor, and B cell maturation antigen were not elevated. Our results show that fingolimod induces BAFF in the circulation and expands transitional B cells, but does not activate memory B cells or plasma cells in MS, which is favorable for the treatment of this disease.

Fingolimod suppresses bone resorption in female patients with multiple sclerosis.

Fingolimod is a sphingosine-1-phosphate receptor agonist used to inhibit the inflammatory activity of multiple sclerosis (MS), and has been shown to suppress osteoporosis in mouse models. In this study, levels of bone turnover markers were quantified in serum and urine samples from MS patients treated with fingolimod. Compared with untreated MS patients and healthy controls, fingolimod-treated MS patients had a significantly lower level of the bone resorption marker type I collagen cross-linked N-telopeptide in urine. This finding was prominent in female but was not seen in male subjects. Our results suggest that fingolimod may have a beneficial effect on bone mass loss in female MS patients.

Suppressed pro-inflammatory properties of circulating B cells in patients with multiple sclerosis treated with fingolimod, based on altered proportions of B-cell subpopulations.

The chief therapeutic mechanism of fingolimod in multiple sclerosis (MS) is considered to be sequestration of pathogenic lymphocytes into secondary lymphoid tissues. B cells have recently been recognized as important immune regulators in MS. In this study, the effects of fingolimod on B cells in MS patients were analyzed. MS patients treated with fingolimod (MS-F) had a significantly lower number of B cells in the circulation. The remaining B cells in the blood of MS-F had a reduced proportion of memory B cells and an increased proportion of naïve B cells, expressed lower levels of the costimulatory molecule CD80, and produced less tumor necrosis factor-α and more interleukin-10. These observations in MS-F were based on an increased proportion of the transitional B-cell subpopulation within the naïve B-cell compartment. The observed findings in B cells of MS-F might be related to the therapeutic effect of this drug in MS.

Five-year follow-up with low-dose tacrolimus in patients with myasthenia gravis.

Myasthenia gravis (MG) is an antibody-mediated autoimmune disease of the neuromuscular junction, and prednisolone (PSL) and immunosuppressive drugs are available for treatment. Tacrolimus, a macrolide that suppresses the immune system, is used as a second-line treatment for MG. There have been several reports of the effects of tacrolimus over a few years of follow-up. Here, we report data from 9 patients with steroid-dependent generalized MG treated with low-dose tacrolimus (2-3 mg/day) for 5 years. Following treatment with tacrolimus, mean MG-activities of daily living score improved from 4.6 at baseline to 3.3 at 5 years after initiation of treatment. Mean dose of PSL could also be reduced, from 24.0 mg/day at baseline to 10.2 mg/day at 5 years, although there were no cases of total withdrawal of PSL. By contrast, 5 of the 9 patients experienced exacerbation of symptoms and transient increases in PSL dose during the 5-year period. Tacrolimus is an important option for treatment of MG; however, careful management is needed for long-term treatment with this drug.

Dropped head sign as the only symptom of myasthenia gravis.

Neck extensor muscle weakness and the dropped head sign are associated with various neuromuscular disorders. However, these symptoms are comparatively rare in myasthenia gravis (MG). We report a MG case that presented with dropped head sign as the main symptom. A 55-year-old man developed subacute weakness of the neck extensor muscle and presented with dropped head. We established a diagnosis of MG based on the results of an edrophonium test and a voluntary single fiber electromyogram (vSFEMG), and a high serum antiacetylcholine receptor antibody level. This patient was treated with pyridostigmine and his neurological symptoms improved. There are reported cases of dropped head sign as the first symptom of MG, however, in those cases, other muscles showed weakness during the first few months after onset. In the present case, throughout the clinical course no other symptoms outside of dropped head sign were seen.