Autoimmune Neuromuscular Diseases Induced by Immunomodulating Drugs

Case Report: Interferon-Alpha-Induced Neuromyelitis Optica Spectrum Disorder

Background and Objectives

To describe a new case of neuromyelitis optica spectrum disorder (NMOSD) induced by the administration of interferon-alpha (IFNα) and to raise awareness of this rare drug-induced disease of IFNα treatment.

Methods

A single case study and comprehensive literature review of eight cases.

Results

A 24-year-old man was diagnosed with cerebral venous thrombosis and essential thrombocythemia. He had been undergoing IFNα treatment (IFNα-2b, 3 million IU per day) without any side effects for 18 months, at which point the patient developed persistent hiccups, nausea, urinary retention, and numbness. Spinal magnetic resonance imaging revealed a longitudinal abnormality extending from the medulla to the entire spinal cord. The patient was positive for anti-aquaporin-4 antibody (AQP4-IgG) in both the serum and cerebrospinal fluid (CSF), which confirmed the diagnosis of NMOSD. Thus, recombinant IFNα-2b was suspended immediately. Because his condition did not improve after 6-day treatment of methylprednisolone pulse therapy (1,000 mg for 3 days, then 500 mg for 3 days), intravenous immunoglobulin (0.4 g/kg/day for 5 days) was administered. The patient gradually improved. Low-dose prednisolone and mycophenolate mofetil were subsequently administered as a long-term treatment. The patient was discharged with subtle limb numbness and their expanded disability status score (EDSS) was 1. At the 1-year follow-up, the patient had not relapsed and tested negative for AQP4-IgG. We further identified the eight patients with IFNα-induced NMOSD. The median onset age was 59 years, and the median time of IFNα exposure was 18 months. Optic neuritis was the most common initial symptom (five, 55.6%), followed by myelitis in three patients and area postrema syndrome in one patient. More than half (five, 55.6%) of the patients were monophasic. After IFNα discontinuation and immunotherapy, most (seven, 77.8%) patients remained relapse-free. However, only one patient was free of sequelae.

Conclusion

This study highlights the potential pathogenic risk of NMOSD of IFNα treatment. Given the high disability rates of this rare drug-induced disease, it is crucial to monitor the early manifestations of NMOSD during IFNα treatment.

Idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM), also known as myositis, are a heterogeneous group of autoimmune disorders with varying clinical manifestations, treatment responses and prognoses. Muscle weakness is usually the classical clinical manifestation but other organs can be affected, including the skin, joints, lungs, heart and gastrointestinal tract, and they can even result in the predominant manifestations, supporting that IIM are systemic inflammatory disorders. Different myositis-specific auto-antibodies have been identified and, on the basis of clinical, histopathological and serological features, IIM can be classified into several subgroups - dermatomyositis (including amyopathic dermatomyositis), antisynthetase syndrome, immune-mediated necrotizing myopathy, inclusion body myositis, polymyositis and overlap myositis. The prognoses, treatment responses and organ manifestations vary among these groups, implicating different pathophysiological mechanisms in each subtype. A deeper understanding of the molecular pathways underlying the pathogenesis and identifying the auto-antigens of the immune reactions in these subgroups is crucial to improving outcomes. New, more homogeneous subgroups defined by auto-antibodies may help define disease mechanisms and will also be important in future clinical trials for the development of targeted therapies and in identifying biomarkers to guide treatment decisions for the individual patient.

Education Research: Multiple sclerosis and neuroimmunology fellowship training status in the United States

OBJECTIVE

To investigate the current status of postgraduate training in neuroimmunology and multiple sclerosis (NI/MS) in the United States.

METHODS

We developed a questionnaire to collect information on fellowship training focus, duration of training, number of fellows, funding application process, rotations, visa sponsorship, and an open-ended question about challenges facing training in NI/MS. We identified target programs and sent the questionnaires electronically to fellowship program directors.

RESULTS

We identified and sent the questionnaire to 69 NI/MS fellowship programs. We successfully obtained data from 64 programs. Most programs were small, matriculating 1-2 fellows per year, and incorporated both NI and MS training into the curriculum. Most programs were flexible in their duration, typically lasting 1-2 years, and offered opportunities for research during training. Only 56% reported the ability to sponsor nonimmigrant visas. Most institutions reported having some internal funding, although the availability of these funds varied from year to year. Several program directors identified funding availability and the current absence of national subspecialty certification as major challenges facing NI/MS training.

CONCLUSION

Our study is the first to describe the current status of NI/MS training in the United States. We found many similarities across programs. We anticipate that these data will serve as a first step towards developing a standard NI/MS curriculum and help identify areas where shared resources could enhance trainee education despite differences in training environments. We identified funding availability, certification status, and nonimmigrant visa sponsorship as potential barriers to future growth in the field.