Myasthenia gravis exacerbation after melatonin administration: case series from a tertiary referral centre.

BACKGROUND: Myasthenia gravis is an autoimmune disease mediated by antibodies against proteins associated with the postsynaptic membrane of the neuromuscular junction. Several drugs may trigger an exacerbation of the disease. Melatonin supplements are widely used for the treatment of insomnia as they are well tolerated with few side effects. The role of melatonin in the immune system and its effects in autoimmune disorders remain uncertain. CASE PRESENTATION: We identified three patients in our referral centre from 2014 to 2019 who presented a worsening within days or weeks of starting melatonin. Two of them stopped the treatment without clinical improvement in the next week. Increasing dose of corticosteroids did not lead to clinical improvement in the next month and one of the patients was finally administered intravenous immunoglobulins. CONCLUSION: Melatonin may trigger exacerbations of myasthenia gravis, probably due to an upregulation of the adaptive immune system and an interaction with the corticosteroids and other immunosuppressant treatments. We consider that melatonin should be administered with caution in these patients.

Biomarker Identification, Safety, and Efficacy of High-Dose Antioxidants for Adrenomyeloneuropathy: a Phase II Pilot Study.

X-Adrenoleukodystrophy (X-ALD) and its adult-onset, most prevalent variant adrenomyeloneuropathy (AMN) are caused by mutations in the peroxisomal transporter of the very long-chain fatty acid ABCD1. AMN patients classically present spastic paraparesis that can progress over decades, and a satisfactory treatment is currently lacking. Oxidative stress is an early culprit in X-ALD pathogenesis. A combination of antioxidants halts the clinical progression and axonal damage in a murine model of AMN, providing a strong rationale for clinical translation. In this phase II pilot, open-label study, 13 subjects with AMN were administered a high dose of α-tocopherol, N-acetylcysteine, and α-lipoic acid in combination. The primary outcome was the validation of a set of biomarkers for monitoring the biological effects of this and future treatments. Functional clinical scales, the 6-minute walk test (6MWT), electrophysiological studies, and cerebral MRI served as secondary outcomes. Most biomarkers of oxidative damage and inflammation were normalized upon treatment, indicating an interlinked redox and inflammatory homeostasis. Two of the inflammatory markers, MCP1 and 15-HETE, were predictive of the response to treatment. We also observed a significant decrease in central motor conduction time, together with an improvement or stabilization of the 6MWT in 8/10 subjects. This study provides a series of biomarkers that are useful to monitor redox and pro-inflammatory target engagement in future trials, together with candidate biomarkers that may serve for patient stratification and disease progression, which merit replication in future clinical trials. Moreover, the clinical results suggest a positive signal for extending these studies to phase III randomized, placebo-controlled, longer-term trials with the actual identified dose. ClinicalTrials.gov Identifier: NCT01495260.