Microscopic polyangiitis and myasthenia gravis: the battle of Occam and Hickam

Microscopic polyangiitis associated with thymic tumor: a case report and review of the literature

Background

Thymic hyperplasia and thymic epithelial tumor (thymoma) have been associated with a variety of autoimmune diseases. Renal involvement has been reported in patients with thymoma. Minimal change disease and membranous nephropathy are frequently observed in glomerular lesions of thymoma patients, but ANCA-associated renal vasculitis is rare. We present a case of thymoma-associated microscopic polyangiitis with positivity for three ANCAs: MPO-ANCA, PR3-ANCA and azurocidin-ANCA.

Case presentation

An 89-year-old Japanese woman was admitted to our hospital following an episode of general fatigue, nausea, muscle weakness of the lower limbs, and ophthalmoplegia. On urinalysis, proteinuria, hematuria, and cellular casts were observed. Elevated levels of serum creatinine and C-reactive protein were also demonstrated, and MPO-, PR3- and azurocidin-ANCA were detected on serological examination. Renal biopsy showed pauci-immune crescentic glomerulonephritis. We therefore diagnosed rapidly progressive glomerulonephritis due to microscopic polyangiitis. Acetylcholine-receptor antibody was also detected. Chest computed tomography and MRI revealed a lobulated tumor in the anterior mediastinum. We thus also diagnosed myasthenia gravis with thymoma.

Conclusion

Considering the patient’s triple-ANCA positivity, thymic diseases may be associated with the pathogenesis of ANCA-associated vasculitis due to central T-cell tolerance. A further accumulation of cases is needed, because thymectomy does not always induce the remission of thymoma-associated autoimmune diseases.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1319-9) contains supplementary material, which is available to authorized users.

Leukocytoclastic Vasculitis Secondary to Pyridostigmine (Mestinon): Report of a Possible First Case

INTRODUCTION

Pyridostigmine is an acetylcholinesterase inhibitor commonly used in the treatment of myasthenia gravis. We describe a patient who developed a rash after recently being started on pyridostigmine and give a general review of leukocytoclastic vasculitis.

CASE PRESENTATION

A 91-year-old man was diagnosed with ocular myasthenia gravis. He was started on pyridostigmine, and 2 weeks later he developed a rash. The rash was biopsied and found to be secondary to leukocytoclastic vasculitis; the pyridostigmine was stopped, loratadine was started, and the rash resolved.

DISCUSSION

Leukocytoclastic vasculitis is commonly caused by a hypersensitivity reaction to medications, or it can be associated with certain medical conditions. We present a brief review of the most common medications and medical conditions known to cause this reaction, but to our knowledge this is the first description of pyridostigmine causing this reaction.

Myasthenia gravis and stroke in the setting of giant cell arteritis

This case report concerns the diagnosis of two independent chronic diseases in a patient hospitalized for stroke, myasthenia gravis (MG) and giant cell arteritis (GCA). MG has been found to be associated with several diseases, but there are very few cases documenting its coexistence with GCA. We report the case of a 79-year-old woman initially hospitalized for stroke. Patient's concurrent symptoms of blepharoptosis, dysphagia, and proximal muscle weakness were strongly suggestive of myasthenia gravis. The persistent low-grade fever and elevated inflammatory markers in combination with the visual deterioration that developed also raised the suspicion of GCA. Histological examination confirmed GCA, while muscle acetylcholine receptor antibodies were also present. Even though in medicine one strives to interpret a patient's symptoms with one diagnosis, when one entity cannot fully interpret the clinical and laboratory findings, clinicians must consider the possibility of a second coexisting illness.

Conceptualizing withdrawal-induced escalation of alcohol self-administration as a learned, plasticity-dependent process

This article represents one of five contributions focusing on the topic "Plasticity and neuroadaptive responses within the extended amygdala in response to chronic or excessive alcohol exposure" that were developed by awardees participating in the Young Investigator Award Symposium at the "Alcoholism and Stress: A Framework for Future Treatment Strategies" conference in Volterra, Italy on May 3-6, 2011 that was organized/chaired by Drs. Antonio Noronha and Fulton Crews and sponsored by the National Institute on Alcohol Abuse and Alcoholism. This review discusses the dependence-induced neuroadaptations in affective systems that provide a basis for negative reinforcement learning and presents evidence demonstrating that escalated alcohol consumption during withdrawal is a learned, plasticity-dependent process. The review concludes by identifying changes within extended amygdala dynorphin/kappa-opioid receptor systems that could serve as the foundation for the occurrence of negative reinforcement processes. While some evidence contained herein may be specific to alcohol dependence-related learning and plasticity, much of the information will be of relevance to any addictive disorder involving negative reinforcement mechanisms. Collectively, the information presented within this review provides a framework to assess the negative reinforcing effects of alcohol in a manner that distinguishes neuroadaptations produced by chronic alcohol exposure from the actual plasticity that is associated with negative reinforcement learning in dependent organisms.