Infantile anti-MuSK positive myasthenia gravis in a patient with autoimmune polyendocrinopathy type 3

A Patient with Fulminant Myasthenia Gravis Is Seropositive for Both AChR and LRP4 Antibodies, Complicated by Autoimmune Polyglandular Syndrome Type 3

This article describes the first reported case of myasthenia gravis (MG) seropositive for both acetylcholine receptor antibody and low-density lipoprotein receptor-related protein 4 antibody, complicated by autoimmune polyglandular syndrome (APS) type 3. The patient exhibited myasthenic weakness restricted to the ocular muscles and ptosis. Severe clinical deterioration ensued with predominant bulbar symptoms. MG rapidly worsened, the patient was intubated, and agranulocytosis due to thiamazole was also present, so it was necessary to perform thyroidectomy with tracheostomy and thymectomy in two phases. Both the double-seropositive MG and the APS were involved in the patient's rapid deterioration.

Autoimmune polyglandular syndrome type III associated with antineutrophil cytoplasmic autoantibody-mediated crescentic glomerulonephritis: A case report and literature review

RATIONALE

Polyglandular autoimmune syndromes (PAS) are a heterogeneous group of rare diseases characterized by the association of at least 2 organ-specific autoimmune disorders, concerning both the endocrine and nonendocrine organs. Type III is defined as the combination of autoimmune thyroid disease and other autoimmune conditions (other than Addison disease), and is divided into 4 subtypes. We describe a patient with Hashimoto thyroiditis, adult-onset Still disease, alopecia, vasculitis, antineutrophil cytoplasmic antibody (ANCA)-mediated crescentic glomerulonephritis, and hyperparathyroidism. Co-occurrence of these 5 diseases allowed us to diagnose PAS type IIIc. The rare combination of these different diseases has not been reported before.

PATIENT CONCERNS

A 51-year-old woman was admitted in April, 2019 after the complaint of an enlarged thyroid. She was diagnosed with Hashimoto thyroiditis at the age of 36. At age 40, she was diagnosed with an adult-onset Still disease. Three months before admission, she experienced renal insufficiency. After admission, she was diagnosed with hyperparathyroidism.

DIAGNOSIS

Renal biopsy revealed renal vasculitis and crescentic nephritis. Antineutrophil cytoplasmic autoantibody showed that human perinuclear ANCA and myeloperoxidase ANCA were positive. Therefore, the patient was diagnosed with vasculitis and ANCA-mediated crescentic glomerulonephritis. After admission, parathyroid single-photon emission computed tomography/computed tomography fusion image demonstrated the presence of hyperparathyroidism.

INTERVENTIONS

The patient was treated with high-dose methylprednisolone pulse therapy (0.1 g/d) for vasculitis and ANCA-mediated crescentic glomerulonephritis, calcium and vitamin D3 (600 mg/d elemental calcium [calcium carbonate] and 2.5 μg/d active vitamin D3) for hyperparathyroidism, and levothyroxine sodium (50 ug/d) for Hashimoto thyroiditis.

OUTCOMES

Up to now, serum thyroid-stimulating hormone, total triiodothyronine, total thyroxine, free triiodothyronine, and free thyroxine were within the normal ranges. Patient's renal function did not deteriorate.

LESSONS

We report a patient with Hashimoto thyroiditis, adult-onset Still disease, alopecia, vasculitis, ANCA-mediated crescentic glomerulonephritis, and hyperparathyroidism, which is a very rare combination. We present this case as evidence for the coexistence of several different immune-mediated diseases in the clinical context of a PAS IIIc.