A Case of Triple-Negative Myasthenia Gravis Lambert-Eaton Overlap Syndrome With Negative Agrin and LRP-4 Antibodies.

A case of triple-negative myasthenia gravis Lambert-Eaton overlap syndrome with negative Agrin and LRP-4 antibodies. Myasthenia gravis (MG) is an autoimmune disorder that shares similar features with Lambert-Eaton myasthenic syndrome. The combined clinical and electrophysiological findings of MG and Lambert-Eaton myasthenic syndrome have been reported, these cases represent the so-called "myasthenia gravis Lambert-Eaton overlap syndrome" (MLOS). A total of 55 MLOS cases have been identified, 13 cases were reported before the acetylcholine receptor (AChR) antibody (ab) testing era, 14 during the AChR-ab era, 26 during the voltage-gated calcium channel (VGCC)-ab era, and 2 cases have been reported during the muscle-specific kinase (MuSK)-ab era, of these; only 1 patient tested negative for all 3 antibodies. New immunological markers have been identified in the study of MG [Agrin and the low-density lipopro-tein receptor-related protein 4 (LRP-4)]. We present a patient with MLOS who tested negative for all 5 (AChR, MuSK, VGCC, Agrin, and LRP-4) serologic markers.

Comparative Long-Term Evaluation of Patients With Juvenile Inflammatory Myopathies.

OBJECTIVES: We conducted a retrospective study analyzing the clinical features, laboratory findings, demographics, and long-term prognoses of patients with juvenile inflammatory myopathies to determine possible predictors indicating the use of aggressive immunotherapy and the response to and complications of treatment. METHODS: The medical records of 41 patients with juvenile inflammatory myopathies seen at University of Tennessee-affiliated hospitals in Memphis from 1969 to 2008 were evaluated. Patients' clinical characteristics, laboratory studies, muscle biopsies, and electromyography were reviewed. All patients were treated with prednisone initially; additionally, 14 patients received varying combinations of other immunosuppressant therapies. RESULTS: Seventy-three percent of the patients experienced remission. Patients in the group that did not go into remission had specific characteristics at onset: they were comparatively older and had more severe rashes, contractures, arthritis, and systemic involvement. Also, patients with positive autoantibodies (antinuclear antibody, rheumatoid arthritis factor) had better outcomes. CONCLUSIONS: Juvenile inflammatory myopathies have relatively good prognoses. Initial presentation at advanced age or with severe rash, systemic vasculopathies, anemia, or arthritis portends refractory disease; in these patients, second- and third-line therapies improve outcome.