BACKGROUND AND OBJECTIVES: Myasthenia gravis (MG) is an autoimmune disease characterized by dysfunction at the neuromuscular junction. Treatment frequently includes corticosteroids (CSs) and IV immunoglobulin (IVIG). This study was conducted to determine whether immune globulin (human), 10% caprylate/chromatography purified (IGIV-C) could facilitate CS dose reduction in CS-dependent patients with MG. METHODS: In this randomized double-blind placebo-controlled trial, CS-dependent patients with MG (Myasthenia Gravis Foundation of America Class II-Iva; AChR+) received a loading dose of 2 g/kg IGIV-C over 2 days (maximum 80 g/d) or placebo at week 0 (baseline). Maintenance doses (1 g/kg IGIV-C or placebo) were administered every 3 weeks through week 36. Tapering of CS was initiated at week 9 and continued through week 36 unless the patient worsened (quantitative MG score ≥4 points from baseline). CS doses were increased (based on the current CS dose) in patients who worsened. Patients were withdrawn if worsening failed to improve within 6 weeks or if a second CS increase was required. The primary efficacy end point (at week 39) was a ≥50% reduction in CS dose. Secondary and safety end points were assessed throughout the study and follow-up (weeks 42 and 45). The study results and full protocol are available at clinicaltrials.gov/ct2/show/NCT02473965. RESULTS: The primary end point (≥50% reduction in CS dose) showed no significant difference between the IGIV-C treatment (60.0% of patients) and placebo (63.3%). There were no significant differences for secondary end points. Safety data indicated that IGIV-C was well tolerated. DISCUSSION: In this study, IGIV-C was not more effective than placebo in reducing daily CS dose. These results suggest that the effects of IGIV-C and CS are not synergistic and may be mechanistically different. TRIAL REGISTRATION INFORMATION: The trial was registered on clinicaltrialsregister.eu (EudraCT #: 2013-005099-17) and clinicaltrials.gov (identifier NCT02473965). CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that IVIG infusions in adult patients with MG do not increase the percentage of patients achieving a ≥50% reduction in corticosteroid dose compared with placebo.

• MeSH
• dospělí MeSH
• dvojitá slepá metoda MeSH
• hormony kůry nadledvin terapeutické užití   MeSH
• intravenózní imunoglobuliny * terapeutické užití   MeSH
• lidé MeSH
• myasthenia gravis * farmakoterapie   MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Názvy látek
• hormony kůry nadledvin MeSH
• intravenózní imunoglobuliny * MeSH

Selective atrophy of type II muscle fibres has been long recognized as an enigmatic but consistent feature of myasthenia gravis (MG) muscle; however, the pathophysiology and the mechanism of that change have remained obscure. In the present study, the results of histomorphometric analysis performed on muscle biopsies from 207 thymectomized seropositive MG patients were correlated with clinical features of MG to demonstrate possible pathophysiological associations and potential prognostic impact. The atrophy of type II fibres was verified in 35 cases (16.9%), being more pronounced in fibres of IIB subtype. It was neither significantly associated with the duration and severity of MG nor with the age of the patients. On the other hand, we demonstrated that the atrophy associated with long-term treatment with corticosteroids, and correlated with increasing doses. Thus, we suppose that the atrophy of type II muscle fibres in seropositive MG is steroid induced rather than MG-associated event. Although the MG patients with atrophy of type II fibres did not differ from the remaining MG cases in terms of improvement in the disease during the follow-up period, our analysis provides clear evidence that they presented a significantly slower tendency to reach an asymptomatic state after thymectomy. Therefore, the steroid-induced atrophy of type II fibres in MG muscle might be considered to be an unfavourable prognostic factor.

• MeSH
• biopsie MeSH
• dospělí MeSH
• hormony kůry nadledvin farmakologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• myasthenia gravis patologie   MeSH
• prognóza MeSH
• svalová atrofie MeSH
• thymektomie * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hormony kůry nadledvin MeSH