Abklärung und Differenzialdiagnose der Myositiden

Zusammenfassung

Die immunogenen entzündlichen Muskelerkrankungen stellen die größte Gruppe der Myositiden dar. Sie sind seltene Erkrankungen und umfassen die Dermatomyositis, die Polymyositis und die Einschlusskörperchenmyositis. Diese Erkrankungen zeigen viele Gemeinsamkeiten. Leitsymptome sind Muskelschwäche und Muskelatrophie. Wenn typische Hautveränderungen auftreten, ist die Diagnosestellung der Dermatomyositis relativ einfach. Die Diagnostik umfasst die klinische Untersuchung, Laboruntersuchungen, Bildgebung, elektrophysiologische Untersuchung und Muskelbiopsie. Typische Befunde sind erhöhte Muskelenzyme, der Nachweis von Myositis-spezifischen Antikörpern, ein Muskelödem in der Magnetresonanztomografie (MRT) und ein myopathisches Muster im Elektromyogramm (EMG). Die definitive Einordnung des Krankheitsbildes wird durch die Histopathologie ermöglicht. Die Muskelpathologie zeigt ein entzündliches Infiltrat mit unterschiedlicher Verteilung im Muskelfaszikel. Differenzialdiagnostisch müssen alle Erkrankungen, die mit Muskelschwäche und CK-Erhöhung einhergehen, ausgeschlossen werden. Diese beinhalten auch Malignome und Overlap-Syndrome.

Summary

Idiopathic inflammatory myopathies constitute the largest group of myositis. It is a group of rare disorders including dermatomyositis, polymyositis and sporadic inclusion body myositis. These disorders share many similarities. Clinical hallmarks are muscle weakness and muscle atrophy. Diagnosis of dermatomyositis is relatively easy when the typical skin changes are apparent. Diagnostic tools include physical examination, laboratory tests, imaging, electrophysiological studies and muscle biopsy. Characteristic findings are elevated levels of muscle enzymes, myositis-specific antibodies, muscle edema on MRI and EMG findings of a myopathic pattern. Definitive diagnosis is established by the histopathological examination of muscle biopsies. Typical findings are inflammatory exudates of variable distribution within the muscle fascicle. For differential diagnosis other diseases associated with muscle weakness and elevated muscle enzymes including malignancies and overlap syndroms have to be excluded.

Schlüsselwörter

Immunogene idiopathische Myositiden - Dermatomyositis - Polymyositis - Einschlusskörperchenmyositis

Keywords

Idiopathic inflammatory myopathies - dermatomyositis - polymyositis - inclusion body myositis

• Literatur

• 1 Cox S, Limaye V, Hill C. et al. Idiopathic inflammatory myopathy: diagnostic criteria, classification and epidemiological features. Int J Rheum Dis 2010; 13 (02) 117-124.
• 2 Dalakas MC, Hohlfeld R. Polymyositis and dermatomyositis. Lancet 2003; 362 9388 971-982.
• 3 Dalakas MC. Sporadic inclusion body myositis-diagnosis, pathogenesis and therapeutic strategies. Nature Clin Practice Neurol 2006; 2: 437-447.
• 4 Cox FM, Delgado V, Verschuuren JJ. et al. The heart in sporadic inclusion body myositis: a study in 51 patients. J Neurol 2010; 257 (03) 447-451.
• 5 Volk-Platzer B. Update: Dermatomyositis. Hautarzt 2010; 61: 69-80.
• 6 Ji SY, Zeng FQ, Guo Q. et al. Predictive factors and unfavorable, prognostic factors of interstitial lung disease in patients with Polymyositis or Dermatomyositis. Chin Med J (Engl) 2010; 123 (05) 517-522.
• 7 Gonzlez-Lopez L. Cardiac manifestations in dermato-polymyositis. Clin Exp Rheumatol 1996; 14 (04) 373-379.
• 8 Lu Z, Guo-Chun W, Li M, Ning Z. Cardiac Involvement in Adult Polymyositis. Clin Cardiol. 2012 doi: [Epub ahead of print]
• 9 Hill CL, Zhang Y, Sigurgeirsson B. et al. Frequency of specific cancer types in dermatomyositis and polymyositis: a population-based study. Lancet 2001; 357 9250 96-100.
• 10 Basset-Seguin N, Roujeau JC, Gherardi R. et al. Prognostic factors and predictive signs of malignancy in adult dermatomyositis. A study of 32 cases. Arch Dermatol 1990; 126 (05) 633.
• 11 Marie I. Influence of age on characteristics of polymyositis and dermatomyositis in adults. Medicine (Baltimore) 1999; 78: 139.
• 12 Brewster LM, de Visser M. Persistent hyperCKemia: fourteen patients studied in retrospect. Acta Neurol Scand 1988; 77 (01) 60.
• 13 Hengstman GJ, ter Laak HJ, Vree Egberts WT. et al. Anti-signal recognition particle autoantibodies: marker of a necrotising myopathy. Ann Rheum Dis 2006; 65 (12) 1635-1638 [Epub 2006 May 5].
• 14 Trallero-Araguás E. Cancer-associated myositis and anti-p155 autoantibody in a series of 85 patients with idiopathic inflammatory myopathy. Medicine (Baltimore) 2010; 89 (01) 47.
• 15 Gunawardena H, Betteridge ZE, McHugh NJ. Myositis-specific autoantibodies: their clinical and pathogenic significance in disease expression. Rheumatology (Oxford) 2009; 48 (06) 607-612.
• 16 Chinoy H, Fertig N, Oddis CV. et al. The diagnostic utility of myositis autoantibody testing for predicting the risk of cancer associated myositis. Ann Rheum Dis 2007; 66 (10) 1345-1349.
• 17 Theodorou DJ. Skeletal muscle disease: pattern of MRI appearences. Br J Radiol. 2012 85. (1020): e1298-e308 doi: [Epub 2012 Sep 6]
• 18 May DA, Disler DG, Jones EA. et al. Abnormal Signal Intensity in Skeletal Muscle at MR Imaging: Patterns, Pearls, and Pitfalls. Radiographics 2000; 20 (Spec No): S295-S315.
• 19 Bowyer SL, LaMothe MP, Hollister JR. Steroid myopathy: incidence and detection in a population with asthma. J Allergy Clin Immunol 1985; 76 (02) (Suppl. 01) 234.
• 20 Khaleeli AA, Edwards RH, Gohil K. et al. Corticosteroid myopathy: a clinical and pathological study. Clin Endocrinol (Oxf) 1983; 18 (02) 155.
• 21 Ballantyne CM, Corsini A, Davidson MH. et al. Risk for myopathy with statin therapy in high-risk patients. Arch Intern Med 2003; 163 (05) 553-564.
• 22 Otake S, Banno T, Ohba S. et al. Muscular sarcoidosis: findings at MR imaging. Radiology 1990; 176 (01) 145.
• 23 Liakou AI, Trebing D, Zouboulis CC. Paraneoplastische Dermatomyositis bei metastasiertem malignem Melanom. J Dtsch Dermatol Ges 2012; 10: 63-64.