McConville John, Farrugia Maria Elena, Beeson David, Kishore Uday, Metcalfe Richard, Newsom-Davis John, Vincent Angela
Weatherall Institute of Molecular Medicine and Department of Clinical Neurology, Oxford, UK.
Ann Neurol. 2004 Apr;55(4):580-4. doi: 10.1002/ana.20061.
Antibodies to rat muscle specific kinase, MuSK, have recently been identified in some generalized "seronegative" myasthenia gravis (SNMG) patients, who are often females with marked bulbar symptoms. Using immunoprecipitation of (125)I-labelled-human MuSK, 27 of 66 (41%) seronegative patients were positive, but 18 ocular SNMG patients, 105 AChR antibody positive MG patients, and 108 controls were negative. The antibodies are of high affinity (Kds around 100 pM) with titers between 1 and 200 nM. They bind to the extracellular Ig-like domains of soluble or native MuSK. Surprisingly they are predominantly in the IgG4 subclass. MuSK-antibody associated MG may be different in etiological and pathological mechanisms.
最近在一些全身性“血清阴性”重症肌无力（SNMG）患者中发现了抗大鼠肌肉特异性激酶（MuSK）抗体，这些患者通常为有明显延髓症状的女性。通过对（125）I标记的人MuSK进行免疫沉淀，66例血清阴性患者中有27例（41%）呈阳性，但18例眼肌型SNMG患者、105例乙酰胆碱受体（AChR）抗体阳性的重症肌无力患者及108例对照均为阴性。这些抗体具有高亲和力（解离常数约为100 pM），滴度在1至200 nM之间。它们与可溶性或天然MuSK的细胞外免疫球蛋白样结构域结合。令人惊讶的是，它们主要属于IgG4亚类。MuSK抗体相关的重症肌无力在病因和病理机制上可能有所不同。
