頑固型重症肌無力症之靜脈注射免疫球蛋白療法

Intravenous Immunoglobulin Therapy for Myasthenia Gravis

廣泛型重症肌無力（MG）患者血漿內大部分皆有濃度高低不一之乙醯膽鹼受體抗體（AchRAb）。靜脈注射免疫球蛋白（IVIG）療法將大量各種免疫蛋白打入血中，調節免疫機能並使病情迅速恢復。7例重度MG病患（6女1男，平均年齡48.4歲）在接受胸腺切除術及免疫抑制療法仍控制不良前提下，接受IVIG療法。IVIG使用Venoglobulin-S（Alpha Therapeutic Corporation, Los Angeles, USA） 0.4g/kg/天連續施打5天。過程中，在治療前（D0），治療開始後第3天（D3），第5天（D5），第12天（D12），第1個月（M1），第2個月（M2）及第3個月（M3），分別以臨床肌無力分數及血漿中AchRAb濃度來連續監控IVIG對病情之影響。7例病人在Dl2內進步之MG分數中間值為2（0-6）分。其中4例（57%）進步大於2分，具有實際臨床療效。臨床進步開始於D3有2例，D5及D12各1例。4例中除1例未合併免疫抑制劑外，其療效皆可維持3個月。AchRAb部份，在M1以內，AchRAb幾乎皆未見下降。治療中肌力暫時性惡化現象，有3例皆發生於D3，且於D5改善。併發症方面，短暫發燒及低白血球血症各1例。總結，IVIG對重度MG且傳統療法反應不佳之頑固型個案是一有效且安全的治療。

Circulating antibodies to the acetylcholine receptor (AchRAb) are detectable in most patients with generalized myasthenia gravis (MG). Intravenous immunoglobulin (IVIG) therapy has been shown to induce a rapid recovery based on immunomodulatory mechanisms. Seven patients (six women and one man, mean age 48.4 years) with advanced MG who were refractory to thymectomy and immunosuppressants received daily 0.4g/kg doses of IVIG for 5 consecutive days. We recorded the MG score and measured the AchRAb concentration at baseline (D0) and 3 days (D3), 5 days (D5), 12 days (D12), 1 month (M1), 2 months (M2), and 3 months (M3) after the start of IVIG therapy. The median improvement of MG score was 2 (0-6) points in all 7 patients within 12 days. Four out of 7 patients (57%) had significant improvement after IVIG treatment. The onset of improvement occurred at D3 in 2 patients, at D5 in 1，and at Dl2 in 1. All of clinical responders except for one without immunosuppression achieved sustained improvement over three months. AchRAb titer remained unchanged within 1 month of IVIG therapy. Transient worsening of myasthenic weakness, occurring at D3 and resolving at D5, was noted in 3 patients. As for the IVIG-related complications, one patient developed of transient fever and one patient developed transient leukopenia. In conclusion, IVIG therapy is an effective and safe treatment for refractory MG.