Cavanna B, Carpo M, Pedotti R, Scarpini E, Meucci N, Allaria S, Scarlato G, Nobile-Orazio E
Centro Dino Ferrari, Institute of Clinical Neurology, IRCCS Ospedale Maggiore Policlinico, University of Milan, Italy.
J Neuroimmunol. 1999 Feb 1;94(1-2):157-64. doi: 10.1016/s0165-5728(98)00245-8.
Anti-GM2 IgM antibodies have been reported in some patients with dysimmune neuropathy or lower motor neuron syndrome, in whom they were often associated with a concomitant reactivity with GM1. To investigate the possible clinical and pathogenetic relevance of these antibodies we measured serum anti-GM2 IgM titers by ELISA in 224 patients with different neuropathies and motor neuron disease and examined their binding to SK-N-SH neuroblastoma cells by indirect immunofluorescence (IIF). High titers of anti-GM2 IgM antibodies were found in eight patients with dysimmune neuropathies including two with multifocal motor neuropathy (MMN), two with purely motor demyelinating neuropathy without conduction block (MN) and four with Guillain-Barré syndrome (GBS). In two MMN patients reactivity with GM2 was associated with anti-GM1 reactivity and in one MN patient with anti-GM1, -GD1a and -GD1b reactivity. All but one patient had a concomitant reactivity with GalNAc-GD1a. Serum IgM from all positive patients intensely stained by IIF the surface of SK-N-SH neuroblastoma cells. This reactivity was blocked by serum pre-incubation with GM2, was not observed with sera from patients without anti-GM2 antibodies including those with high anti-GM1 or other anti-glycolipid antibodies, and correlated with the presence of GM2 in the SK-N-SH neuroblastoma cells. These findings indicate that anti-GM2 antibodies, though infrequent, are strictly associated with dysimmune neuropathies and suggest that SK-N-SH neuroblastoma cells can be a suitable in vitro model to study the functional and biological effects of these antibodies.
在一些免疫失调性神经病或下运动神经元综合征患者中已报道存在抗GM2 IgM抗体，这些患者中该抗体常与GM1的伴随反应性相关。为了研究这些抗体可能的临床和发病机制相关性，我们通过酶联免疫吸附测定（ELISA）检测了224例患有不同神经病和运动神经元疾病患者的血清抗GM2 IgM滴度，并通过间接免疫荧光法（IIF）检测了它们与SK-N-SH神经母细胞瘤细胞的结合情况。在8例免疫失调性神经病患者中发现了高滴度的抗GM2 IgM抗体，其中包括2例多灶性运动神经病（MMN）患者、2例无传导阻滞的纯运动性脱髓鞘神经病（MN）患者和4例吉兰-巴雷综合征（GBS）患者。在2例MMN患者中，与GM2的反应性与抗GM1反应性相关，在1例MN患者中与抗GM1、-GD1a和-GD1b反应性相关。除1例患者外，所有患者均与GalNAc-GD1a有伴随反应性。所有阳性患者的血清IgM通过IIF强烈染色SK-N-SH神经母细胞瘤细胞表面。这种反应性可被与GM2预孵育的血清阻断，在无抗GM2抗体患者（包括那些具有高抗GM1或其他抗糖脂抗体的患者）的血清中未观察到，并且与SK-N-SH神经母细胞瘤细胞中GM2的存在相关。这些发现表明，抗GM2抗体虽然不常见，但与免疫失调性神经病密切相关，并提示SK-N-SH神经母细胞瘤细胞可能是研究这些抗体功能和生物学效应的合适体外模型。
