Vital C, Vital A, Deminiere C, Julien J, Lagueny A, Steck A J
Neuropathology Laboratory, Victor Segalen University, Bordeaux, France.
Ultrastruct Pathol. 1997 Nov-Dec;21(6):509-16. doi: 10.3109/01913129709016367.
Characteristic myelin modifications in patients with IgM monoclonal gammopathy and anti-MAG activity have mainly been studied in cases of undetermined significance, but also exist in cases with indolent Waldenström's macroglobulinemia, i.e., when lymphoplasmocytic infiltration in bone marrow is 15% or more, without any visceral involvement. Since 1983, the authors have examined nerve biopsies from 8 cases with Waldenström's macroglobulinelia by direct immunofluorescence examination on frozen sections and ultrastructural examination. At direct immunofluorescence, fixation of anti-IgM serum on myelinated fibers was present in 7 cases. At ultrastructural examination, a widening of some myelin lamellae at the periphery of a few fibers was visible in 8 cases. A few fibers with hypermyelination were present in 5 cases. In 2 of these 5 cases widening of some myelin lamellae was present in numerous fibers, 88% in one of them. Frequently, there was a major widening of some myelin lamellae with dilated lamellae present in the inner part of the myelin sheath. Certain lamellae were more dilated, up to 50 nm. Occasionally, enlarged lamellae were not compacted with each other. The authors also examined nerve biopsies from 36 patients with IgM monoclonal gammopathy of undetermined significance and anti-MAG activity, but found only one case with major widening of some myelin lamellae. Five other cases with major widening of some myelin lamellae, 4 Waldenström's macroglobulinemia and 1 IgM monoclonal gammopathy of undetermined significance, have been reported. Given that demyelinating neuropathies are far more numerous in cases with IgM monoclonal gammopathy of undetermined significance, it is likely that cases of indolent Waldenström's macroglobulinemia are prone to develop major myelin modifications, possibly due to another mechanism, added to the classic anti-MAG activity.
IgM单克隆丙种球蛋白病且具有抗MAG活性患者的特征性髓鞘改变，主要在意义未明的病例中进行了研究，但也存在于惰性华氏巨球蛋白血症病例中，即骨髓中淋巴细胞浆细胞浸润达15%或更多且无任何内脏受累的情况。自1983年以来，作者通过对冰冻切片进行直接免疫荧光检查和超微结构检查，对8例华氏巨球蛋白血症患者的神经活检标本进行了研究。在直接免疫荧光检查中，7例患者的有髓纤维上出现抗IgM血清固定现象。在超微结构检查中，8例患者可见少数纤维外周的一些髓鞘板层增宽。5例患者存在少数纤维髓鞘增厚。在这5例患者中的2例，许多纤维出现一些髓鞘板层增宽，其中1例达88%。通常，一些髓鞘板层明显增宽，髓鞘鞘内部分出现扩张的板层。某些板层扩张更明显，可达50纳米。偶尔，扩张的板层彼此不紧密。作者还对36例意义未明的IgM单克隆丙种球蛋白病且具有抗MAG活性患者的神经活检标本进行了检查，但仅发现1例有一些髓鞘板层明显增宽。另外还报道了5例有一些髓鞘板层明显增宽的病例，4例为华氏巨球蛋白血症，1例为意义未明的IgM单克隆丙种球蛋白病。鉴于意义未明的IgM单克隆丙种球蛋白病患者中脱髓鞘性神经病更为常见，惰性华氏巨球蛋白血症病例可能易于发生主要的髓鞘改变，这可能是由于除经典抗MAG活性之外的另一种机制所致。
