Clinical heterogeneity of chronic inflammatory demyelinating polyneuropathy: diagnostic challenges

Сhronic inflammatory demyelinating polyneuropathy (CIDP) is the most prevalent acquired dysimmune neuropathy with clinical picture of symmetric motor and sensory disturbances. Since the first description of CIDP, many atypical variants have been described, which may reach up to 50% of cases. Diagnosis of atypical CIDP may be challenging due to different clinical presentation and treatment response. Current researches improve our knowledge about dysimmune neuropathies and highlight the importance of its classification. Nowadays CIDP is considered as a spectrum of disorders rather than a separate disease entity. Up to date, more than 15 diagnostic criteria have been proposed reflecting the complexity of СIDP diagnosis. Many polyneuropathies may mimic CIDP, therefore CIDP is frequently a diagnosis of exclusion. The key diagnostic instrument is electroneuromyography; however, the issues related to results misinterpretation and some technical aspects are the most important in CIDP misdiagnosis. Supportive instrumental and laboratory methods have variable sensitivity and specificity, making challenging CIDP diagnosis, especially its atypical forms. The importance of an early and accurate diagnosis of CIDP is supported by an effective pathogenic treatment, which affects the patient's prognosis and level of disability.

Ultrastructural Lesions of Nodo-Paranodopathies in Peripheral Neuropathies

Whatever the cause of myelin damage of the peripheral nervous system, the initial attack on myelin by a dysimmune process may begin either at the internodal area or in the paranodal and nodal regions. The term “nodo-paranodopathy” was first applied to some “axonal Guillain-Barré syndrome” subtypes, then extended to cases classified as chronic inflammatory demyelinating polyradiculoneuropathy bearing IgG4 antibodies against paranodal axoglial proteins. In these cases, paranodal dissection develops in the absence of macrophage-induced demyelination. In contrast, the mechanisms of demyelination of other dysimmune neuropathies induced by macrophages are unexplained, as no antibodies have been identified in such cases. Electron microscopy of longitudinal sections of nerve biopsies is useful to visualize and authenticate the characteristic lesions of paranodes/nodes. However, it should be borne in mind that identical ultrastructural aspects are seen in other types of polyneuropathies: Genetic, experimental, and in a few polyneuropathies for which there is no obvious etiology. Ultrastructural nerve studies confirm the initial involvement of nodes/paranodes in various types of acquired and genetic neuropathies. For some of them, the antibodies or the proteins involved by mutations are clearly identified such as Caspr-1, Contactin-1, NFasc155, and NFasc186; other unidentified proteins are likely to be involved as well.

The use of rituximab in the treatment of disimmune polyneuropathy: a description of clinical cases and a literature review

Dysimmune neuropathies are heterogeneous group of acquired immune-mediated diseases, accompanied by damage to the peripheral nervous system. As a standard therapy, prednisolone and intravenous immunoglobulins are used. Also encouraging efficacy is demonstrated by the use of a genetically engineered chimeric monoclonal antibody to the CD20 antigen found on the surface of normal and malignant B-cells – rituximab. Rituximab shows encouraging results. We reviewed the use of rituximab for dysimmune polyneuropathies and described our experience in administration of Lewis–Sumner syndrome and myelin-associated glycoprotein related neuropathy with rituximab.