Neuropathy and IgM M-proteins: prognostic value of antibodies to MAG, SGPG, and sulfatide.

BACKGROUND: In polyneuropathy associated with immunoglobulin M (IgM) monoclonal gammopathy, antibodies to myelin-associated glycoprotein (MAG), sulfoglucuronyl paragloboside (SGPG), and sulfatide have been associated with specific clinical and electrophysiologic features. However, it is not known whether the results of antibody tests provide additional information for the individual patient (and the neurologist) in terms of future neurologic deficit or outcome. OBJECTIVE: To study the independent contribution of potential prognostic factors to the prediction of outcome of neuropathy associated with IgM monoclonal gammopathy. METHODS: In accordance with the chronology in which prognostic factors are available in clinical practice, the association between prognostic factors and outcome was evaluated by univariate and multivariate logistic regression analysis in 65 patients with polyneuropathy and IgM monoclonal gammopathy. RESULTS: In univariate analysis, the initial symptoms, the IgM light chain type, electrophysiologic and pathologic studies, the presence of sural nerve IgM deposition, and anti-MAG or anti-SGPG antibodies were significantly associated with outcome. However, multivariate analysis showed that only initial symptoms and electrophysiologic studies are independent prognostic factors: initial sensory symptoms of the feet are prognostic for a slowly progressive disease course and less disability at 4 years, and evidence for demyelination on electrophysiologic examination is prognostic for development of weakness and symptoms of the upper extremities at 4 years. Addition of anti-MAG or anti-SGPG antibody tests did not yield any additional prediction of outcome. CONCLUSION: These results indicate that in clinical practice, antibody tests in polyneuropathy associated with IgM monoclonal gammopathy do not have a prognostic value in terms of future neurologic deficit or outcome.

Sural nerve T-cell receptor Vbeta gene utilization in chronic inflammatory demyelinating polyneuropathy and vasculitic neuropathy.

OBJECTIVE: To investigate the utilization of T-cell receptor (TCR) variable (V) regions in infiltrates of sural nerve biopsies of patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and vasculitic neuropathy. BACKGROUND: The presence of infiltrating T lymphocytes in sural nerve biopsies may suggest a T cell-mediated immune mechanism in the pathogenesis of CIDP and vasculitic neuropathy. PATIENTS AND METHODS: The utilization of TCR Vbeta regions in sural nerves of 13 patients with CIDP and five patients with vasculitic neuropathy was determined by immunohistochemistry, reverse-transcription PCR, and nucleotide sequence analysis. These techniques were also applied in four patients with chronic idiopathic axonal polyneuropathy (CIAP) who acted as noninflammatory controls, and in five autopsy controls. RESULTS: The TCR Vbeta utilization of infiltrating T cells in sural nerves of patients with CIDP, vasculitic neuropathy, and noninflammatory controls is heterogeneous. A dominant TCR Vbeta utilization was not found in any of the patients or controls. CONCLUSION: There is no evidence for the presence of clonally expanded T cells in sural nerves of patients with CIDP and vasculitic neuropathy.