Polyneuropathy in Multiple Myeloma Patients Correlate with the Presence of Autoantibodies (P7.013)

Background and goal of the study: Multiple myeloma is a lymphoproliferative disease often requiring neurotoxic treatment (thalidomide/bortezomibe). Patients may develop length dependent axonal polyneuropathy related with the treatment. Because of variable degree of neural involvement in patients with similar MM picture we analyzed the presence of different types of autoantibodies as a possible risk factor of more severe polyneuropathy. DESIGN/METHODS: We selected 36 consecutive patients (age: 55-71, 22 males and 14 females) referred to our clinic because of paresthesias between 2008-2011 with one year history of MM treated with thalidomide/bortezomibe. All of them were examined clinically (Toronto Clinical Neuropathy Score, TCNS) and electrophysiologically. We examined the presence of autoantibodies using indirect immunofluorescence (IIF, Euroimmun, Germany) as a screening, and in cases with positive pattern indicating the presence of onconeural antibodies line blot (Euroimmun, Germany)was performed as the confirmation test. IIF enables detection of a spectrum of autoantibodies (anti-myelin associated glycoprotein - MAG, anti-glutamic acid decarboxylase - GAD, anti-glial fibrillary acid protein - GFAP, anti-gangliosides, anti-neuroendothelium, anti-myelin). RESULTS: We found autoantibodies in 20 of them (55%) - 12 (33%) had antibodies against nucleosome antigens (ANA), 4 (11%) had anty-PNMa2/Ta(+/-), 2 (5.5%) anti-myelin and 2 (5.5%) had abnormal granular and molecular layer of cerebellar cortex staining. Mean TCNS score in patients with autoantibodies was significantly higher (mean= 7.5, SD=1.8) than in patients without autoantibodies (mean=3.5, SD 0,7) t-Student test, p<0,05. TCNS correlated with the severity of electrophysiological abnormalities (length-dependent axonal sensory [6 patients] or sensory-motor [14 patients]); no motor involvement was found in the 16 patients without autoantibodies. . CONCLUSIONS: MM patients who develop autoantibodies have higher risk of more severe polyneuropathy with motor fiber involvement in comparison to those without immunological response. EMG-ENG assessment as well as autoantibodies analysis prior to potentially neurotoxic therapy initiation may be helpful in choosing the appropriate drug. Disclosure: Dr. Niezgoda has nothing to disclose. Dr. Michalak has received personal compensation for activities with Euroimmun Poland. Dr. Gil has nothing to disclose. Dr. Komarnicki has nothing to disclose. Dr. Kozubski has received personal compensation for activities with Novartis and Biogen Idec. as a speaker.