Investigation of antineuronal autoantibodies in patients with paraneoplastic syndrome symptoms

The clinical picture of Paraneoplastic Neurological Syndrome (PNS), which is not caused by the physical effects of the primary tumor itself or its metastases, but consists of signs and symptoms due to the presence of the tumor, is called. In the early 1980s, the first onconeuronal antibodies were identified in PNS patients. Identification of antibodies by antigens expressed by tumor cells and nervous system cells led to the recognition of PNS as immune-mediated distant effects of cancer that occurred in <0.01% of cancer patients. The aim of the current study was to investigate the antineuronal autoantibodies in serum samples of patients who presented to the neurology clinic with PNS symptoms. Serum samples of 48 patients admitted to Gaziantep University Şahinbey Research Hospital Neurology Department between May 2017 and March 2019 with suspicion of PNS who had an episode of optic neuritis (ON) were collected. In these samples, IgG antineuronal antibodies against ANA and 12 different antigens were investigated by indirect immunofluorescence method and immunoblot method. Other autoimmune test results and infection factors of the patients included in the study were obtained from the Neurology Clinic automation database. Of the 48 patients included in the study, 30 were female (62.5%) and 18 were male (37.5%). The mean age of the patients was 33.56 ± 11.34 years. Antineuronal antibodies were detected in 3 (6.3%) of the patients, anti-recoverin antibody was detected in 2 (4.2%) 1 (2.1%) of them anti-SOX1 antibody. ANA was positive in 2 patients (4.2%) and ANA negative in 46 patients (95.8%). ANA was found to be negative in patients with antineuronal antibodies. In our study, when the patients with anconeuronal antibody were detected for tumor presence, no tumor was found. However, when evaluated according to the literature, it was concluded that the follow-up of these patients in terms of tumor presence would be appropriate in the coming years.