Preliminary Study on Clinical Utility of Autoimmune Target Test in Psychiatric Disorders

BACKGROUND: Autoantibodies have been detected in patients with psychiatric disorders. However, there is no standard test for the detection of these autoantibodies. In this study, we analyzed autoimmune target (AIT) test results in patients with psychiatric disorders and investigated the clinical utility of the AIT test for psychiatric disorders. METHODS: We retrospectively analyzed data from patients diagnosed with psychiatric disorders between August 1995 and May 2015. Of these, 100 patients assessed using the AIT test were enrolled in this study. Data regarding positive rates, immunofluorescent patterns of AIT results, and the presence of autoimmune diseases in patients with psychiatric disorders were retrospectively collected and analyzed. RESULTS: The autoantibody-positive rate was high in patients with psychiatric disorders (70.0%, 70/100). The positive rates in patients with schizophrenia, depressive disorders, bipolar and related disorders, adjustment disorders, anxiety disorders, and others were 82.9%, 64.7%, 88.9%, 57.1%, 66.7%, and 53.8%, respectively. The most frequent pattern of immunofluorescence was a speckled pattern in 30 cases, followed by microtubule organizing center with microtubule (MTOC-MT) in 17 cases. Twenty-one patients were diagnosed with autoimmune diseases. CONCLUSIONS: In this study, the incidence of autoantibodies was high in patients with psychiatric disorders not specific to schizophrenia. This suggests that the AIT test may therefore have the potential to be a screening test for psychiatric disorders. Further, additional AIT tests in patients with psychiatric disorders may help to clarify the relationships between psychiatric disorders and autoimmune disease.

The Clinical Utility of the Autoimmune Target Test for Neurologic Disease

BACKGROUND: Many studies have reported the association between several anti-neuronal antibodies and neurologic diseases. However, there is no useful autoantibody screening test for neurologic diseases unlike the antinuclear antibody test for rheumatologic diseases. Hence, we investigated the clinical utility of the autoimmune target (AIT) test as screening test for autoantibodies in neurologic diseases. METHODS: We retrospectively analyzed the results of the AIT test for 375 serum samples of patients diagnosed with several neurologic diseases such as motor neuron disease (MND), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), encephalopathy (EC), polyneuropathy (PN), cerebral ischemic attack, encephalitis, myelitis, epilepsy, and stroke. RESULTS: The overall positive rate of the AIT test in aforementioned diseases was 77.9%. The positive rates for MND, ALS, PD, EC, PN, and the others were 81.3%, 83.9%, 84.8%, 59.3%, 73%, and 75%, respectively. CONCLUSIONS: Our results indicate high positive rates in the AIT test. We believe that the AIT test has potential application for autoantibody screening in the neurologic diseases. We look forward to last as the study about relations between the results of the AIT test and the specific antibodies for neurologic diseases.

A Case of Small Cell Lung Carcinoma with Coexisting Autoantibodies against Proliferating Cell Nuclear Antigen and Centriole Detected Using the Autoimmune Target Test

Approximately 60-70% of small cell lung carcinoma (SCLC) cases are diagnosed at extensive stage, thus tumor markers for its early detection are needed. Autoantibodies associated with malignancy are present before radiographic detection. Autoantibodies detected using the autoimmune target (AIT) test in patients with some tumors have shown the possibility of autoantibodies to be used as a tumor marker. To overcome the limitations of antinuclear antibody (ANA) test using HEp-2 cell line, the AIT test was developed using human macrophage cell line, IT-1, as a substrate, which showed positive identification of various autoantibodies with a higher level of sensitivity. We report a case of SCLC with autoantibodies against proliferating cell nuclear antigen (PCNA) and centriole in a 70-yr-old man who had a history of heavy alcohol consumption and a 50 pack-yr history of smoking. Results of computed tomography of the chest and abdomen showed a lung mass and multiple metastases. Extensive stage SCLC was confirmed using sputum cytology and lymph node aspiration biopsy. Anti-PCNA (1:1,280) and anti-centriolar (1:320) patterns were detected using the AIT test. Neuron-specific enolase was elevated (38.2 ng/mL). There was no evidence of systemic autoimmune rheumatic disease or chronic hepatitis. This is the first case report in which coexisting autoantibodies against PCNA and centriole associated with SCLC were detected using the AIT test. This case provides some evidence that autoantibodies may be used as a tumor marker for SCLC.