Associated Immunological Disorders and Cellular Immune Dysfunction in Thymoma: A Study of 87 Cases from Thailand

Several immune disorders are often associated with thymoma. The aim of this study was to analyze the correlation between clinicopathological features of Thai patients with thymoma and concomitant immune-mediated diseases. Medical records of 87 patients diagnosed with thymoma during a 10-year period were retrospectively reviewed. Peripheral blood T cell subsets along with cytokine responses in 15 thymoma patients and 15 healthy controls were comparatively analyzed. The results demonstrated that thymoma type AB and B2 were the most common types among patients diagnosed with thymoma. The most common presentation was incidentaloma, followed by local chest symptoms and autoimmune diseases. The prevalence of autoimmune diseases, immunodeficiency states, and secondary neoplasms was 34.5, 10.3, and 10.3 %, respectively. Autoimmune diseases were most frequently found in thymoma type B2 and sometimes associated with clinical immunodeficiency, although classic Good's syndrome was rare. Patients with thymoma had significantly lower percentage CD4(+ve) T cells and interferon gamma response, but higher percentage regulatory T cells than those in healthy controls. This study indicated that the aberrant immunologic disorders comprising autoimmune diseases, immunodeficiency states, and secondary neoplasms were found in almost 40 % of Thai patients with thymoma and possibly related to defectiva cytokine responses and altered T cell subsets.