Immunodeficiency in patients with thymoma-associated myasthenia gravis

Thymoma with immunodeficiency is sometimes accompanied by myasthenia gravis (MG), but the clinical characteristics have not been elucidated. This study aimed to characterize its clinical and immunological features. Of the 132 thymoma-associated MG patients, 9 patients presented with immunodeficiency. All suffered from severe pneumonia, and most had invasive thymoma and autoimmune disorders. DRB1*08:03 and DQB1*06:01 alleles were frequently detected. Compared to group without immunodeficiency, they showed no significant differences in the severity of MG, significantly lower IgG concentrations and higher mortality rate. Thymoma-associated MG with immunodeficiency is a distinct subset requiring special attention to prevent infection during the follow-up period. [Display omitted] •Seven percent of thymoma-associated MG patients presented with immunodeficiency.•Thymoma-associated MG with immunodeficiency had a poor prognosis due to infection.•Invasive thymoma was often seen in thymoma-associated MG with immunodeficiency.•Low serum IgG and autoimmune disorders were related to immunodeficient cases.•Frequency of certain HLAs was higher in thymoma-associated MG with immunodeficiency.