Persistence of CD16+/CD56−/2B4+ natural killer cells: A highly dysfunctional NK subset expanded in ocular myasthenia gravis

We report a case of myasthenia gravis associated with marked expansion of an unusual CD16+CD56−2B4+ NK subset. These atypical cells were characterized by poor cytotoxicity against CD48+ target cells and high proliferation due to 2B4/CD48 interaction. IL18, IFN-γ and TGF-β levels were profoundly different in this patient than in healthy donors. Immunosuppressive treatment induced disease remission and decreased the CD16+CD56−2B4+NK cells count. Our data suggest that expansion of this NK subset in myasthenia gravis patients may account for the deleterious NK cell functioning that occurs in this autoimmune disease.