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-gamma and TGF-beta 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. (c) 2006 Elsevier B.V. All rights reserved.