Immune reconstitution syndrome and the thyroid.

Reconstitution Graves' disease occurs in three settings. First, bone marrow transplantation from a donor with Graves' disease may cause this disease to appear in the recipient, as a result of adoptive immunity, although disordered immunoregulation secondary to graft-versus-host disease may also play a role. Second, alemtuzumab treatment for multiple sclerosis leads to the development of Graves' disease in up to a third of patients during the phase of naive T-cell expansion, which follows therapeutic lymphocyte depletion. Other reconstitution autoimmune phenomena, including immune thrombocytopaenic purpura, are also recognised after alemtuzumab administration. Finally, reconstitution Graves' disease may occur during a similar phase of CD4(+) T-cell expansion, which follows highly active antiretroviral therapy for human immunodeficiency virus infection. Again, this complication is part of a broader spectrum of immunoregulatory disturbances, which can arise after immune reconstitution. The mechanisms responsible for reconstitution Graves' disease are at present unclear, but may include a relative bias towards a Th2-mediated immune response and reduced competition for autoreactive lymphocytes to expand during the time when recovery from lymphopenia commences.