Large granular lymphocyte leukemia with pure red cell aplasia associated with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy: an unfortuitous association?

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a recessively inherited monogenic disease caused by a mutation in the autoimmune regulator (AIRE) gene. AIRE plays a major role in central (thymic) immune tolerance. In the absence of AIRE, autoimmunity develops that is especially targeted at endocrine tissues. T-cell large granular lymphocyte (T-LGL) leukemia is a monoclonal lymphoproliferative disease characterized by persistent and indolent lymphocytosis. Autoimmune manifestations, such as rheumatoid arthritis or autoimmune cytopenia, are also common. We report the case of a patient with APECED, who presented with pure red cell aplasia associated with T-LGL leukemia. The association of T-LGL leukemia and APECED is very rare and may not be fortuitous. The immunological mechanisms of this association are discussed.