T-Large Granular Lymphocyte Leukemia Accompanied by an Increase of Natural Killer Cells (CD3-) and Associated with Ulcerative Colitis and Autoimmune Hepatitis

Abstract

Clonal expansion of large granular lymphocyte(LGL) have been classified into T-LGL and NK-LGL leukemia. T-LGL leukemia cells have a CD3+ phenotype and show clonal T-cell receptor(TCR) gene rearrangement. NK-LGL leukemia cells have a CD3-phenotype and no TCR gene rearrangement. We report a case of T-LGL leukemia accompanied by NK LGL expansions in a 65-year-old man who was observed 3 years earlier to have a LGL lymphocytosis in association with ulcerative colitis(UC) and autoimmune hepatitis (AIH). Phenotypic analysis of peripheral blood by flow cytometry disclosed an increase of both T-LGL(CD3+,CD56-,CD57+,and TCRαβ+) and NK-LGL (CD3-,CD16+,CD56+, and CD57+). Clonal rearrangement of the TCR β gene was detected. A diagnosis of UC and AIH was made on the basis of the X-ray and mucosal biopsy findings of the large intestine, and on the scoring system for diagnosis of AIH, respectively. The disease was nonprogressive, and mesalazine and prednisolone were successful for treatment of UC and AIH. Previously reported cases of T-LGL, NK-LGL leukemia, or NK cell lymphocytosis had no association with UC or AIH, and there have been no reports having both T-LGL leukemia with T-cell receptor gene rearrangement and chronic NK cell lymphocytosis co-existing in a single patient.