CHARACTERIZATION OF TRISOMIC NATURAL KILLER CELL ABNORMALITIES IN A PATIENT WITH CONSTITUTIONAL TRISOMY 8 MOSAICISM

Malignancies found in children and adults with constitutional trisomy 8 mosaicism (CT8M) could be in part the consequence of dysfunction of trisomic immune cells. An adult patient exhibiting trisomy in the entire natural killer (NK) cell population has made possible the characterization of trisomy 8-positive NK cells. The study showed normal cytotoxic activity but predominance of an immunosenescent phenotype (CD56dimCD94/NKG2bright) characterized by a weak response to IL-2, increased upregulation of CD95/Fas, and impaired TNF-α production. As these defects may contribute to the escape and expansion of neoplastic cells, the authors hypothesize that cancer predisposition in CT8M may be partly a result of altered immunosurveillance.