Spontaneously immortalized T lymphocytes from Nijmegen Breakage Syndrome patients display phenotypes typical for lymphoma cells.

We found that the peripheral T lymphocytes from four of eight patients with the lymphoma predisposing Nijmegen Breakage Syndrome (NBS) acquired an unlimited growth potential following in vitro mitogen stimulation and subsequent interleukin-2-dependent propagation. The immortal T cell lines revealed morphological and other features typical for anaplastic large cell lymphoma (ALCL). In addition, multiple copies of ALK, but with no ALK gene rearrangements were found in a subpopulation of cells of one of the immortalized lines. These cell lines may be useful for the in vitro elucidation of mechanisms involved in the development of ALCL.