Functional Antibody Responses Following Allogeneic Stem Cell Transplantation for TP53 Mutant pre-B-ALL in a Patient With X-Linked Agammaglobulinemia

Discussion This case demonstrates successful cure of pre-B-ALL complicating XLA by alloSCT with restoration of B-cell development and functional antibody response. We are aware of only one previous case of pre-B-ALL in an XLA patient (21), which suggests that human BTK deficiency in itself does not predispose to pre-B-ALL. However, there are data to suggest that BTK may act as a tumor suppressor, and BTK deficiency may predispose to tumor development following a “second hit.” Mice with a genetic deficiency in Slp65, a gene encoding an adaptor protein that functions together with BTK, have a block in progenitor B-cell development and spontaneously develop pre-B-cell leukemia. Concomitant deficiency of Btk and in Slp65-deficient mice enhances development of pre-B-cell leukemia (22). The ALL in our patient contained the dominant negative TP53 R273H mutation. TP53 mutations are found in 4% of all pre-B-ALLs and are a known risk factor for therapy resistance (23). Deficiency of P53 enhances pre-B-ALL formation in Slp65 deficient mice (24). Although BTK/p53 double knockout mice have not been reported to spontaneously develop leukemia, their B-cells demonstrate both a block in development and an enhanced proliferative capacity (25). It is possible in our patient that the somatic TP53 mutation in itself was sufficient to lead to a rapidly progressive and chemoresistant ALL. In our case, the germline BTK mutation may have a been a contributing predisposing factor, bu...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research