ABSTRACT
Chronic myelogenous leukemia at blast crisis with a T-cell phenotype (T-ALL CML-BC) at diagnosis, without any prior history of CML is extremely rare. After the introduction of tyrosine kinase inhibitors (TKIs), CML patients have a median survival comparable to general population and accelerated/blast crisis are rarely encountered. Most CML patients (80%) transform into acute myeloid leukemia and the rest into B-ALL. Anecdotal cases of Ph+ T-ALL, either de novo or in the context of CML-BC have been reported. Left shift in the blood, the presence of splenomegaly/extramedullary infiltration and the occurrence of BCR::ABL1 rearrangement in both the blastic population, as well as in the myeloid cell compartment are key points in differentiating de novo Ph+ T-ALL from T-ALL CML-BC. The latter is a rare entity, characterized by extramedullary disease, p210 transcript and clonal evolution. Lack of preceding CML does not rule out the diagnosis of T-ALL CML-BC. Prompt TKI treatment with ALL-directed therapy followed by allogeneic stem cell transplantation may offer long-term survival in this otherwise poor prognosis entity. In this paper, we describe a patient with T-ALL CML-BC at presentation, still alive 51 months after diagnosis and we offer a review of the literature on this rare subject. All clinical and laboratory features are provided in order to distinguish de novo Ph+ T-ALL from T-ALL CML-BC, underscoring the prognostic and therapeutic significance of such a differentiation.
Subject(s)
Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma , Humans , Blast Crisis/therapy , Blast Crisis/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/therapy , Phenotype , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/diagnosis , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/genetics , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/therapy , T-LymphocytesABSTRACT
OBJECTIVES: As the interaction between hematopoietic stem cells (HSCs) and endosteal and endothelial niches in HSCs homing is essential, we aimed to study bone turnover and angiogenesis in 29 patients with lymphoma/multiple myeloma undergoing hematopoietic stem cell transplantation (HSCT). METHODS: Serum samples were collected before high-dose chemotherapy (HDT), at the end of HDT, after HSC infusion, at the nadir of myelotoxicity, and at engraftment. Bone metabolism (CTX, TRACP-5b, bALP, OC, DKK1, RANKL, OPG), and angiogenesis (Ang1, Ang2) markers were measured. These markers were also measured in 21 control patients before and after conventional chemotherapy. RESULTS AND CONCLUSIONS: Bone resorption declined during HSCT (decrease in TRACP-5b [P < .001] and CTX [P = .006]). Bone formation declined as well (decrease in bALP and OC [P < .001 for both]). RANKL/OPG ratio, an indicator of osteoclastic activation, did not change significantly (P = .5). Ang1/Ang2 ratio, a vessel equilibrium marker, decreased significantly (P < .001) suggesting endothelial destabilization. The changes observed in the control group were similar except of bALP and RANKL/OPG ratio. Moreover, Ang1/Ang2 ratio on the day after HSC infusion strongly correlated with time to neutrophil and platelet engraftment (P < .001 for both). Conclusively, bone turnover and vessel destabilization represent important events during HSCT probably reflecting the effect of chemotherapy.