Expression of Coagulation Factor XIII Subunit A Correlates with Outcome in Childhood Acute Lymphoblastic Leukemia.

Previously we identified B-cell lineage leukemic lymphoblasts as a new expression site for subunit A of blood coagulation factor XIII (FXIII-A). On the basis of FXIII-A expression, various subgroups of B-cell precursor acute lymphoblastic leukemia (BCP-ALL) can be identified. Fifty-five children with BCP-ALL were included in the study. Bone marrow samples were obtained by aspiration and the presence of FXIII-A was detected by flow cytometry. G-banding and fluorescent in situ hybridization was performed according to standard procedures. The 10-year event-free survival (EFS) and overall survival (OS) rate of FXIII-A-positive and FXIII-A-negative patients showed significant differences (EFS: 84% vs. 61%, respectively; p = 0.031; OS: 89% vs. 61%; p = 0.008). Of all the parameters examined, there was correlation only between FXIII-A expression and 'B-other' genetic subgroup. Further multivariate Cox regression analysis of FXIII-subtype and genetic group or 'B-other' subgroup identified the FXIII-A negative characteristic as an independent factor associated with poor outcome in BCP-ALL. We found an excellent correlation between long-term survival and the FXIII-A-positive phenotype of BCP lymphoblasts at presentation. The results presented seem to be convincing enough to suggest a possible role for FXIII-A expression in the prognostic grouping of childhood BCP-ALL patients.