LAUSR

Hematopoietic stem cell transplant (HSCT) with matched sibling donor (MSD) is considered the first line of therapy for patients with severe aplastic anemia (SAA) who are <40 years of age (Young, 2013) [1]. Immunosuppressive therapy (IST) and alternative donor HSCT are other modalities of treatment (Young, 2013) [1]. Due to non-availability of a MSD for two- thirds of the SAA patients and a significant rate of failure of IST, alternative donor HSCT has been tried with encouraging results (Socié, 2013) [2]. In 2003, Fernandez et al, in a cohort of 11 patients with high risk hematological malignancies, successfully utilized a novel approach of supplementing cord blood unit (CBU) with CD34+ cells from haplo-identical donor to use the latter as a bridge for rapid neutrophil recovery followed by a persistent dominant CBU chimerism (Fernández et al., 2003) [3]. In 2011, Gromley et al., pioneered the use of haplo-cord transplant for SAA patients lacking HLA compatible MSD/unrelated donor who failed IST (Gormley et al., 2011) [4]. Typically, hematopoietic reconstitution after haplo-cord transplant shows a pattern of transient myeloid engraftment with haploidentical graft followed by dominant CBU chimerism (van Besien and Childs, 2016) [5]. Here, we report a case of haplo-cord HSCT for SAA that showed a unique hematopoietic reconstitution kinetics. The patient was found to have a dominant CBU peripheral blood chimerism (97%) on T + 12 with no evidence of haploidentical graft dominance at anytime during the post-HSCT period.