Leukapheresis and exchange transfusion in children with acute leukemia and hyperleukocytosis. A single center experience.

BACKGROUND: The risk of severe complications or death during the initial period of acute leukemia was markedly decreased due to the progress in pediatric oncology and use of simple measures like hyperhydration, forced diuresis, treatment of hyperuricemia, correction of electrolyte and coagulation disturbances and the careful use of antileukemic drugs. The incidence of leukostasis and tumor lysis syndrome depends on absolute initial white blood cell counts and the underlying type of leukemia. Leukapheresis or exchange transfusion may improve the prognosis of high risk patients. METHODS: Records of all pediatric patients who were newly diagnosed with acute leukemia between 1 / 1998 und 12 / 2008 were retrospectively reviewed for presence of hyperleukocytosis(white blood cell count > 100 GPT / l) at diagnosis and subsequent leukapheresis or exchange transfusion in regards to the clinical outcome. RESULTS: At diagnosis 11 (14 % ) of 77 children with acute leukemia (7 acute lymphoblastic leukemia / ALL; 4 acute myeloblastic leukemia /AML) had hyperleukocytosis. 4 patients (2 ALL, 2 AML) received exchange transfusion and 2 others (1 ALL, 1 AML) underwent leukapheresis. Marked cytoreduction was achieved in all patients within 24 h after therapy initiation. There were no procedure-related adverse events. Symptoms due to hyperleukocytosis markedly improved after cytoreduction. CONCLUSION: Leukapheresis or exchange transfusion together with conservative management and specific oncological therapy may contribute to rapid leukocyte reduction with acceptable risk. The exact impact of leukapheresis or exchange transfusion on short and long term outcome in pediatric patients with acute leukemia and initial hyperleukocytosis has to be evaluated in future multicentre studies or by the formation of clinical registries.

Unusual presentation of central nervous system relapse with oculomotor nerve palsy in a case of CD56-positive acute myeloid leukemia following allogeneic stem cell transplantation.

Allogeneic stem cell transplantation (allo-SCT) plays an important role in the treatment of infants and children with acute myelogenous leukemia (AML). Leukemic relapse after allo-SCT is responsible for a high rate of treatment failure. Extra-medullary relapse (EMR), without involvement of bone marrow, is rare compared to medullary relapse. CD56, the neural cell adhesion molecule, may contribute to the higher frequency of CNS relapse in CD56-positive AML. We observed an isolated EMR on the oculomotor nerve of a 17-month-old girl 12 weeks after cord blood transplantation (CBT), who was transplanted because of CD56-positive AML. Diagnosis of relapse was suspected clinically and confirmed by magnetic resonance imaging (MRI), and fluorescence-activated cell sorter (FACS) and chimerism analysis of cerebrospinal fluid (CSF). Therapy consisted of intra-thecal chemotherapy, CNS irradiation, and systemic immunomodulation by cyclosporin A (CsA) and basiliximab withdrawal. Twenty-one months after relapse, the patient shows full remission of symptoms and previously described oculomotor nerve infiltration.