A. Tondo

In vivo cytoreduction studies and cell sorting-enhanced tumor-cell detection in high-risk neuroblastoma patients: Implications for leukapheresis strategies

PURPOSE To improve autologous leukapheresis strategies in high-risk neuroblastoma (NB) patients with extensive bone marrow involvement at diagnosis. PATIENTS AND METHODS Anti-G(D2) immunocytochemistry (sensitivity, 1 in 10(5) to 10(6) leukocytes) was used to evaluate blood and bone marrow disease at diagnosis and during the recovery phase of the first six chemotherapy cycles in 57 patients with stage 4 NB and bone marrow disease at diagnosis. A total of 42 leukapheresis samples from the same patients were evaluated with immunocytology, and in 24 of these patients, an anti-G(D2) immunomagnetic enrichment step was used to enhance tumor-cell detection. RESULTS Tumor cytoreduction was much faster in blood compared with bone marrow (3.2 logs after the first cycle and 2.1 logs after the first two cycles, respectively). Bone marrow disease was often detectable throughout induction, with a trend to plateau after the fourth cycle. By direct anti-G(D2) immunocytology, a positive leukapheresis sample was obtained in 7% of patients after either the fifth or sixth cycle; when NB cell immunomagnetic enrichment was applied, 25% of patients had a positive leukapheresis sample (sensitivity, 1 in 10(7) to 10(8) leukocytes). CONCLUSION Standard chemotherapy seems to deliver most of its in vivo purging effect within the first four cycles. In patients with overt marrow disease at diagnosis, postponing hematopoietic stem-cell collection beyond this point may not be justified. Tumor-cell clearance in blood seems to be quite rapid, and earlier collections via peripheral-blood leukapheresis might be feasible. Immunomagnetically enhanced NB cell detection can be highly sensitive and can indicate whether ex vivo purging should be considered.

Use of percutaneous radial artery catheter for peripheral blood progenitor cell collection in pediatric patients.

BACKGROUND : Leukapheresis procedures require adequate flow rates, which in children may frequently involve invasive vascular access placement.

Adenovirus pneumonia during induction therapy for childhood acute lymphoblastic leukemia

To the Editor: Although most infections are self-limited, adenoviruses have been associated with severe and even fatal infections in immunocompromised [1,2] patients who can develop persistent infection, severe localized disease, or disseminated disease with multiorgan failure [3]. In a recent review of patients receiving stem cell transplant (SCT), 11% of those infected with adenovirus developed clinical signs [4] with a higher incidence in children (21–31%) compared with adults (9–13%) [5]. Case fatality rates can reach 50–80% [6,7]. In ECIL guidelines for diagnosis and treatment of adenovirus infection in leukemia and SCT, children at high risk for adenovirus infection are those undergoing allogeneic

Non‐Hodgkin lymphoma in children with an associated inherited condition: A retrospective analysis of the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP)

Inherited conditions affecting genetic aberration, viral oncogenesis, reduced immune surveillance, and long‐lasting antigen stimulation may build the way to lymphomagenesis in humans.

Primary mediastinal large B-cell lymphoma: Outcome of a series of pediatric patients treated with high-dose methotrexate and cytarabine plus anti-CD20

Between 2007 and 2013, 13 children diagnosed with primary mediastinal large B‐cell lymphoma (PMLBL) were treated according to a modified version of AIEOP (Associazione Italiana Ematologia Oncologia Pediatrica) LNH‐97 protocol based on high‐dose methotrexate, anthracyclines, and addition of anti‐CD20. Ten patients achieved a continuous complete remission with front‐line therapy. The overall 5‐year survival was 91.7%, and event‐free survival was 83.9%, with only one patient dying of progressive disease. Despite the few cases, these results demonstrate that this therapy, which includes anti‐CD20, given in a multicenter setting, is feasible with acceptable toxicity in children with PMLBL.