Allogeneic hematopoietic stem cell transplantation from unrelated donors is associated with higher infection rates in children with acute lymphoblastic leukemia-A prospective international multicenter trial on behalf of the BFM-SG and the EBMT-PDWP.

Severe infections (SI) significantly impact on non-relapse mortality after hematopoietic stem cell transplantation (HSCT). We assessed 432 children and adolescents with acute lymphoblastic leukemia (ALL) after total body irradiation based myeloablative HSCT within the multicenter ALL-BFM-SCT 2003 trial for SI grade 3 or higher according to common terminology criteria for adverse events. A total 172 patients experienced at least one SI. Transplantation from matched unrelated donors (MUD) was associated with any type of SI in the pre-engraftment period (hazard ratio [HR]: 2.57; P < .001), and with any SI between day +30 and + 100 (HR: 2.91; P = .011). Bacterial (HR: 2.24; P = .041) and fungal infections (HR: 4.06; P = .057) occurred more often in the pre-engraftment phase and viral infections more often before day +30 (HR: 2.66; P = .007) or between day +30 and + 100 (HR: 3.89; P = .002) after HSCT from MUD as compared to matched sibling donors. Chronic GvHD was an independent risk factor for any type of SI after day +100 (HR: 2.57; P < .002). We conclude that allogeneic HSCT from MUD in children and adolescents with pediatric ALL is associated with higher infection rates, which seems attributable to an intensified GvHD prophylaxis including serotherapy and methotrexate.

Outcome of relapse after allogeneic HSCT in children with ALL enrolled in the ALL-SCT 2003/2007 trial.

Relapse remains the major cause of treatment failure in children with high-risk acute lymphoblastic leukaemia (ALL) undergoing allogeneic haematopoietic stem-cell transplantation (allo-SCT). Prognosis is considered dismal but data on risk factors and outcome are lacking from prospective studies. We analysed 242 children with recurrence of ALL after first allo-SCT enrolled in the Berlin-Frankfurt-Munster (BFM) ALL-SCT-BFM 2003 and ALL-SCT-BFM international 2007 studies. Median time from allo-SCT to relapse was 7·7 months; median follow-up from relapse after allo-SCT until last follow-up was 3·4 years. The 3-year event-free survival (EFS) was 15% and overall survival (OS) was 20%. The main cause of death was disease progression or relapse (86·5%). The majority of children (48%) received salvage therapy without second allo-SCT, 26% of the children underwent a second allo-SCT and 25% received palliative treatment only. In multivariate analyses, age, site of relapse, time to relapse and type of salvage therapy were identified as significant prognostic factors for OS and EFS, whereas factors associated with first SCT were not statistically significant. Combined approaches incorporating novel immunotherapeutic treatment options and second allo-SCT hold promise to improve outcome in children with post allo-SCT relapse.

Astrovirus infection in hospitalized infants with severe combined immunodeficiency after allogeneic hematopoietic stem cell transplantation.

Infants with severe primary combined immunodeficiency (SCID) and children post-allogeneic hematopoietic stem cell transplantation (HSCT) are extremely susceptible to unusual infections. The lack of generic tools to detect disease-causing viruses among more than 200 potential human viral pathogens represents a major challenge to clinicians and virologists. We investigated retrospectively the causes of a fatal disseminated viral infection with meningoencephalitis in an infant with gamma C-SCID and of chronic gastroenteritis in 2 other infants admitted for HSCT during the same time period. Analysis was undertaken by combining cell culture, electron microscopy and sequence-independent single primer amplification (SISPA) techniques. Caco-2 cells inoculated with fecal samples developed a cytopathic effect and non-enveloped viral particles in infected cells were detected by electron microscopy. SISPA led to the identification of astrovirus as the pathogen. Both sequencing of the capsid gene and the pattern of infection suggested nosocomial transmission from a chronically excreting index case to 2 other patients leading to fatal infection in 1 and to transient disease in the others. Virus-specific, real-time reverse transcription polymerase chain reaction was then performed on different stored samples to assess the extent of infection. Infection was associated with viremia in 2 cases and contributed to death in 1. At autopsy, viral RNA was detected in the brain and different other organs, while immunochemistry confirmed infection of gastrointestinal tissues. This report illustrates the usefulness of the combined use of classical virology procedures and modern molecular tools for the diagnosis of unexpected infections. It illustrates that astrovirus has the potential to cause severe disseminated lethal infection in highly immunocompromised pediatric patients.