Adenovirus infection and disease in paediatric haematopoietic stem cell transplant patients: clues for antiviral pre-emptive treatment.

Human adenovirus (HAdV) infections constitute a major cause of morbidity in paediatric haematopoietic stem cell transplant (HSCT) patients. New antiviral treatments offer promising perspectives. However, it remains challenging to identify patients at risk for disseminated infection, and who should receive early antiviral intervention. We conducted a longitudinal study of allogeneic HSCT recipients, including weekly HAdV monitoring, to determine the risks factors associated with HAdV infection and dissemination, and to assess whether HAdV loads in stools may be used as surrogate markers for HAdV dissemination. Between September 2010 and December 2011, out of 72 patients, the cumulative incidence rates at day 100 of HAdV digestive infection, systemic infection and related disease were 35.9%, 24.0%, and 18.3%, respectively. In multivariate analysis, the risk factors for HAdV digestive and systemic infection were cord blood and in vitro T-cell depletion. Graft-versus-host disease (GVHD) grade >2 was also associated with systemic infection. In patients with HAdV digestive shedding, GVHD grade >2 and HAdV load in stools were the only risk factors for systemic infection. The median peak levels of HAdV in stool were 7.9 and 4.0 log10 copies/mL, respectively, in patients with HAdV systemic infection and in those without. HAdV monitoring in stools of paediatric HSCT recipients receiving cord blood or in vitro T-cell depleted transplants helps to predict patients at risk for HAdV systemic infection. Our results provide a rationale for randomized controlled trials to evaluate the benefit of anti-HAdV pre-emptive treatments based on HAdV DNA levels in stools.

Omenn syndrome: a rare case of neonatal erythroderma.

Omenn syndrome is a severe combined immunodeficiency characterized by erythroderma, hepatosplenomegaly, lymphadenopathy and failure to thrive, with activated oligoclonal T lymphocytes and an absence of circulating B cells.A 3 day-old boy presented with a congenital erythroderma. Investigations revealed a marked neutropenia and lymphopenia and the absence of a thymus. Genetic studies showed RAG 1 mutations. He was successfully treated with an HLA identical bone marrow transplantation. Omenn syndrome is a rare severe combined immunodeficiency. Most cases are due to mutations in the RAG genes with autosomal recessive transmission. Our observation is original because of an incomplete clinical presentation. During the course of the disease, the child had no failure to thrive, no organomegaly and no recurrent infection. Immunodeficiency must be excluded in every case of neonatal erythroderma and an immunological assessment should be performed without delay.

Description of an adenovirus A31 outbreak in a paediatric haematology unit.

Adenovirus infections result in significant morbidity and mortality in allogeneic haematopoietic stem cell transplanted (hSCT) children. Adenovirus from species C and B account for more than 90% of adenoviruses recovered after hSCT. However, infections due to adenovirus A31 have been increasingly reported in recent years. Between April 2002 and April 2005, blood samples obtained every 2 weeks from 58 hSCT children were screened for adenovirus species A to C by quantitative real-time PCR. Phylogenetic analysis was realized after amplification and sequencing of the entire hexon gene. Fifteen cases of adenovirus infection with viraemia were recovered during this 3 years period. During spring/summer 2003, seven cases occurred and were due to an adenovirus species A. Phylogenetic analysis of the seven strains showed that they belonged to the A31 genotype and shared 100% homology. Clinical features of the seven HSCT children with A31 adenovirus viraemia are described. We describe here an epidemic spread of adenovirus genotype A31 in a paediatric haematology unit. Timing, location and hexon gene genotyping results highly suggested a nosocomial origin to this epidemic. The burden of adenovirus A31 infection needs to be further assessed in this context.

Improved outcome of treatment-resistant high-risk Langerhans cell histiocytosis after allogeneic stem cell transplantation with reduced-intensity conditioning.

Children with multisystem Langerhans cell histiocytosis (LCH) and risk organ involvement who fail to respond to conventional chemotherapy have an extremely poor prognosis. Myeloablative stem cell transplantation (SCT) as a possible salvage approach for these patients has been associated with a high risk of transplant-related mortality. Therefore, allogeneic stem cell transplantation following a reduced-intensity conditioning regimen (RIC-SCT) has recently been performed as an alternative salvage approach. We report on the experience with allogeneic RIC-SCT in nine pediatric high-risk LCH patients. Conditioning regimen included fludarabine in all patients, melphalan in eight patients, total lymphoid irradiation in six patients, total body irradiation in two, antithymocyte globulin in five, and Campath in four patients. RIC-SCT was well tolerated with regard to common procedure-related complications. Two patients died 50 and 69 days after RIC-SCT, respectively. Seven out of the nine patients survived and showed no signs of disease activity (including one with nonengraftment and full autologous hematopoietic recovery) after median follow-up of 390 days post-SCT. Based on this observation, we conclude that RIC-SCT is a feasible procedure with low transplant-related morbidity and mortality and a promising new salvage approach for high-risk LCH patients with resistant risk organ involvement.

Hematopoietic stem cell transplantation in severe congenital neutropenia: experience of the French SCN register.

Our objective was to study the outcome of allogeneic hematopoietic stem cell transplantation (HSCT) in patients with severe congenital neutropenia (SCN). Among 101 cases of SCN included in the French Severe Chronic Neutropenia Registry, nine patients received HSCT between 1993 and 2003, in seven institutions. The indications were nonresponse to G-CSF therapy in four cases, bone marrow failure in one case, and myelodysplastic syndrome or leukemia in four cases. The conditioning regimen consisted of total body irradiation in two cases and chemotherapy alone in the other seven cases. Seven patients received stem cells from unrelated donors and two from identical siblings. Engraftment occurred in all but one of the patients. Three patients died. The respective causes of death were graft-versus-host disease, infection, and EBV post-transplant lymphoproliferative disease. Six patients are alive and in complete remission, with a median follow-up of 3.1 years. These results indicate that HSCT is feasible for patients with SCN who do not respond to G-CSF, who have malignant transformation, or who are at a high risk of malignant transformation, even if an HLA-identical sibling donor is not available.

High-dose chemotherapy with hematopoietic stem cell transplantation in patients with mantle cell or diffuse centrocytic non-Hodgkin's lymphomas: a single center experience on 18 patients.

Between 1985 and 1996, 18 patients with diffuse centrocytic lymphoma (DCL), including nine patients with an established histological and phenotypic diagnosis of mantle cell lymphoma (MCL), received 19 courses of high-dose chemotherapy (HDCT) followed by hematopoietic stem cell transplantation. Five patients received HDCT as consolidation treatment after first-line standard chemotherapy, and 14 after a relapse or progression, including one patient in early relapse after the first transplant. Six patients (33%) were in complete response (CR) prior to HDCT and 12 (67%) were in partial response: 10 (83%) of these 12 patients achieved CR at day 60 following HDCT. With a median follow-up of 30 months after HDCT, the 2-year overall and progression-free survivals of the whole series are 91 and 75%, respectively. The 2-year progression-free survivals are 74 and 75%, respectively, in the MCL and DCL subgroups.