Early vascular toxicity after pediatric allogeneic hematopoietic stem cell transplantation.

Treatment-related mortality and morbidity remain a challenge in hematopoietic stem cell transplantation (HSCT). In this retrospective, single-center study, we analyzed endothelial damage as a potential, common denominator and mechanism for the adverse effects. We evaluated the prevalence of key vascular complications and graft-versus-host disease among 122 pediatric patients with an allogeneic HSCT between 2001 and 2013. The spectrum and frequency of acute adverse events emerging ≤100 days post transplant were graded according to the CTCAE 4.03 and analyzed. We identified a total of 19/122 (15.6%) patients with vascular complications, fulfilling the criteria of capillary leak syndrome, veno-occlusive disease/sinusoidal obstruction syndrome or thrombotic microangiopathy. The patients had a poorer overall survival (77% versus 26%, p < 0.001). Nearly one half (56/122, 45.9%) had at least one, severe (grade 3 or 4) adverse event. Patients with vascular complications had more often edema/effusions (p = 0.023), thrombocytopenia (p = 0.001), gastrointestinal bleeding (p < 0.001), acute kidney injury (p < 0.001), ascites (p < 0.001) or bilirubin increase (p = 0.027). These endotheliopathy-related adverse events appeared early post HSCT, varied in their clinical phenotype and predicted a poor outcome. An unrelated donor but not previous exposure to leukemia or irradiation-based conditioning was identified as a risk factor for vascular complications and endotheliopathy.

[Immune deficiency and infections in children having cancer]. / Syöpää sairastavien lasten immuuni- vajavuustila ja infektiot.

Childhood cancer and its treatment weaken the immune defenses and predispose the patient to infections. The recovery of immune defences depends on the provided cancer therapy and associated complications such as the graft-versus-host reaction. Recovery takes place gradually and the spectrum of infections suffered by the patient reflects the different stages of restoration of the immune defenses. Bacterial and fungal infections dominate the early, neutropenic phase, viral infections being predominant during the later lymphocytopenic phase. In the follow-up it is essential to recognize the risk factors, to observe the recuperation of the immune system and to treat the complications.

Immunity after (re)vaccination of paediatric patients following haematopoietic stem cell transplantation.

AIMS: Loss of specific immunity follows allogeneic haematopoietic stem cell transplantation (HSCT) in the majority of cases. Responses to (re)vaccinations can be used as indicators of a functional immunological recovery. METHODS: Twenty-three paediatric recipients of HSCT were enrolled in a single centre setting and responses to scheduled immunizations analysed. RESULTS: Immunity to vaccine-preventable diseases was impaired post HSCT, but (re)vaccinations induced protective responses in 59-100%, depending on the vaccine, regardless of prior graft-versus-host disease (GVHD) history. CONCLUSION: Despite the marked impact of moderate to severe chronic prior GVHD on both the qualitative and quantitative T-cell recovery post allogenic HSCT, most paediatric recipients of allogeneic stem cell grafts appear to attain protective antibody levels after immunization.

Multiple viral infections post-hematopoietic stem cell transplantation are linked to the appearance of chronic GVHD among pediatric recipients of allogeneic grafts.

Delayed immune reconstitution and the ensuing opportunistic infections among children following hematopoietic stem cell transplantation (HSCT) are associated with increased treatment-related morbidity and mortality (TRM). We retrospectively evaluated the impact of viral infections on the posttransplant recovery of pediatric recipients of stem cell grafts as a reflection of their posttransplant immunoreconstitution in a single institution setting. The case histories of 124 children (during 1/1999-9/2006) were reviewed for infectious episodes, and correlated with their respective clinical parameters. Patients with a high risk for CMV received prophylaxis, but failures in the prophylaxis were common (40%). 110/124 (89%) of these allogeneic patients had at least one viral reactivation/clinical infection posttransplant. In this group of pediatric patients chronic GVHD (P<0.001) and secondary graft failure were significantly (P=0.001) associated with early (during the first 100 days post HSCT), multiple (> or = 2) viral infections. Our data indicate that viruses are common pathogens among pediatric recipients of allogeneic stem cell grafts. In this group of patients multiple viral infections early on seem to reflect an even more severe degree of immunological derangement in the recipient and identify a group of patients with an increased risk of chronic GVHD and secondary graft failure.