Revaccination of children after completion of standard chemotherapy for acute lymphoblastic leukaemia: a pilot study comparing different schedules.

Given that a significant proportion of children with acute lymphoblastic leukaemia (ALL) lose immune protection to tetanus, diphtheria, and poliomyelitis, revaccination is indicated after chemotherapy. Our randomized pilot study comparing different revaccination schedules suggests that children with ALL might be revaccinated with non-live vaccines as early as 3 months after chemotherapy.

Pneumococcal conjugate vaccine provides early protective antibody responses in children after related and unrelated allogeneic hematopoietic stem cell transplantation.

Following allogeneic hematopoietic stem cell transplantation (alloHSCT), children are at risk of life-threatening pneumococcal infections. Whereas vaccination with polysaccharide vaccines fails to elicit protective immunity in most alloHSC transplant recipients, pneumococcal conjugate vaccines may effectively prevent invasive disease by eliciting T-cell-dependent antibody responses. Here, we report safety and immunogenicity in 53 children immunized with a regimen of 3 consecutive doses of a heptavalent pneumococcal conjugate vaccine (7vPCV) in monthly intervals starting 6 to 9 months after alloHSCT. Immunization was well tolerated with no vaccine-related serious adverse events. Serologic response rates evaluable in 43 patients ranged from 41.9% to 86.0% and 58.1% to 93.0% after 2 and 3 vaccinations, respectively, with 55.8% and 74.4% of patients achieving protective antibody levels to all 7 vaccine serotypes. Our study provides the first evidence that vaccination with 7vPCV is safe and elicits protective antipneumococcal antibody responses in pediatric recipients of related or unrelated donor alloHSC transplants within the first year following transplantation. This trial was registered at www.clinicaltrials.gov as NCT00169728.

IL-2 activated NK cell immunotherapy of three children after haploidentical stem cell transplantation.

Natural killer (NK) cells are thought to be of benefit in HLA-mismatched hematopoietic transplantation (H-SCT). Therefore, we developed a protocol for clinical-use expansion of highly enriched and IL-2-stimulated NK cells. Purification of unstimulated leukaphereses by a two-step T cell depletion with a final CD56 enrichment procedure leads to a mean purity of 95% CD56(+)CD3- NK cells with a four- to five-log depletion of T cells. So far, three pediatric patients with multiply relapsed acute lymphoblastic leukemia (ALL) or acute myelogenous leukemia (AML) were treated with repeated transfusions post-H-SCT. Directed killer immunoglobulin-like receptor (KIR) mismatches were demonstrated in all three cases. Although all patients showed blast persistence at the time of transplant, they reached complete remission and complete donor chimerism within 1 month post-H-SCT. NK cell therapy was tolerated well without graft-versus-host disease (GvHD) induction or other adverse events. The AML patient died of early relapse on day +80, while the ALL patients died of thrombotic-thrombocytopenic purpura and atypical viral pneumonia on days +45 and +152, respectively. This initial trial showed the feasibility of good manufacturing practice (GMP)-compliant NK cell isolation and expansion for clinical applications. We now launch a clinical phase I trial with activated NK cells post-H-SCT.

Severe isolated pulmonary Langerhans cell histiocytosis in a 6-year-old girl.

UNLABELLED: Langerhans cell histiocytosis (LCH) usually affects different organs or bones. Isolated pulmonary disease is rare in childhood. We report about a 6-year-old girl with progressive pulmonary insufficiency, onset of clubbing at 4 years of age and honeycombing lung infiltrations on X-ray films. The radiological suspicion of primary pulmonary LCH was confirmed by the presence of CD1a positive cells in the bronchoalveolar lavage fluid. Other organs were not involved. The girl was treated according to the LCH-III International Study Protocol with a good response. Follow-up showed no reactivation of LCH but a reduced vital capacity and signs of interstitial pulmonary involvement on a CT scan. CONCLUSION: Langerhans cell histiocytosis should be considered in the aetiology of cystic lung diseases. Early responders to treatment have a high likelihood of becoming free of disease. However, pulmonary fibrosis is an important mechanism of lung remodelling in pulmonary Langerhans cell histiocytosis and the long-term prognosis is unclear.

Ocular symptoms in children treated with human-mouse chimeric anti-GD2 mAb ch14.18 for neuroblastoma.

Unusual ocular symptoms observed during intravenous treatment with anti-disialoganglioside antibody (Ab) in children suffering from neuroblastoma were analyzed and the results reported. Within the framework of the German Collaborative Neuroblastoma Study NB97, 85 children with high-risk neuroblastoma received anti-GD2 monoclonal antibody ch14.18 intravenously. Side effects were regularly reported to the study center. Ocular symptoms were recorded in clinical detail, duration and development over time. Symptoms of a parasympathetic deficit corresponding to internal ophthalmoplegia, i.e. mydriasis and accommodation deficit, were found in 10 patients. They were uni- or bilateral, began after the termination of Ab infusion and improved or disappeared in all surviving children. They did not reappear or worsen upon repeated Ab infusions. The pathophysiology of these disorders remains poorly understood. It is concluded that during systemic treatment with the anti-GD2 antibody ch14.18, reversible symptoms of parasympathetic denervation of the eye may occur which, however, do not warrant termination of this treatment.