Edoardo Lanino

Natural Killer Cell-Mediated Killing of Freshly Isolated Neuroblastoma Cells Critical Role of DNAX Accessory Molecule-1–Poliovirus Receptor Interaction

In the present study, we assessed the susceptibility of freshly isolated neuroblastoma cells to killing mediated by normal human natural killer (NK) cells and analyzed the receptor–ligand interactions that regulate this event. We show that killing of freshly isolated neuroblasts, similar to neuroblastoma cell lines, involves NKp46 and NKp30 (natural cytotoxicity receptors). However, freshly isolated neuroblasts were generally more resistant to NK-mediated lysis than conventional neuroblastoma cell lines. Moreover, a significant heterogeneity in susceptibility to lysis existed among neuroblastomas derived from different patients. Remarkably, susceptibility to lysis directly correlated with the surface expression, on neuroblasts, of poliovirus receptor [PVR (CD155)], a ligand for the DNAX accessory molecule-1 [DNAM-1 (CD226)] triggering receptor expressed by NK cells. Indeed, PVR-expressing neuroblastomas were efficiently killed by NK cells. Moreover, monoclonal antibody-mediated masking of either DNAM-1 (on NK cells) or PVR (on neuroblasts) resulted in strong inhibition of tumor cell lysis. Thus, assessment of the PVR surface levels may represent a novel useful criterion to predict the susceptibility/resistance of neuroblastomas to NK-mediated killing.

Extracorporeal photochemotherapy for paediatric patients with graft‐versus‐host disease after haematopoietic stem cell transplantation

Summary. This study aimed to ascertain whether extracorporeal photochemotherapy (ECP) is an effective treatment for paediatric patients with refractory graft‐versus‐host disease (GVHD). From January 1992 to December 2000, 77 children (median age 8·6 years) with either acute (n = 33) or chronic (n = 44) GVHD, resistant to conventional immunosuppressive therapy, were treated with ECP in four Italian paediatric hospitals. After ECP, acute GVHD involving skin, liver and gut responded completely in 76%, 60% and 75% of patients respectively. The 5‐year overall survival was 69% for responding patients vs 12% for non‐responders (P = 0·001). Among the 44 children with chronic GVHD, 15 (44%) showed a complete response and 10 (29%) a significant improvement after ECP. The 5‐year overall survival was 96% for responders vs 58% for non‐responders (P = 0·04). Our results suggest that ECP is an effective treatment that may be useful in paediatric patients with either acute or chronic GVHD who have failed to respond to standard immunosuppressive therapy.

Fludarabine, cyclophosphamide and anti-thymocyte globulin for alternative donor transplants in acquired severe aplastic anemia: a report from the EBMT-SAA Working Party

Summary:We have developed a reduced-intensity conditioning regimen for patients with severe aplastic anemia (SAA) undergoing alternative donor transplants, which includes fludarabine (120 mg/m2), cyclophosphamide (1200 mg/m2) and antithymocyte globulin (7.5 mg/kg). Graft-versus-host disease (GvHD) prophylaxis consisted of cyclosporine and methotrexate. We have enrolled 38 SAA patients in this trial: median age of 14 (3–37) years, transplanted from unrelated (n=33) or family mismatched (n=5) donors, with unmanipulated marrow (n=36) or peripheral blood (n=2). Seven patients (18%) had evidence of graft failure, 11% developed grade II–III acute GvHD and 27% developed chronic GvHD. The actuarial 2-year survival is 73%, with a median follow-up of 621 days. Younger patients (⩽14 years) had a lower risk of rejection (5%) and improved actuarial survival (84%). Causes of death were infections (n=3), graft failure (n=2), Epstein–Barr virus lymphoma (n=2) and hemorrhage (n=2). In conclusion, the actuarial 2-year survival is encouraging in young SAA patients receiving a radiation-free conditioning regimen. The significant risk of graft failure in patients 15 years or older may require modification of the conditioning regimen in adults.

Clinical, genetic, and cellular analysis of 49 osteopetrotic patients: implications for diagnosis and treatment

Background: Osteopetrosis, a genetic disease characterised by osteoclast failure, is classified into three forms: infantile malignant autosomal recessive osteopetrosis (ARO), intermediate autosomal recessive osteopetrosis (IRO), and autosomal dominant osteopetrosis (ADO). Methods: We studied 49 patients, 21 with ARO, one with IRO, and 27 with type II ADO (ADO II). Results: Most ARO patients bore known or novel (one case) ATP6i (TCIRG1) gene mutations. Six ADO II patients had no mutations in ClCN7, the only so far recognised gene implicated, suggesting involvement of yet unknown genes. Identical ClCN7 mutations produced differing phenotypes with variable degrees of severity. In ADO II, serum tartrate resistant acid phosphatase was always elevated. Bone alkaline phosphatase (BALP) was generally low, but osteocalcin was high, suggesting perturbed osteoblast differentiation or function. In contrast, BALP was high in ARO patients. Elevated osteoclast surface/bone surface was noted in biopsies from most ARO patients. Cases with high osteoclasts also showed increased osteoblast surface/bone surface. ARO osteoclasts were morphologically normal, with unaltered formation rates, intracellular pH handling, and response to acidification. Their resorption activity was greatly reduced, but not abolished. In control osteoclasts, all resorption activity was abolished by combined inhibition of proton pumping and sodium/proton antiport. Conclusions: These findings provide a rationale for novel therapies targeting pH handling mechanisms in osteoclasts and their microenvironment.

Fludarabine, cyclophosphamide, antithymocyte globulin, with or without low dose total body irradiation, for alternative donor transplants, in acquired severe aplastic anemia: a retrospective study from the EBMT-SAA working party

Background We analyzed the outcome of 100 patients with acquired severe aplastic anemia undergoing an alternative donor transplant, after immune suppressive therapy had failed. Design and Methods As a conditioning regimen, patients received either a combination of fludarabine, cyclophosphamide, and antithymocyte globulin (n=52, median age 13 years) or this combination with the addition of low dose (2 Gy) total body irradiation (n=48, median age 27 years). Results With a median follow-up of 1665 and 765 days, the actuarial 5-year survival was 73% for the group that received fludarabine, cyclophosphamide, and antithymocyte globulin and 79% for the group given the conditioning regimen including total body irradiation. Acute graft-versus-host disease grade III–IV was seen in 18% and 7% of the groups, respectively. Graft failure was seen in 17 patients with an overall cumulative incidence of 17% in patients receiving conditioning with or without total body irradiation: 9 of these 17 patients survive in the long-term. The most significant predictor of survival was the interval between diagnosis and transplantation, with 5-year survival rates of 87% and 55% for patients grafted within 2 years of diagnosis and more than 2 years after diagnosis, respectively (P=0.0004). Major causes of death were graft failure (n=7), post-transplant-lymphoproliferative-disease (n=4) and graft-versus-host disease (n=4). Conclusions This study confirms positive results of alternative donor transplants in patients with severe aplastic anemia, the best outcomes being achieved in patients grafted within 2 years of diagnosis. Prevention of rejection and Epstein-Barr virus reactivation may further improve these results.

Genotype-Phenotype Relationship in Human ATP6i-Dependent Autosomal Recessive Osteopetrosis

Autosomal-recessive osteopetrosis is a severe genetic disease caused by osteoclast failure. Approximately 50% of the patients harbor mutations of the ATP6i gene, encoding for the osteoclast-specific a3 subunit of V-ATPase. We found inactivating ATP6i mutations in four patients, and three of these were novel. Patients shared macrocephaly, growth retardation and optic nerve alteration, osteosclerotic and endobone patterns, and high alkaline phosphatase and parathyroid hormone levels. Bone biopsies revealed primary spongiosa lined with active osteoblasts and high numbers of tartrate-resistant acid phosphatase (TRAP)-positive, a3 subunit-negative, morphologically unremarkable osteoclasts, some of which located in shallow Howship lacunae. Scarce hematopoietic cells and abundant fibrous tissue containing TRAP-positive putative osteoclast precursors were noted. In vitro osteoclasts were a3-negative, morphologically normal, with prominent clear zones and actin rings, and TRAP activity more elevated than in control patients. Podosomes, alphaVbeta3 receptor, c-Src, and PYK2 were unremarkable. Consistent with the finding in the bone biopsies, these cells excavated pits faintly stained with toluidine blue, indicating inefficient bone resorption. Bone marrow transplantation was successful in all patients, and posttransplant osteoclasts showed rescue of a3 subunit immunoreactivity.

Risk factors and severe outcome in thrombotic microangiopathy after allogeneic hematopoietic stem cell transplantation

Background. Thrombotic microangiopathy (TMA) has been described as severe complication after hematopoietic stem cell transplantation (HSCT). The principal aim of this study was to focus the incidence and the outcome of TMA in the era of more complex HSCTs. Methods. We analyzed the role of some predicting factors for the incidence and the outcome of TMA after HSCT. We enrolled 539 consecutive patients (307 males, median age 31 years) undergoing HSCT from match or mismatch human leukocyte antigen family donor (314) or match/mismatch unrelated (195) and haploidentical donor (30) for malignant or nonmalignant diseases. TMA diagnosis was performed by homogeneous clinical and laboratory criteria. Results. Sixty-four of 539 patients presented TMA (11,87%) and the five-year cumulative incidence of TMA was 14% (HR=0.13). Fifty nine of 64 patients were affected by malignant and 5/64 by non-malignant diseases. On multivariate analysis, TMA occurrence was influenced by graft versus host disease >grade II (P=0.0001), donor type (P=0.029), gender (P=0.0233), total body irradiation based conditioning regimen (P=0.0041). Three factors for TMA outcome proved to be statistically significant by multivariate analysis: age (P=0.009), donor type (P=0.0187) and TMA index (P=0.029). The TMA mortality rate was 50%. The outcome was influenced by defibrotide (P=0.02 in univariate analysis). Conclusions. The study underlines the possibility of finding out which patients are more prone to developing post-HSCT TMA, and identifies which risk factors are more frequently associated with a dismal outcome after TMA.

Improvement over time in outcome for children with acute lymphoblastic leukemia in second remission given hematopoietic stem cell transplantation from unrelated donors

Aims of this study were to verify whether reduction in transplant-related mortality (TRM) of children with acute lymphoblastic leukemia (ALL) in second complete remission (CR) given allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated volunteers has occurred over time and to investigate the role of other variables on the probabilities of relapse, TRM and event-free survival (EFS). We compared results obtained in 26 children given HSCT before January 1998 with those of 37 patients transplanted beyond that date. In all donor–recipient pairs, histocompatibility was determined by serology for HLA-A and -B antigens and by high-resolution DNA typing for DRB1 antigen. High-resolution molecular typing of HLA class I antigens was employed in 20 of the 37 children transplanted more recently. Probability of both acute and chronic GVHD was comparable in the two groups of patients. In multivariate analysis, children transplanted before January 1998, those with T-lineage ALL and those experiencing grade II–IV acute GVHD had a higher relative risk of TRM at 6 months after transplantation. Relapse rate was unfavorably affected by a time interval between diagnosis and relapse <30 months. The 2-year probability of EFS for children transplanted before and after 1 January 1998 was 27% (10–44) and 58% (42–75), respectively (P = 0.02), this difference remaining significant in multivariate analysis. EFS of unrelated donor HSCT in children with ALL in second CR has improved in the last few years, mainly due to a decreased TRM. This information is of value for counseling of patients with relapsed ALL.

Severe neurologic complications after hematopoietic stem cell transplantation in children

Objective: To describe and evaluate the incidence and risk factors of severe neurologic events (SNE) in pediatric recipients of allogeneic or autologous hematopoietic stem cell transplantation (HSCT) for hematologic or nonhematologic diseases. Methods: Retrospective analysis of 272 consecutive children admitted to the G. Gaslini Children’s Research Institute and given HSCT (70 from unrelated donors, 115 from related donors, and 87 autologous) between June 1985 and January 2001. Results: Thirty-seven children (13.6%) developed SNE after a median of 90 days (range, 5 days to 8.8 years) after HSCT. Cyclosporine A (CSA) neurotoxicity was the most frequent SNE (n = 21), followed by irradiation or chemotherapy injury (n = 7), CNS infections (n = 7), cerebrovascular events (n = 3), and immune-mediated etiology SNE (n = 2). Eleven patients (30%) died because of the neurologic complications. Type of HSCT, treatment with total body irradiation (TBI), acute graft-vs-host disease (GvHD), GvHD >grade 2, and treatment with CSA were associated with a significant increased risk of SNE. Conclusions: Severe neurologic complications are frequent (14%) among children receiving HSCT, causing 8.5% of deaths after transplant. Transplant from allogeneic donor, especially if unrelated, the development of severe acute GvHD grade >2, and the use of TBI in the preparative regimen are the main risk factors for such complications.

Risk for Secondary Thyroid Carcinoma After Hematopoietic Stem-Cell Transplantation: An EBMT Late Effects Working Party Study

PURPOSE The effects of hematopoietic stem-cell transplantation (HSCT) on thyroid carcinogenesis needs to be determined in a large population. This study evaluates the incidence and the risk factors contributing to secondary thyroid carcinoma (STC) in patients who receive transplantation. PATIENTS AND METHODS We performed a retrospective investigational study, comparing data obtained by means of a two-step questionnaire from the 166 centers who replied, and data reported to the European Group for Blood and Marrow Transplantation (EBMT) registry on their transplantation activity. During the follow-up period (1985 to 2003), 32 instances of STC were found within the EBMT cohort of 68,936 patients who received transplants. These patients were then compared with age- and sex-specific incidence rates in the European population and risk factors for STC were analyzed. RESULTS The standardized incidence ratios (SIRs) of STC in the population who underwent transplantation was 3.26, in comparison with the European population. Multivariate analysis revealed that young age at transplantation was the strongest risk factor for STC (relative risk [RR], 24.61 for age 0 to 10 years; RR, 4.80 for age 11 to 20). Other risk factors were irradiation (RR, 3.44), female sex (RR, 2.79), and chronic graft-versus-host disease (RR, 2.94). Nine patients showed no clinical signs of thyroid illness at diagnosis. Total thyroidectomy and iodine ablation was the standard treatment for the majority of patients, and only one patient died due to STC progression. CONCLUSION Long-term survivors of HSCT are at risk for STCs. These results should promote efforts in screening for early detection and treatment guidelines of secondary thyroid cancer after HSCT, especially in patients who receive transplants during childhood and adolescence.