[Adenovirus infections in children: experience in the field of the allogeneic stem cell transplantation]

Adenovirus (Adv) infections are frequent in pediatric patients, sometimes serious, above all in immunocompromised children. We report the cases of 2 children who presented an Adv infection after allogeneic stem cell transplantation (SCT).

CASE REPORTS

Case n(o) 1 concerns a boy who received SCT at the age of 6 years. He had a hemorragic cystitis, which resolved after antiviral treatment and successful engraftment. Case n(o) 2 concerns a boy who received SCT at the age of 2. He shortly presented a disseminated infection, and died in spite of antiviral treatment and re-infusion of an autologous transplant.

DISCUSSION

T-cell depletion (mainly carried out in vivo at present) is the major risk factor of Adv infection after allogeneic SCT. It is important to be recognized, in order to proceed to a routine screening among transplanted patients. Moreover, the detection of viral genoma by molecular biology is a predictive factor of disseminated disease development, with mortality rates higher than 50%. Early treatment is thus crucial. Immunotherapy is to be developed, by tapering of immunosuppression, or by manipulating grafts and donor lymphocyte infusions, in order to improve Adv specific responses. The possibility of a prophylaxis is still to be investigated.

Treatment of childhood acute myeloblastic leukemia: dose intensification improves outcome and maintenance therapy is of no benefit--multicenter studies of the French LAME (Leucémie Aiguë Myéloblastique Enfant) Cooperative Group

From 1989 to 1998, 341 children were included in the French multicentric LAME (Leucémie Aiguë Myéloblastique Enfant) trials. A total of 309 children were registered in the LAME 89/91 protocol. This intensive regimen included an induction phase (mitoxantrone plus cytarabine), two consolidation courses, one containing timed-sequential high-dose cytarabine, asparaginase and amsacrine; 276 (90%) achieved a CR. The 5-year overall survival (OS) and event-free survival (EFS) were 60+/-4 and 48+/-4%, respectively. From 1997, timed-sequencing of the LAME SP induction chemotherapy led to an unacceptable frequency of consolidation delay; future improvements are unlikely to come from further increases in intensity. The role of allogenic bone-marrow transplantation from an HLA-identical sibling in CR1 was examined. The disease-free survival (DFS) was 52+/-4% for non-allografted patients and 57+/-7% for allografted patients (P=NS); a better OS for allografted patients was shown and could be related either to allo-BMT early in CR1 or to a second allo-BMT in CR2. For the complete responders after consolidation therapy, the 5-year OS was significantly better in patients randomized for no maintenance therapy (MT-) than in patients randomized for MT (77.6+/-8 vs 59+/-8%; P=0.05), while the 5-year DFS was not significantly different. Exposure to low-dose MT might contribute to clinical drug resistance and treatment failure in relapsing patients.

Infectious diseases in the first year of life, perinatal characteristics and childhood acute leukaemia

The objective of the present study was to investigate the role of early common infections and perinatal characteristics in the aetiology of childhood common leukaemia. A case–control study was conducted from 1995 to 1998 in France, and included 473 incident cases of acute leukaemia (AL) (408 acute lymphoblastic leukaemia (ALL), 65 acute myeloid leukaemia (AML) age-, sex- and region-matched with 567 population-based controls. Data on the medical history of the child and his/her environment were collected using self-administered questionnaires. Analyses were conducted using nonconditional logistic regression. A slight negative association with early infections was observed (OR=0.8; 95% CI (0.6–1.0)). The association was stronger for early gastrointestinal infections. Early day-care was found to be associated with a decreased risk of AL (OR=0.6; 95% CI (0.4–0.8) and OR=0.8; 95% CI (0.5–1.2) for day-care starting before age 3 months and between 3 and 6 months, respectively). No association with breast-feeding was observed, irrespective of its duration. A birth order of 4 or more was associated with a significantly increased risk of AL (OR=2.0; 95% CI (1.1–3.7) with ALL). A history of asthma was associated with a decreased risk of ALL (OR 0.5; 95% CI (0.3–0.90). Although the results regarding birth order and breast-feeding do not fit with Greaves' hypothesis, the study supports the hypothesis that early common infections may play a protective role in the aetiology of childhood leukaemia, although this effect was not more marked for common ALL.

Amplification of AML1 gene is present in childhood acute lymphoblastic leukemia but not in adult, and is not associated with AML1 gene mutation

The AML1/CBFA2/RUNX1 gene is the target of many recurrent translocations seen in different leukemia subtypes. The t(12;21)(p13;q22) is the most frequent translocation observed in childhood B acute lymphoblastic leukemia (ALL), occurring in 20% to 25% of cases. In adult ALL this rearrangement is scarce. Another route of AML1deregulation could be point mutations in the runt domain. We now report on AML1amplification in two cases of childhood ALL, found in a series of 107 consecutive children with B-lineage ALL analyzed by fluorescence in situ hybridization (FISH). A parallel analysis of 42 adult B-ALL failed to detect any AML1 rearrangement by FISH. The two patients with AML1 amplification were further analyzed using molecular techniques. SSCP analysis did not detect any mutation. Furthermore, direct sequencing of the cDNA did not reveal any mutation. In conclusion, AML1amplification seems to be observed only in childhood ALL and is not associated with AML1 gene mutation. Other mechanisms, such as gene dosage effects could be hypothesized.

Pharmacokinetics of liposomal daunorubicin (DaunoXome) during a phase I-II study in children with relapsed acute lymphoblastic leukaemia

PURPOSE

The pharmacokinetics of DaunoXome were studied during a multicentric phase I-II study performed in children suffering from relapsed acute lymphoblastic leukaemia and treated on a weekly schedule.

PATIENTS AND METHODS

A group of 18 patients were studied during the first course of treatment at dose levels between 40 and 120 mg/m2. Blood samples were obtained up to 72 h after infusion. The liposomal and free forms of daunorubicin, as well as daunorubicinol, were separated and quantified by HPLC using fluorometric detection, and data were analysed using a model-independent approach.

RESULTS

Unchanged liposomal daunorubicin disappeared from plasma following a monoexponential decay. Its AUC represented 95.8% of the total fluorescent species found in plasma and increased linearly with the dose administered. The elimination half-life was 5.23 h, total plasma clearance 0.344 1/h per m2, and volume of distribution at steady state 2.08 l/m2. Free daunorubicin and daunorubicinol were detected in plasma at all time-points studied. Their AUCs represented, respectively, 2.53% and 1.70% of total fluorescent species and their elimination half-lives were, respectively, 16.6 h and 22.3 h. The daunorubicinol/daunorubicin AUC ratio was 0.82%.

CONCLUSIONS

This study is the first to demonstrate that free daunorubicin is present in plasma after DaunoXome administration and that it originates from in vivo release from the liposomes. The pharmacokinetics of free daunorubicin appeared to be comparable to those observed after conventional administration. However, the concentration of daunorubicinol appeared to be lower than that found after conventional administration of daunorubicin.

Deletion of chromosomal region 13q14.3 in childhood acute lymphoblastic leukemia

Deletion of the 13q14 chromosomal region is frequent in B cell chronic lymphocytic leukemia (B-CLL) and is believed to inactivate a tumor supressor gene (TSG) next to RB1. We studied microsatellite markers spanning the 13q14 chromosomal region in 138 children with acute lymphoblastic leukemia (ALL). Allelic loss was demonstrated in six cases (4.3%). Deletion did not include RB1 in two cases. In five patients, the deleted region overlapped that described in B-CLL. A sixth patient harbored a smaller deletion, slightly more telomeric than minimal deleted regions reported in B-CLL. Apparent differences in the delineation of the minimal deleted region could be due to the fact that the putative TSG is a very large gene, with some deletions affecting only a part of it. Our present findings suggest that at least some of its exons lie within a region of less than 100 kb more telomeric that previously thought.

High-dose thiotepa and hematopoietic stem cell transplantation in pediatric malignant mesenchymal tumors: a phase II study

The prognosis of metastatic malignant mesenchymal tumors (MMT) remains poor. Given the chemosensitivity of these neoplasms, a phase II study of high-dose thiotepa (HDT) was performed to evaluate the efficacy of this drug in this particular subset of pediatric tumors. Between 1986 and 1998, 18 patients, previously treated with conventional therapy for metastatic or refractory MMT, entered the study. Thiotepa was administered at a daily dose of 300 mg/m2 for 3 consecutive days. Hematopoietic stem cell rescue, consisting of bone marrow transplantation or peripheral stem cell transplantation, was performed 2 days after completion of HDT. A response exceeding 50% was observed in 6/18 patients (response rate 33%). Toxicity was severe but never led to death. HDT used at a dose of 900 mg/m2 yields measurable anti-tumor activity in previously treated patients. The next step in these particularly poor prognosis metastatic MMT will be to investigate HDT combined with other drugs, known to be efficient at high doses.

Unresectable localized neuroblastoma: improved survival after primary chemotherapy including carboplatin-etoposide. Neuroblastoma Study Group of the Société Française d'Oncologie Pédiatrique (SFOP)

Neuroblastomas (NBs) were assessed according to INSS recommendations including MIBG scan and extensive bone marrow staging to eliminate metastatic spread. Patients with unresectable tumour received primary chemotherapy including two courses of carboplatin-etoposide (CE) and two of vincristine-cyclophosphamide-doxorubicin (CAdO). Post-operative treatment was to be given only in children over 1 year of age at diagnosis who had residual disease or lymph node (LN) involvement. Between 1990 and 1994, 130 consecutive children were registered. In comparison with resectable primaries, these tumours were more commonly abdominal, larger and associated with N-myc amplification (NMA). Complete, very good and partial response (CR, VGPR, PR) to CE were, respectively, 1%, 7% and 44%, overall response rate (RR) to two courses of CE and two courses of CAdO was 71%, and the tumour could be removed in all but four of the children. The toxicity was manageable. The 5-year overall survival (OS) and event-free survival (EFS) were, respectively, 88% and 78% with a median follow-up of 38 months. In multivariate analysis, only NMA and LN involvement adversely influenced the outcome, particularly NMA. Children with unresectable NBs and no NMA fared as well as children with resectable ones as OS were, respectively, 95% and 99% and EFS 89% and 91%. Our data show encouraging results in localized but unresectable NBs as 90% of children may be considered as definitely cured, especially those without NMA.

Hereditary spherocytosis with spectrin deficiency related to null mutations of the beta-spectrin gene

Spectrin deficiency is the most common deficiency found in HS. It is heterogeneous in terms of clinical expression, inheritance (dominant or recessive) and underlying genetic defects (related to alpha- or beta-spectrin gene defects or secondary to ankyrin gene defects). We studied a sampling of French dominant HS families, selected after linkage analyses, and found the presence of mutations resulting in the silencing of the mutant beta-spectrin allele. In three HS families, one haploid set of beta-spectrin mRNA was undectectable. In two families, a deletion of 8 bases (leading to a frameshift and a premature stop codon) and a nonsense mutation were identified, respectively. In the third HS family, we were unable to characterize a relevant mutation but the loss of heterozygosity at the cDNA level suggested the presence of a null mutation of the beta-spectrin allele. Sequencing of the beta-spectrin gene has also uncovered several new polymorphisms in the coding region of the beta-spectrin gene which will be very useful for detecting loss of heterozygosity at the cDNA level and designating the beta-spectrin gene as the culprit one.

Comparative genomic hybridization is a powerful tool, complementary to cytogenetics, to identify chromosomal abnormalities in childhood acute lymphoblastic leukaemia

Cytogenetics has a strong prognostic value in childhood acute lymphoblastic leukaemia (ALL), but results are often incomplete because of the poor chromosome morphology. To improve this analysis, we tested comparative genomic hybridization (CGH) for the detection of chromosomal imbalances. 72 children were retrospectively analysed using CGH. Only 53% of the patients had been fully banded by standard methods. With CGH, 36 patients retained a normal chromosomal profile and 36 had unbalanced abnormalities. No amplification was detected. Fluorescence in situ hybridization (FISH) with centromeric and unique sequence probes was used in those cases with discrepancies or unsuccessful karyotype to validate CGH results. CGH enabled clear identification of unbalanced chromosomal abnormalities, even in some cases which had a normal karyotype. In view of the strong prognostic value of hyperdiploidy in childhood ALL, CGH appears to be a powerful technique, complementary to conventional cytogenetics.

Successful allogeneic bone marrow transplantation for early relapse after autologous bone marrow transplantation in two cases of aggressive high-grade non-Hodgkin's lymphoma

Two patients with high-grade disseminated non-Hodgkin's lymphoma relapsed 3 and 7 months respectively after high-dose chemotherapy and autologous BMT performed in first complete remission. Both patients had an HLA-identical sibling and received an allogeneic BMT 5 and 10 months after autologous BMT, after conditioning with fractionated 12 Gy total body irradiation plus cyclophosphamide. They both are alive and well, with a Karnofsky score of 100%, 15 and 27 months after allogeneic BMT. For selected patients with HLA-identical siblings and good performance status who relapse after autologous transplantation for high-grade non-Hodgkin's lymphoma, allogeneic BMT may be an option.

Rothmund-Thomson syndrome and osteosarcoma

The Rothmund-Thomson syndrome (RTS), also called poikiloderma congenitale is a rare autosomal recessive disease first described in 1868. This syndrome includes most frequently seen skin lesions (atrophy, telangiectases, pigmentation), cataracts and bone defects (dysostosis, dysplasia). Some authors describe an association with malignancy. We report three cases of Rothmund-Thomson syndrome associated with osteosarcoma. After cutaneous epithelioma, osteosarcoma is the most frequent malignancy. Thus, patients with RTS need a careful survey. The treatment did not differ from sporadic osteosarcoma. Chemosensitivity and toxicity are also not different.