Allergy and acute leukaemia in children with Down syndrome: a population study. Report from the Mexican inter-institutional group for the identification of the causes of childhood leukaemia.

BACKGROUND: Allergies have been described as protective factors against the development of childhood acute leukaemia (AL). Our objective was to investigate the associations between allergy history and the development of AL and acute lymphoblastic leukaemia (ALL) in children with Down syndrome (DS). METHODS: A case-control study was performed in Mexico City. The cases (n=97) were diagnosed at nine public hospitals, and the controls (n=222) were recruited at institutions for children with DS. Odds ratios (OR) were calculated. RESULTS: Asthma was positively associated with AL development (OR=4.18; 95% confidence interval (CI): 1.47-11.87), whereas skin allergies were negatively associated (OR=0.42; 95% CI: 0.20-0.91). CONCLUSION: Our findings suggest that allergies and AL in children with DS share biological and immune mechanisms. To our knowledge, this is the first study reporting associations between allergies and AL in children with DS.

Breastfeeding and early infection in the aetiology of childhood leukaemia in Down syndrome.

BACKGROUND: For a child to develop acute leukaemia (AL), environmental exposure may not be sufficient: interaction with a susceptibility factor to the disease, such as Down syndrome (DS), may also be necessary. We assessed whether breastfeeding and early infection were associated with the risk of developing AL in children with DS. METHODS: Children with DS in Mexico City, and either with or without AL, were the cases (N=57) and controls (N=218), respectively. Population was divided in children with AL and with acute lymphoblastic leukaemia (ALL) and also in children < or = 6 and >6 years old. RESULTS: Breastfeeding and early infections showed moderate (but not significant) association for AL, whereas hospitalisation by infection during the first year of life increased the risk: odds ratios (confidence interval 95%) were 0.84 (0.43-1.61), 1.70 (0.82-3.52); and 3.57 (1.59-8.05), respectively. A similar result was obtained when only ALL was analysed. CONCLUSION: We found that breastfeeding was a protective factor for developing AL and ALL, and during the first year of life, infections requiring hospitalisation were related to a risk for developing the disease in those children with DS >6 years of age. These data do not support the Greaves's hypothesis of early infection being protective for developing ALL.

[Granulocyte colony-stimulating factor in the treatment of febrile neutropenia]. / Factor estimulante de colonias de granulocitos en el tratamiento de neutropenia febril.

PURPOSE: To determine whether granulocyte colony-stimulating factor (G-CSF) used in addition to antibiotic therapy, in patients with chemotherapy-induced febrile neutropenia shortens the period of fever, neutropenia and hospitalization. PATIENTS AND METHODS: The study was prospective. Patients with lymphoblastic acute leukemia (LAL) were included. They received intensive chemotherapy of induction, intensification, or consolidation. At random, a group received amikacin-ceftriaxone; if no had response after 3 days, we added vancomicin and, after 7 days, amphotericin. The other group received in addition these antibiotics, granulocyte colony-stimulating factor. RESULTS: The groups were comparable in the magnitude of the initial neutropenia (< 0.5 x 10(9)/L), site of the infection, chemotherapy received germs isolated, age, and sex. The patients of the group that received FEC-G were cured in the course of 3.1 days; in the group without FEC-G, this occurred in 7.2 days (p = 0.0001). At the end of the infectious episode, the number of neutrophils, in the group with FEC-G, was of 1.9 x 10(9)/L versus 0.7 x 10(9)/L (p = 0.0009). The mortality was of one and two cases (p = 0.46). The global mortality was 7.5%. CONCLUSIONS: The addition of FEC-G to the treatment with antibiotics, in febrile neutropenia, decreases duration of days with fever, hospitalization and neutropenia. However, the frequency of cure is not augmented.

[Long-term results of 2 therapeutic protocols in children with acute lymphoblastic leukemia of usual risk. Experience at the 20th of November National Medical Center]. / Resultados a largo plazo de dos protocolos terapéuticos, en niños con leucemia linfoblástica aguda de riesgo habitual. Experiencia en el Centro Médico Nacional "20 de Noviembre".

The purpose of this study is to know the disease-free survival in children with acute lymphoblastic leukemia (ALL), submitted to two therapeutic programs. Habitual risk was defined as age older than 2 and younger than 10 years, without neurological, mediastinal or testicular infiltrations, leukocytes < 25 x 10(9)/l and morphologic cell type distinct of L-3. The first group (LAL81) included 30 patients, from 1981 to 1986, and they received: induction with vincristine (VCR) and prednisone (PDN); consolidation with mercaptopurine (MP), cytosine arabinoside (ARA) and doxorubicin (DOX); prophylaxis to the central nervous system (CNS) with radiotherapy and methotrexate (MTX)-ARA-hydrocortisone (HDR) intrathecal, and maintenance with MP and MTX. In the second group (LAL87), 28 patients were included from 1987 to 1993. They received: induction with VCR, PDN and lasparaginase (ASP); consolidation with MP, ARA, DOX, carmustine (BCNU) and cyclophosphamide (CFA); prophylaxis to the (CNS) with intrathecal MTX-ARA-HDR, and maintenance with MP and MTX. There was just one therapeutic failure. In the LAL81, protocol 11 relapses and 9 in LAL87 (p = 0.71) were observed. Of these, two in each group went to the CNS. The disease-free survival in LAL81 was 0.39 at 14 years; in LAL87, was 0.53 at 8 years (p = 0.62).