EBV, HCMV, HHV6, and HHV7 screening in bone marrow samples from children with acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is the most common cancer in childhood worldwide and Mexico has reported one of the highest incidence rates. An infectious etiology has been suggested and supported by epidemiological evidences; however, the identity of the involved agent(s) is not known. We considered that early transmitted lymphotropic herpes viruses were good candidates, since transforming mechanisms have been described for them and some are already associated with human cancers. In this study we interrogated the direct role of EBV, HCMV, HHV6, and HHV7 human herpes viruses in childhood ALL. Viral genomes were screened in 70 bone marrow samples from ALL patients through standard and a more sensitive nested PCR. Positive samples were detected only by nested PCR indicating a low level of infection. Our result argues that viral genomes were not present in all leukemic cells, and, hence, infection most likely was not part of the initial genetic lesions leading to ALL. The high statistical power of the study suggested that these agents are not involved in the genesis of ALL in Mexican children. Additional analysis showed that detected infections or coinfections were not associated with prognosis.

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.

Neutrophil recovery time and adverse side effects in acute leukemia patients treated with intensive chemotherapy and concomitant G or GM-CSF.

OBJECTIVE: Compare the speed of neutrophil recovery and the unwanted secondary effects in two groups of acute leukemia patients treated with intensive chemotherapy and G or GM-CSF. PATIENTS AND METHODS: Patients were randomly assigned to receive subcutaneous G-CSF at a daily dose of 300 micrograms for adults and 150 micrograms for children or GM-CSF at 400 and 200 micrograms respectively, starting With chemotherapy and stopping when the absolute neutrophil count (ANC) reached 500/microL. Secondary effects were attributed to growth factors only when not coincidental with infection, chemotherapy or hemoderivative transfusion. RESULTS: 34 patients were included in the G-CSF arm and 37 in the GM-CSF arm. Distribution by sex, age, type of acute leukemia, induction or post-induction therapy, as well as initial neutrophil count were comparable among the two groups. Mean time for ANC > 500/microL was 19 days for G-CSF group and 16 days for GM-CSF group (p = 0.08). There were no statistically significant differences in secondary unwanted side effects between the two groups. There were two cases of growth factor-related-fever in the G-CSF group and five in the GM-CSF group (p = 0.25). There was a case of systemic reaction in the G-CSF group. Twenty-nine patients in each group presented febrile neutropenia episodes (p = 0.45). The only factor that showed significance on neutrophil recovery speed was type of leukemia (p = 0.04). CONCLUSIONS: We found no clear advantage of one growth factor over the other for this indication.