In vitro characterization of the hematopoietic system in pediatric patients with acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) has been recognized as a hematologic neoplasia that originates at the level of a primitive lymphoid stem/progenitor cell. To date, however, the biology of the hematopoietic system in this disorder is still not fully understood. In the present study, we have determined the progenitor cell content (including myeloid, erythroid and multipotent progenitors) in 14 children with ALL and followed the proliferation kinetics of these cells in Dexter-type long-term marrow cultures. We have also characterized some aspects related to the composition and function of the hematopoietic microenvironment developed in vitro. All patients included in this study showed extremely reduced levels of progenitor cells (median of 6.2% of the levels found in normal marrow). Proliferation of these cells in long-term cultures was markedly deficient, since they showed very low numbers - compared to normal cultures - and reached undetectable levels after only a few weeks. Regarding the microenvironment developed in vitro, whereas normal marrow samples contained a median of 8 fibroblastic progenitors/10(5) marrow cells and the stromal cell layers developed in culture contained a median of 341000 adherent cells per well, ALL marrow samples showed no fibroblastic progenitors and the numbers of adherent cells were 21% of those in normal cultures. Interestingly, the levels of TNFalpha and IL-6 in ALL culture supernatants were significantly increased, compared to normal cultures. Bone marrow samples from all 14 children were also analyzed once they reached a complete clinical and hematological remission. Myeloid, erythroid and multipotent progenitor cell levels were significantly increased, compared to patients at diagnosis, and proliferation of myeloid progenitors in long-term cultures was also improved. In contrast, proliferation of erythroid progenitors showed no difference to that in cultures from patients at diagnosis. The numbers of fibroblastic progenitors and adherent cells were significantly increased, compared to patients at diagnosis, and TNFalpha and IL-6 levels returned to normal. In summary, in the present study, we have demonstrated significant in vitro alterations of the hematopoietic system, both in terms of its composition and function, in pediatric patients with ALL. Importantly, most of these alterations are corrected, at least partially, after chemotherapy.

Long-term proliferation in vitro of hematopoietic progenitor cells from children with congenital bone marrow failure: effect of rhGM-CSF and rhEPO.

We have characterized the proliferation kinetics of hematopoietic cells in long-term marrow cultures (LTMC) from five normal children and seven children with congenital bone marrow failure (four with Fanconi anemia [FA] and three with congenital pure red cell aplasia [PRCA]). Total nonadherent and adherent cells, as well as nonadherent progenitors, were determined weekly in the presence or in the absence of rhGM-CSF (10 ng/ml) or rhEPO (3 U/ml). As compared to normal LTMC, hematopoiesis was drastically reduced in cultures from FA patients. Myeloid and erythroid progenitor cells reached undetectable levels after only 3 and 1 weeks of culture, respectively. This was observed even in cultures supplemented with rhGM-CSF, in which no response to this cytokine occurred. In LTMC from PRCA children, the growth of erythroid and multipotent progenitors was also drastically reduced. Myelopoiesis, on the other hand, showed normal levels during the first three weeks of culture; however, from week 4, there was a significant decrease in the levels of both progenitor and mature cells, reaching undetectable levels several weeks before normal cells did. Response to rhGM-CSF and rhEPO was transient and deficient. Our results suggest that in FA, alterations at the level of primitive progenitor cells are so severe that myeloid, erythroid and multipotent progenitors are unable to proliferate in LTMC, even in the presence of rhGM-CSF. In patients with PRCA the erythroid arm of hematopoiesis is preferentially affected and addition of rhGM-CSF and/or rhEPO to these cultures had little or no effect on erythroid cell production. Interestingly, myelopoiesis in this culture system was deficient as well and response to rhGM-CSF was defective, suggesting that the myeloid lineage is also altered in congenital PRCA.

[Instrument to measure quality of life based on daily performance in pediatric patients with leukemia]. / Un instrumento para medir la calidad de vida por medio del desempeño diario en pacientes pediátricos con leucemia.

The objective of this study was to determine the validity of a questionnaire to measure daily performance as an evaluation of quality of life in pediatric leukemia patients. A questionnaire of the daily activities of a child according to Lickert's criteria was done. A pilot survey was performed in patients without a chronic or disabling disease in order to assess its validity. The impression of the medical attendance of each pediatric patient with leukemia, of their daily performance, was compared with the results of the instrument. A trained nurse applied the questionnaire to 60 mothers of patients (29 female/31 male) as outpatients during the clinical review. Fifteen questionnaires were applied twice to evaluate its consistency. According to the results, 77% of the patients were in remission. 15% in relapse, and 8% during induction to remission. The mean age of the patients was 9 = 3.6 years, ranging from 2-16 years. One hundred percent of the patients obtained a satisfactory grade greater than 35 points. In conclusion, the questionnaire identified adequately the level of the daily performance in addition to the specific affected areas of the patients with leukemia. Our findings are that their level of performance is satisfactory and is not affected because of the disease or the phase of the treatment.

[Granulocytopenia and fever in children with leukemia as indicator of quality of medical care]. / Granulocitopenia y fiebre en niños con leucemia como indicador de calidad de la atención médica.

OBJECTIVES: 1. To identify the quality degree of medical care in patients with acute leukaemia who had fever and granulocytopenia during the hospitalization period. 2. To establish the relationship between the medical care process and the results in this concern. DESIGN: Retrospective survey. STUDY AREA: Children's Hospital of the Mexican Institute of Social Security. STUDY SUBJECTS: Twenty three patients with acute leukaemia were studied. Also, hospitalization episode of these patients, in which they suffered fever and granulocytopenia, was randomly selected. MAIN MEASUREMENTS: Compliance of diagnostic and therapeutic process was measured during hospitalization, according to the protocolized recommendations made by consensus of the hospital expert group. In order to identify the quality degree of medical care, it was taken into account the protocol compliance besides the results observed in the patients. Results were assessed based on patients' survival to fever and granulocytopenia episode, as well as on fever's duration. The correlation was calculated by using Spearman's coefficient. RESULTS: The medical care quality of the hospital was "adequate" (85% on average). Compliance degree, including the total process was 71%; with diagnostic process 63%, and with therapeutic process 76%. The results observed in the patients were considered as "adequate" (89%). By evaluating individual cases, the medical care quality was considered excellent or adequate in 17 patients (74%) regular in five (22%) and poor in one (4%). Diagnostic process was adequate in 6 patients (26%) regular in 12 (53%) poor in three (13%) and very bad in two (8%). On the other hand, therapeutic process was excellent in 14 patients (60%) regular in one (4%) poor in six (26%) and very bad in two (9%). Results observed in 13 cases were excellent (57%) adequate in eight (35%) regular in one (4%) and very bad in one (4%). The relationship between process and result was 0.41 (P < 0.05) between diagnostic process and result 0.14 and, between therapeutic process and result 0.34. CONCLUSIONS: The medical care quality rendered to patients with leukaemia, who suffered a granulocytopenia episode and fever, was considered as adequate. Therapeutic recommendations were followed accurately, meanwhile, diagnostic process had a lower adherence. A positive relationship between process and result was observed.