Severe osteopenia in a young boy with Kostmann's congenital neutropenia treated with granulocyte colony-stimulating factor: suggested therapeutic approach.

Kostmann's syndrome is a congenital disorder that causes an impairment of myeloid differentiation in the bone marrow characterized by severe neutropenia, which can be treated with recombinant human granulocyte colony-stimulating factor (G-CSF). We present the case of a 13-year-old boy with Kostmann's syndrome who was treated with recombinant human G-CSF from age 3.5 years. His growth and development was normal, although complicated by intermittent infections. Bone mineral density (BMD) measurement revealed severe osteopenia at the spine and hips (lumbar spine BMD 0.486 g/cm(2); Z score -3.6), and he was referred to the Endocrine Service. Relevant laboratory evaluation showed a pretreatment ionized calcium level at the upper limit of normal (1.28 mmol/L; range: 1.13-1.32 mmol/L), suppressed intact parathyroid hormone (iPTH) level (12 pg/mL; range: 10-65 pg/mL), and a low 1,25-dihydroxy vitamin D level (21 pg/mL; range: 24-65 pg/mL). He had evidence of increased bone turnover evidenced by elevated urinary deoxypyridinoline (DPD) cross-links (46.9 nmol/mmol creatinine; range: 2-34 nmol/mmol creatinine) and a simultaneous increase in markers of bone formation with elevated osteocalcin level (200 ng/mL; normal: 20-80 ng/mL) and alkaline phosphatase level (236 IU/mL; normal: 38-126 IU/mL). Because of clinical concern for his skeletal health, bisphosphonate therapy with intravenous pamidronate was initiated. One month after treatment, the iPTH and DPD cross-links were in the normal range (54 pg/mL and 17.7 nmol/mmol creatinine, respectively) and the 1,25-dihydroxy vitamin D level was elevated (111 pg/mL). Four months after treatment, there was a striking increase in BMD at the lumbar spine (+30.86%), femoral necks (left, +20.02%; right, +17.98%), and total hips (left, +18.40%; right, +15.94%). Seven months after bisphosphonate therapy, his biochemical parameters showed a return toward pretreatment levels with increasing urinary DPD cross-links (28.7 nmol/mmol creatinine) and decreasing iPTH (26 pg/mL). However, the BMD continued to increase (8 months posttreatment), but the magnitude of the increment was attenuated (lumbar-spine, +4.8%; left total hip, +1.2% and right total hip +2.4%), relative to BMD at 4 months. Eight months after the initial treatment, his iPTH was suppressed at 14 pg/mL and he again received pamidronate (at a lower dose); 3 months later, he had an additional increase in BMD (lumbar spine +7.4%, left total hip +3.9%, right total hip +2.7%), relative to the previous study. We hypothesize that prolonged administration of G-CSF as treatment for Kostmann's syndrome is associated with increased bone resorption, mediated by osteoclast activation and leading to bone loss. In children, the resulting osteopenia can be successfully managed with antisreorptive bisphosphonate therapy with significant improvement in bone density. Measurements of biochemical parameters of bone turnover can be used to monitor the magnitude and duration of the therapeutic response and the need for BMD reassessment and, perhaps, retreatment.

Doxorubicin cardiotoxicity in children: reduced incidence of cardiac dysfunction associated with continuous-infusion schedules.

We retrospectively reviewed the medical records of 97 children (59 boys and 38 girls) with a median age of 13 +/- 4 years who had been treated with continuous infusion of doxorubicin at a dosage of 60 mg/m2 over 24 h (61 patients) or at a dosage of 75 mg/m2 over 72 h (36 patients). The drug was administered every 3 weeks. The cardiac status of patients was evaluated as a baseline and every 6 months during, and following therapy (median, 30.5 months). The evaluations included M-mode and two-dimensional echocardiography. Congestive heart failure developed in only one patient in this series, an 8-year-old girl who ultimately died of her cardiac complication. This incidence of doxorubicin-induced cardiotoxicity was compared with that seen in a control group of pediatric patients previously treated with doxorubicin at similar dosages but with a rapid infusion. The result compared favorably to the 13% incidence of cardiotoxicity (p = 0.03) and 7% mortality (p < 0.01) in the control group. No changes in the levels of tumor response were noted in children treated by continuous infusion when compared with historical controls. Continuous-infusion schedules of doxorubicin thus result in fewer incidences of cardiotoxicity in children and should be considered for wider application in pediatric cancer patients receiving doxorubicin.

The clavicle: a vulnerable bone in pediatric oncology.

The clavicle is frequently incorporated into the radiation field in the treatment of malignant tumors located in the head and neck. From 1954 to 1995, 499 pediatric patients were treated with moderate to high-dose radiation therapy to the head and neck at the University of Texas M.D. Anderson Cancer Center. The medical records of 312 of these patients were available and were reviewed. The period of observation ranged from 5 to 30 years. Five late radiation-induced abnormalities of the clavicle were encountered: osteosarcoma; osteochondroma; malignant fibrous histiocytoma; radionecrosis and impaired healing following trauma and radionecrosis and lysis. The doses of radiation therapy which induced the abnormalities varied from 35 to 60.5 Gy (median 34.75 Gy). The interval from radiation therapy to discovery of the complications varied from 6 to 11 years. Two patients died: one from malignant fibrous histiocytoma and another from a radiation-induced meningioma of the brain (which accompanied radionecrosis of the clavicle). We conclude that the incidence of radiation-induced abnormalities of the clavicle in pediatric long-term survivors is low (1.5%). However, some of the late sequela are potentially fatal. The clavicle should be considered a vulnerable bone to radiation therapy and should be monitored in long-term survivors of childhood cancer. The experience is compared to radiation-induced abnormalities recorded in the literature.

Spontaneous remission of granulocyte colony-stimulating factor-associated leukemia in a child with severe congenital neutropenia.

Leukemia is observed with increased frequency in patients with severe congenital neutropenia (SCN). In the past decade, recombinant human granulocyte colony-stimulating factor (rh G-CSF) has prolonged the survival of patients with SCN increasingly reported to have leukemias. In this communication acute myelogenous leukemia (AML) associated with a mutation of the G-CSF receptor (G-CSF-R) developed in a patient with SCN maintained on long-term G-CSF therapy. The blast count in the blood and bone marrow fell to undetectable levels twice on withholding G-CSF and without chemotherapy administration, but the mutant G-CSF-R was detectable during this period. The patient subsequently underwent successful allogeneic bone marrow transplantation. After transplantation, the patient's neutrophil elastase (ELA-2) mutation and G-CSF-R mutation became undetectable by polymerase chain reaction. This report provides novel insights on leukemia developing in congenital neutropenia.

Multilineage Immune-Mediated Cytopenias in Childhood: A Report of Five Patients.

This study was performed to determine whether there is any distinction to be made between single and multiple-lineage cytopenias particularly with regard to natural history and prognosis. From December 1989 to May 1994, five of 50 children (median age 7 years) with chronic immune cytopenias were diagnosed with multi-lineage immune- ediated cytopenias. Two patients presented with immune thrombocytopenia (ITP) and later developed autoimmune hemolytic anemia (AIHA); one had ITP and immune eutropenia who subsequently became Coombs' positive but never developed AIHA. One child presented with ITP and immune neutropenia and later developed AIHA. The fifth child presented simultaneously with thrombocytopenia and neutropenia with positive antineutrophil antibody but without antiplatelet antibody and Coombs' positivity. Four patients were given primary therapy with IVIG and one with prednisone. One patient responded to prednisone but relapsed subsequently. Further treatment with IVIG roduced initial normalization of his counts with occasional fluctuation of the absolute neutrophil count. Two responded to IVIG and are in complete remission (CR). Of the two nonresponders to IVIG, one responded subsequently to prednisone and is in CR. The other one, after being refractory to multimodality treatment, was diagnosed with a lupus erythematosis variant and is currently on alternate day prednisone. Moderate thrombocytopenia and absolute neutropenia still persist. Multi-lineage immune-mediated cytopenias may represent a pathogenic phenomenon that is distinct from autoimmune single-lineage disease. Clinical response to treatment may correlate with these differences that may be genetic in origin. Clinical course and response to therapy are less predictable when autoimmune disease is present.

Osteopenia in young adult survivors of childhood cancer.

BACKGROUND: Improved survival of children with malignant diseases is in part due to the application of intensive, multimodality therapies, including radiotherapy, surgery, glucocorticoids, and cytotoxic agents. Such interventions have the potential to induce complex hormonal, metabolic and nutritional effects that may interfere with skeletal mass acquisition during childhood and adolescence: it is possible that such childhood cancer survivors may therefore reach adulthood with diminished peak bone mass and be at increased risk for clinically significant osteoporosis later in their life. PROCEDURE: A bone mineral density (BMD) was measured in 26 unselected former cancer patients attending the Pediatric Long-Term Clinic at M.D. Anderson Cancer Center. BMD was measured at the lumbar spine and the hip using dual X-ray absorptiometry (Hologic QDR-4500W). In addition, the patients' complete medical records were reviewed with particular attention to disease type, age modalities of treatment, and hormonal residual deficiencies. RESULTS: The median age of patients at the time of cancer diagnosis was 8 years (range, 0.3 to 16 years). Median age at BMD determination was 23 years (range, 18 to 41 years), and the median interval since cancer diagnosis and BMD was 18 years (range, 5 to 29). Overall, their BMD was decreased relative to peak bone mass at all sites: osteopenia was especially pronounced in patients with a history of cranial irradiation who had developed evidence of pituitary insufficiency during childhood or adolescence. Overall, the median BMD T-score was -1.41 at the lumbar spine, -1.04 at the femoral neck, and -1.06 for total hip. For patients with prior cranial irradiation, T-score at the lumbar spine was -2.18 (range, -4.06 to -0.98), at the femoral neck -1.92 (range, -4.11 to +1.10), and for total hip -1.67 (range, -4.79 to +0.56); BMD for irradiated patients was significantly lower than BMD of patients without cranial irradiation. We could not discern an independent impact of other disease characteristics or treatment modalities in this small group of patients. CONCLUSIONS: Osteopenia is a prominent finding in young adults who are survivors of childhood cancers; it is likely that antineoplastic treatments during childhood and adolescence impede peak bone mass acquisition. We suggest that systematic attention to this potential complication is needed in order to identify what subgroups of children may require regular surveillance and what interventions are required for its prevention or treatment.

Doxorubicin cardiotoxicity in children: comparison of a consecutive divided daily dose administration schedule with single dose (rapid) infusion administration.

BACKGROUND: Doxorubicin cardiotoxicity remains a serious problem in children with malignancy. The present study was undertaken to determine if the administration of consecutive divided daily doses of doxorubicin would significantly reduce the likelihood of cardiotoxicity in children compared with a single dose administration regimen. PROCEDURE: One hundred thirteen children (60 boys and 53 girls) received doxorubicin either by single dose infusion or by a consecutive divided daily dose schedule. The divided dose patients received one third of the total cycle dose over 20 minutes for 3 consecutive days. Patients treated according to a single dose schedule received the cycle dose as a 20-minute infusion. The mean doxorubicin dose was 341 mg/m2. Patients were followed up for 4-180 months. There were 60 boys and 53 girls in the series. RESULTS: Fifteen patients developed cardiacdysfunction, eight of whom died of progressive cardiac failure. There was no significant difference in the incidence of cardiac dysfunction between the divided and single dose infusion groups. More girls than boys developed cardiac dysfunction and more girls died of progressive cardiac failure; this difference was not statistically significant. The median time to the development of cardiac failure was 2 months. CONCLUSIONS: The divided dose regimen did not alter the incidence of cardiotoxicity. Other schedules should therefore be investigated. Our data suggest that, at similar cumulative doses, girls are more likely to develop cardiac dysfunction than are boys. If the sex-related difference is proved in larger series of patients, it may be prudent to lower the recommended cumulative doses for girls.

Efficacy of growth hormone replacement therapy in children with organic growth hormone deficiency after cranial irradiation.

We evaluated the growth response of 20 childhood cancer survivors who received growth hormone (GH) replacement therapy (0.3 mg/kg/week) for at least 12 months. In all subjects, GH deficiency was associated with cranial irradiation and was documented with growth charts, bone age, and somatomedin C levels; at least one GH stimulation test was available for 14 children. Pretreatment overall growth velocity was 3.3 +/- 0.5 cm/year (mean +/- SE) over a 3-year period. After GH replacement, growth velocity was 8.6 +/- 0.6 cm/year during the first year (n = 20), 7.2 +/- 0.5 cm/year during the second year (n = 17), 5.9 +/- 0.6 cm/year during the third year (n = 11), and (6.1 +/- 0.6 cm/year during the fourth year (n = 7). Growth response, tabulated by age at onset of GH replacement, was compared with the response in GH-naive children with idiopathic GH deficiency (data obtained through the Genentech Inc. National Cooperative Growth Study Summary, September 1991); the growth velocity fell within the range described for idiopathic GH deficiency adjusted for either chronological or bone age. We conclude that children with GH deficiency after cranial irradiation for neoplastic diseases respond to GH replacement therapy as well as children with idiopathic GH deficiency.

Long-term effects of radiotherapy administered in childhood for the treatment of malignant diseases.

BACKGROUND: The use of radiotherapy for the treatment of childhood malignancy has improved long-term survival significantly, and many treated children now survive well into adulthood. As a consequence, long-term effects of childhood irradiation are being seen with increasing frequency. METHODS: The medical records of 236 patients who had been treated for malignant disease with radiotherapy during childhood were examined to determine the long-term effect of the radiation on their growth and development. RESULTS: Mean treatment dose was 35.5 Gy; mean age at treatment was 7.2 years; and mean follow-up was 14.5 years. Adjuvant chemotherapy was given to 82%. Some degree of bone deformity (usually with overlying soft-tissue hypoplasia) was seen in 40%; 21% developed some type of endocrine deficiency; 30% developed atrophic skin changes; and 7% developed second malignancies. The incidence of bone deformity and hormonal deficiency increased with the radiation dose; the incidence of second malignancy was independent of dose. Bone deformities were more common when radiation was administered before the age of 2 years. CONCLUSIONS: The consequences of radiotherapy in childhood are significant and must be considered when planning treatment. Even when treatment is essential, families should be informed of the possibility of growth disturbance to prevent subsequent misunderstanding.

Forty-year experience with second malignancies after treatment of childhood cancer: analysis of outcome following the development of the second malignancy.

As the cure rate for childhood malignancies increases, the number of patients at risk for development of second malignancies also increases. Due to the potentially long remaining life span, long-term follow-up is difficult and patients are often at risk after presumptive cures. Some authors believe that cure rates for second malignancies are similar to cure rates for primary malignancies. We reviewed the records of 162 patients seen at our institution who had developed a second malignancy after treatment for childhood cancer. Presentation, age at diagnosis, tumor histology, extent of tumor, treatment (including radiotherapy with dosage when available, and chemotherapy) plus outcome were recorded. Mean age at diagnosis of the primary malignancy was 10.3 years. The most common primary malignancy was Hodgkin's disease (33) followed by soft tissue sarcoma (28), retinoblastoma (20), bone tumor (17), central nervous system (CNS) tumor (13), leukemia (8), Wilms' tumor (7), non-Hodgkin's lymphoma (6), neuroblastoma (5), thyroid neoplasm (5), and others (20). The average interval between diagnosis of the first and second malignancy was 10.8 years. These second tumors carried a high mortality. Only 56 patients have no evidence of disease. Five patients are known to be alive with disease and 92 patients have expired due to their second malignancy. Disease status in 8 patients is unknown. The most common second malignancy was osteosarcoma (35) followed by soft tissue sarcoma (24), breast cancer (15), leukemia (14), thyroid carcinoma (14), CNS tumors (12), melanoma (8), nonmelanomatous skin cancer (8), lymphoma (5), and others (27).(ABSTRACT TRUNCATED AT 250 WORDS)

Modification of yeast phosphofructokinase by trypsin and subtilisin in the presence of effectors.

Yeast phosphofructokinase was subjected to limited proteolysis by trypsin in the presence of different effectors. It could be demonstrated that the substrates MgATP and fructose-6-phosphate are able to protect the enzyme from inactivation by trypsin. Other effectors like AMP, ADP, phosphoenolpyruvate, citrate and ammonium ions exhibit only negligible effects. During the first step of degradation consisting in the conversion of the subunits from Mr 120,000 to 90,000 no significant effects of the substrates and effectors on the proteolytic inactivation of yeast phosphofructokinase can be observed. In the presence of ATP as well as of ADP the sensitivity of the enzyme against ATP inhibition is either not or only slightly influenced by proteolytic modification. The modified enzyme retains its sensitivity against activation by AMP, independently of whether effectors are present or absent during proteolysis. The kinetic parameters of the enzyme modified by subtilisin in the presence of ATP or of fructose-6-phosphate have been determined.