Biomedical subjects

Karl Welte

Publications and source records attributed to Karl Welte.

41 records · Page 3Linked to original sources

PubMed2002

Polymorphisms within glutathione S-transferase genes in pediatric non-Hodgkin's lymphoma.

BACKGROUND AND OBJECTIVES: Glutathione S-transferases (GSTs) are involved in the metabolism of a number of cancer chemotherapeutic agents. Certain members within the GST superfamily exhibit phenotypically relevant genetic polymorphisms which have been associated with outcome in hematologic malignant disease. DESIGN AND METHODS: In the present study we genotyped a cohort of 169 pediatric non-Hodgkin's lymphoma (NHL) patients with available specimens from the NHL-BFM trials 86 and 90 conducted by the Berlin-Frankfurt-Münster (BFM) study group to assess a potential association of phenotypically relevant glutathione S-transferase polymorphisms (GSTM1, GSTT1, GSTP1 codon 105) with treatment outcome in this patient group. RESULTS: Treatment failure in patients with mature B-cell NHL was significantly less likely to occur in patients carrying at least one GSTM1 allele in comparison to those with a homozygous deletion of GSTM1. This protective effect mediated by the presence of GSTM1 was even more pronounced within the subset of therapy group B patients at highest clinical risk of treatment failure (B-ALL, disease stage IV, disease stage III with unresected abdominal tumor, and LDH activity > or = 500 U/L). Of all events in therapy group B, 87.5% occurred in this high risk group. Within this subset, the multivariate relative risk reached 4.98 (95% CI = 1.27-19.52; p= 0.021). INTERPRETATION AND CONCLUSIONS: Our results suggest that genetic variation at the GSTM1 locus may be of clinical importance in pediatric NHL and may be a potential candidate for indicating future treatment stratification strategies.

Adolescent↗

PubMed2001

Tumor necrosis factor and lymphotoxin-alpha genetic polymorphisms and risk of relapse in childhood B-cell precursor acute lymphoblastic leukemia: a case-control study of patients treated with BFM therapy.

BACKGROUND: Circulating levels of tumor necrosis factor (TNF) and lymphotoxin-alpha (LT-alpha) have been associated with outcome in solid and hematologic malignancies. Within the TNF gene and the LT-alpha gene, polymorphisms have been identified at nucleotide positions -308 and +252, respectively. The variant alleles for TNF are designated TNF1 and TNF2, the ones for LT-alpha LT-alpha (10.5 kb) and LT-alpha (5.5 kb). Of interest, TNF2 and LT-alpha (5.5 kb) were shown to be associated with higher TNF and LT-alpha plasma levels than their counterparts. In the present study, we investigated the associations of the above mentioned polymorphisms with risk of relapse in childhood acute lymphoblastic leukemia (ALL) treated according to Berlin-Frankfurt-Münster (BFM) protocols. METHODS: Matched case-control study of 64 relapsed and 64 successfully treated non-relapsed childhood B-cell precursor ALL patients of standard and intermediate risk for treatment failure. RESULTS: The odds ratio (OR) for the combined category of TNF1/TNF2 and TNF2/TNF2 genotypes in comparison to the TNF1/TNF1 genotype was 1.17 (95 % confidence interval (CI) = 0.53 - 2.56, P = 0.697). The ORs for the LT-alpha (10.5 kb/5.5 kb) and the LT-alpha (5.5 kb/5.5 kb) genotypes with reference to the LT-alpha (10.5 kb/10.5 kb) genotype were 2.17 (95 % CI = 0.84 - 5.58, P = 0.107) and 0.5 (95 % CI = 0.09 - 2.66, P = 0.418), respectively. CONCLUSIONS: Our results do not suggest a major role of the investigated genetic polymorphisms with regard to risk of relapse in standard- and intermediate-risk childhood B-cell precursor ALL treated according to BFM protocols.

Journal Article↗

PubMed1994

Long-term safety of treatment with recombinant human granulocyte colony-stimulating factor (r-metHuG-CSF) in patients with severe congenital neutropenias.

Congenital neutropenias include a heterogenous group of diseases characterized by a decrease in circulating neutrophils. In phase I/II/III studies in patients with severe congenital and cyclic neutropenia, treatment with recombinant human granulocyte colony-stimulating factor (r-metHuG-CSF) resulted in a rise in the absolute neutrophil counts (ANC) and a reduction in infections. We report the effects of long-term safety of subcutaneous r-metHuG-CSF administration in 54 patients (congenital n = 44. cyclic n = 10) treated for 4-6 years. A sustained ANC response was seen in 40/44 severe congenital neutropenia patients and 10/10 cyclic neutropenia patients. Two patients required an increase of > 25% in dose to maintain a clinical response; one patient became refractory to therapy. A significant decrease in the incidence of severe infections and the need for intravenous antibiotics was noted. Significant adverse events noted which may or may not be related to therapy included: osteopenia (n = 15), splenomegaly (n = 12), hypersplenism (n = 1), vasculitis (n = 2), glomerulonephritis (n = 1), BM fibrosis (n = 2), MDS/leukaemia (n = 3), and transient inverted chromosome 5q with excess blasts (n = 1). R-metHuG-CSF has been well tolerated in the majority of patients and resulted in a long-term improvement in their clinical status.

Adolescent↗

PubMed1989

Effects of recombinant human granulocyte colony-stimulating factor on neutropenia in patients with congenital agranulocytosis.

Congenital agranulocytosis is a disorder characterized by severe neutropenia and a profound deficiency of identifiable neutrophil progenitors in bone marrow. In an attempt to stimulate neutrophil production and thereby reduce the morbidity and mortality associated with this disease, we administered recombinant human granulocyte colony-stimulating factor (rhG-CSF) in doses of 3 to 60 micrograms per kilogram of body weight per day to five patients with congenital agranulocytosis. In all five patients, an increase in the number of neutrophils was noted eight to nine days after the initiation of the effective dosage (the dose at which the neutrophil count reached 1000 cells per microliter or more and the bone marrow showed granulocyte maturation beyond the myelocyte stage). The absolute neutrophil counts rose from less than 100 to between 1300 and 9500 cells per microliter. Marrow aspirates obtained after 14 days at the effective dosage showed maturation to the mature neutrophil stage. The side effects that were observed were medullary pain, splenomegaly, and an elevation of levels of leukocyte alkaline phosphatase. All five patients have had sustained neutrophil counts of 1000 cells per microliter or more for 9 to 13 months while receiving subcutaneous maintenance therapy. Preexisting chronic infections have resolved clinically, and the number of new infectious episodes and the requirement for intravenous antibiotics have decreased. We conclude that treatment with rhG-CSF can lead to a large increase in the numbers of functional neutrophils in patients with congenital agranulocytosis.

Adult↗

PubMed1988

Effect of granulocyte colony-stimulating factor on neutropenia and associated morbidity due to chemotherapy for transitional-cell carcinoma of the urothelium.

We evaluated the ability of human recombinant granulocyte colony-stimulating factor (rhG-CSF) to prevent chemotherapy-induced neutropenia or to accelerate recovery from this complication and thus allow patients to receive full doses of antineoplastic agents on time, according to protocol design. Twenty-seven patients with transitional-cell carcinoma of the urothelium who were undergoing treatment with methotrexate, doxorubicin, vinblastine, and cisplatin were given rhG-CSF (up to 60 micrograms per kilogram of body weight per day) before their first cycle of combination chemotherapy, during the first cycle, or at both points. Treatment with rhG-CSF before chemotherapy resulted in a dose-dependent increase in the absolute neutrophil count. Treatment with rhG-CSF after chemotherapy significantly reduced the number of days (91 percent) per patient on which the absolute neutrophil count was 1000 per microliter or less (P = 0.0039), reduced the number of days (1 vs. 35) on which antibiotics were used to treat fever and neutropenia, and significantly increased the percentage (100 vs. 29 percent) of patients qualified to receive planned chemotherapy on day 14 of the treatment cycle (P = 0.0015). In addition, the incidence of mucositis was significantly decreased (11 vs. 44 percent, P = 0.041), as was its severity. These findings demonstrate that rhG-CSF is a potent stimulus of normal neutrophil proliferation and maturation. In addition, its administration can reduce both the hematopoietic and oral toxicity of chemotherapy.

Adult↗