ABSTRACT
Mediation of Epstein-Barr virus (EBV)-specific cytotoxicity in T lymphocyte via the perforin/granzyme pathway has been demonstrated; therefore, a study involving cytolytic molecules was essential for the clarification of hemophagocytic lymphohistiocytosis (HLH) pathogenesis. This investigation, which analysed the frequency of three allelic mutations of granzyme-B (55Q/R, 95P/A and 247Y/H) in patients with EBV-HLH and infectious mononucleosis, identified the high prevalence of the QPY haplotype in EBV-HLH patients in comparison with healthy controls. A > G polymorphism was also detected in intron 5; furthermore, nearly complete linkage disequilibrium was observed among these polymorphisms. The recessive role of the QPY haplotype of granzyme-B might be responsible for the pathogenesis of EBV-HLH. Cytotoxicity and DNA fragmentation of cytotoxic T lymphocytes did not differ among patients characterized by the QPY/QPY, RAH/RAH and QPY/RAH genotypes. This finding suggested that DNA fragmentation in target cells is mediated not only by granzyme-B but also by other molecules, including other granzymes or Fas.
Subject(s)
Genetic Predisposition to Disease , Histiocytosis, Non-Langerhans-Cell/genetics , Linkage Disequilibrium , Serine Endopeptidases/genetics , Granzymes , Herpesvirus 4, Human/metabolism , Histiocytosis, Non-Langerhans-Cell/immunology , Histiocytosis, Non-Langerhans-Cell/virology , Point Mutation , T-Lymphocytes/immunologyABSTRACT
An intermittent and cyclic regimen with All-Trans Retinoic Acid (ATRA) and intensive chemotherapy was conducted due to pharmacokinetic studies on ATRA for acute promyelocytic leukemia (APL) in children. We have treated 17 children with APL using ATRA for remission induction followed by an intermittent schedule of ATRA plus intensive chemotherapy (APL-ATRA protocol). There were 10 males and 7 females. The median age was 9.0 years old. The median baseline white blood cell count was 12.1 x 10(3)/microliter, hemoglobin 7.8 g/dl, platelet 4.5 x 10(4) microliters at diagnosis. Sixteen patients showed t(15; 17) translocation. RT-PCR analysis was available in 15 patients and showed PML/RAR alpha rearrangement in all patients. Overall, 13 or 17 newly diagnosed patients (88%) achieved complete remission and EFS was 67%. Compared to the control (same chemotherapy without ATRA regimen), remission induction and EFS were significantly increased. The toxicity of ATRA consisted of retinoic acid syndrome in 1 and pseudotumor cerebli in another. Other toxicities included headache, chelitis, gastrointestinal trouble and bone pain. These results suggest that intermittent and cyclic regimen with ATRA and intensive chemotherapy (APL-ATRA protocol) is highly effective for APL patients.
Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Leukemia, Promyelocytic, Acute/drug therapy , Tretinoin/administration & dosage , Aclarubicin/administration & dosage , Administration, Oral , Adolescent , Antineoplastic Agents/adverse effects , Child , Cyclophosphamide/administration & dosage , Cytarabine/administration & dosage , Cytarabine/analogs & derivatives , Daunorubicin/administration & dosage , Doxorubicin/administration & dosage , Drug Administration Schedule , Female , Humans , Male , Mercaptopurine/administration & dosage , Prednisolone/administration & dosage , Tretinoin/adverse effects , Vincristine/administration & dosageABSTRACT
Eight children with Philadelphia (Ph1) chromosome positive chronic myelocytic leukemia (CML) were available for cytogenetic studies and breakpoint cluster region (bcr) rearrangement analysis as compared to the features of adults with Ph1-positive CML. In chronic phase additional abnormalities other than Ph1 chromosome were found in none of our cases. On the other hand, in blastic crisis all of 6 cases had additional chromosomal abnormalities like as i(17q), double Ph1 and +8. The frequency of the appearance of additional chromosomal abnormalities, especially i(17q), is higher in children than in adult cases. In the DNA of 7 of 7 examined patients, rearrangement of bcr could be demonstrated by Southern blot analysis. These findings were similar to those observed in adults. An analysis of the location of the bcr breakpoint indicated that 5' breakpoints were found in four cases who were long-term survivors, and two of the other cases had blastic crisis from the onset of the disease. These findings showed the cytogenetic findings of children with Ph1+CML were different from those of the adult cases in the frequency of the appearance of the additional chromosomal abnormalities, and the location of the bcr breakpoint in children cases might be different from that in the adult cases and influence its prognosis.