A peptide mimic blocks the cross-reaction of anti-DNA antibodies with glomerular antigens.

Anti-DNA antibodies play a pivotal role in the pathogenesis of lupus nephritis by cross-reacting with renal antigens. Previously, we demonstrated that the binding affinity of anti-DNA antibodies to self-antigens is isotype-dependent. Furthermore, significant variability in renal pathogenicity was seen among a panel of anti-DNA isotypes [derived from a single murine immunoglobulin (Ig)G3 monoclonal antibody, PL9-11] that share identical variable regions. In this study, we sought to select peptide mimics that effectively inhibit the binding of all murine and human anti-DNA IgG isotypes to glomerular antigens. The PL9-11 panel of IgG anti-DNA antibodies (IgG1, IgG2a, IgG2b and IgG3) was used for screening a 12-mer phage display library. Binding affinity was determined by surface plasmon resonance. Enzyme-linked immunosorbent assay (ELISA), flow cytometry and glomerular binding assays were used for the assessment of peptide inhibition of antibody binding to nuclear and kidney antigens. We identified a 12 amino acid peptide (ALWPPNLHAWVP, or 'ALW') which binds to all PL9-11 IgG isotypes. Preincubation with the ALW peptide reduced the binding of the PL9-11 anti-DNA antibodies to DNA, laminin, mesangial cells and isolated glomeruli significantly. Furthermore, we confirmed the specificity of the amino acid sequence in the binding of ALW to anti-DNA antibodies by alanine scanning. Finally, ALW inhibited the binding of murine and human lupus sera to dsDNA and glomeruli significantly. In conclusion, by inhibiting the binding of polyclonal anti-DNA antibodies to autoantigens in vivo, the ALW peptide (or its derivatives) may potentially be a useful approach to block anti-DNA antibody binding to renal tissue.

Cost-effectiveness of cefepime + netilmicin or ceftazidime + amikacin or meropenem monotherapy in febrile neutropenic children with malignancy in Turkey.

Infection remains the major cause of morbidity and mortality in immunocompromised children with malignancy. In addition, the economic impact of antibiotic treatment should always be evaluated, especially in developing countries. In our center between January 1998 and January 1999, 73 children with hematological malignancies [acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML)]; 9 children with solid tumors (rhabdomyosarcoma, neuroblastoma) had 87 febrile neutropenic episodes (related to chemotherapy). These children were randomized prospectively into three treatment groups. The first group (n: 28) received cefepime plus netilmicin, while the second group (n: 29) was treated with ceftazidime plus amikacin and the third (n: 30) with meropenem as monotherapy. The aim of the study was to compare the success rates and cost of fourth generation cephalosporin plus aminoglycoside and monotherapy of meropenem with ceftazidime plus amikacin, which is the standard therapy for febrile neutropenia. Microbiologically documented infections were 29.9%, clinically documented infections were 9.2% and 60.9% of the febrile neutropenic episodes were considered to be FUO. Gram-positive microorganisms were the most commonly isolated agents from blood cultures [MRSA (Methicillin Resistant Staphylococcus aureus) in 6 patients and MSSA (Methicillin Sensitive Staphylococcus aureus) in 4 patients]. The success rates were 78.5%, 79.3% and 73.3 % for the 1st, 2nd and 3rd groups respectively. In 4 patients (4.5%) fever responded only to amphotericin-B therapy. There was no statistically significant difference between the three treatment regimens with respect to efficacy, safety and tolerance (chi2 test, p>0.05), but while the third and fourth generation cephalosporins + aminoglycosides were comparable for cost, the monotherapy regimen was the most expensive. The main determining factors for the choice of treatment of febrile neutropenic children, especially in a developing country, are cost, presence of indwelling catheter and the bacterial flora of the unit, as well as efficacy.

Fludarabine, cytarabine, G-CSF and idarubicin (FLAG-IDA) for the treatment of relapsed or poor risk childhood acute leukemia.

The prognosis of relapsed acute leukemia or chronic leukemia in acute blast crisis is poor and new chemotherapeutic regimens could be useful for these patients. Six relapsed acute lymphoblastic leukemia (ALL), nine relapsed acute myeloblastic leukemia (AML), one chronic myelomonocytic leukemia (CMML) and one chronic myeloid leukemia (CML) in acute blast crisis between three to 18 years (median 10 years) received fludarabine, cytarabine, G-CSF and idarubicin (FLAG-IDA) chemotherapy (CT). Five of the AML relapses were after bone marrow transplantation (BMT) and four were recurrent relapses. At the end of the second course only three patients (2 AML, 1 ALL) were in complete remission (CR). Of the three patients in CR, one patient with AML had her first donor lymphocyte transfusion (DLT) on the 7th day of the second FLAG-IDA course and she is disease-free on the 30th month of the second remission. The remaining two patients were transplanted from unrelated donors in a BMT center abroad on the 5th and 8th month of the last remission and both died with BMT-related complications. Out of 25 courses, seven resulted in fatal infections. The regimen was ineffective in B-cell ALL as in acute blastic crisis of CMML and CML. We could not evaluate the remission-inducing effect accurately in most of the patients due to induction failure. FLAG-IDA appears to be a myelotoxic therapy for relapsed or poor risk leukemia in a developing country. It is not cost-effective; dose modifications or a regimen without IDA may be tried if there is an available marrow donor.

Is AML1/ETO gene expression a good prognostic factor in pediatric acute myeloblastic leukemia?

To assess the clinical significance of AML1/ETO gene detected by nested reverse transcriptase polymerase chain reaction, the outcome of 7 patients with acute myeloblastic leukemia between 3 and 14 years of age were presented. All patients had complete remission (CR) at the end of induction (AML-MRC 10 protocol) and 4 underwent unpurged autologous, 2 allogeneic (from matched siblings) non-T-cell-depleted bone marrow transplantations (BMT) in first CR. One patient died due to allogeneic BMT-related complications, and 4 patients relapsed at 13, 17, 18, and 26 months. Only one patient achieved second CR. All relapsed patients died between 18 and 36 months with resistant disease (n = 3) or infection during salvage chemotherapy (n = 1). Two patients who had autologous BMT are alive and disease free at 44 and 50 months. Although statistical significance could not be shown, event-free survival and overall survival rates of AML1/ETO-positive patients (28.57 and 28.57%, respectively) at 3.5 years were even lower than those of AML1/ETO-negative patients. The results confirm some previous reports that AML1/ETO gene in children and adolescents is not a favorable prognostic factor.

A comparison of the effects of Veau-Wardill-Kilner palatoplasty and furlow double-opposing Z-plasty operations on eustachian tube function.

OBJECTIVE: The purpose of this study was to compare the effects of Veau-Wardill-Kilner (VWK) two-flap palatoplasty and Furlow double-opposing Z-plasty operations on eustachian tube (ET) opening in patients with cleft palate (CP). DESIGN: Twenty-six patients underwent CP repair between 1993 and 1997. VWK and Furlow operations were used in 13 patients each. All patients were examined by the otorhinolaryngologist before and after the operations; mean follow-up time was 27.3 months. Secretory otitis media (SOM), as identified by tympanograms, was the comparison criterion used. RESULTS: The prevalence of SOM was 69% (n = 18) in all CP patients preoperatively. Among those with preoperative SOM, we did not find any statistically significant difference in the frequency of postoperative SOM between the two techniques. CONCLUSION: This study suggests that there is no difference in postoperative ET function between patients undergoing either VWK or Furlow operations, in spite of the differences in muscle positioning in these operations. We discuss the implications of this finding in relation to surgical anatomy and histology of the soft palate muscles.

Prognostic significance of wilms tumor 1 gene in childhood acute Lymphoblastic Leukemia.

Wilms tumor 1 (WT1) gene is a tumor supressor gene, expressed in malignant and normal hematopoietic progenitor cells. Prognostic significance of this gene in childhood acute lymphoid leukemia (ALL) is not clear. We evaluated the presence of WT1 expression in bone marrow samples of 28 children with de novo ALL at diagnosis by two step RT-PCR. Expression of WT1 gene was detected in 78.5% of patients. There was no correlation between WT1 gene expression and age, sex, FAB type, leukocyte count, and presence of t(4;11) and t(9;22). All patients were treated with modified BFM 86 protocol. There was no difference in the complete remission (CR) rate between WT1 positive and negative patients. Event free survival (EFS) and overall survival (OS) of WT1 positive and negative patients were also not significant. We conclude that expression of WT1 gene is not associated with specific characteristics of ALL blast cells and is not a prognostic factor for CR, remission duration and overall survival.

Detection of BCR/ABL transcripts by reverse transcriptase polimerase chain reaction in pediatric acute Lymphoblastic Leukemia: incidence and clinical eatures.

BCR/ABL expression, which is the molecular equivalent of the Philadelphia chromosome, is an independent poor risk factor in acute lymphoblastic leukemia (ALL). We used a two-step (nested) reverse transcriptase polimerase chain reaction (RT-PCR) assay to examine BCR/ABL expression in the diagnostic bone marrow specimen of children with ALL, prospectively. Among 75 de novo ALL patients, 4 (%5.3) were found to be BCR/ABL- ositive, whereas 4 of 17 relapsed patients (23.5%) were positive. This preliminary study in Turkish children showed an incidence similar to reports from Europe and the U.S.A. More intensive chemotherapies and allogeneic bone marrow transplantations (BMT) uring the first remission were planned if a donor was available. Out of 8 BCR/ABL-positive patients, complete remission (CR) was achieved in 7 patients and partial remission (PR) was achieved in 1 patient. Three patients underwent allogeneic BMT during the first CR and 1 under went autologous BMT during the first PR. The Kaplan-Meier estimate of vent-free survival (EFS) of BCR/ABL negative de novo ALL patients was 78.36% at 3 years, whereas the EFS of positive patients was 31.25% at 26 ± 6.4 months. Molecular screening for the Philadelphia chromosome should become a part of the routine diagnostic panel in ALL patients in order to predict which patients have a poor prognosis and need tailored therapy.