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Background: In Japan, mass screening for neuroblastoma has been performed at 6 months of age to improve the prognosis of this condition for more than 20 years. In recent years, most neuroblastomas detected by mass screening were considered to have favorable biological features and sometimes tend to regress spontaneously. Methods: The authors established non-treated observation criteria in 1997 and criteria for observation of residual tumor after first-line chemotherapy in 1999, and have made an effort to reduce the intensity of medical treatment for neuroblastoma. The authors examined outcomes of 79 patients who were found in the Shizuoka neuroblastoma mass screening at 6 months of age and who received medical treatment or underwent observation in Shizuoka Children's Hospital, Shizuoka, Japan, between December 1981 and December 2004. Results: A total of 77 patients survived but the remaining two patients died from complications of medical treatment. None of the patients died due to progression of neuroblastoma. In the cases, non-treated observation was performed in 17. Of those, 12 patients are now under non-treated observation. Of their tumors, two have disappeared, nine have become smaller and another one has not change in size. Observation of residual tumor after first-line chemotherapy was performed in 15 cases, and three disappeared and the other 12 cases became smaller. Medical treatment-related complications were observed in 20 of 67 patients who received medical treatment, and 18 of the 20 patients were seen before establishing non-treated observation criteria. Conclusion: Non-treated observation and observation of residual tumor after first-line chemotherapy were useful to reduce medical treatment-related complications. [ABSTRACT FROM AUTHOR]

Hodgkin lymphoma is an easily curable malignancy in the pediatric age group and is less frequently observed in Japan. No study with a large sample size of Japanese patients has been conducted. From 1985 to 2000, 157 Japanese patients with Hodgkin lymphoma were retrospectively analyzed based on their clinical characteristics, treatment regimen, and treatment outcome by 4 pediatiric cancer study groups. There were 107 male and 50 female patients with a median age of 10 years 1 month (range: 1 year 8 months to 17 years 8 months). Clinical stage I lymphoma was observed in 37 patients, stage II in 62, stage III in 40, and stage IV in 18. Fifty patients presented with B symptoms (32%). Most patients (n=125, 82%) received more than 6 courses of combination chemotherapy mainly comprising cyclophosphamide, vincristine, procarbazine, prednisolone (COPP), doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). The 5-year overall and event-free survival rates were 81.5% and 94.8%, respectively. High-risk disease and age (>10 years) were considered to be poor prognostic factors.

Mutations in RAS, neurofibromatosis type 1 (NF1), and PTPN11, constituents of the granulocyte-macrophage colony-stimulating factor signaling pathway, have been recognized in patients with juvenile myelomonocytic leukemia (JMML). We assessed 71 children with JMML for NRAS, KRAS, and PTPN11 mutations and evaluated their clinical significance. Of the 71 patients, three had been clinically diagnosed with neurofibromatosis type 1, and PTPN11 and NRAS/KRAS mutations were found in 32 (45%) and 13 (18%) patients, respectively. No simultaneous aberrations were found. Compared with patients with RAS mutation or without any aberrations, patients with PTPN11 mutation were significantly older at diagnosis and had higher fetal Hb levels, both of which have been recognized as poor prognostic factors. As was expected, overall survival was lower for patients with the PTPN11 mutation than for those without (25 versus 64%; p = 0.0029). In an analysis of 48 patients who received hematopoietic stem cell transplantation, PTPN11 mutations were also associated with poor prognosis for survival. Mutation in PTPN11 was the only unfavorable factor for relapse after hematopoietic stem cell transplantation (p = 0.001). All patients who died after relapse had PTPN11 mutation. These results suggest that JMML with PTPN11 mutation might be a distinct subgroup with specific clinical characteristics and poor outcome.

Background: We evaluated the clinical pictures, outcome for childhood idiopathic thrombocytopenic purpura (ITP) and the trends of the choice of management for childhood ITP in Japan., Method: Every year, questionnaires were sent to all institutions that employ the active members of the Japanese Society of Pediatric Hematology. The questionnaires included age, sex, date of diagnosis, platelet count at diagnosis, the presence or absence of antecedent infection, hemorrhagic symptoms, initial management, and the outcome of all patients newly diagnosed with ITP., Results: A total of 986 newly diagnosed as ITP patients were reported between January 2000 and December 2005. The occurrence of ITP peaked in boys less than 1 year of age, and at 1 year of age in girls. The male-to-female ratio was 1.24:1. Wet purpura was observed in more than half of the patients with platelet counts of <10,000/microL. The initial treatment varied among the patients with different platelet counts at diagnosis; most of the patients with platelet counts <20,000/microL received intravenous immunoglobulin or oral corticosteroids. Conversely, cases without any aggressive treatment increased to a larger degree in patients with > or =20,000/microL of platelet., Conclusions: These findings indicate that overall compliance to the Japanese guideline is considered to be relatively good in Japan.

We herein report on the current status of Japanese HIV-positive patients with coagulation disorders, primarily hemophilia, based on the national survey of 31 May 2006. The total number of registered patients was 1,431 (Hemophilia A 1,086; Hemophilia B 325; von Willebrand disease 8; others 12), and 604 of these patients were deceased by 31 May 2006. The survival rate after the beginning of 1983 was evaluated by the Kaplan-Meier method. The total number of surviving patients was 827, and the survival rate on 31 May 2006 was 55.7 +/- 1.4%. Among the 827 surviving patients, HCV antibody was observed in 740, was negative in 16, and was not reported in 71 patients. Thus, the prevalence of HCV infection was 98% in the surviving patients based on the presence of HCV antibody. Among the 604 deceased patients, liver disease was reported as a cause of death in 149 cases (25%), and infection with HCV was reported as the possible cause of liver disease in 120 cases (20%). After 1997, 63 cases among the subtotal of 148 deaths had critical hepatic disease that originated from HCV infection, which accounted for 43% of the subtotal. The cumulative rate of patients who received interferon therapy was 32%. Interferon therapy should be prescribed more frequently to HIV-positive patients with coagulation disorders in order to realize the survival benefits, although clinicians should be aware of side effects and toxicities.

Transient leukaemia (TL) in neonates with Down syndrome (DS) is characterized by the transient appearance of blast cells in the peripheral blood that resolves spontaneously. Some TL patients die at an early age due to organ failure. Seventy DS patients with TL were studied retrospectively to identify clinical and laboratory characteristics associated with early death (<6 months of age). Sixteen of 70 patients (22.9%) died early. The main causes of death were organ failure, particularly hepatic and cardiopulmonary failure. On univariate analysis, early gestational age (EGA), high white blood cell (WBC) count (> or =100 x 10(9)/l), percentage of peripheral blasts, elevated aspartate transaminase (AST), elevated direct bilirubin (DB), and low Apgar score were significantly associated with poor survival. On multivariate analysis, EGA, WBC count, and DB were independent predictors of poor outcome. A simple risk stratification system combining EGA and WBC count was devised to predict poor outcome. Term infants (EGA > or = 37 weeks) whose WBC count was lower than 100 x 10(9)/l had the best outcome [7.7% (3/39) died early], while preterm infants (EGA < 37 weeks) whose WBC count was higher than 100 x 10(9)/l had the worst outcome [54.5% (6/11) died early]. This stratification system may be useful for identifying high-risk patients who need early therapeutic interventions.

Human immunodeficiency virus type 1 (HIV-1) utilizes the macromolecular machinery of the infected host cell to produce progeny virus. The discovery of cellular factors that participate in HIV-1 replication pathways has provided further insight into the molecular basis of virus-host cell interactions. Here, we report that the suppressor of cytokine signaling 1 (SOCS1) is an inducible host factor during HIV-1 infection and regulates the late stages of the HIV-1 replication pathway. SOCS1 can directly bind to the matrix and nucleocapsid regions of the HIV-1 p55 Gag polyprotein and enhance its stability and trafficking, resulting in the efficient production of HIV-1 particles via an IFN signaling-independent mechanism. The depletion of SOCS1 by siRNA reduces both the targeted trafficking and assembly of HIV-1 Gag, resulting in its accumulation as perinuclear solid aggregates that are eventually subjected to lysosomal degradation. These results together indicate that SOCS1 is a crucial host factor that regulates the intracellular dynamism of HIV-1 Gag and could therefore be a potential new therapeutic target for AIDS and its related disorders.

We analyzed the outcomes of 44 children with hepatitis associated aplastic anemia (HAA) who received immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and cyclosporine (CsA). Fourteen (31.8%) patients achieved complete response and 17 (38.6%) achieved partial response, for an overall response rate of 70.4% after 6 months. Seven non-responders received bone marrow transplantation from an HLA-matched unrelated donor and 6 out of 7 are alive. The probability of overall survival at 10 years was 88.3+/-4.9%, which supports the role of IST with ATG and CsA as treatment of choice for children with HAA without an HLA identical sibling donor.

Vpr, an accessory gene product of HIV-1, has been reported in the plasma of HIV-1-positive patients, and exogenous Vpr induces the reactivation of viral production from latently infected cells and the apoptosis of T cells in vitro. These observations imply that Vpr is important in AIDS development, but the clinical relevance of the findings cannot be evaluated fully because the actual plasma Vpr concentration in HIV-1-positive patients is unknown. Here we generated two monoclonal antibodies against different portions of Vpr and successfully identified Vpr as a 14-kDa protein in HIV-1-positive patients. Semiquantitative analysis using a recombinant Vpr revealed that the concentration of Vpr in patient plasma was approximately 0.7 nM (10 ng/ml). Cross-sectional analysis of 52 HIV-1-positive patients revealed that the presence of Vpr detected in 20 patients was positively correlated with HIV-1 RNA copy number (p > 0.03), but not with the number of CD4(+) T cells. This is the first report demonstrating the actual amount of Vpr in HIV-1-positive patients, and the possible linkage of Vpr and viral titers indicates that it is important to continue to carry out the sequential analysis of Vpr, especially in clinical courses of HIV-1-positive patients. The threshold of viral titers, where Vpr appears in the patients' plasma, if present, contributes to better understanding the role of Vpr in AIDS pathogenesis.

Neuroblastoma is the most common extracranial solid tumor in childhood. Spontaneous regression has been well described in infants, especially in those with stage 4S and those with low-stage neuroblastoma detected by screening. However, neuroblastoma presenting with intracranial metastasis is generally considered to need a postoperative chemotherapy. Here, we report a 3-month-old girl with stage 4 neuroblastoma presenting with spontaneous regression of metastatic tumor including meningeal metastasis after gross resection of primary tumor. Further investigation may be required to detect patients of this kind without the need of postoperative chemotherapy regardless of their stage at diagnosis.

Irinotecan is expected to become a new drug for childhood solid tumors. Sixteen children with relapsed solid tumors received irinotecan 180 mg/m2/day for 3 consecutive days, repeated once after 25 days off. Their original tumors were neuroblastoma in 7, rhabdomyosarcoma in 3, nephroblastoma and undifferentiated sarcoma in 2 each, and primitive neuroectodermal tumor and leiomyosarcoma in 1 each. The average age at trials was 6 years. Partial response was achieved in 5 (31.3%) (neuro-blastoma, rhabdomyosarcoma, nephroblastoma, undifferentiated sarcoma, and leiomyosarcoma), and decrease in tumor marker in the other 2. Irinotecan appears promising, and could become included in the first-line treatment.

A practice guideline aimed at standardizing the treatment for childhood idiopathic thrombocytopenic purpura (ITP) is presented. This consensus guideline is based on a survey carried out via a questionnaire prepared by the ITP Committee of the Japanese Society of Pediatric Hematology and sent to society members. The survey questionnaire included questions on the diagnosis of ITP submitted for the purpose of revising the ITP diagnostic guideline prepared in 1990 by the Research Group for Intractable Hematopoietic Disorders; a revised diagnostic guideline also is presented.

Approximately 30% of patients with hemophilia in Japan were infected with human immunodeficiency virus (HIV) in early 1980s through contaminated blood products. In 1995, a cohort of HIV-infected, asymptomatic patients with hemophilia was set up for follow-up study. Although the patients met the criteria for long-term non-progressor (LTNP) at the entry to the cohort, some of them later developed lymphopenia during five more years of observation. We collected blood samples from 80 long-term survivors; 42 of them did not require antiviral therapy, but the rest were under treatment. Analysis of HLA-B genotype revealed that carriers of known HIV-resistant alleles such as HLA-B*5701, B*5801, and alleles of B27 antigenic group were not increased in frequency, but that HLA-B*1507 was increased in the cohort (6.25% vs. 1.03%, OR = 6.40, p = 0.039). We also observed the decrease in carriers of HLA-B*5401 (3.75% vs. 14.95%, OR = 0.22, p = 0.016). HLAB* 5401 is a relatively common allele in East Asian populations and belongs to the same B22 antigenic group as B55 and B56 which were reported to associate with rapid progression. Our data indicated that HLA class I is one of the host factors involved in the retardation of HIV disease progression as also reported in the previous studies; however, the alleles associated with this resistance were not the same because of divergent host genetic background.

Japan has a nationwide mass-screening program for neuroblastoma in 6-month-old infants. Neuroblastoma can regress spontaneously, and some institutions observe selected cases. We evaluated the management of screened neuroblastoma at our hospital since 1997 when an observation program was introduced. Criteria for the observation program were stage-I, stage-II, or stage-IVs tumors, urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) levels <40 microg/mg creatinine, tumor <5 cm in diameter, no invasion to the intraspinal canal or great vessels, and parental consent to participate. Patients who did not meet observation criteria underwent surgery or mild chemotherapy according to the location of the tumor. If patients met observation criteria after chemotherapy, surgical intervention was no longer performed. Thirty-six patients attended our hospital for screened neuroblastoma from 1997 to 2002. Thirty-three patients who were managed at our hospital participated in this study. Ten subjects met observation criteria. Tumors regressed in 7 patients (mean follow-up period 36.3 months) with corresponding decreases in VMA and HVA levels (group A). Three underwent surgery (group B) because of increasing VMA and HVA levels, increase in tumor size, or guardian's request. Twenty-three subjects did not meet observation criteria. Four patients underwent primary surgery (group C), and 19 patients had chemotherapy initially. Fourteen patients met observation criteria after chemotherapy and two are still having chemotherapy (group D). Three patients required surgery due to insufficient regression of their tumors (group E). Fourteen subjects in group D had marked decreases in VMA and HVA levels and tumor size (mean follow-up period 29.1 months), and tumors were not detected using imaging techniques in 8 patients. Histological examination of all resected specimens during the study period showed favorable histology and no N-myc amplification. There was no evidence of unfavorable prognosis in any of the 33 subjects, although 1 patient who underwent primary surgery had a vanishing kidney 1 year later and 1 patient had multiple bony metastases after complete resection of tumor, which was treated by chemotherapy. Until the real significance of mass screening for neuroblastoma as a public health measure is confirmed, observation with careful follow-up should be adopted more extensively because it has a favorable outcome in many cases, and is associated with minimal therapeutic complications.

Critical liver diseases are now major causes of death in HIV-1-infected patients after the remarkable improvement in the clinical status resulting from highly active antiretroviral therapy. We report the results of an analysis on causes of deaths related to liver diseases based on our surveillance of hemophiliacs infected with HIV-1 up until May 31, 2002. A total of 1,405 patients (hemophilia A, 1,084, and hemophilia B, 321) were registered. The cumulative number of deaths was 534 (hemophilia A, 414, and hemophilia B, 120) by May 31, 2002. Hepatic disease due to HCV infection was found in 29.8% (95% confidence interval: 20.3-40.7%) of the total cases with known causes of death after 1997, whereas this value was 14.0% (95% confidence interval: 10.8-17.7%) before 1997 (p < 0.01). We observed an increasing incidence of critical hepatic diseases among HIV-1-infected hemophiliacs, thus suggesting that treatment of HCV infection is essential for HIV-1-infected hemophiliacs., (Copyright 2004 S. Karger AG, Basel)

We analyzed the minimal residual disease (MRD) in 50 children with acute lymphoblastic leukemia (ALL) by amplifying the clonally rearranged T-cell receptor (TCR) gamma/delta chain and/or immunoglobulin (Ig) kappa chain gene using the allele-specific-PCR method. All children were treated according to the protocols of the Children's Cancer and Leukemia Study Group of Japan (CCLSG). The patients were stratified into four risk-groups according to the leukocyte count and age at diagnosis. We prospectively sampled the patients' bone marrow at 1 month (point 1) and 3 months (point 2) after the initiation of chemotherapy and quantitated the MRD retrospectively. The results of MRD were closely related with the clinical outcome. The relapse rate of the patients MRD-positive at points 1 and 2 was 46% (6/13) and 86% (6/7), respectively, whereas those MRD-negative results at point 1 and 2 were 13% (3/13) and 3% (3/30), respectively. We found significant differences in the event-free survival between MRD-positive children and MRD-negative children like the reports, which have been made by BFM and EORTC groups. We conclude that MRD in an early phase of chemotherapy can be a good predictor of the prognosis of childhood ALL regardless of the protocol of chemotherapy or race.

Recombinant activated factor VII (rFVIIa) is a recently added new agent for the treatment of hemophiliacs with inhibitors. A major drawback to the use of rFVIIa is its short half-life, necessitating frequent and intermittent bolus injections. Continuous infusion of rFVIIa has been reported as a feasible, convenient, safe and cost-effective alternative to intermittent bolus injections. We report the use of continuous rFVIIa infusion during and after left elbow arthroplasty in a hemophiliac with a high titer of inhibitor to factor VIII. rFVIIa was administered as a bolus injection (100 micrograms/kg) at the start of the operation, after which continuous infusion (10-30 micrograms/kg/h) was immediately started and continued for 6 days. Tranexamic acid (50 mg/kg/day, p.o.) was also administered as an antifibrinolytic treatment. Laboratory monitoring of hemostatic efficacy was performed in this case using prothrombin time and the thrombelastogram. Finally, effective intra- and postoperative hemostasis and normal healing of the surgical incisions were achieved, except for local thrombophlebitis. Although the optimal maintenance or target level of rFVIIa has been a matter of debate, we consider continuous infusion of rFVIIa to be a feasible, convenient, safe and cost-effective alternative to intermittent bolus injections.

Purpose: To determine the dose-limiting toxicity, maximum tolerated dose, and potential efficacy of irinotecan in children with refractory malignant solid tumors., Patients and Methods: In the present phase I clinical trial, 28 patients received irinotecan 50 to 200 mg/m2 per day by intravenous 2-hour infusion over the course of 3 days, repeated once after an interval of 25 days. Fifty-one treatment courses were administered to these patients., Results: Dose-limiting toxicities were observed at the dose of 200 mg/m2 per day for 3 days. Diarrhea and hematopoietic toxicities were the dose-limiting factors, and the former required support with intravenous fluid administration. The occurrence of vomiting was variable. Decreases in clinical tumor marker levels were observed in the majority of patients who received two cycles of irinotecan 80 mg/m2 per day to 200 mg/m2 per day over the course of 3 days, and partial response was attained in four patients who received irinotecan in two cycles of 140 mg/m2 per day to 200 mg/m2 per day over the course of 3 days. Pharmacokinetic studies showed that the plasma concentration of irinotecan and its active metabolite SN-38 ranged from 93 to 2,820 ng/mL and 5.2 to 34.8 ng/mL, respectively, during 3-day infusions of irinotecan 200 mg/m2 per day. The mean clearance of irinotecan was 14.54 L/h per m2 (range 8.45-20.83 L/h per m2)., Conclusion: The maximum tolerated dose was determined to be a dose of irinotecan between 160 mg/m2 per day and 180 mg/m2 per day administered over the course of 3 consecutive days on an inpatient basis, repeated once after 25 days off, and our results indicate that irinotecan is a promising anticancer agent that is worthy of phase II trials in pediatric solid tumors.

Among several factors associated with HIV-1 disease progression, genetic polymorphism of CCR2, CCR5, and CXCR4 in HIV-1 infection has been found. Single-nucleotide polymorphisms (SNPs) in the CCR2, CCR5, and CXCR4 genes as well as a 32-base pair deletion in the open reading frame of the CCR5 gene are associated with HIV disease progression among Caucasians and African-Americans in North America and Europe. However, in populations other than Caucasians and African-Americans, SNPs have not been fully examined. In our study SNPs in CCR2 coding and CCR5 regulatory regions have been examined in 98 Japanese HIV-positive individuals. The alleles of CCR5 regulatory regions at -2135T and -2086G are associated with late onset of AIDS (p < 0.05; odds ratio for the early onset of AIDS, 0.502 and 0.404, respectively). In contrast to this, the allele of CCR5 at -2086A is associated with the early onset of AIDS (p < 0.05; odds ratio for the early onset of AIDS, 2.133). A haplotype including two alleles at -2135G and -2086G is associated with the late onset of AIDS (p < 0.05; odds ratio for the early onset of AIDS, 0.372). Thus we found that a CCR5 SNP and haplotype polymorphism affect HIV disease progression even in the Japanese population. This indicates that the CCR5 genetic polymorphism affecting disease progression should be studied in a wider range of population.

To evaluate the clinical implications of CD45 expression in acute childhood lymphoblastic leukemia (ALL), we measured the CD45 expression of blast cells from 133 untreated patients with childhood B-precursor ALL (n = 118) or T-ALL (n = 15). CD45 expression (> or = 20%) was detected in all 15 cases (100%) of T-ALL, and 101 cases (86%) of B-precursor ALL. In 122 cases, the fluorescence intensity of the CD45 expression was measured as a relative value; the ratio of average linear values (RALV) of CD45 on the blasts to that on CD3-positive T-lymphocytes from the same specimen. The expression was more intense in the T-ALL cases than in the B-precursor ALL cases (RALV, mean +/- SE: T-ALL 0.230 +/- 0.04 vs. pro-B ALL 0.150 +/- 0.012/pre-B ALL 0.153 +/- 0.019, p < 0.05). However, the intensity of the CD10, CD19, CD20 and CD34 antigen immunoreactivity did not correlate with the CD45 expression. Patients with hyperdiploidy (chromosome number > 50) showed significantly lower levels of CD45 expression than patients with t(1;19) or normal karyotypes (RALV, mean +/- SE: 0.081 +/- 0.022 vs. 0.133 +/- 0.03/0.143 +/- 0.019, p < 0.05). Other clinical features such as age, gender and WBC count did not correlate with CD45 expression. The prognostic implications of CD45 expression were studied in non-high-risk (low-risk + intermediate-risk) (n = 60) and high-risk patients (n = 52) with B-precursor ALL who had been treated with the risk-directed protocol of ALL-941 trial. Although CD45 expression did not correlate with the event-free survival (EFS) of the non-high-risk patients, there was a significant correlation between the expression levels and the EFS of the high-risk patients: the 3-year EFS rate of the CD45low group (n = 26, RALV = 0.017-0.132) was 88 +/- 7% versus the CD45high group (n = 26, RALV = 0.133-0.450) at 34 +/- 24% (p < 0.05). These results show that the levels of expression of the CD45 antigen on leukemic lymphoblasts are significantly correlated with the clinical features and prognosis of childhood ALL.

Background: The primary object of this study was to identify treatment-related variables that may predict relapse of acute myelogenous leukemia (AML) after autologous peripheral blood stem cell transplantation (PBSCT), which will be critical for the development of a suitable protocol for wider application., Methods: A total of 28 children (age 0-18 years) with AML underwent PBSCT and have had a minimum follow-up of 25 months; including 24 patients in their first complete remission (CR) and four in their second CR. The patients were divided into two cohorts according to the study phase: 16 patients were treated in an early phase pilot study and 12 patients in their first CR were treated in a prospective trial. Fifteen of the first-CR patients had any of the cited high-risk features of high WBC count (>100x10(9)/l; n = 5), FAB M0/M4/M5/M7 subtypes (n = 11) or delayed achievement of CR (n = 9). Except in one patient, cytoreductive regimens did not include total body irradiation (TBI)., Results: After PBSCT, one patient died of veno-occulsive disease (VOD) and another patient relapsed early on day 43, but the remaining patients showed engraftment. Leukemic relapse was observed 1-29 months after PBSCT (median, 8 months); in all of the 4 children treated in their second CR and in 11 of the 24 patients (46%) treated in their first CR. The remaining patients have been disease-free for 24 to 97 months (median, 53 months). Using a multivariate analysis, the timing of apheresis was the most significant prognostic factor for those treated in their first CR (p = 0.03); 12 of the 16 patients whose PBSC were collected beyond 2.5 months of CR continue to remain in CR, while seven of the eight patients whose PBSC were harvested within 2.5 months of CR relapsed., Conclusion: Although the small number of patients studied does not allow firm conclusions to be drawn regarding the relative effectiveness of this therapy, the results do suggest the feasibility of further studies of PBSCT for the treatment of childhood AML with high-risk features including the assessment of minimum residual disease.

Quantification of human immunodeficiency virus type 1 (HIV-1) genomic RNA levels below the detection limit (400 copies/ml) of commercially available quantification kits is possible by increasing the amount of serum samples using competitive PCR conditions. We evaluated disease prognosis in patients without symptoms for a long period after infection (long-term non-progressors) and patients in whom the virus was controlled to a low level by administration of anti-HIV drugs. For 102 of the 414 serum samples stored at -80 degrees C which showed HIV-1 RNA below 400 copies/ml by competitive PCR using 100 to 200 microl sera, an increase in the sample volume to 500-2000 microl, extraction of HIV-1 RNA, and quantitative detection by competitive PCR was performed. Follow-up quantification of serum HIV-1 RNA from 4 patients indicated that this method is useful in assessing prognosis in the early stage of the disease in patients without symptoms for a long period after infection (long-term non-progressors) and patients in whom the virus in the serum was controlled by administration of anti-HIV drugs to below the detection limit of commercially available quantification kits. Quantification of low level serum HIV-1 RNA was also considered useful as a parameter of treatment.

Objective: A novel 2-amino acid insertion between codons 69 and 70 of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) which confers multiple drug resistance has recently been reported. Independently, we have identified similar insertion mutations in Japanese hemophiliacs and attempted to analyze their emergence in conjunction with therapy regimens and their contribution to drug resistance using recombinant technology., Methods: The plasma and peripheral blood mononuclear cells (PBMCs) of 348 HIV-1-infected hemophiliacs were screened for HIV-1 RT mutations relevant to nucleoside analogue inhibitors and isolating viruses. Contribution of each insertion to drug resistance was studied by introducing the mutations into a T-cell line-tropic NL4-3 infectious clone and testing the drug susceptibilities of the recovered virus., Results: Insertion of the 2-amino acid residue was found in 4 of the 348 cases and was strongly associated with prolonged chemotherapy with zidovudine (AZT) and didanosine (ddI). The virus isolated from 1 of the 4 cases possessed the same insertion. Characterization of these virus and the recombinant NL4-3 with the insertion strongly suggested that the insertion caused resistance not only to AZT and ddI but also to lamivudine (3TC) and zalcitabine (ddC)., Conclusion: A 2-amino acid insertion between codons 69 and 70 of RT was detected in 4 of 348 (1.1%) Japanese hemophiliacs and was found to be associated with multiple drug resistance to nucleoside analogue RT inhibitors.

Background: Prevention of central nervous system (CNS) leukemia by early introduction of therapy to this sanctuary site is an essential component of modern treatment strategy for acute lymphoblastic leukemia (ALL). However, the optimal form of preventive CNS therapy remains debatable., Procedure: To address this issue, we evaluated the efficacy of CNS preventive therapy for 572 children with ALL who achieved complete remission in the Children's Cancer and Leukemia Study Group (CCLSG) ALL874 (1987-1990) and ALL911 (1991-1993) studies. They received risk-directed therapy based on age and leukocyte count. In the ALL 874 study, the non-high-risk (low-risk [LR] + intermediate risk [IR]) patients were randomly assigned to the conventional cranial irradiation (CRT) regimen (L874A and I874A) and the high-dose methotrexate (HDMTX) regimen without CRT (L874B and I874B). The former patients received 18-Gy CRT plus 3 doses of intrathecal (i.t.) MTX and the latter patients received 3 courses of HDMTX at 2 g/m2 plus 13 doses of ITMTX (L874B) or 4 courses of HDMTX at 4.5 g/m2 plus 1 dose of ITMTX (I874B)., Results: The 7-year probabilities (+/- SE) of CNS relapse-free survival were 97.3% +/- 2.6% (L874A, n = 41) vs. 90.3% +/- 5.3% (L874B, n = 39) (P = 0.25) in the LR patients, and 100% (I874A, n = 55) vs. 78.5% +/- 6.5% (I874B, n = 54) (P = 0.002) in the IR patients. The corresponding disease-free survival (DFS) rates were 79.4% +/- 6.5% vs. 74.4% +/- 7.3% (P = 0.62) in the LR group and 63.3% +/- 6.8% vs. 58.3% +/- 7.2% (P = 0.66) in the IR group. Thus, the HDMTX regimen could not provide better protection of CNS relapse as compared with the CRT regimen, although their overall efficacy was not significantly different. In the ALL 911 study, intensive systemic chemotherapy with extended i,t, injections of MTX plus cytarabine achieved a high CNS relapse-free survival (98% +/- 1.9% at 7 years) and a favorable DFS (85.5% +/- 5% at 7 years) in the IR patients. The patients in the high-risk (HR) group in both ALL874 and ALL911 studies received the 18-Gy or 24-Gy CRT with intensive systemic chemotherapy. Their 7-year probabilities of CNS relapse-free survival ranged from 88% to 95%, among which the T-ALL patients had a risk of CNS leukemia, which was 3-4 times higher compared with B-precursor ALL patients., Conclusions: These results indicate that long-term intrathecal CNS prophylaxis as well as appropriate systemic therapy for the non-high-risk patients can provide protection against CNS relapse equivalent to that provided by cranial irradiation.