A Rare Inherited Bone Marrow Failure Syndrome Disclosed by Reanalysis of the Exome Data of a Patient Evaluated for Cytopenia and Dysmorphic Features

BACKGROUND

Multisystemic findings of inherited bone marrow failure syndromes may cause difficulty in diagnosis. Exome sequencing (ES) helps to define the etiology of rare diseases and reanalysis offers a valuable new diagnostic approach. Herein, we present the clinical and molecular characteristics of a girl who was referred for cytopenia and frequent infections.

CASE REPORT

A 5-year-old girl with cytopenia, dysmorphism, short stature, developmental delay, and myopia was referred for genetic counseling. Reanalysis of the ES data revealed a homozygous splice-site variant in the DNAJC21 (NM_001012339.3:c.983+1G>A), causing Shwachman-Diamond Syndrome (SDS). It was shown by the RNA sequencing that exon 7 was skipped, causing an 88-nucleotide deletion.

CONCLUSIONS

Precise genetic diagnosis enables genetic counseling and improves patient management by avoiding inappropriate treatment and unnecessary testing. This report would contribute to the clinical and molecular understanding of this rare type of SDS caused by DNAJC21 variants and expand the phenotypic features of this condition.

Identification of the molecular etiology in rare congenital hemolytic anemias using next-generation sequencing with exome-based copy number variant analysis

OBJECTIVES

In congenital hemolytic anemias (CHA), it is not always possible to determine the specific diagnosis by evaluating clinical findings and conventional laboratory tests. The aim of this study is to evaluate the utility of next-generation sequencing (NGS) and clinical-exome-based copy number variant (CNV) analysis in patients with CHA.

METHODS

One hundred and forty-three CHA cases from 115 unrelated families referred for molecular analysis were enrolled in the study. Molecular analysis was performed using two different clinical exome panels in 130 patients, and whole-exome sequencing in nine patients. Exome-based CNV calling was incorporated into the traditional single-nucleotide variant and small insertion/deletion analysis pipeline for NGS data in 92 cases. In four patients from the same family, the PK Gypsy variant was investigated using long-range polymerase chain reaction.

RESULTS

Molecular diagnosis was established in 86% of the study group. The most frequently mutated genes were SPTB (31.7%) and PKLR (28.5%). CNV analysis of 92 cases revealed that three patients had different sizes of large deletions in the SPTB and six patients had a deletion in the PKLR.

CONCLUSIONS

In this study, NGS provided a high molecular diagnostic rate in cases with rare CHA. Analysis of the CNVs contributed to the diagnostic success.

Central nervous system thrombosis in pediatric acute lymphoblastic leukemia in Turkey: A multicenter study

BACKGROUND

In patients with acute lymphoblastic leukemia (ALL), the risk of thromboembolism increases due to hemostatic changes secondary to the primary disease and due to treatment-related factors. In this multicenter study, we aimed to research the frequency of central nervous system (CNS) thrombosis occurring during treatment, hereditary and acquired risk factors, clinical and laboratory features of patients with thrombosis, treatment approaches, and thrombosis-related mortality and morbidity rates in pediatric ALL patients.

PROCEDURE

Pediatric patients who developed CNS thrombosis during ALL treatment from 2010 to 2021 were analyzed retrospectively in 25 different Pediatric Hematology Oncology centers in Türkiye. The demographic characteristics of the patients, symptoms associated with thrombosis, the stage of the leukemia treatment during thrombosis, the anticoagulant therapy applied for thrombosis, and the final status of the patients recorded through electronic medical records were determined.

RESULTS

Data from 70 patients with CNS thrombosis during treatment, out of 3968 pediatric patients with ALL, were reviewed. The incidence of CNS thrombosis was 1.8% (venous: 1.5 %; arterial: 0.03%). Among patients with CNS thrombosis, 47 had the event in the first 2 months. Low molecular weight heparin (LMWH) was the most commonly used treatment with a median of 6 months (min-max: 3-28 months). No treatment-related complications occurred. Chronic thrombosis findings occurred in four patients (6%). In five (7%) patients who developed cerebral vein thrombosis, neurological sequelae (epilepsy and neurological deficit) remained. One patient died related to thrombosis, and the mortality rate was 1.4%.

CONCLUSION

Cerebral venous thrombosis and, less frequently, cerebral arterial thrombosis may develop in patients with ALL. The incidence of CNS thrombosis is higher during induction therapy than during other courses of treatment. Therefore, patients receiving induction therapy should be monitored carefully for clinical findings suggestive of CNS thrombosis.

Central Nervous System Fungal Infections in Children With Leukemia and Undergoing Hematopoietic Stem Cell Transplantation: A Retrospective Multicenter Study

BACKGROUND

Central nervous system fungal infections (CNSFI) are seen in patients with hematologic malignancies and have high morbidity and mortality. Because of their rarity, there is limited data on CNSFI in children with no established treatment protocols or guidelines.

MATERIALS AND METHODS

In this multicenter retrospective study, 51 pediatric patients with leukemia, 6 of whom had undergone bone marrow transplantation, with proven or probable CNSFI were evaluated. Fungal infections were defined as proven or probable based on European Organisation for Research and Treatment of Cancer criteria. Proven CNSFI was diagnosed by appropriate central nervous system (CNS) imaging or tissue sample findings in combination with positive microbiological results of cerebrospinal fluid. A positive culture, microscopic evidence of hyphae, a positive result of the galactomannan assays are defined as positive microbiological evidence. Probable CNSFI was defined as appropriate CNS imaging findings together with proven or probable invasive fungal infections at another focus without CNS when there is no other explanatory condition. Data was collected by using the questionnaire form (Supplemental Digital Content 1, http://links.lww.com/JPHO/A541 ).

RESULTS

Seventeen patients had proven, 34 patients had probable CNSFI. Headaches and seizures were the most common clinical findings. The median time between the onset of fever and diagnosis was 5 days. The most common fungal agent identified was Aspergillus . Sixteen patients received single-agent, 35 received combination antifungal therapy. Surgery was performed in 23 patients. Twenty-two patients (43%) died, 29 of the CNSFI episodes recovered with a 20% neurological sequelae.

CONCLUSION

CNSFIs should be considered in the differential diagnosis in patients with leukemia and refractory/recurrent fever, headache, neurologicalocular symptoms, and a radiologic-serological evaluation should be performed immediately. Early diagnosis and prompt management, both medical and surgical, are essential for improving clinical outcomes.

Hepatitis B Vaccination in Children With Ongoing Cancer Treatment: A Safety and Efficacy Study of Super-Accelerated Vaccination Scheme

OBJECTIVE

Children with cancer have an increased risk for hepatitis B virus (HBV) infections due to chemotherapy-induced secondary immunodeficiency and frequent blood transfusions. The aim of this study is to evaluate the efficacy and safety of hepatitis B vaccination during the intensive induction chemotherapy in children with cancer found to be seronegative for hepatitis B on admission.

MATERIALS AND METHODS

Children newly diagnosed with cancer were evaluated for the presence of hepatitis B surface antigen (HBsAg) and antibody on admission. The children negative for both were included in the study. A super-accelerated vaccination scheme (3 booster doses at days 1-5, 8-12, and 28-33) was administered to these seronegative children concurrently with induction chemotherapy. Antibody response was checked 4-8 weeks after the last vaccination and 6 months after the end of the treatment.

RESULTS

Eleven out of 122 children were seronegative for hepatitis B on admission (9%). Acute lymphoblastic leukemia, lymphoma, and solid tumors were diagnosed in 5, 4, and 2 children, respectively. Complete seroconversion was achieved in 4-8 weeks after the last vaccination with high titers of anti-HBs antibody, and all patients remained antibody-positive until 6 months after the completion of chemotherapy.

CONCLUSION

The risk of transfusion-related infections increases with a number of transfused products and donor exposures, and it is more significant for immunosuppressed children with hematologic and oncologic malignancies. Hepatitis B vaccination could safely be applied with brisk and sustained responses in this vulnerable population, based on the local epidemiological data.

Evaluation of Chromogenic Factor VIII Assay Compared with One-Stage Clotting Assay

BACKGROUND

Congenital factor VIII (FVIII) deficiency causes hemophilia A due to different types of defects in the FVIII gene. Although the chromogenic measurement is the reference method and shows less variability, a one-stage assay is the most commonly preferred method for measurement of FVIII. In this study, we aimed to evaluate the analytical performances of chromogenic and one-stage assays, and compare the results prior to introduction of newly developed extended half-life recombinant FVIII products.

METHODS

Sixty-six blood samples from residual material of Istanbul Faculty of Medicine, Central Laboratory workflow comprised the study group. Samples were classified; plasma FVIII > 40 IU and FVIII < 40 IU. FVIII activities were measured using one-stage clotting and chromogenic assays on a CS-2500 analyzer. Analytical performances were determined through precision, linearity, carryover, and comparability studies.

RESULTS

The within-run CV% of the one-stage assay on the CS-2500 had 1.6%, 2.6%, the between day CV% were 8.5%, 4.9 % for low and high controls, respectively. The within-run CV% of chromogenic method had 1.2% and 0.9%. Both methods demonstrated good linearity (R2 > 0.998), and the comparisons of both assays exhibited good agreement with minor bias for FVIII activity > 40 IU. However, a significant bias was obtained for FVIII activity < 40 IU.

CONCLUSIONS

We obtained higher results using the one-stage assay compared with the chromogenic assay, and a significant bias was found for the samples lower than 40 IU. The discrepancy can explained by the presence of a weak agreement for samples lower than 10 IU due to the lower detection limit of the chromogenic assay used in this study (1.5%).

SET Oncogene is Upregulated in Pediatric Acute Lymphoblastic Leukemia

Aims and background

The SET gene is a target of chromosomal translocations in acute leukemia and encodes a widely expressed multifunctional phosphoprotein. It has been shown that SET is upregulated in BCR-ABL1-positive cell lines, patient-derived chronic myeloid leukemia CD34-positive cells, and some solid tumors.

Methods and study design

We determined the expression level of SET in 59 pediatric acute lymphoblastic leukemia patients who were BCR-ABL-negative using quantitative real-time reverse-transcriptase-polymerase chain reaction.

Results

We showed that SET expression was significantly upregulated in 96.5% of B-acute lymphoblastic leukemia (28 of 29; 16.6 fold) and 93% of T-acute lymphoblastic leukemia (28 of 30; 47.6 fold) patients. This upregulation was not associated with any clinical features or overall and relapse-free survival.

Conclusions

Our results showed that SET is significantly overexpressed in pediatric acute lymphoblastic leukemia samples, and an increased level of SET might contribute to leukemic process.

Targeted high-throughput sequencing for genetic diagnostics of hemophagocytic lymphohistiocytosis

Background

Hemophagocytic lymphohistiocytosis (HLH) is a rapid-onset, potentially fatal hyperinflammatory syndrome. A prompt molecular diagnosis is crucial for appropriate clinical management. Here, we validated and prospectively evaluated a targeted high-throughput sequencing approach for HLH diagnostics.

Methods

A high-throughput sequencing strategy of 12 genes linked to HLH was validated in 13 patients with previously identified HLH-associated mutations and prospectively evaluated in 58 HLH patients. Moreover, 2504 healthy individuals from the 1000 Genomes project were analyzed in silico for variants in the same genes.

Results

Analyses revealed a mutation detection sensitivity of 97.3 %, an average coverage per gene of 98.0 %, and adequate coverage over 98.6 % of sites previously reported as mutated in these genes. In the prospective cohort, we achieved a diagnosis in 22 out of 58 patients (38 %). Genetically undiagnosed HLH patients had a later age at onset and manifested higher frequencies of known secondary HLH triggers. Rare, putatively pathogenic monoallelic variants were identified in nine patients. However, such monoallelic variants were not enriched compared with healthy individuals.

Conclusions

We have established a comprehensive high-throughput platform for genetic screening of patients with HLH. Almost all cases with reduced natural killer cell function received a diagnosis, but the majority of the prospective cases remain genetically unexplained, highlighting genetic heterogeneity and environmental impact within HLH. Moreover, in silico analyses of the genetic variation affecting HLH-related genes in the general population suggest caution with respect to interpreting causality between monoallelic mutations and HLH. A complete understanding of the genetic susceptibility to HLH thus requires further in-depth investigations, including genome sequencing and detailed immunological characterization.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-015-0244-1) contains supplementary material, which is available to authorized users.

Plasma Levels of Plasminogen Activator Inhibitor Type 1 and Vitronectin in Children With Cancer

BACKGROUND

The plasminogen activator system controls intravascular fibrin deposition; besides, it also participates in a wide variety of physiologic and pathologic processes, including cancer.

PROCEDURE

In this study, we examined the levels of plasminogen activator inhibitor 1 (PAI-1) and vitronectin in 32 newly diagnosed pediatric patients with malignancies, determined by enzyme-linked immunosorbent assay between January 2009 and January 2010 and compared them to 35 age-matched healthy children, using SPSS 16.0 software.

RESULTS

The mean level of PAI-1 was 23.02 ± 15 (8.2-71.19) ng/mL and vitronectin was 83.10% ± 23.77% (12%-126%) in the tumor group. Thirty-five healthy children in the same age range were enrolled in the control group. The levels of PAI-1 and vitronectin were 23.63 ± 10.44 (11.67-58.85) ng/mL and 85% ± 20.85% (39%-126%), respectively. No significant difference was found between the 2 groups by independent sample t-test (P = .86 and P = .69).

CONCLUSIONS

This is a preliminary study done in children with malignancies, investigating PAI-1 and vitronectin. Further study is needed, including larger trials and tumor tissue with histopathological examination as in adults.

SET oncogene is upregulated in pediatric acute lymphoblastic leukemia

AIMS AND BACKGROUND

The SET gene is a target of chromosomal translocations in acute leukemia and encodes a widely expressed multifunctional phosphoprotein. It has been shown that SET is upregulated in BCR-ABL1-positive cell lines, patient-derived chronic myeloid leukemia CD34-positive cells, and some solid tumors.

METHODS AND STUDY DESIGN

We determined the expression level of SET in 59 pediatric acute lymphoblastic leukemia patients who were BCR-ABL-negative using quantitative real-time reverse-transcriptase-polymerase chain reaction. Results. We showed that SET expression was significantly upregulated in 96.5% of B-acute lymphoblastic leukemia (28 of 29; 16.6 fold) and 93% of T-acute lymphoblastic leukemia (28 of 30; 47.6 fold) patients. This upregulation was not associated with any clinical features or overall and relapse-free survival.

CONCLUSIONS

Our results showed that SET is significantly overexpressed in pediatric acute lymphoblastic leukemia samples, and an increased level of SET might contribute to leukemic process.

Infantile hemangiomas, complications and follow-up

OBJECTIVE

To study the risk factors for hemangioma-related complications, treatment indications and analyze the outcome of patients with infantile hemangioma.

DESIGN

Retrospective.

SETTING

University hospital.

PATIENTS

Fifty-five patients (1-69 months; median: 12 months) with infantile hemangioma with mean follow-up 19 months. The eligibility was based on the criteria of the International Society for the Study of Vascular Anomalies (ISSVA).

INTERVENTION

The surgical treatment included total excision whereas medical treatment was carried out by interferon and /or corticosteroids.

MAIN OUTCOME MEASURES

Data was collected including sex, age, prematurity, age at onset, number, anatomic location and size of hemangioma, age at treatment, cause of treatment decision, family history, presence of extra malformations, involvement of internal organs, presence of life altering or life threatening complications, response to treatment, dose and duration of medications, complications associated with treatment, follow-up period, and final outcome.

RESULTS

Thirty-four (62%) patients were followed-up without treatment, whereas 21 others underwent treatment including steroids, interferon, and surgery. The size of hemangioma was a major factor that predicted hemangioma-related complications (P=0.002). Patients with hemangioma related complications had bigger lesions (size >40 cm² or the longest size on a single plane >5 cm). Nineteen patients (34%) had complications, but only 8 (14.5%) out of them had life or function-threatening complications.

CONCLUSION

Although dosing and treatment protocol is still debatable, steroids and interferon are good options for hemangioma treatment. The management strategy should be individualized for each case.

How to manage an unresectable or recurrent sialoblastoma

Only 2-5% of all salivary gland tumors occur in children. Sialoblastoma is an extremely rare salivary gland tumor diagnosed at birth or shortly thereafter with significant variability in histological range and clinical course, so that it may be difficult to predict the most appropriate therapy. In cases where surgical removal is not curative or technically feasible, chemotherapy may be attempted. We report herein a patient with progression of a huge partially resected sialoblastoma who was successfully treated with chemotherapy. Systemic chemotherapy with vincristine, actinomycin D, and cyclophosphamide (VAC) seems to be an effective adjuvant or neoadjuvant treatment option for unresectable or recurrent sialoblastoma.

Li-Fraumeni syndrome in a Turkish family

Li-Fraumeni syndrome (LFS) is one of the familial cancers characterized by different tumors and hereditary TP53 mutations. The adrenocortical carcinoma (ACC) association with acute leukemia is unusual in childhood, even in LFS. The authors here present a family with pR337P mutation in TP53 gene who had a child with acute lymphoblastic leukemia (ALL) and associated adrenocortical carcinoma as a case 1 and his cousin with brain tumor as a case 2. A hereditary TP53 mutation supported the diagnosis of LFS in this family. The patients had many difficulties in treatment strategies and succumbed to death. The availability of a reliable molecular marker to detect the R337P TP53 mutation allows the rapid identification of carriers in families that have a child with ACC. Once identified, carriers could be screened for early detection of ACC by imaging and endocrine studies and should be given psychological support to prevent anxiety for death. Whether early detection of ACC will reduce the mortality in these patients remains to be determined.

Respiratory syncytial virus infection outbreak among pediatric patients with oncologic diseases and/or BMT

BACKGROUND

Respiratory syncytial virus (RSV) has been reported to cause severe morbidity and mortality among cancer patients receiving chemotherapy with or without autologous/allogeneic hematopoetic stem cell transplantation (HSCT). There have been few reports describing the outcome of RSV infection specifically among pediatric oncology patients.

METHODS

Two RSV infection outbreaks developed between February-April 2006 and January-March 2009 in hospitalized pediatric patients for various hemato-oncological diseases + or - HSCT. A survey of respiratory viruses was done using direct immunofluorescent antibody assay from nasopharyngeal washing aspirate.

RESULTS

In two RSV infection outbreaks (2006 and 2009), RSV antigen was detected in 6/30 patients. Five of six patients with RSV antigen were all treated with 0.2-0.4 g/kg intravenous immune globulin (IVIG) and specific antiviral therapy, oral ribavirin (20-25 mg/kg/day in three doses). Five patients recovered fully, although two were retreated due to recurrent (+) RSV antigen and respiratory symptoms within 2 weeks. We did not give oral ribavirin to one patient with (+) RSV antigen due to mild symptoms. All patients are alive and well.

CONCLUSIONS

In contrast with the outcome of RSV infection in adult oncology patients, the mortality associated with RSV infection in pediatric oncology patients even in post bone marrow transplantation (BMT) period, is low when diagnosed and treated early enough. Oral ribavirin might be an option together with IVIG in the treatment of RSV especially when other forms of antivirals could not be obtained. This approach will make it possible to give the scheduled anti-neoplastic therapy on time.

Stroke in childhood: experience in Istanbul, Turkey

Our objective was to characterize the etiologic factors and outcome for stroke in children. We retrospectively reviewed the charts of patients between the ages of 40 days and 94 months (36.5 +/- 23.7 months) with stroke seen at Istanbul Medical Faculty, Department of Pediatrics between January 1995 and December 2003. We found 79 cases of stroke: 57 ischemic and 22 hemorrhagic strokes. Seventeen children had vitamin K deficiency dependent hemorrhage. In 14 children stroke occurred as a complication of cardiac disease, 7 had moyamoya disease, 3 had protein C deficiency, 2 had thalassemia, 2 had hyperhomocysteinemia (methylene tetrahydrofolate reductase gene mutation), 2 were heterozygote for factor V Leiden, 3 had Down's syndrome, 1 was diagnosed with antiphospholipid syndrome, 1 had glycogen storage disease, and in 28 children no underlying cause could be found. Multiple risk factors were found in 4 children. The outcome in all 79 stroke patients was as follows: asymptomatic 60%; symptomatic epilepsy or persistent neurologic deficit 37%; death 3%; and recurrent stroke 5%. Thus, an underlying cause for stroke was identified in 65% of the children in the study group; 40% of the children either died or suffered motor and/or cognitive sequelae.

Allogeneic versus autologous versus peripheral stem cell transplantation in CR1 pediatric AML patients: a single center experience

BACKGROUND

Treatment of childhood acute myelocytic leukemia (AML) in first remission, is still evolving. Allogeneic bone marrow transplantation (BMT) in patients with a donor has been well established, but the role of autologous transplantation remains of interest, particularly in the light of some encouraging results in adults.

PROCEDURE

Out of 81 pediatric patients with AML in first CR, 67 were biologically randomized for allogeneic (n = 31), autologous (n = 20), or peripheral stem cell transplant (n = 16) after completing consolidation treatment, with the remaining (n = 11) dropping out or receiving chemotherapy. Disease free survival (DFS) of these different groups were analyzed.

RESULTS

Allogeneic transplantation is not superior to autologous and autologous peripheral blood stem cell transplantation (PBSCT) (DFS in 5 years is 61%, 50%, and 75%). The 5 years DFS in the autologous PBSCT group is significantly better than in the autologous BMT group (75% vs. 50%, P < 0.05).

CONCLUSION

In pediatric AML patients without a donor, autologous BMT or autologous PBSCT appears to be an effective treatment option with low transplant related mortality especially in less privileged countries where the chemotherapy only results are still low.

NAD(P)H:quinone oxidoreductase 1 null genotype is not associated with pediatric de novo acute leukemia

BACKGROUND

NAD(P)H:quinone oxidoreductase1 (NQO1) is a two-electron reductase that detoxifies quinones derived from the oxidation of phenolic metabolites of benzene. Exposure to benzene metabolites increases the risk of hematotoxicity and leukemia. NQO1 enzyme activity protects the cells against metabolites of benzene. C to T base substitution at nucleotide 609 of NQO1 cDNA (C609T) results in loss of enzyme activity. Low NQO1 activity may play a role in etiology of acute leukemia.

PROCEDURE

We analyzed NQO1 C609T gene polymorphism using the PCR-RFLP method in 273 patients with de novo acute leukemia (189 acute lymphoblastic leukemia (ALL), and 84 acute myeloid leukemia (AML) and 286 healthy volunteers to investigate the role of NQO1 polymorphism in the etiology of acute leukemia.

RESULTS AND CONCLUSIONS

The frequency of homozygosity for NOQ1 C609T polymorphism was 3.5% in the healthy control population and 2.5% in pediatric acute leukemia. The NQO1 C609T allele frequency was not statistically different in the children with acute leukemia in comparison to the controls (odds ratio (OR), 0.76; 95% confidence interval (CI), 0.58-1.01; P = 0.06). The distribution of NQO1 genotypes among children with acute leukemia was not statistically different from the control group (P = 0.13). These findings do not support the role of NQO1 C609T polymorphism in the etiology of de novo pediatric acute leukemia.

Secondary hemophagocytic lymphohistiocytosis induced by malaria infection in a child with Langerhans cell histiocytosis

Since the first description of infection-associated hemophagocytosis (IAHS), the list of precipitating infectious agents causing hemophagocytic syndrome has grown. A lymphohistiocytic proliferation with hemophagocytosis may develop as a result of macrophage activation, viral or bacterial infection, parasitic infestations, or malignancy. The authors report on a 3-year-old boy with Langerhans cell histiocytosis (LCH), who developed IAHS during malaria infection. Hemophagocytic syndromes may complicate the course of LCH and cause diagnostics problems. Malaria is one of many infections that can precipitate secondary hemophagocytic lymphohistiocytosis.

Pulmonary tuberculosis in children with Hodgkin's lymphoma

The clinical presentation of tuberculosis (TB) and Hodgkin's lymphoma (HL) with pulmonary involvement is similar and raises problems of differential diagnosis. It may also be difficult to distinguish TB from relapsed lymphoma. The purpose of this study was to evaluate the association of HL and pulmonary TB and to discuss differential diagnosis. Medical records of 70 children were reviewed retrospectively. A total of 27 patients (38%) had mediastinal-pulmonary involvement initially. Systemic symptoms were present in 37 (52%) patients. In all, 14 patients (20%) had pulmonary TB; three of them were diagnosed as having TB before HL, two of them had TB and HL concomittantly at initial diagnosis, seven of them during lymphoma therapy and two of them after the cessation of lymphoma treatment. PPD was positive (>10 mm) only in seven patients. In all, 11 patients with pulmonary TB had diffuse pulmonary infiltrations and mediastinal enlargement at lung contrast-enhanced computed tomography and X-ray, which was difficult to differentiate from HL. Biopsies were performed in five patients. No mortality because of the infection was seen. Only one patient had been lost as relapsed-resistant HL. To evaluate mediastinal lymphadenopathies is very crucial and the differential diagnosis is difficult; hence the association between HL and the TB must be considered especially in countries where TB is highly endemic.

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.

Results of rhabdomyosarcoma treatment in a developing country

Fifty-one children (median age: 4.5 years; 4 months-16 years) diagnosed with rhabdomyosarcoma were treated in our center between 1980-1999. The primary sites were head and neck in 31.4%, the genito-urinary system in 21.6%, and extremities in 9.8% of the patients. The histopathologic subtypes were embryonal in 80.4%, alveolar in 9.8%, and undifferentiated in 9.8%. The majority of the patients were considered group III (47%) and group IV (25.5%) according the criteria of the Intergroup Rhabdomyosarcoma Study (IRS). Primary total tumour resection was performed in only 27.5% of the patients. The patients were treated with assigned regimens of IRS II and IRS III protocols. Radiotherapy was applied to 92.1% of the patients. Thirty-four patients (66.7%) were lost to follow up, and of the remaining 17 patients, 7 patients (41.2%) died, relapse occurred in 9 patients (52.9%) and 10 patients (58.8%) are alive. The percentage of cases lost to follow up during the first 10 years and the following 9 years of the study were 77.4% and 50%, respectively. In compliance with cancer treatment remains a major problem in developing countries.

Immune tolerance induction in the treatment of paediatric haemophilia A patients with factor VIII inhibitors

The development of an inhibitor to transfused factor VIII (FVIII) is a serious treatment-related problem in haemophiliac children. The management of patients with high titre FVIII inhibitors is difficult, and immune tolerance induction (ITI) is the only method available for the eradication of these inhibitors. The results of the ITI regimen used at the Children's Hospital of Michigan Haemophilia Treatment Center are described and discussed. ITI was attempted in 14 children with severe haemophilia A (13 high responders, one low responder), with daily doses of FVIII alone. FVIII dosage was chosen according to the patient's historical peak inhibitor titre. ITI included three phases; induction phase, dose reduction phase and maintenance phase. During the first phase, the starting dose was 50 or 100 U kg-1 d-1; during the second phase the FVIII dosage was reduced gradually to 25 U kg-1 every other day according to the inhibitor titre, FVIII recovery and/or half-life study. In the third (maintenance) phase, the children received either prophylactic therapy or episodic therapy for 12 months. The inhibitor elimination was defined as the time taken to achieve a negative inhibitor assay with no anamnestic response and normal FVIII recovery and/or normal half-life. Immune tolerance was achieved in 11 of 14 patients (79%) patients within a median time of 6 months; two children are still on therapy, three failed ITI. We observed either failure or prolongation of immune tolerance if the historical peak titre or the maximum titre during ITI was >200 BU. The success rate of our low dose ITI regimen is not different from that reported by other investigators and the inhibitor elimination time is similar to some of the studies reported previously.