Sema Anak

A male-specific increase in the HLA-DRB4 (DR53) frequency in high-risk and relapsed childhood ALL

Previous studies reported significant HLA-DR associations with various leukemias one of which is with HLA-DRB4 (DR53) family in male patients with childhood ALL. We have HLA-DR-typed 212 high-risk or relapsed patients with childhood (n=114) and adult (n=98) ALL and a total of 250 healthy controls (118 children, 132 adult) by PCR-SSP analysis. The members of the HLA-DRB3 (DR52) family were underrepresented in patients most significantly for HLA-DRB1*12 (P=0.0007) and HLA-DRB1*13 (P=0.0001). In childhood ALL, the protective effect of DRB3 was evident in homozygous form (P=0.001). The DRB4 marker frequency was increased in males with childhood ALL (67.4%) compared to age- and sex-matched controls (42.1%, P=0.003) and female patients (35.7%, P=0.004). Besides being a general marker for increased susceptibility to childhood ALL in males, HLA-DRB4 is over-represented in high-risk patients. These results further suggest that the HLA system is one of the components of genetic susceptibility to leukemia but mainly in childhood and in boys only.

Successful haematopoietic stem cell transplantation in 44 children from healthy siblings conceived after preimplantation HLA matching

Haematopoietic stem cell transplantation (HSCT) remains the best therapeutic option for many acquired and inherited paediatric haematological disorders. Unfortunately, the probability of finding an HLA matched donor is limited. An alternative technique is PGD combined with HLA matching, which offers the possibility of selecting unaffected embryos that are HLA compatible with the sick child, with the aim of possible use of stem cells from the resulting baby in future. Since the first successful report for Fanconi anaemia a decade ago, the therapeutic success of this technique was reported in a few cases and for a limited number of disorders. Here, we report full recovery of 44 sick children who received HSCT from healthy infants conceived after pre-implantation HLA matching for the following 10 indications; beta-thalassaemia, Wiskott-Aldrich syndrome, Fanconi anaemia, sickle cell anaemia, acute myeloid leukaemia, acute lymphoblastic leukaemia, Glanzmanns thrombasthaenia, Diamond-Blackfan anaemia, X-linked adrenoleukodystrophy and mucopolysaccharidosis type I. No serious complications were observed among recipients and donors. Graft failure occurred in four children with beta-thalassaemia where a second HSCT was planned. Preimplantation HLA matching is a reliable technique and provides a realistic option for couples seeking treatment for an affected child when no HLA-matched donor is available.

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

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.

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

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.

Effect and safety of granulocyte transfusions in pediatric patients with febrile neutropenia or defective granulocyte functions.

Background Despite the introduction of new broad-spectrum antibiotics and antifungal therapies over the past decade, infections remains the most frequent cause of death in patients with neutropenia. The aim of this study is to assess the effect and safety of granulocyte transfusions (GTX) for the treatment of severe life-threatening infections in pediatric patients with febrile neutropenia or defective granulocyte functions. Methods In this study, 35 pediatric patients with high-risk febrile neutropenia or defective granulocyte functions, who received 111 GTX, were included. GTX were used for 3 consecutive days during infections not responding to antimicrobial therapy. Results The mean granulocyte content per concentrate was 27.4×109 (min: 4.2×109 to max: 68.4×109) depending on donors white blood cell count before harvest. GTX were well tolerated in all patients. The infection-related survival rate was 82.4% and overall survival rate was 77.1% at day 30. The overall survival rate was 65.7% and 52% at 3 and 48 months, respectively. Conclusions GTX is safe and effective in controlling the life-threatening infections. Further randomized controlled studies with long-term follow-up are needed to assess the exact role of GTX in the outcome of patients with neutropenia and patients with defective granulocyte functions.

Prognostic significance of NOTCH1 and FBXW7 mutations in pediatric T-ALL.

The NOTCH signaling pathway plays important role in the development of multicellular organisms, as it regulates cell proliferation, survival, and differentiation. In adults, it is essential for the T- or B-lymphocyte lineage commitment. NOTCH1 and FBXW7 mutations both lead the activation of the NOTCH1 pathway and are found in the majority of T-ALL patients. In this study, the mutation analysis of NOTCH1 and FBXW7 genes was performed in 87 pediatric T-ALLs who were treated on the ALL-BFM protocols. In 19 patients (22%), activating NOTCH1 mutations were observed either in the heterodimerization domain or in the PEST domain and 7 cases (10%) demonstrated FBXW7 mutations (2 cases had both NOTCH1 and FBXW7 mutations). We also analyzed the relationship of the mutation data between the clinical and biological data of the patients. NOTCH1 and FBXW7, NOTCH1 alone were found correlated with lower initial leucocyte counts which was independent from the sex and T- cell immunophenotype. However, NOTCH1 and FBXW7 mutations were not predictive of outcome in the overall cohort of pediatric T-ALLs.

National survey of hemapheresis practice in Turkey (1998)

The Turkish Apheresis Group has maintained a national registry for apheresis activities since 1997. The hemapheresis practice of Turkey in 1998 is summarized in brief detail in this article. A total of 30, 136 apheresis procedures were performed at 31 different apheresis centers. At 10 centers, 145 peripheral blood stem cell (PBSC) apheresis were performed on 82 patients in allogeneic setting and at 17 centers, 981 PBSC apheresis were performed on 271 patients in autologous setting. Frequently observed adverse effects during PBSC apheresis were mild tremor and chills, paresthesia and nausea in 15% of the patients and donors. Vascular access complications, particularly observed in autologous setting due to central venous catheters were encountered in 10% of the procedures. Eight hundred and sixty-nine therapeutic plasma exchange procedures were performed at 21 centers on 172 patients, most commonly for neurological disorders and thrombotic thrombocytopenic purpura (TTP)/hemolytic uremic syndrome (HUS). Therapeutic cytapheresis procedures like leukapheresis, plateletapheresis and erythrocyte apheresis were performed especially for cytoreduction in myeloproliferative disorders. A total of 204 cytapheresis procedures (66% leukapheresis, 33% plateletapheresis and 1% erythrocytapheresis) were performed on 134 patients in 15 centers. Donor plateletapheresis was the most used apheresis procedure, reaching a total of 28.016 in 1998. Many university hospitals and a few state hospitals are performing above-mentioned apheresis procedures with great success and acceptable side effects. According to these data we are planning prospective trials and will establish National Standards of Practice.

The frequency of HLA class I and II alleles in Turkish childhood acute leukaemia patients.

In this study, blood samples were taken from 200 patients with childhood acute leukaemias, including acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML), and from 100 healthy volunteers (controls). The frequency of the human leucocyte antigen (HLA)-DRB1*04 allele was significantly higher, and the frequencies of the HLA-A23 and HLA-B7 antigens were significantly lower, in patients with ALL compared with controls. Among patients with AML, the frequency of the HLA-B49 antigen and the HLA-DRB1*15 allele were significantly higher, whereas the frequencies of the HLA-A11 and HLA-B38 antigens were significantly lower compared with controls. The frequency of the HLA-DRB1*04 allele was also significantly higher in male patients with ALL and AML, whereas the HLA-DRB1*13 allele was found significantly less frequently in male AML and female ALL patients than in controls. To date, this is the only study to evaluate the associations between HLA molecules and leukaemia in a Turkish population with acute childhood leukaemia.

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 diagnostic problems. Malaria is one of many infections that can precipitate secondary hemophagocytic lymphohistiocytosis.

HLA‐matched family hematopoetic stem cell transplantation in children with beta thalassemia major: The experience of the Turkish Pediatric Bone Marrow Transplantation Group

Yesilipek MA, Ertem M, Cetin M, Öniz H, Kansoy S, Tanyeli A, Anak S, Kurekci E, Hazar V. HLA‐matched family hematopoetic stem cell transplantation in children with beta thalassemia major: The experience of the Turkish Pediatric Bone Marrow Transplantation Group.