[Fanconi Anemia, Complementation Group D1 Caused by Biallelic Mutations of BRCA2 Gene--Case Report]. / Fanconiho anémie, komplementacní skupina D1 v dusledku bialelické mutace genu BRCA2--kazuistika.

Fanconi anemia is a rare autosomal recessive disorder, clinically and genetically heterogeneous, characterized by typical clinical features, such as short stature, microcephaly, skeletal abnormalities, abnormal skin pigmentations, developmental delay and congenital heart, kidney anomalies etc. Pancytopenia leading to bone marrow failure occurs in the first decade. Patients with Fanconi anemia have a high risk of hematologic malignancies and solid tumors. The diagnosis of Fanconi anemia is based on cytogenetic testing for increased rates of spontaneous chromosomal breakage and increased sensitivity to diepoxybutane or mitomycin C. Fanconi anemia is a heterogeneous disorder, at least 15 complementation groups are described, and 15 genes in which mutations are responsible for all of the 15 Fanconi anemia complementation groups have been identified. Unlike other Fanconi anemia complementation groups, for complementation group D1 (FANCD1), the bone marrow failure is not a typical feature, but early-onset leukemia and specific solid tumors, most often medulloblastoma and Wilms tumor, are typical for this complementation group.

[Fluorescent in situ hybridization (FISH) in the diagnosis of acute childhood lymphatic leukemia (ALL)]. / Fluorescencní in situ hybridizace (FISH) v diagnostice detských akutních lymfatických leukémií (ALL).

Classical cytogenetic analysis plays an important role in the diagnosis, classification, therapy monitoring and prognosis of patients with leukemia. Many recurrent cytogenetic abnormalities with major prognostic values have been described in childhood ALL. Hyperdiploidy and/or t(12;21) are associated with good prognosis, whereas t(9;22) and/or rearrangements of MLL gene correlate with poor outcome and therefore early detection of these abnormalities is very important. FISH can overcome some limitations of conventional cytogenetic and molecular-genetic analyses and due to high sensitivity specific chromosomal aberrations in mitoses and/or interphase nuclei can be detected. In the Center of Oncocytogenetics of the 3rd Medical Department for assessment of hyperdiploidy and structural rearrangements we use double-color FISH with centromeric and/or locus-specific probes and complex aberrations are ascertained by whole chromosome painting probes and multicolor FISH. Among 275 children with ALL examined during the last 8 years by different FISH methods we found seven patients with translocation t(9;22) and 14 patients with MLL rearrangements in bone marrow cells. Since 1988 we focus on detection of hyperdiploidy and/or t(12;21). High hyperdiploidy was found in 35 children, 10 of them had further complex rearrangements. Translocation t(12;21) was proved in 37 patients and complex rearrangements were found in 22 of them. FISH, cytogenetic and molecular-genetic analyses become obligatory for the first diagnostic examination as well as for monitoring of treatment effect in children with ALL.

[Allogenic transplantation of hematopoietic stem cells in the treatment of children with high-risk acute leukemia]. / Alogenní transplantace kmenových bunek krvetvorby v lécbe detí s vysoce rizikovou akutní leukémií.

BACKGROUND: Most children with acute lymphoblastic leukemia (ALL) and increasing number of children with acute myelogenous leukemia (AML) are currently cured with conventional chemotherapy. Despite of this success there is a subset of patients with high-risk features at diagnosis who are predisposed to a very high risk of relapse. Relapse of AML and early bone marrow relapse of ALL can not be cured by conventional chemotherapy. Allogeneic hematopoietic stem cell transplantation (HSCT) is therapeutic option in these children with very high-risk acute leukemia. METHODS AND RESULTS: Between XI/1989-XII/1996 33 children with acute leukemia (ALL: 22, AML: 11) underwent an allogeneic HSCT from HLA identical related donors (HLA-identical sibling: 30, twin: 1, other HLA-identical relative: 2) at the 2nd Dept. of Pediatrics, University Hospital Motol. Median age of our group was 9 years (1.5-19 y.), boys (n = 23) clearly dominated over the girls (n = 10). The resource of stem cells was bone marrow in 31 children, bone marrow and peripheral blood progenitor cells (PBPC) and PBPC in one child respectively. Myeloablative conditioning regimen varied, consisting of total body irradiation and chemotherapy in 21 children and chemotherapy in 12 children. HSCT was performed in first complete remission of acute leukemia in 9 children (AML: 7, ALL: 2), in second remission in 14 children (AML: 2, ALL: 12), in third remission in 4 children (ALL: 4). Six children underwent HSCT in first partial remission (n = 1) and in second (n = 4) or third (n = 1) chemoresistant relapse. Seven (21%) children died due to post-transplant complications. Nine (28%) children suffered from clinically significant acute graft-versus-host reaction (GVH) and 15% (4/27) children who survived 100 days post-transplant suffered from chronic GVH disease. Relapse of leukemia was diagnosed in 39% (12/31) children. Fourteen (42%) children are alive and well in continuous remission with median follow-up 42 months. CONCLUSIONS: Allogeneic HSCT can cure children with very high-risk acute leukemia in the situations where conventional chemotherapy fails. Relapse of leukemia and GVH reaction are most important causes of post-transplant morbidity and mortality.

[Consolidation of therapy of acute myeloid leukemia with the AML-BFM 93 protocol in children in the Czech Republic]. / Sjednocení lécby detí s akutní myeloidní leukémií v Ceské republice podle protokolu AML-BFM 93.

BACKGROUND: Acute myeloid leukemia (AML) in children is rare. Although more resistant to chemotherapy than acute lymphoblastic leukemia, its responsiveness and survival rates have considerably improved during the last 15 years by virtue of intensification of chemotherapy and due to the better supportive care. Relapses still remain the main cause of treatment failure. Management of children with AML was unified in the Czech Republic in 1993 according to AML-BFM 93 Study protocol. METHODS AND RESULTS: Treatment results were evaluated in 61 patients, of whom 45 (73.8%) achieved complete remission. Five-year event-free-survival (EFS) was found in 42.3%, and overall survival was 45.3%. Prognosis of the standard-risk patients was significantly better than in the high-risk group (EFS 62.5% vs. 29.7%, p = 0.03). The most important prognostic factor was the early treatment response. Compared to chemotherapy, allogeneic stem-cell transplantation did not significantly improve the outcome of high-risk patients. CONCLUSIONS: Treatment results of children with AML in the Czech Republic are comparable to those achieved by leading leukemia study groups in the world. The aim of the next study is to increase the complete-remission rate by reducing early deaths.

Infection-associated hemophagocytic syndrome complicated by infectious lymphoproliferation: a case report.

The case of a 7-year-old boy with virus-associated hemophagocytic syndrome (VAHS) and serologically proven parvovirus B-19 infection is described. The patient with VAHS presented with fever, hepatosplenomegaly, pancytopenia, and hyperlipidemia type IV. After induction therapy with VP-16 and prednisone, partial remission was achieved. Despite maintenance therapy, reinductions, and the addition of cyclosporine A for 3 months, several relapses occurred. The therapy was stopped because of life-threatening complications (Klebsiella sepsis, neutropenic enterocolitis, and stercoral peritonitis). The complications were treated successfully. The patient status was stabilized after splenectomy. However, hepatomegaly progressed slowly and the hyperlipidemia endured. Ten months after the diagnosis leukocytosis with absolute T lymphocytosis appeared. Reactivation of VAHS was suspected and intravenous immunoglobin and then antilymphocyte immunoglobulin ALG therapy were started. The resultant decrease in leukocytosis was prompt, but lymphopenia did not occur. Virostatic treatment with foscarnet was introduced based on human herpesvirus-6 seroconversion. Twenty-six months after the diagnosis, the patient is well, without any sign of VAHS or lymphoproliferation.