Sevgi Yetgin

Biallelic mutations in PALB2 cause Fanconi anemia subtype FA-N and predispose to childhood cancer

PALB2 was recently identified as a nuclear binding partner of BRCA2. Biallelic BRCA2 mutations cause Fanconi anemia subtype FA-D1 and predispose to childhood malignancies. We identified pathogenic mutations in PALB2 (also known as FANCN) in seven families affected with Fanconi anemia and cancer in early childhood, demonstrating that biallelic PALB2 mutations cause a new subtype of Fanconi anemia, FA-N, and, similar to biallelic BRCA2 mutations, confer a high risk of childhood cancer.

Primary myelodysplastic syndrome in children: the clinical experience in 33 cases

Summary. We describe the clinicomorphological features in 33 cases of primary myelodysplastic syndrome classified according to the FAB classification which presented to a single centre over a 12 year period. Presenting features were typically related to pancytopenia although hepatosplenomegaly and granulocytic sarcomas were far more prevalent than in the adult population.

Virus-associated immune thrombocytopenic purpura in childhood.

Idiopathic thrombocytopenic purpura (ITP) in children is usually a self-limiting disorder. It may follow a viral infection or immunization and is caused by an inappropriate response of the immune system. Many viruses, such as human immuno deficiency virus, cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella, rubeola, mumps, and parvovirus, have been implicated in childhood ITP. This study is a retrospective chart review of pediatric patients diagnosed with virus-associated ITP at the Hacettepe University, G hsan Do < ramaci Childrens Hospital from 1997 to end of 2000. In viral serological studies, the EBV, CMV, and rubella antibodies were investigated for all patients at diagnosis (ELISA). The proportion of children whose ITP was associated with documented acute viral infection was 13.3% in this group. In the present study, clinical manifestations and laboratory data of virus-associated or not associated groups are similar except age. Median age of the virus-associated group is younger than that of the other, but it is not statistically significant.

Role of procalcitonin and CRP in differentiating a stable from a deteriorating clinical course in pediatric febrile neutropenia.

In clinical practice, when neutropenic-fever patients present with no microbiologically and clinically defined infection, the risk of underestimating an occult infection is of major concern, the clinicians have to make a decision on when to modify antibiotic therapy. Hence, a reliable, specific, and sensitive marker, which is regulated independently from the leukocyte count and the underlying disease, is needed for the early diagnosis of infections in cases of neutropenic fever. We have evaluated the diagnostic and follow-up value of procalcitonin (PCT) compared with C-reactive protein (CRP) and erythrocyte sedimentation rate in documenting the infection in neutropenic-fever patients undergoing intensive chemotherapy, as evidenced by the durational change in these parameters in the presence of defined infection. Forty-nine patients, who had 60 febrile episodes, and who were hospitalized in the Hacettepe University Ihsan Doğramacı Childrens Hospital between January 1, 2004 and January 1, 2005 were included in this prospective study. All patients had been diagnosed with neutropenic fever after intensive chemotherapy. In our study, PCT and CRP levels were significantly higher in neutropenic-fever patients (group I and group II separately) than in control patients (P<0.001) throughout the study period; but erythrocyte sedimentation rate levels did not show any significant difference (P>0.05). In sequential analyses of patients without documented infections, the median of PCT concentrations shows a tendency to fall after the 8th hour of onset of fever, whereas in patients with documented infections PCT concentrations fell after the 48th hour. In conclusion, our study suggests that PCT, when measured periodically, is a more useful diagnostic inflammation parameter in pediatric neutropenic-fever patients than CRP, both in estimating the severity of the infection and, the duration and origin of the fever. Hence, PCT might be helpful when deciding on initial therapy modification.

Clinical Importance of Serum Vascular Endothelial and Basic Fibroblast Growth Factors in Children with Acute Lymphoblastic Leukemia

The aim of this study is to evaluate, for the first time serum levels of vascular endothelial growth factor (s-VEGF), and basic fibroblast growth factor (s-b FGF) in children with acute lymphoblastic leukemia (ALL), and its relation to clinical manifestations of the disease. Although VEGF and b FGF have been suggested to be reliable prognostic indicators and important tools for treatment approach in malignant haematopoietic and solid tumours, experience in childhood ALL has been limited to only one study on angiogenesis and urine b FGF. All 31 ALL patients included in the present study at the time of diagnosis and in remission, and all 10 control children had detectable serum levels of VEGF and b FGF. The median level of s-VEGF at the time of diagnosis was significantly lower than in the control group and at the time of remission (respectively p=0,005, p=0,0001). Twenty six of 31 patients had an increasing trend of s-VEGF levels in remission reaching control values compared with the levels obtained at diagnosis. S-b FGF median levels at the time of diagnosis were the same as those of the control group, significantly lower than the median s-b FGF values in remission (p=0,001). In patients with lower platelet counts (< 50 × 109/L) growth factors (VEGF and b FGF) were lower than in patients with higher platelet counts (p=0,0009 and p=0,002 respectively). In patients with hepatosplenomegaly (longitudinal size> 3 cm) b FGF levels were higher than patients without hepatosplenomegaly (P=0,003). We concluded that the increment in both s-VEGF and s-b FGF in patients in remission may be related to the renewal of normal haematopoiesis. The increase in s-VEGF values in 26 out of 31 patients in remission compared to normal control values, may also suggest that there is clinical significance in ALL patients.

Primary hemophagocytic lymphohistiocytosis in Turkish children

Nineteen children with hemophagocytic lymphohistiocytosis (HLH) were studied in the Department of Pediatric Hematology, Hacettepe University. Patients were divided into two groups. Group 1 : Thirteen patients were classified as having a genetic etiology (7 familial, 6 presumed familial) on the basis of an affected sibling and consanguinity. There was a history of consanguineous marriage in 13 of the families. Seven of them had a history of a sibling with HLH. Group 2 : Six patients were diagnosed with sporadic HLH. The age at presentation for familial patients was 0.7-84 months (mean 21.9 - 24.9 months), and for sporadic cases it was 2.5-48 months (mean 22.7 - 19.8 months). The clinical and laboratory data of these two groups were similar at diagnosis. Thirteen cases were diagnosed premortem by bone marrow aspiration. Splenic biopsy was performed in 2 patients. Four patients were diagnosed by postmortem examination. Elevated LDH levels were found in all patients tested. No significant differences for clinical and laboratory data were found between the two groups.

Vitamin D-deficiency rickets and myelofibrosis

This study was aimed at detecting the early appearance of myelofibrosis by bone marrow biopsy examination in children with vitamin D-deficiency rickets. Twelve children, aged 4 to 18 months, were evaluated. Only a minimal increase of the reticulin was shown in rachitic children without anemia in whom no other laboratory evidence of myelofibrosis was present. Early signs of myelofibrosis with increase of reticulin were present in rachitic infants with anemia. In patients of the same age with iron deficiency anemia, the bone marrow reticulin findings were normal. Bone marrow biopsy after successful treatment of rickets could be repeated in one patient with myelofibrosis; results indicated that the myelofibrosis with anemia associated with vitamin D-deficiency rickets is reversible by vitamin D treatment.

Benefit of high-dose methylprednisolone in comparison with conventional-dose prednisolone during remission induction therapy in childhood acute lymphoblastic leukemia for long-term follow-up.

Eight-year event-free survival (EFS) was evaluated in 205 patients with acute lymphoblastic leukemia (ALL), to consider the efficacy of high-dose methylprednisolone (HDMP) given during remission induction chemotherapy between 1 and 29 days. The St Jude Total XI Study protocol was used after some minor modifications in this trial. Patients were randomized into two groups. Group A (n = 108) received conventional dose (60 mg/m2/day orally) prednisolone and group B (n = 97) received HDMP (Prednol-L, 900–600 mg/m2 orally) during remission induction chemotherapy. Complete remission was obtained in 95% of the 205 patients who were followed-up for 11 years; median follow-up was 72 months (range 60–129) and 8-year EFS rate was 60% overall (53% in group A, 66% in group B). The EFS rate of group B was significantly higher than of group A (P = 0.05). The 8-year EFS rate of groups A and B in the high-risk groups was 39% vs 63% (P = 0.002). When we compared 8-year EFS rate in groups A and B in the high-risk subgroup for both ages together ⩽2 or ⩾10 years, it was 44% vs 74%, respectively. Among patients in the high-risk subgroup with a WBC count ⩾50 × 109/l, the 8-year EFS was 38% in group A vs58% in group B. During the 11-year follow-up period, a total of 64 relapses occurred in 205 patients. In group A relapses were higher (39%) than in group B (23%) (P = 0.05). These results suggest that HDMP during remission-induction chemotherapy improves the EFS rate significantly for high-risk patients in terms of the chances of cure.

Acute parvovirus B19 infection mimicking juvenile myelomonocytic leukemia

Abstract: An 11‐month‐old patient with parvovirus infection mimicking juvenile myelomonocytic leukemia (JMML) is presented. The patients history, presenting physical and laboratory features, was suggestive of JMML and consisted of fever, hepatosplenomegaly, lymphadenopathy, desquamation of the skin, anemia, leukocytosis with monocytosis and trilineage dysplastic findings of the peripheral blood and bone marrow. However, positive IgM titers for parvovirus B19 followed by seroconversion, negative cytogenetics and the benign follow‐up of the patient suggested acute parvovirus infection as an etiologic factor for development of dysplastic features in the patient, and thus is recommended for consideration in the differential diagnosis of MDS. Although parvovirus B19 infection mimicking MDS has previously been shown in two patients with spherocytosis and one with subclinical immune deficiency; to our knowledge, the present report is the first describing the association of acute parvovirus B19 infection with dysplastic features mimicking myelodysplasia (MDS) in a child without a demonstrable underlying hematolymphoid disorder.

Myeloperoxidase Activity and Bactericidal Function of PMN in Iron Deficiency

In children with iron deficiency anemia, bactericidal capacity of polymorphonuclear leukocytes (PMN) and serum opsonic activity were studied. Nitroblue tetrazolium test (NBT), hexose monophosphate (HMP) shunt activation, and myeloperoxidase (MPO) activity of PMN of these cases were also examined. Bactericidal capacity and HMP shunt activation were found to be decreased in iron deficiency anemia ( p less than 0.001). MPO activity, NBT test, and serum opsonic activity were found to be within normal limits. After 1 1/2 months of iron therapy there was an improvement in bactericidal capacity and it returned to a normal level after 3 months of therapy.