Hypersensitivity reactions to antiepileptic drugs in children.

BACKGROUND: Antiepileptic drugs (AEDs) can cause hypersensitivity reactions in children. These reactions are mainly cutaneous, self-limiting, and benign, but life-threatening severe cutaneous adverse reactions can occur. Infections can lead to skin eruptions and mimic drug hypersensitivity reactions, if a drug is taken at the same time. The aims of our study were to confirm or rule out the diagnosis of hypersensitivity reactions to AEDs in children and to detect an infection which mimics these reactions. METHODS: A prospective survey was conducted in a group of 100 children with histories of hypersensitivity reactions to AEDs by performing patch tests, delayed-reading intradermal test, and, in case of negative results, challenge test. In all children, a study was performed to detect infections by viruses or Mycoplasma pneumoniae. RESULTS: Maculopapular exanthema and delayed-appearing urticaria were the most reported hypersensitivity reactions to AEDs. Sixty-six (66%) of 100 children had confirmed hypersensitivity reactions to AEDs. Fifty-nine children had positive patch test. No children had positive challenge tests. The most common AEDs causing hypersensitivity reactions were carbamazepine (45.4%) and lamotrigine (43.6%). Thirty-two children had positive tests for viruses or M pneumoniae, and nine of them had also a positive allergy work-up. CONCLUSION: Considering that there are no specific tests to distinguish between a viral infection and hypersensitivity reactions to AEDs in the acute phase, a diagnostic work-up should be performed in all children with suspected hypersensitivity reactions to AEDs, as well as infectious agent study, to remove a false label of hypersensitivity.

The Impact of 22q11.2 Microdeletion on Cardiac Surgery Postoperative Outcome.

22q11.2 microdeletion is the most common microdeletion in humans. The purpose of this study was to evaluate postoperative outcome in children with 22q11.2 microdeletion who had undergone complete surgical correction of a congenital heart defect. The study included 34 patients who underwent complete correction of conotruncal heart defects. Of these, 17 patients diagnosed with 22q11.2 microdeletion represent the investigated group. Another 17 patients without 22q11.2 microdeletion represent the control group. Investigated and control groups differ significantly for total length of stay in the hospital (average 37.35 and 14.12 days, respectively); length of postoperative stay in the intensive care unit (average 10.82 and 6.76 days, respectively); sepsis (eight and two patients, respectively); administration of antibiotics (15 and seven patients, respectively); duration of antibiotic therapy (average 17.65 and 14.59 days, respectively); occurrence of hypocalcemia (16 and 0 patients, respectively); and initiation of peroral nutrition during the postoperative course (average 10.29 and 3.88 days, respectively). No difference was found for duration of ventilatory support (average 6.12 and 4.24 days, respectively), administration of total parenteral nutrition, and postoperative mortality rate. The study results suggest that genotype of 22q11.2 microdeletion affects postoperative outcome after cardiac surgery. Possible targets for intervention in postoperative intensive care management are prevention and treatment of systemic infections, monitoring, and treatment of hypocalcemias, rational administration of antibiotics and careful planning of nutrition. Consequently, this could shorten patients' intensive care stay and overall duration of hospitalization.

Mitotic crossover promotes leukemogenesis in children born with TEL-AML1 via the generation of loss of heterozygosity at 12p.

TEL-AML1 (ETV6-RUNX1) fusion gene which is formed prenatally in 1% of the newborns, is a common genetic abnormality in childhood Bcell precursor acute lymphoblastic leukemia. But only one child out of a hundred children born with this fusion gene develops leukemia (bottleneck phenomenon) later in its life, if contracts the second mutation. In other words, out of a hundred children born with TEL-AML1 only one child is at risk for leukemia development, which means that TEL-AML1 fusion gene is not sufficient for overt leukemia. There is a stringent requirement for a second genetic abnormality for leukemia development and this is the real or the ultimate cause of the leukemia bottleneck phenomenon. In most cases of TEL-AML1+ leukemia, the translocation t(12;21) is complemented with the loss of the normal TEL gene, not involved in the translocation, on the contralateral 12p. The loss of the normal TEL gene, i.e. loss of heterozygosity at 12p, occurs postnatally during the mitotic proliferation of TEL-AML1+ cell in the mitotic crossing over process. Mitotic crossing over is a very rare event with a frequency rate of 10-6 in a 10 kb region. The exploration and identification of the environmental exposure(s) that cause(s) proliferation of the TELAML1+ cell in which approximately 106 mitoses are generated to cause 12p loss of heterozygosity, i.e. TEL gene deletion, may contribute to the introduction of preventive measures for leukemia.

Methylenetetrahydrofolate reductase and glutathione S-tranferase gene polymorphisms in secondary mixed phenotype acute leukemia: a case report.

BACKGROUND: Therapy-induced leukemia is a well-known clinical syndrome occurring as a late complication in patients treated with cytotoxic therapy. OBSERVATION: We herein present results of analysis of common gene polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and glutathione S-transferase (GST) genes in a 10-year-old boy who developed very rare type of cancer, mixed phenotype acute leukemia, 6 years after treatment of acute lymphoblastic leukemia. CONCLUSIONS: Impairment in function of GST and MTHFR enzymes found in our patient may have contributed to the development of secondary mixed phenotype acute leukemia, although precise mechanism remains elusive.

Improving the Diagnosis of Children with 22q11.2 Deletion Syndrome: A Single-center Experience from Serbia.

OBJECTIVE: The incidence of the 22q11.2 microdeletion among children who have at least two out of five major clinical criteria for 22q11.2 deletion syndrome. DESIGN: Prospective study. SETTING: University Childrens Hospital in Belgrade, Serbia between 2005 and 2014. PARTICIPANTS: 57 patients with clinical characteristics of 22q11.2 deletion syndrome. METHODS: Standard G-banding cytogenetic analysis was performed in all children, and the 22q11.2 genomic region was examined using fluorescence in situ hybridization (FISH). For patients with no deletion detected by FISH, multiplex ligation-dependent probe amplification (MLPA) analysis was also done in order to detect cryptic deletions of this region and to analyze other genomic loci associated with phenotypes resembling the syndrome. A selected group of patients diagnosed to have 22q11.2 microdeletion by FISH underwent MLPA testing in order to characterize the size and position of deletion. OUTCOME MEASURES: The frequency of 22q11.2 microdeletion among children with at least two of the five major characteristics of 22q11.2 deletion syndrome (heart malformations, facial dysmorphism, T-cell immunodeficiency, palatal clefts and hypocalcemia/hypoparathyroidism). RESULTS: Typical 22q11.2 microdeletion was detected in 42.1% of patients; heart malformation were identified in all of them, facial dysmorphism in 79.2%, immunological problems in 63.6%, hypocalcemia in 62.5% and cleft palate in 8.3%. CONCLUSION: A higher detection rate compared to one-feature criterion is obtained when at least two major features of 22q11.2 deletion syndrome are taking into consideration. The criteria applied in this study could be considered by centers in low-income countries.

Wiskott-Aldrich syndrome with macrothrombocytopenia.

BACKGROUND: Wiskott-Aldrich syndrome is a rare X-linked immunodeficiency disorder with a variable phenotype. CASE CHARACTERISTICS: 3.5-year-old boy diagnosed with Wiskott-Aldrich syndrome. OBSERVATION: Unusual and persistent thrombocytopenia with increased platelet volume (>10fL). He did not exhibit characteristic clinical and laboratory finding for the syndrome. OUTCOME: Maternally inherited causative mutation in the exon 2 of the WAS gene was disclosed. MESSAGE: This is a need for multidisciplinary assessment of patients with congenital or early infantile thrombocytopenia, including testing for mutations of the WAS gene in all unexplained cases even in the absence of characteristic microthrombocytopenia.

Chromosomal instability in patients with Fanconi anemia from Serbia.

BACKGROUND/AIM: Fanconi anemia (FA) is a rare hereditary disease in a heterogeneous group of syndromes, so-called chromosome breakage disorders. Specific hypersensitivity of its cells to chemical agents, such as diepoxybutane (DEB), was used as a part of screening among patients with clinical suspicion of FA. The aim of this study was to determine chromosomal instability in patients with FA symptoms in Serbia. METHODS: A total of 70 patients with phenotypic symptoms of FA, diagnosed at the Mother and Child Health Care Institute of Serbia "Dr Vukan Cupic, Belgrade and University Children's Hospital, Belgrade from February 2004 to September 2011, were included in this study. Cytogenetic instability analysis was performed on untreated and DEB-treated 72 h-cultures of peripheral blood. RESULTS: Ten patients in the group of 70 suspected of FA, showed increased DEB induced chromosome breakage and were classified into the FA group. The range of DEB induced aberrant cells percentages in the FA group was from 32% to 82%. DEB sensitivity of 58 tested patients were bellow FA values (range: 0-6%) (non-FA group), with no overlapping. The remaining two patients showed borderline sensitivity (borderline FA group - FA*), comparing to the healthy controls. CONCLUSION: This study revealed 10 patients with FA on the basis of cytogenetic analysis of DEB induced chromosome aberrations. Our results are in consistency with those from the literature. Early and precise diagnosis of FA is very important in further treatment of these patients, considering its cancer prone and lethal effects.

[Frequency and characteristics of hepatitis B infection in children with malignant diseases].

INTRODUCTION: Hepatitis B, a complication of blood transfusion or other means of transmission, occurs with variable frequency in children with malignant diseases. OBJECTIVE: The objective of this study was to determine the frequency of hepatitis B virus infection in children with malignant diseases, to investigate the clinical course of the illness, and to analyse the influence of hepatitis on cytotoxic treatment. METHOD: The study included children diagnosed and treated for malignant diseases at the University Children's Hospital in Belgrade from 1997 to 2003. HBs Ag was analysed in all patients who had elevated transaminases of twice normal value, in children who had icterus, and in one group of patients treated routinely after 2001 before, during, and after therapy. RESULTS A total of 137 male and 107 female children who had malignancies were treated. From 113 children who were evaluated for the presence of HBs Ag at the beginning of treatment, 2 (1.7%) were HBsAg+. In this group of patients HBsAg was tested in 58 (51%) children during and after chemotherapy, and HBsAg was discovered in 17 (29%) of them. Of 123 children, in whom HBsAg was not tested at the beginning of their illness, 36 (55%) out of 66 (51%) tested patients were HBsAg+. No statistical difference between those two groups of patients was ascertained (chi2 = 3.27, p > 0.05). In summary, the presence of HBsAg was discovered in 53 patients, 22% out of 244 patients and 43% of tested patients. Nine patients had the icteric form of illness, with one case proving fatal due to fulminating hepatitis. CONCLUSION: Taking into consideration the uncertain long-term prognoses of these patients, follow-up and treatment is essential.

Size of the protein-coding genome and rate of molecular evolution.

In diploid populations of size N, there will be 2 Nmu mutations per nucleotide (nt) site (or per locus) per generation (mu stands for mutation rate). If either the population or the coding genome double in size, one expects 4 Nmu mutations. What is important is not the population size per se but the number of genes (coding sites), the two being often interconverted. Here we compared the total physical length of protein-coding genomes (n) with the corresponding absolute rates of synonymous substitution (K(S)), an empirical neutral reference. In the classical occupancy problem and in the coupons collector (CC) problem, n was expressed as the mean rate of change (K(CC)). Despite inherently very low power of the approaches involving averaging of rates, the mode of molecular evolution of the total size phenotype of the coding genome could be evidenced through differences between the genomic estimates of K(CC) [K(CC)=1/(ln n + 0.57721) n] and rate of molecular evolution, K(S). We found that (1) the estimates of n and K(S) are reciprocally correlated across taxa (r=0.812; p<< 0.001); (2) the gamete-cell division hypothesis (Chang et al. Proc Natl Acad Sci USA 91:827-831, 1994) can be confirmed independently in terms of K(CC)/K(S) ratios; (3) the time scale of molecular evolution changes with change in mutation rate, as previously shown by Takahata (Proc Natl Acad Sci USA 87:2419-2423, 1990), Takahata et al. (Genetics 130:925-938, 1992), and Vekemans and Slatkin (Genetics 137:1157-1165, 1994); (4) the generation time and population size (Lynch and Conery, Science 302:1401-1404, 2003) effects left their "signatures" at the level of the size phenotype of the protein-coding genome.

[Results of treatment of children with acute lymphoblastic leukemia with a modified BFM protocol]. / Rezultati lecenja dece obolelo od akutne limfoblastne leukemije po modifikovanom BFM protokolu.

Our study presents the results of ALL treatment from year 1995 to 2002 according to modified BFM protocol at the Department of Hematology of the University Children's Hospital, Belgrade. Modification was necessary due to inadequate drug and diagnostic reagent supply at that time and related mainly to reduced intensity of therapy and difference of definition of risk factors in relation to original BFM protocol. A total of 69 patients were treated, 36 girls (52.2%) and 33 boys (47.8%), mean age 4.5 years (range 0.4-16.8 yrs.). Thirteen children were classified as high risk, out of whom, one had Down syndrome, two had earlier corticosteroid treatment, nine were with T immunophenotype, out of whom three were poor prednisone responders and one was female infant. Clinical and laboratory parameters on diagnosis in our group were similar to the characteristics of patients in large published studies which exclude selection bias. There were four toxic deaths (5.8%) and ten relapses (14.5%). Five year event-free survival (EFS) with median follow-up of 5.2 years (range 2.2-9.2 years) was 70%.