Invasive pneumococcal disease in Danish children, 1996-2007, prior to the introduction of heptavalent pneumococcal conjugate vaccine.

AIM: The aim of this study was to document the epidemiology, microbiology and outcome of invasive pneumococcal disease (IPD) among children <16 years with quality surveillance data, just prior to the introduction of the heptavalent pneumococcal conjugate vaccine (PCV7) into the Danish routine immunization programme October 2007. METHODS: Clinical and microbiological records on cases of IPD in children <16 years admitted to Hvidovre Hospital, Denmark 1996-2007, were retrospectively reviewed. RESULTS: We identified 106 cases of IPD. The annual incidence of IPD was 11 per 100 000 in children <16 years, but considerably higher, 62 per 100 000, in children <2 years. Additionally, of the children with pneumococcal meningitis 86% were <2 years. We observed no fatalities. A total of 10% developed sequelae, but of the patients with pneumococcal meningitis 27% developed sequelae. Nine patients had known risk factors. The Streptococcus pneumoniae serotype was available for 81 cases. Seventy-five percent of the IPD cases in children aged <2 years were caused by one of the serotypes contained within PCV7, compared to only 24% in children >/=2 years. CONCLUSION: Our data indicate that an estimated 75% of all IPD cases among children <2 years are caused by PCV7 serotypes and might therefore be prevented by PCV7 vaccination.

Flow cytometric DNA index, G-band karyotyping, and comparative genomic hybridization in detection of high hyperdiploidy in childhood acute lymphoblastic leukemia.

High hyperdiploid acute lymphoblastic leukemia in children is related to a good outcome. Because these patients may be stratified to a low-intensity treatment, we have investigated the sensitivity of flow cytometry (FCM), G-band karyotyping (GBK), and high-resolution comparative genomic hybridization (HR-CGH) in detecting high hyperdiploid leukemic clones. Twenty-six girls and 34 boys with acute lymphoblastic leukemia diagnosed in 1998 to 1999 were analyzed by FCM, GBK, and HR-CGH. The correlations between DNA indices obtained by FCM, GBK, and HR-CGH were significant (rs=0.61 to 0.77; P<0.001 for all comparisons). However, in 4 of 18 patients, high hyperdiploidy was overlooked by GBK or HR-CGH, and even when FCM was applied, 2 of 18 patients with high hyperdiploidy by GBK and/or HR-CGH were classified as nonhigh hyperdiploid. If high hyperdiploid subclones were included, FCM could detect all high hyperdiploid patients found by either GBK or HR-CGH, but would then in addition classify 15% to 20% of the remaining patients as high hyperdiploid. Thus, both GBK and HR-CGH overlook patients with high hyperdiploidy, and FCM only detects all high hyperdiploid patients if small high hyperdiploid clones are included. In addition, FCM detects patients with high hyperdiploid subclones, not detected by either GBK or HR-CGH, and the challenge remains to determine the prognosis of patients with such high hyperdiploid subclones.

High-resolution comparative genomic hybridisation yields a high detection rate of chromosomal aberrations in childhood acute lymphoblastic leukaemia.

BACKGROUND: Cytogenetic aberrations are of prognostic significance in childhood acute lymphoblastic leukaemias and a high detection rate could improve the biological understanding and classification of these diseases. METHODS: Bone-marrow samples from 92 children with acute lymphoblastic leukaemia were studied by high-resolution comparative genomic hybridisation (HRCGH) using dynamic standard reference intervals that enhance both specificity and sensitivity in the detection of aberrations. RESULTS: In 80 patients (87%) HRCGH revealed a total of 405 aberrations, mostly whole chromosome gains (n = 265) and partial losses (n = 80). The 25 leukaemias with a gain of more than five whole chromosomes by HRCGH harboured only 7% of all losses. With G-band karyotyping 59 patients (64%) had aberrations. HRCGH revealed more aberrations per patient than did G-band karyotyping (median: 3 vs. 1, P = 0.005), revealed aberrations in 27 of the 34 patients for whom the G-band karyotyping failed or was found to be normal, and specifically revealed more 9p losses (21% vs. 5%, P < 0.005), 12p losses (12% vs. 2%, P < 0.05) and 17q gains (11% vs. 1%, P < 0.01). Compared to the present study, the frequency of patients with aberrant karyotypes was significantly lower in previous conventional CGH studies (64% vs. 87%, P < 0.0001), as was the rate of partial aberrations per patient (1.1% vs. 1.7, P < 0.001), particularly with fewer 6q losses, 9p losses and 17q gains detected. CONCLUSION: HRCGH is superior to conventional CGH as an adjunct to G-band karyotyping as it detects recurrent aberrations at a significantly higher rate than both these techniques.

A new mutation causing autosomal dominant periodic fever syndrome in a Danish family.

We describe four members in a family of 8 individuals over 3 generations with the autosomal dominant inherited periodic fever syndrome tumor necrosis factor receptor-associated periodic syndrome (TRAPS). The patients had recurrent episodes of fever, abdominal pain, arthritis, and rash. We examined the gene coding for the tumor necrosis factor receptor TNFRSF1A in all first-degree family members. In all 4 symptomatic members of the family, a hitherto undescribed mutation C98Y (380G-->A) in the TNFRSF1A gene was identified. In contrast, this mutation was not found in the 4 family members reported to be healthy nor in 50 normal control patients. The youngest member of the family, a 2-year-old boy, was treated successfully with etanercept.