Osteoarticular Infections in Pediatric Hospitals in Europe: A Prospective Cohort Study From the EUCLIDS Consortium.

Background: Pediatric osteoarticular infections (POAIs) are serious diseases requiring early diagnosis and treatment. Methods: In this prospective multicenter cohort study, children with POAIs were selected from the European Union Childhood Life-threatening Infectious Diseases Study (EUCLIDS) database to analyze their demographic, clinical, and microbiological data. Results: A cohort of 380 patients with POAIs, 203 with osteomyelitis (OM), 158 with septic arthritis (SA), and 19 with both OM and SA, was analyzed. Thirty-five patients were admitted to the Pediatric Intensive Care Unit; out of these, six suffered from shock, one needed an amputation of the right foot and of four left toes, and two had skin transplantation. According to the Pediatric Overall Performance Score, 36 (10.5%) showed a mild overall disability, 3 (0.8%) a moderate, and 1 (0.2%) a severe overall disability at discharge. A causative organism was detected in 65% (247/380) of patients. Staphylococcus aureus (S. aureus) was identified in 57.1% (141/247) of microbiological confirmed cases, including 1 (0.7%) methicillin-resistant S. aureus (MRSA) and 6 (4.2%) Panton-Valentine leukocidin (PVL)-producing S. aureus, followed by Group A Streptococcus (18.2%) and Kingella kingae (8.9%). K. kingae and PVL production in S. aureus were less frequently reported than expected from the literature. Conclusion: POAIs are associated with a substantial morbidity in European children, with S. aureus being the major detected pathogen. In one-third of patients, no causative organism is identified. Our observations show an urgent need for the development of a vaccine against S. aureus and for the development of new microbiologic diagnostic guidelines for POAIs in European pediatric hospitals.

A neomorphic variant in SP7 alters sequence specificity and causes a high-turnover bone disorder.

SP7/Osterix is a transcription factor critical for osteoblast maturation and bone formation. Homozygous loss-of-function mutations in SP7 cause osteogenesis imperfecta type XII, but neomorphic (gain-of-new-function) mutations of SP7 have not been reported in humans. Here we describe a de novo dominant neomorphic missense variant (c.926 C > G:p.S309W) in SP7 in a patient with craniosynostosis, cranial hyperostosis, and long bone fragility. Histomorphometry shows increased osteoblasts but decreased bone mineralization. Mice with the corresponding variant also show a complex skeletal phenotype distinct from that of Sp7-null mice. The mutation alters the binding specificity of SP7 from AT-rich motifs to a GC-consensus sequence (typical of other SP family members) and produces an aberrant gene expression profile, including increased expression of Col1a1 and endogenous Sp7, but decreased expression of genes involved in matrix mineralization. Our study identifies a pathogenic mechanism in which a mutation in a transcription factor shifts DNA binding specificity and provides important in vivo evidence that the affinity of SP7 for AT-rich motifs, unique among SP proteins, is critical for normal osteoblast differentiation.

Mucormycosis in paediatric patients: demographics, risk factors and outcome of 12 contemporary cases.

Mucormycosis is associated with high morbidity and mortality and is perceived as an emerging fungal infection. However, contemporary paediatric data are limited. We present a series of paediatric cases of mucormycosis reported from Germany and Austria collected within a voluntary epidemiological survey through standardised, anonymized case report forms. Twelve cases were reported between January 2004 and December 2008 (six men; mean age: 12.6 years, range: 0.1-17 years). Mucormycosis was proven in nine, and probable in three cases. Isolates included Lichtheimia (syn. Absidia pro parte, Mycocladus) (five), Rhizopus (three) and Mucor (one) species. Infection was limited to soft tissue in three cases, the lung in two cases, and an infected thrombus in one case; rhinocerebral disease was found in three cases, and pulmonary-mediastinal, pulmonary-cerebral and soft tissue-cerebral involvement in one case each. All three patients with isolated soft tissue infection were cured, whereas seven of the remaining patients died (one patient without follow-up). The overall mortality rate was 67%. While these data cannot provide conclusive data on incidence and disease burden of mucormycosis in paediatric patients, they reflect the continuing threat of these infections to immunocompromised patients and the need for improved diagnosis and management.

Addison's disease and severe encephalopathy in an infant with HIV infection.

AIM: To discuss the overlapping clinical spectrum of encephalopathy due to Addison's disease and HIV infection. PATIENT: We report a 2.5-year-old boy from Uzbekistan with recurrent episodes of encephalopathy and seizures, triggered by infection or vaccinations, in whom adrenal insufficiency and infection with HIV and HCV was diagnosed. Presumably, Addisonian crises prompted hypovolemic shock and blood transfusions, which were responsible for horizontal HIV infection. The combination of adrenal insufficiency and HIV infection eventually led to progressive severe encephalopathy. Despite highly active antiretroviral therapy (which led to substantial reduction of blood viral load), the neurological condition did not improve. DISCUSSION: The interactions of Addison's disease and HIV in the pathogenesis of encephalopathy are discussed.

X-linked thrombocytopenia (XLT) due to WAS mutations: clinical characteristics, long-term outcome, and treatment options.

A large proportion of patients with mutations in the Wiskott-Aldrich syndrome (WAS) protein gene exhibit the milder phenotype termed X-linked thrombocytopenia (XLT). Whereas stem cell transplantation at an early age is the treatment of choice for patients with WAS, therapeutic options for patients with XLT are controversial. In a retrospective multicenter study we defined the clinical phenotype of XLT and determined the probability of severe disease-related complications in patients older than 2 years with documented WAS gene mutations and mild-to-moderate eczema or mild, infrequent infections. Enrolled were 173 patients (median age, 11.5 years) from 12 countries spanning 2830 patient-years. Serious bleeding episodes occurred in 13.9%, life-threatening infections in 6.9%, autoimmunity in 12.1%, and malignancy in 5.2% of patients. Overall and event-free survival probabilities were not significantly influenced by the type of mutation or intravenous immunoglobulin or antibiotic prophylaxis. Splenectomy resulted in increased risk of severe infections. This analysis of the clinical outcome and molecular basis of patients with XLT shows excellent long-term survival but also a high probability of severe disease-related complications. These observations will allow better decision making when considering treatment options for individual patients with XLT.

PENTA 2009 guidelines for the use of antiretroviral therapy in paediatric HIV-1 infection.

PENTA Guidelines aim to provide practical recommendations for treating children with HIV infection in Europe. Changes to guidance since 2004 have been informed by new evidence and by expectations of better outcomes following the ongoing success of antiretroviral therapy (ART). Participation in PENTA trials of simplifying treatment is encouraged. The main changes are in the following sections: 'When to start ART': Treatment is recommended for all infants, and at higher CD4 cell counts and percentages in older children, in line with changes to adult guidelines. The number of age bands has been reduced to simplify and harmonize with other paediatric guidelines. Greater emphasis is placed on CD4 cell count in children over 5 years, and guidance is provided where CD4% and CD4 criteria differ. 'What to start with': A three-drug regimen of two nucleoside reverse transcriptase inhibitors (NRTIs) with either a nonnucleoside reverse transcriptase inhibitor (NNRTI) or a boosted protease inhibitor (PI) remains the first choice combination. Lamivudine and abacavir are the NRTI backbone of choice for most children, based on long-term follow-up in the PENTA 5 trial. Stavudine is no longer recommended. Whether to start with an NNRTI or PI remains unclear, but PENPACT 1 trial results in 2009 may help to inform this. All PIs should be ritonavir boosted. Recommendations on use of resistance testing, therapeutic drug monitoring and HLA testing draw from data in adults and from European paediatric cohort studies. Recently updated US and WHO paediatric guidelines provide more detailed review of the evidence base. Differences between guidelines are highlighted and explained.

Common variable immunodeficiency disorders in children: delayed diagnosis despite typical clinical presentation.

OBJECTIVE: To characterize common variable immunodeficiency disorder (CVID) in childhood. STUDY DESIGN: We retrospectively investigated clinical findings in 32 children with primary CVID by questionnaire and file review. RESULTS: Clinical presentation included recurrent or chronic respiratory tract infections (88%), sinusitis (78%), otitis media (78%), and intestinal tract infections (34%), mainly with encapsulated bacteria. Meningitis was found in 25%, sepsis in 16%, and pyelonephritis in 16% of patients. Poliomyelitis after vaccination occurred in 2 patients and opportunistic infections occasionally. Allergic disorders were present in 38%, and autoimmune disease in 31% of patients. Eighty percent of the patients underwent surgical procedures because of recurrent infections. Growth retardation was seen in 28% of patients, and 16% showed retarded mental development. Bronchiectasis developed in 34%, and lymphoid proliferative disease in 13%. Incidence of allergic and autoimmune diseases was increased in first-degree relatives with normal immunologic findings. Mean time between symptoms and induction of immunoglobulin substitution therapy was 5.8 years (0.2-14.3). CONCLUSIONS: CVID in children presents with comparable symptoms and disorders as in adults. We found a significant influence on growth and development. The marked delay of diagnosis may be due to overlap with common pediatric disorders, while also reflecting insufficient awareness of these disorders.

Gene therapy for immunodeficiency due to adenosine deaminase deficiency.

BACKGROUND: We investigated the long-term outcome of gene therapy for severe combined immunodeficiency (SCID) due to the lack of adenosine deaminase (ADA), a fatal disorder of purine metabolism and immunodeficiency. METHODS: We infused autologous CD34+ bone marrow cells transduced with a retroviral vector containing the ADA gene into 10 children with SCID due to ADA deficiency who lacked an HLA-identical sibling donor, after nonmyeloablative conditioning with busulfan. Enzyme-replacement therapy was not given after infusion of the cells. RESULTS: All patients are alive after a median follow-up of 4.0 years (range, 1.8 to 8.0). Transduced hematopoietic stem cells have stably engrafted and differentiated into myeloid cells containing ADA (mean range at 1 year in bone marrow lineages, 3.5 to 8.9%) and lymphoid cells (mean range in peripheral blood, 52.4 to 88.0%). Eight patients do not require enzyme-replacement therapy, their blood cells continue to express ADA, and they have no signs of defective detoxification of purine metabolites. Nine patients had immune reconstitution with increases in T-cell counts (median count at 3 years, 1.07x10(9) per liter) and normalization of T-cell function. In the five patients in whom intravenous immune globulin replacement was discontinued, antigen-specific antibody responses were elicited after exposure to vaccines or viral antigens. Effective protection against infections and improvement in physical development made a normal lifestyle possible. Serious adverse events included prolonged neutropenia (in two patients), hypertension (in one), central-venous-catheter-related infections (in two), Epstein-Barr virus reactivation (in one), and autoimmune hepatitis (in one). CONCLUSIONS: Gene therapy, combined with reduced-intensity conditioning, is a safe and effective treatment for SCID in patients with ADA deficiency. (ClinicalTrials.gov numbers, NCT00598481 and NCT00599781.)

Long-term posaconazole treatment and follow-up of rhino-orbital-cerebral mucormycosis in a diabetic girl.

To demonstrate that the 2-yr clinical follow-up of our patient strongly suggests that long-term therapy with posaconazole (POS) is safe and beneficial in treatment and prevention of relapses of, otherwise fatal, central nervous system mucormycosis. Mucormycosis is a very rare opportunistic mycotic infection of diabetic children. We present the 30-month follow-up of a 12-yr-old girl affected by diabetic ketoacidotic coma, complicated by rhinocerebral mucormycosis and successfully treated with POS at the initial daily dose of 5 mg/kg t.i.d. with fatty food for 3 wk, followed by a daily dose of 10 mg/kg in four doses for 2 months and then 20 mg/kg/d in four doses for 16 months and in two doses for further 5 months. The previous amphotericin B, granulocyte colony-stimulating factor, hyperbaric oxygen and nasal and left maxillary sinus surgical debridement therapy was ineffective in stopping the progression of the infection to the brain. The patient improved within 10 d with reduced ocular swelling and pain, and 6 months after therapy stop, she is in good health and cultures are sterile. This article demonstrates that POS may be a useful drug in mucormycosis in children. We also strongly draw the attention to the main preventive procedure against invasive fungal infection that is the correct management of antidiabetic therapy that prevents the predisposing temporary neutrophils activity deficit, contributing to a better survival rate of diabetic children.

Insertional oncogenesis in 4 patients after retrovirus-mediated gene therapy of SCID-X1.

Previously, several individuals with X-linked SCID (SCID-X1) were treated by gene therapy to restore the missing IL-2 receptor gamma (IL2RG) gene to CD34+ BM precursor cells using gammaretroviral vectors. While 9 of 10 patients were successfully treated, 4 of the 9 developed T cell leukemia 31-68 months after gene therapy. In 2 of these cases, blast cells contained activating vector insertions near the LIM domain-only 2 (LMO2) proto-oncogene. Here, we report data on the 2 most recent adverse events, which occurred in patients 7 and 10. In patient 10, blast cells contained an integrated vector near LMO2 and a second integrated vector near the proto-oncogene BMI1. In patient 7, blast cells contained an integrated vector near a third proto-oncogene,CCND2. Additional genetic abnormalities in the patients' blast cells included chromosomal translocations, gain-of-function mutations activating NOTCH1, and copy number changes, including deletion of tumor suppressor gene CDKN2A, 6q interstitial losses, and SIL-TAL1 rearrangement. These findings functionally specify a genetic network that controls growth in T cell progenitors. Chemotherapy led to sustained remission in 3 of the 4 cases of T cell leukemia, but failed in the fourth. Successful chemotherapy was associated with restoration of polyclonal transduced T cell populations. As a result, the treated patients continued to benefit from therapeutic gene transfer.

Response to combination antiretroviral therapy: variation by age.

OBJECTIVE: To provide information on responses to combination antiretroviral therapy in children, adolescents and older HIV-infected persons. DESIGN AND SETTING: Multicohort collaboration of 33 European cohorts. SUBJECTS: : Forty-nine thousand nine hundred and twenty-one antiretroviral-naive individuals starting combination antiretroviral therapy from 1998 to 2006. OUTCOME MEASURES: Time from combination antiretroviral therapy initiation to HIV RNA less than 50 copies/ml (virological response), CD4 increase of more than 100 cells/microl (immunological response) and new AIDS/death were analysed using survival methods. Ten age strata were chosen: less than 2, 2-5, 6-12, 13-17, 18-29, 30-39 (reference group), 40-49, 50-54, 55-59 and 60 years or older; those aged 6 years or more were included in multivariable analyses. RESULTS: The four youngest age groups had 223, 184, 219 and 201 individuals and the three oldest age groups had 2693, 1656 and 1613 individuals. Precombination antiretroviral therapy CD4 cell counts were highest in young children and declined with age. By 12 months, 53.7% (95% confidence interval: 53.2-54.1%) and 59.2% (58.7-59.6%) had experienced a virological and immunological response. The probability of virological response was lower in those aged 6-12 (adjusted hazard ratio: 0.87) and 13-17 (0.78) years, but was higher in those aged 50-54 (1.24), 55-59 (1.24) and at least 60 (1.18) years. The probability of immunological response was higher in children and younger adults and reduced in those 60 years or older. Those aged 55-59 and 60 years or older had poorer clinical outcomes after adjusting for the latest CD4 cell count. CONCLUSION: Better virological responses but poorer immunological responses in older individuals, together with low precombination antiretroviral therapy CD4 cell counts, may place this group at increased clinical risk. The poorer virological responses in children may increase the likelihood of emergence of resistance.

Dysregulation of innate immune receptors on neutrophils in chronic granulomatous disease.

BACKGROUND: Chronic granulomatous disease (CGD) is the most common inherited disorder of neutrophil function, is caused by mutations in the reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and results in recurrent bacterial infections. OBJECTIVE: We sought to investigate the expression and function of innate immune receptors on neutrophils in patients with CGD. METHODS: We quantified mRNA and protein expression of Toll-like receptors (TLRs), complement receptors, and chemokine receptors on neutrophils from 15 patients with CGD compared with that seen in healthy control subjects (n = 15) and control patients with bacterial pneumonia (n = 15). Phagocytosis, chemotaxis, and TLR function of isolated neutrophils were analyzed. The effect of NADPH oxidase inhibition on receptor expression and function was analyzed in control neutrophils. RESULTS: Neutrophils from patients with CGD had lower expression levels of TLR5, TLR9, CD11b, CD18, CD35, and CXCR1 compared with those from healthy control subjects, whereas similar or increased receptor expressions were found in patients without CGD but with bacterial pneumonia. Reduced TLR5 expression resulted in impaired neutrophil activation by bacterial flagella, reduced CD11b/CD18 expression was associated with impaired phagocytosis of Staphylococcus aureus, and reduced CXCR1 expression was associated with decreased chemotaxis. TLR5 and CD18 expression levels correlated with disease severity in patients with CGD. TLR5 and TLR9 expression were greater in patients with residual NADPH oxidase activity. Inhibition of the NADPH oxidase in control neutrophils in vitro decreased TLR5 and TLR9 expression and impaired TLR5 function. CONCLUSION: These results provide the first evidence that innate immune receptors are dysregulated in patients with CGD.

Haemophilus paraphrophilus, a rare cause of intracerebral abscess in children.

We report on a 3-year-old boy presenting with left-sided eyelid myocloni due to an intracranial abscess harboring Haemophilus paraphrophilus. This is the first description of an intracranial infection with this pathogen in a child.

Mimotopes selected with antibodies from HIV-1-neutralizing long-term non-progressor plasma.

A promising approach to identify HIV-1 vaccine candidates is to dissect the natural immune response against the virus in persons controlling the infection over decades without any antiviral therapy. Here we focus on a group of such persons, eight long-term non-progressors (LTNP), in which we proved the presence of broadly neutralizing antibodies against HIV-1 in the plasma as very likely cause for their LTNP status. The aim of this study was to identify the epitopes for these neutralizing antibodies, as these should represent immunogens potentially able to elicit neutralizing antibodies upon vaccination. We screened random peptide phage libraries with plasma antibodies from eight LTNP. After several rounds of positive and negative selection, about 700 HIV-specific mimotopes were sequenced. The mimotope sequences were analyzed for homology to HIV-1 Env, in particular for their capacity to represent conformational epitopes on the surface of the gp120 structure using our software 3DEX. Related phage groups were analyzed for crossreactivity with the LTNP plasma by ELISA as well as for their capacity to induce HIV-1-neutralizing antibodies in mice. Based on this study interesting mimotopes can now be selected for further immunization studies.