Multi-component meningococcal serogroup B (MenB)-4C vaccine induces effective opsonophagocytic killing in children with a complement deficiency.

Vaccination against meningococcal serogroup B is recommended for patients with a complement deficiency; however, although immunogenicity in this patient group has been shown, efficacy has not yet been established. In this study, we collected serum from children with a complement deficiency in the alternative pathway or in late terminal pathway before and after vaccination with multi-component meningococcal serogroup B (MenB)-4C. MenB-4C is a multi-component, protein-based vaccine against MenB consisting of factor H-binding protein, Neisserial heparin-binding protein, Neisserial adhesion A and outer membrane vesicles containing Porin A. We assessed the vaccine immunogenicity and vaccine-mediated protection by a whole cell enzyme-linked immunosorbent assay with Neisseria meningitidis serogroup B strains H44/76, 5/99 and NZ98/254, which shows that vaccination induced antibody titers against meningococcus. We show that the classical serum bactericidal activity assay with exogenous serum indicates the presence of vaccine-induced antibodies and capacity to activate complement-mediated pathogen lysis. However, in children with a late terminal pathway deficiency, no complement-mediated pathogen lysis was observed when autologous serum was applied in the serum bactericidal activity assay, demonstrating a lack of serum bactericidal activity in children with complement deficiencies. However, MenB-4C vaccination still induced effective complement-dependent opsonophagocytic killing against N. meningitidis serogroup B in reconstituted whole blood with autologous serum from children with an alternative pathway or late terminal pathway deficiency. These findings support the recommendation to vaccinate all complement-deficient children against MenB.

Primary immunodeficiencies in the Netherlands: national patient data demonstrate the increased risk of malignancy.

PURPOSE: To analyze the data of the national registry of all Dutch primary immune deficiency (PID) patients, according to the European Society for Immunodeficiencies (ESID) definitions. RESULTS: In the Netherlands, 745 patients had been registered between 2009 and 2012. An overall prevalence of 4.0 per 100,000 inhabitants was calculated. The most prevalent PID was 'predominantly antibody disorder (PAD)' (60.4%). In total, 118 transplantations were reported, mostly hematopoietic stem cell transplantations (HSCT). Almost 10% of the PID patients suffered from a malignancy, in particular 'lymphoma' and 'skin cancer'. Compared to the general Dutch population, the relative risk of developing any malignancy was 2.3-fold increased, with a >10-fold increase for some solid tumors (thymus, endocrine organs) and hematological disease (lymphoma, leukemia), varying per disease category. CONCLUSIONS: The incidence rate and characteristics of PID in the Netherlands are similar to those in other European countries. Compared to the general population, PID patients carry an increased risk to develop a malignancy.

Central line bloodstream infections can be reduced in newborn infants using the modified Seldinger technique and care bundles of preventative measures.

AIM: There has been no evidence to show whether care bundles of preventive measures reduce central line-associated bloodstream infection (CLABSI) in peripherally inserted central catheters using the modified Seldinger technique, which requires more specific skills than the traditional technique. The aim of this study was to address that gap in our knowledge and to determine whether other variables influenced the outcome. METHODS: This prospective observational study was conducted on a neonatal intensive care unit. We observed the incidence of CLABSI in 45 newborn infants with peripheral catheters before the introduction of bundles of preventative measures and 88 infants after the introduction. RESULTS: Laboratory-confirmed CLABSI decreased after the introduction of the bundles, from 12.9 per 1000 days to 4.7/1000 days (p = 0.09). When we combined the rates for laboratory-confirmed CLABSI and clinical CLABSI in a survival analysis, the incidence reduced significantly after introduction of the bundles (p = 0.02). There were no other variables that affected the outcome. CONCLUSION: Cost-effective care bundles reduced CLABSI in peripherally inserted central catheters using the modified Seldinger technique, despite the specific insertion skills that were required. The bundles of preventative measures may increase healthcare professionals' awareness of the need to care for central catheters and reduce CLABSI infections.

A case promoting use of ultrasound-guided sampling techniques to correctly diagnose MDR-TB in children.

A paediatric case of multidrug-resistant tuberculosis in which endo-oesophageal ultrasound-guided fine-needle aspiration using an endobronchial ultrasound-guided bronchoscope was used to collect a sample for microbial analyses is presented. In our experience, ultrasound-guided sampling techniques, both endo-oesophageal and endobronchial, can be safely used for the diagnosis of paediatric intrathoracic tuberculous lymphadenopathy in children aged 3 years. Interventional pulmonologists with experience in using these techniques should be part of the multidisciplinary team treating these patients.

Bacteremia in Childhood Life-Threatening Infections in Urban Gambia: EUCLIDS in West Africa.

BACKGROUND: The limited availability of microbiology services in sub-Saharan Africa impedes accurate diagnosis of bacterial pathogens and understanding of trends in prevalence and antibiotic sensitivities. We aimed to characterize bacteremia among hospitalized children in The Gambia and to identify factors associated with bacteremia and mortality. METHODS: We prospectively studied children presenting with suspected severe infection to 2 urban hospitals in The Gambia, between January 2013 and September 2015. Demographic and anthropometric data, clinical features, management, and blood culture results were documented. Urine screens for antibiotic activity were performed in a subset of participants. RESULTS: Of 411 children enrolled (median age, 29 months; interquartile range, 11-82), 79.5% (325 of 409) reported prehospital antibiotic use. Antimicrobial activity by urinary screen for antibiotic activity was detected in 70.8% (n = 80 of 113). Sixty-six bacterial pathogens were identified in 65 (15.8%) participants and Staphylococcus aureus predominated. Gram-positive organisms were more commonly identified than Gram-negative (P < .01). Antibiotic resistance against first-line antimicrobials (ampicillin and gentamicin) was common among Gram-negative bacteria (39%; range, 25%-100%). Factors significantly associated with bacteremia included the following: gender, hydration status, musculoskeletal examination findings, admission to the Medical Research Council The Gambia at London School of Hygiene & Tropical Medicine hospital, and meeting sepsis criteria. Those associated with increased mortality were presence of a comorbidity, clinical pallor, tachypnea, and altered consciousness. Tachycardia was associated with reduced mortality. CONCLUSIONS: The bacteremia rate in children with suspected childhood life-threatening infectious diseases in The Gambia is high. The pattern of pathogen prevalence and antimicrobial resistance has changed over time compared with previous studies illustrating the importance of robust bacterial surveillance programs in resource-limited settings.

Telangiectasias in Ataxia Telangiectasia: Clinical significance, role of ATM deficiency and potential pathophysiological mechanisms.

Ataxia Telangiectasia (AT) is named after the two key clinical features that characterize its classical phenotype, namely a progressive cerebellar gait disorder (ataxia) and vascular anomalies (telangiectasias) visible in the conjunctivae and skin. AT is an autosomal recessively inherited disorder, caused by mutations in the ATM gene that encodes the ATM protein. While the ataxia is subject of many publications, the telangiectasias are under emphasised. We here describe the observation that the absence or presence of ATM protein and the level of residual ATM kinase activity are related to the occurrence of telangiectasias and describe the clinical consequences of these vascular malformations. Finally, we hypothesize that ATM dysfunction dysregulates angiogenesis.

Inhibition of leukocyte-endothelial cell interactions and inflammation by peptides from a bacterial adhesin which mimic coagulation factor X.

Factor X (factor ten) of the coagulation cascade binds to the integrin CD11b/CD18 during inflammation, initiating procoagulant activity on the surface of leukocytes (Altieri, D.C., O.R. Etingin, D.S. Fair, T.K. Brunk, J.E. Geltosky, D.P. Hajjar, and T. S. Edgington. 1991. Science [Wash.DC]. 254:1200-1202). Filamentous hemagglutinin (FHA), an adhesin of Bordetella pertussis also binds to the CD11b/CD18 integrin (Relman D., E. Tuomanen, S. Falkow, D.T. Golenbock, K. Saukkonen, and S.D. Wright. 1990. Cell. 61:1375-1382). FHA and the CD11b/CD18 binding loops of Factor X share amino acid sequence similarity. FHA peptides similar to Factor X binding loops inhibited 125I-Factor X binding to human neutrophils and prolonged clotting time. In addition, ETKEVDG and its Factor X analogue prevented transendothelial migration of leukocytes in vitro and reduced leukocytosis and blood brain barrier disruption in vivo. Interference with leukocyte migration by a coagulation-based peptide suggests a novel strategy for antiinflammatory therapy.

Telangiectasias: Small lesions referring to serious disorders.

Telangiectasias are prominent small vessels (venules, capillaries or arterioles) that are visible as small red-purple focal lesions in the skin and mucous membranes. They can serve as a cutaneous marker for a number of primary (mostly hereditary) disorders and they can be secondary to other (systemic) diseases. Patients with telangiectasias are seen by general health practitioners, pediatricians, (pediatric) neurologists, dermatologists, and ophthalmologists. In this article we give an overview of the different disorders in which telangiectasias are a prominent feature, focusing on neurocutaneous disorders in which they serve as a marker for establishing the right diagnosis. The pattern of distribution of the telangiectasias, their age of onset and associated features are helpful to distinguish between the different disorders.

Antibody neutralization of vascular endothelial growth factor (VEGF) fails to attenuate vascular permeability and brain edema in experimental pneumococcal meningitis.

To determine the contribution of vascular endothelial growth factor (VEGF) to cerebral edema formation in bacterial meningitis, we used a VEGF neutralizing antibody to block VEGF in rabbits, following induction of meningitis by intracisternal inoculation with 10(9) heat-killed pneumococci. At 8 h, cerebrospinal fluid (CSF) VEGF was significantly elevated in infected untreated animals, and correlated with CSF white blood cell (WBC) count (r=0.56, P=0.004), and brain water content (r=0.42, P=0.04). Blocking of VEGF did not attenuate brain edema, blood-brain barrier disruption, or CSF pleocytosis. The functional role of VEGF in the pathophysiology of BM remains elusive.

A case of carbimazole-induced intrahepatic cholestasis. An immune-mediated reaction?

A patient is described with cholestatic hepatitis following the use of carbimazole. A liver biopsy specimen showed intracanalicular cholestasis and some mononuclear cell infiltrate in the portal triades, consistent with drug toxicity; indications of an autoimmune or viral pathogenesis were absent. Rechallenge with the drug precipitated jaundice and disturbed liver function once more. Carbimazole induced a blastogenic response of patient lymphocytes in vitro. Both may suggest the involvement of an immune-mediated reaction, especially as it has been shown that sensitized lymphocytes may produce a cholestatic factor on stimulation with antigen.

Induction of contact sensitivity to a broad variety of allergens with haptenized macrophages.

Using guinea pigs an analysis could be made of various aspects of contact sensitivity (CS) induced by subcutaneous injection of syngeneic haptenized macrophages (oil-induced peritoneal exudate cells, PEC) as compared to epicutaneous sensitization. Very little PEC-bound hapten (dinitrochlorobenzene, or oxazolone) is needed for optimum sensitization. Nevertheless, both sensitization methods induce a state of CS that may last for over 6 months, give rise to hapten-specific antibodies with a similar isotype distribution, and show susceptibility to cyclophosphamide pretreatment. In addition, time courses and microscopic appearance of skin test reactions after either way of sensitization are identical. CS to a broad variety of physicochemically different antigens, including nickel, penicillin, and acrylates, is readily induced by syngeneic PEC, haptenized following a standardized procedure. As Freund's complete adjuvant is known to cause serious side effects like ulceration and long-lasting granuloma formation, immunization with haptenized PEC should now be considered as a clean and effective alternative in experimental CS studies.

In vitro studies in nickel allergy: diagnostic value of a dual parameter analysis.

A comparison was made between the diagnostic value of assaying nickel-induced lymphocyte proliferation (lymphocyte transformation test, LTT) and migration inhibition factor (MIF) production in nickel contact sensitivity. Although lymphocyte proliferation was significantly increased in the group of patients with skin test reactivity to nickel, positive LTT were also frequently found in skin test-negative subjects: in 63% of subjects with and in 30% of subjects without a history of metal allergy. This would limit the value of the LTT as an in vitro correlate of skin test reactivity. However, in certain patients positive lymphocyte transformation may reveal nickel sensitization at a time of undetectable skin reactivity. Data obtained with the macrophage migration inhibition test (MMIT) showed a good correlation with nickel patch test reactions. Accurate determination of MIF became feasible by using cells from the human monocytoid cell line U937 as target cells in a microdroplet agarose assay. Using this MMIT, positive reactions occurred in 13% of the healthy controls and false-negative reactions were found in 26% of patients with positive skin test reactivity to nickel. As LTT and MMIT data appeared to be only weakly correlated in the individuals tested, a dual parameter analysis was performed. An excellent correlation [p = 1.8 (10(-8]] was found between skin test and in vitro reactivity for individuals with matching in vitro results (60% of all individuals tested). In those individuals with discordant in vitro data, skin testing will remain indispensable for diagnosing nickel allergy.

[Fatal pneumonia in an adolescent due to community-acquired methicillin-resistant Staphylococcus aureus positive for Panton-Valentine-leukocidin]. / Fatale pneumonie bij een adolescent door thuis opgelopen meticillineresistente Staphylococcus aureus positief voor Panton-Valentine-leukocidine.

A 15-year-old girl developed a severe Staphylococcus aureus pneumonia following an influenza virus infection. The patient was admitted to a paediatric intensive-care facility because of respiratory and circulatory failure. Despite aggressive therapy, she died on the third day following admission to the intensive care unit due to secondary hypoxic-ischaemic encephalopathy. Blood and respiratory aspirate cultures showed community-acquired methicillin-resistant S. aureus (CA-MRSA) with a normal antibiotic sensitivity except for betalactam antibiotics. PCR-based methods demonstrated that the isolate possessed the Panton-Valentine-leukocidin (PVL) gene, encoding an S. aureus exotoxin that is associated with fulminant necrotising pneumonia. This case shows that clinicians in the Netherlands should also be aware of the possibility of CA-MRSA in patients without risk factors for MRSA carriage. Especially in children and adolescents with an influenza virus infection, pneumonia due to PVL-positive S. aureus strains may be life-threatening.

Angry back or the excited skin syndrome. A prospective study.

Allergens eliciting weak positive reactions were retested to ascertain their reproducibility. Weak positive patch test reactions, concomitant to other weak or strong positive reactions, were retested after 3 weeks in 61 patients. 79 reactions were retested; 35 (44.3%) were negative. Allergens which are marginal irritants, e.g., formaldehyde, often gave weak positive reactions which were lost at retesting. In patients without dermatitis but with several strong positive reactions, lost reactions were frequently encountered, suggesting that strong reactions induced a state of hyperirritability. False positive reactions were often found in the proximity of strong reactions. We attempted to develop a nonspecific irritant (sodium lauryl sulfate) as a hyperirritability marker. A correlation between the score of this test and false positive reactions was not found. It is concluded that weak positive reactions should not be accepted as a proof of sensitization. The allergens eliciting these reactions should be retested at a later date.

Depression or enhancement of skin reactivity by inflammatory processes in the guinea pig.

An animal model for the excited skin syndrome was developed in the guinea pig. Hyperirritability of the skin could be induced by immunization with Freund's complete adjuvant (FCA). This hyperirritability was evident from the enhancement of both patch test reactions to an irritant (sodium lauryl sulfate) and open epicutaneous test reactions to a contact sensitizer (2,4-dinitrochlorobenzene). The skin tests were performed at sites other than those pretreated with FCA. Maximum enhancement was observed in a period 3-5 weeks after FCA immunization. A similar but less marked hyperirritability could be induced by eliciting a localized chronic croton oil dermatitis. The period of hyperirritability induced by FCA or croton oil was preceded by a short period (1-14 days) of depressed skin reactivity.

Adherence of Streptococcus pneumoniae to immobilized fibronectin.

Adherence to extracellular matrix proteins, such as fibronectin, affords pathogens with a mechanism to invade injured epithelia. Streptococcus pneumoniae was found to adhere to immobilized fibronectin more avidly than other streptococci and staphylococci do. Binding was dose, time, and temperature dependent. Trypsin treatment of the bacteria resulted in decreased binding, suggesting that the bacterial adhesive component was a protein. Fragments of fibronectin generated by proteolysis or by expression of recombinant gene segments were compared for the ability to bind pneumococci and to compete against bacterial binding to immobilized fibronectin. Fragments from the carboxy-terminal heparin binding domain were consistently active, suggesting that this region contains the pneumococcal binding site, a region distinct from that supporting the attachment of most other bacteria.

Streptococcus pneumoniae induces secretion of vascular endothelial growth factor by human neutrophils.

Infection by pneumococci causes an acute inflammatory response associated with neutrophil influx, increased vascular permeability, and edema. Vascular endothelial growth factor (VEGF) is one of the most potent regulators of endothelial permeability. In vitro stimulation of neutrophils showed that pneumococci and purified pneumococcal cell wall induce VEGF secretion, independent of the presence of pneumolysin or polysaccharide capsule. The results of this study indicate VEGF is secreted in pneumococcal disease, suggesting a role as a mediator of increased vascular permeability.

Reprogramming the host response in bacterial meningitis: how best to improve outcome?

Despite effective antibiotic therapy, bacterial meningitis is still associated with high morbidity and mortality in both children and adults. Animal studies have shown that the host inflammatory response induced by bacterial products in the subarachnoid space is associated with central nervous system injury. Thus, attenuation of inflammation early in the disease process might improve the outcome. The feasibility of such an approach is demonstrated by the reduction in neurologic sequelae achieved with adjuvant dexamethasone therapy. Increased understanding of the pathways of inflammation and neuronal damage has suggested rational new targets to modulate the host response in bacterial meningitis, but prediction of which agents would be optimal has been difficult. This review compares the future promise of benefit from the use of diverse adjuvant agents. It appears unlikely that inhibition of a single proinflammatory mediator will prove useful in clinical practice, but several avenues to reprogram a wider array of mediators simultaneously are encouraging. Particularly promising are efforts to adjust combinations of cytokines, to inhibit neuronal apoptosis and to enhance brain repair.

Penicillin allergy and the relevance of epicutaneous tests.

Epicutaneous tests with penicillins are important in the evaluation of penicillin allergy in patients who have shown a delayed urticarial or maculo-papular rash after the administration of penicillin derivatives. Of 23 patients who showed positive epicutaneous tests only 5 also showed immediate-type reactivity upon subsequent intracutaneous tests with the major determinant of penicillin. Moreover, patients with positive epicutaneous tests were evidently immunologically reactive on penicillins, since lymphocytes from 14 out of 17 patients showed increased DNA synthesis induced by penicillin G and ampicillin in vitro. The performance of epicutaneous tests with various penicillin derivatives is recommended as a first step in establishing penicillin allergy, because it is a safe method and because an extra group of sensitized patients is detected.