Different degrees of NADPH oxidase 2 regulation and in vivo platelet activation: lesson from chronic granulomatous disease

Background

In vitro study showed that NADPH oxidase (NOx), the most important enzyme producing reactive oxygen species (ROS), plays a role in the process of platelet activation. However, it is unclear if changes in its activity affect platelet activation in vivo.

Methods and Results

In vivo and ex vivo experiments assessing platelet activation were investigated in healthy subjects, obese patients, and subjects with different low rates of NOx2 activity, namely X‐linked chronic granulomatous disease (X‐CGD) patients and X‐CGD carriers. We included 27 X‐CGD patients, 31 women carriers of hereditary deficiency of NOx2, 31 obese women, and 62 healthy subjects matched for sex and age. Plasma levels of soluble sCD40 L (sCD40L) and soluble P (sP)‐selectin, 2 markers of in vivo platelet activation, were reduced in X‐CGD patients (sCD40L=−55%; sP‐selectin=−51%, P<0.001) and in X‐CGD carriers (sCD40L=−41%; sP‐selectin=−57%, P<0.001) compared with respective controls. Conversely, obese women, who disclosed NOx2 upregulation, had significantly higher plasma levels of sCD40L (+47%, P<0.001) and sP‐selectin (+70%, P<0.001) compared with controls. Ex vivo study showed platelet isoprostane downexpression and enhanced platelet NO generation in both X‐CGD patients and X‐CGD carriers compared with controls; opposite findings were observed in obese patients. Correlation analysis showed that platelet NOx2 regulation was directly associated with plasma levels of sCD40L (R=0.336, P<0.001) and sP‐selectin (R=0.441; P<0.001).

Conclusions

The study provides the first evidence that in vivo platelet activation is significantly and directly associated with NOx2 activity. Platelet NOx2 may be a novel target for platelet activation inhibition.

Clinical features and follow-up in patients with 22q11.2 deletion syndrome

OBJECTIVE

To investigate the clinical manifestations at diagnosis and during follow-up in patients with 22q11.2 deletion syndrome to better define the natural history of the disease.

STUDY DESIGN

A retrospective and prospective multicenter study was conducted with 228 patients in the context of the Italian Network for Primary Immunodeficiencies. Clinical diagnosis was confirmed by cytogenetic or molecular analysis.

RESULTS

The cohort consisted of 112 males and 116 females; median age at diagnosis was 4 months (range 0 to 36 years 10 months). The diagnosis was made before 2 years of age in 71% of patients, predominantly related to the presence of heart anomalies and neonatal hypocalcemia. In patients diagnosed after 2 years of age, clinical features such as speech and language impairment, developmental delay, minor cardiac defects, recurrent infections, and facial features were the main elements leading to diagnosis. During follow-up (available for 172 patients), the frequency of autoimmune manifestations (P = .015) and speech disorders (P = .002) increased. After a median follow-up of 43 months, the survival probability was 0.92 at 15 years from diagnosis.

CONCLUSIONS

Our data show a delay in the diagnosis of 22q11.2 deletion syndrome with noncardiac symptoms. This study provides guidelines for pediatricians and specialists for early identification of cases that can be confirmed by genetic testing, which would permit the provision of appropriate clinical management.

Coeliac disease and risk for other autoimmune diseases in patients with Williams-Beuren syndrome

BACKGROUND

A higher prevalence of coeliac disease (CD) has been reported in patients with Williams-Beuren syndrome (WBS), though coexistence with other autoimmune diseases has not been evaluated.

OBJECTIVE

The aim of this study was to examine the prevalence of the more frequent autoimmune diseases and organ- and non-organ specific autoantibodies in WBS.

METHODS

We longitudinally analysed 46 WBS patients to evaluate the prevalence and co-occurrence of the major autoantibodies and HLA typing for CD diagnosis. These data were compared with healthy age- and sex-matched controls and Down (DS) and Turner (TS) syndrome patients.

RESULTS

CD was diagnosed in one (2.2%) WBS patient; this differed significantly from DS and TS (respectively, 10.5% and 9.4%; P < 0.005) but not from healthy controls (0.6%; P = NS). However, no patients with WBS showed anti-thyroid antibodies or other organ- and non-organ specific autoantibodies, which differed significantly from DS (respectively, 10.5% and 7.0%; P < 0.005) and TS (respectively, 9.4% and 9.3%; P < 0.005) patients but not from healthy controls (1.1% and 2.3%). The frequencies of CD-specific HLA-DQ heterodimers were not significantly higher than controls, even though the WBS patients more frequently carried the DQA1*0505 allele (57% vs. 39%; P < 0.05).

CONCLUSIONS

CD may not be more frequent in patients with WBS. In fact, no evidence of a significantly higher prevalence of other autoimmune diseases or positivity of the main organ and non-organ specific autoantibodies was found in WBS, such as showed in the healthy controls and unlike by the patients with Turner or Down syndrome. This should prompt us to better understand the occurrence of CD in WBS. Other studies or longer follow-up might be useful to clarify this issue.

Interleukin 28B rs12979860 single-nucleotide polymorphism predicts spontaneous clearance of hepatitis C virus in children

OBJECTIVE

Recent genome-wide association studies performed in adults correlated single-nucleotide polymorphisms (SNPs rs12979860 and rs8099917) located on chromosome 19, upstream of the interleukin 28B gene, with spontaneous clearance of hepatitis C virus and with response to treatment with paginated interferon and ribavirin. The aim of the present collaborative study was to evaluate the rs12979860 SNP in a large cohort of Italian children with perinatal acquisition of hepatitis C.

METHODS

Children were prospectively enrolled in 2 Italian centers. The interleukin 28B rs12979860 SNP was studied according to the diagnosis of chronic infection or spontaneous clearance.

RESULTS

One hundred thirty children (86.7%) with chronic infection and 23 (13.3%) with spontaneous clearance of the virus were enrolled. Overall, the interleukin 28B C/C and C/T-T/T genotypes were found in 57 (37.3%) and 96 (62.7%) children, respectively. The proportion of C/C genotype was higher among children who cleared infection (14/23; 60.9%) compared with children with chronic infection (43/130; 33.1%; P = 0.01; odds ratio 3.15; 90% confidence intervals 1.34-7.53).

CONCLUSIONS

The present study showed that, as already demonstrated in adults, children with the rs12979860 C/C SNP of the interleukin 28B gene have a higher probability of spontaneous clearance of hepatitis C virus.

Hospitalization rates of complicated pneumococcal community-acquired pneumonia is increasing in Tuscan children

To provide epidemiological data on community-acquired pneumonia (CAP) and complicated CAP, a retrospective study was conducted on a partially vaccinated paediatric population. Data from children hospitalized for CAP in Tuscan hospitals between January 1st, 1999 and December 31st, 2009 were analysed. A total of 5,450 children with CAP were hospitalized. Annual hospitalization rates for CAP did not change significantly over the study period (X2 for trend= 0.652; p=0.419). The total annual hospitalization rate for pneumococcal CAP varied according to age (28.04 per 100,000 children aged less than 5 years, 10.06 per 100,000 children aged 6-12 years and 0.98 per 100,000 children aged greater than13years). Hospitalization rates for pneumococcal CAP increased from12.84 (95 percent CI:7.35-18.34) in 2001 to 45.4 (95 percent CI:35.93-54.90) per 100,000 children aged less than 5 years in 2009 (p less than 0.0001). In addition, a significant increase of hospitalization rates for complicated CAP (from 6.07 in 1999 to 13.66 in 2009 per 100,000 children; P less than 0.0001) and pneumococcal complicated CAP (from 0.19 in 1999 to 3.41 in 2009 per 100,000 children) over the study period were highlighted. Our epidemiological data confirm the decision to introduce the PCV13 vaccine, to satisfy the need to prevent a wider group of pneumococcal serotypes.

Pneumococcal serotype distribution in 1315 nasopharyngeal swabs from a highly vaccinated cohort of Italian children as detected by RT-PCR

The long term impact of 7-valent pneumococcal conjugate vaccine (PCV7) on pneumococcal colonization patterns remains unclear. Carriage and distribution of Streptococcus pneumoniae serotypes as detected by RT-PCR were evaluated in a cohort of 1315 children. S. pneumoniae was identified in the nasopharyngeal swab of 734 children (55.8%); 488/734 (66.5%) children carried more than 1 pneumococcal serotype. As a consequence of co-colonization, a total of 1,728 S. pneumoniae (belonging to 33 serotypes) were identified. As immunogenicity between 2 and 3 doses of PCV7 in the first year of life has been demonstrated to be similar, serotypes distribution was evaluated categorizing vaccination status as 0,1 and 2 or more doses in the first year of life. Among children who started vaccination in the first year of life, PCV7 serotypes were carried in 296 of 1,123 (29.5%) children who had received ≥2 PCV7 doses while were carried in 26 of 108 (26.8%) who had received no doses (p=not significant); only 17 children received 1 PCV7 and 3 of them were found positive for PCV7 serotypes. Among those who had received ≥2 doses of PCV7 in the first year of life, 47 of 192 (19.7%) carried a PCV7 serotype during the first year after last vaccination, 50 of 125 (28.6%) during the second year, 79 of 224 (35.3%) during the third year, and 65 of 143 (45.5%) during the fourth year (p 0.0001). We did not identify risk factors for PCV7 carriage among children that had received >2 vaccine doses. This study suggests that S. pneumoniae is present in the nasopharynx of the majority of children 0-5 years even if vaccinated, that PCV7 serotypes can be found in nasopharyngeal swabs of PCV7 vaccinated children and that the frequency of PCV7 serotypes increases with the increase of interval from vaccination.

Comparative analysis of rs12979860 SNP of the IFNL3 gene in children with hepatitis C and ethnic matched controls using 1000 Genomes Project data

The rs12979860 single nucleotide polymorphism located on chromosome 19q13.13 near the interferon L3 gene (formerly and commonly known as interleukin 28B gene) has been associated in adults with both spontaneous and treatment induced clearance of hepatitis C virus. Although the exact mechanism of these associations remains unclear, it suggests that variation in genes involved in the immune response against the virus favours viral clearance. Limited and preliminary data are available on this issue in children. The aim of the present study was to evaluate, in a representative cohort of children with perinatal infection, the potential association between rs12979860 single nucleotide polymorphism and the outcome of hepatitis C virus infection. Alleles and genotypes frequencies were evaluated in 30 children who spontaneously cleared the virus and in 147 children with persistent infection and were compared with a population sample of ethnically matched controls with unknown hepatitis C status obtained using the 1000 Genomes Project data. The C allele and the C/C genotype showed greater frequencies in the clearance group (76.7% and 56.7%, respectively) when compared with both children with viral persistence (C allele 56.5%, p = 0.004; C/C genotype 32.7%, p = 0.02) and with the ethnically matched individuals (C allele 59.7%, p = 0.02; C/C genotype 34.7%, p = 0.03). Children with the C/C genotype were 2 times more likely to clear hepatitis C virus relative to children with the C/T and T/T genotypes combined (odds ratio: 2.7; 90% confidence intervals: 1.3-5.8). The present study provides the evidence that the rs12979860 single nucleotide polymorphism influences the natural history of hepatitis C virus in children.

Intergenerational and intrafamilial phenotypic variability in 22q11.2 deletion syndrome subjects

BACKGROUND

22q11.2 deletion syndrome (22q11.2DS) is a common microdeletion syndrome, which occurs in approximately 1:4000 births. Familial autosomal dominant recurrence of the syndrome is detected in about 8-28% of the cases. Aim of this study is to evaluate the intergenerational and intrafamilial phenotypic variability in a cohort of familial cases carrying a 22q11.2 deletion.

METHODS

Thirty-two 22q11.2DS subjects among 26 families were enrolled.

RESULTS

Second generation subjects showed a significantly higher number of features than their transmitting parents (212 vs 129, P = 0.0015). Congenital heart defect, calcium-phosphorus metabolism abnormalities, developmental and speech delay were more represented in the second generation (P < 0.05). Ocular disorders were more frequent in the parent group. No significant difference was observed for the other clinical variables. Intrafamilial phenotypic heterogeneity was identified in the pedigrees. In 23/32 families, a higher number of features were found in individuals from the second generation and a more severe phenotype was observed in almost all of them, indicating the worsening of the phenotype over generations. Both genetic and epigenetic mechanisms may be involved in the phenotypic variability.

CONCLUSIONS

Second generation subjects showed a more complex phenotype in comparison to those from the first generation. Both ascertainment bias related to patient selection or to the low rate of reproductive fitness of adults with a more severe phenotype, and several not well defined molecular mechanism, could explain intergenerational and intrafamilial phenotypic variability in this syndrome.

Evaluation of bivalent human papillomavirus (HPV) vaccine safety and tolerability in a sample of 25 year old Tuscan women

The aim of this study was to gather data on the safety of the HPV-16/18 AS04-adjuvated vaccine among women aged 25, evaluating the frequency and severity of adverse events reported after vaccination and to compare the results obtained with previously published data regarding a sample of Italian preadolescents. Every woman residing in the province of Florence and in the age group targeted by the cervical cancer screening was invited to participate. Participants registered daily, for 14 d post-vaccination, solicited local and systemic reactions, as well as unsolicited adverse events in a developed ad hoc safety diary card. Data were collected in a database in Access and analyzed using STATA 11 SE statistical software. A total of 271 participants were recruited in the study group. All three diary cards were completed and delivered by 186 subjects (85.7% of participants). In all, a total of 616 diary cards were collected: 216 after the 1st dose, 209 after the 2nd dose and 191 after the 3rd dose. No severe symptoms were registered. The most frequently reported adverse reaction proved to be pain at the site of injection (83.4% of doses), followed by local swelling (20.8%) and pyrexia (14.6%). The safety and tolerability of the HPV-16/18 AS04-adjuvated vaccine in this sample of adult women aged 25 did not differ much from that previously observed in a sample of preadolescents Italian girls. Fever and local pain were however more frequently registered in our sample of adult women.

Bcgitis and Vaccine-Derived Poliovirus Infection in a Patient with a Novel Deletion in RAG1 Binding Site

A girl who developed severe BCGitis and vaccine-derived poliovirus infection was discovered to have a novel deletion of RAG1. A neonatal screening program for SCID would identify affected infants at birth, before live vaccines are administered.

Development of a specific method to evaluate 8-hydroxy,2-deoxyguanosine in sperm nuclei: relationship with semen quality in a cohort of 94 subjects

Oxidative stress (OS) is involved in many disoders including male infertility. Human spermatozoa are very sensitive targets of reactive oxygen species (ROS) and most sperm functions are impaired in the case of OS. In addition unbalanced production of ROS is considered one of the most important causes of sperm DNA fragmentation, a semen trait of infertile men. The relationship between oxidative damage and semen quality is partially controversial, probably due to the different methods and/or targets used to reveal the OS. In this study, by fluorescence microscopy and flow cytometry, we compared two methods to reveal 8-hydroxy,2-deoxyguanosine (8-OHdG), the hallmark of oxidative DNA damage: an immunofluorescence method and the commercial OxyDNA kit. We found that although both methods localized the labelling in sperm nuclei they yielded different measures, and only with the immunofluorescence method was the labelling specific for sperm 8-OHdG. The immunofluorescence method, coupled to flow cytometry, was thus selected to analyse the 8-OHdG content in semen samples from 94 subfertile patients and to investigate the relationship with semen quality. We found that the percentages of spermatozoa with 8-OHdG (mean±s.d., 11.4±6.9%) were related to sperm count (Pearson's correlation coefficient (r)=−0.27, P=0.04 (ANOVA and student's t-test)), motility (progressive: r=−0.22, P=0.04; non-progressive: r=0.25, P=0.01), and normal morphology (r=−0.27, P=0.01). In conclusion, we demonstrate that immunofluorescence/flow cytometry is a reliable and specific method to detect 8-OHdG at single-cell level and show that oxidative damage only partially overlaps poor semen quality, suggesting that it could provide additional information on male fertility with respect to routine semen analysis.

[Prospective multicentre survey on clinical features and management approach to community-acquired pneumonia in emergency departments in Italy: focus on hospital admitted cases]

BACKGROUND

The correct management of community-acquired pneumonia (CAP) in emergency departments (EDs) is pivotal for the proper use of hospital resources and to ensure optimal management for each patient. Despite a significant body of relevant literature, several doubts remain, namely related to the optimal definition of clinical severity, the most useful criteria for sound patient allocation, the value of immediate microbiological diagnosis, and the criteria for treatment choice.

METHODS

Prospective, multicentric cohort study, enrolling for a period of 24 months all the CAP cases referred to 9 EDs in Italian hospitals. For every enrolled patient demographics and clinical data were collected and clinical severity was defined using and comparing three different predictive rules.

RESULTS

Of 1214 patients who enrolled, 844 were admitted to hospital. Of these, the mean age was 64 and only 56.9% were over 65 years. Nearly 50% of patients admitted had low scores of severity but over 70% had one or more comorbidities. Overall mortality was 8.5%. Streptococcus pneumoniae was the most represented aetiological agent, but globally the yield of microbiological work up was scant (16%).

COMMENT

In a real-life study condition, predictive rules, very attractive for prognosis, are not useful for clinicians to decide on admission of a patient with CAP, mainly when compared with assessment of comorbidities.

Impact on disease incidence of a routine universal and catch-up vaccination strategy against Neisseria meningitidis C in Tuscany, Italy

BACKGROUND

Invasive infections due to Neisseria meningitidis are still an important public health issue worldwide. In Europe, meningococcal meningitis is differently distributed in the EU countries, but most cases of meningococcal diseases are caused by serogroups B and C. In Italy, each year about 900 cases of bacterial meningitis occur, of whom one third are caused by N. meningitidis. In March 2005, the Regional Health Authority of Tuscany approved a policy of active offer of conjugate meningococcus C (MCC) vaccination with three doses to all newborns at 3, 5 and 13 months of age (subsequently turning to a single dose at 13 months as of 2008) and a catch-up until age 6 years with a single dose.

OBJECTIVE

The aim of the present study was to evaluate the effectiveness of the vaccination strategy adopted by Tuscany in preventing cases of invasive meningococcal C disease.

METHODS

Surveillance data for the calculation of disease incidence, immunization coverage with MCC vaccine and vaccination status of meningitis cases were collected from 2005 to 2011.

RESULTS

Incidence rates of meningococcal meningitis and septicemia decreased in all age groups involved in the immunization campaign, as a result of the progressively increasing vaccination coverage. Since 2006, no cases of invasive meningococcal C infection in vaccinated subjects were observed in Tuscany. A herd immunity effect was measured in unvaccinated age groups.

CONCLUSION

MCC vaccination implementation in Tuscany was successful in the prevention of meningococcal C disease. Our results should prompt all Italian Regions to consider introducing MCC vaccination in order to protect their population.

Streptococcus pneumoniae: elusive mechanisms of the body's defense systems

Streptococcus pneumoniae is one of the most important human pathogens. It represents the most frequent cause of pneumonia, meningitis, sinusitis and otitis. After the PCV7 vaccine introduction, a serotypic switch was noticed. This phenomenon led to the replacement of the seven serotypes contained in the vaccine with other less common ones, some of which are invasive or characterised by antibiotic-resistance. This replacement is only partially due to the vaccination. Many causes have been suggested to explain this effect: apearance of new serotypes, diffusion of minority serotypes and replacement of common serotypes due to natural secular trend. Pneumococcus has a promiscuous "sex life", characterized by homologous recombinations within the same species and also between different species. This fact can unlock the secret of how these pathogens can develop antibiotic or vaccine-resistance. The serotypic switch involves big loci that are responsible for capsular polysaccharide synthesis. The most important region of the genome involved in this process is near the gene tetM. The same mechanisms are also responsible for antibiotic resistance. In recent years the growth of penicillin, macrolides and clindamycine resistance has been noticed. It is also important to underline that multidrug-resistant bacteria isolation has increased. In conclusion, to obtain more information about bacteria composition and evolution, antibiotic-resistance and vaccine response, it is fundamental to improve the epidemiological surveillance of pneumococcal infections using modern molecular diagnostic techinques.

Potential serotype coverage of three pneumococcal conjugate vaccines against invasive pneumococcal infection in Italian children

BACKGROUND AND AIM OF THE WORK

Since the introduction of the 7-valent vaccine, invasive pneumococcal disease have greatly decreased; however, changes in the distribution of pneumococcal serotypes have recently highlighted the need for vaccines with wider coverage. The aim of the work was to assess the potential serotype coverage of three pneumococcal conjugate vaccines (7-, 10- and 13-valent) against bacteremic pneumococcal pneumonia and meningitis/sepsis in Italian children.

PATIENTS AND METHODS

We determined pneumococcal serotypes in immunocompetent patients who had been admitted to hospital with suspicion of invasive bacterial disease and had confirmed bacteremic pneumococcal pneumonia or meningitis/sepsis determined by molecular detection of Streptococcus pneumoniae in a normally sterile site. Positive samples were serotyped using Realtime-PCR.

RESULTS

Between April 2008 and March 2011, a total of 144 patients (age median 4.1 years; Interquartile range 1.8-5.6) with pneumococcal meningitis/sepsis (n=43) or pneumonia (n=101) from 83 participating centers located in 19 of 20 Italian regions were serotyped. The 10 most prevalent serotypes were 1 (29.9%), 3 (16.0%), 19A (13.2%), 7F (8.3%), 5 (4.2%), 14 (4.2%), 6A (3.5%), 6B (3.5%), 18C (3.5%), 19F (3.5%). Overall, serotype coverage for PCV-7, -10 and -13 were respectively 19.4%, 61.8% and 94.4% with no statistical difference between pneumonia and meningitis/sepsis. Potential coverage was similar for children 0-2 or 2-5 years of age. Cultures resulted positive in 35/99 (35.4%) samples simultaneously obtained for both culture and RT-PCR.

CONCLUSION

These findings indicate that increasing the potential serotype coverage by introducing PCV13 in the vaccination schedule for infancy could provide substantial added benefit for protection from pneumococcal pneumonia or meningitis/sepsis in Italy in children below 2 years as well in older children. The importance of molecular methods for diagnosis and serotyping of invasive pneumococcal disease was confirmed.

Severe Necrotizing Pneumonia Complicating Influenza A (H1N1): The Role of Immunologic Interaction

This report describes the successful management of a documented necrotizing pneumonia due to Streptococcus pneumoniae in a child with pandemic influenza A (H1N1). The importance of early recognition of bacterial superinfection in patients with influenza and the immunologic interactive mechanisms between viruses and bacteria in determining respiratory diseases are highlighted. The role of modern molecular techniques in improving diagnostic microbiology sensitivity and informing consequent clinical care is emphasized.