Underestimation of Invasive Meningococcal Disease in Italy

Underestimation is attributable to misdiagnosis, especially in fatal cases, and use of insufficiently sensitive laboratory methods.

Knowing the incidence of invasive meningococcal disease (IMD) is essential for planning appropriate vaccination policies. However, IMD may be underestimated because of misdiagnosis or insufficiently sensitive laboratory methods. Using a national molecular surveillance register, we assessed the number of cases misdiagnosed and diagnoses obtained postmortem with real-time PCR (rPCR), and we compared sensitivity of rPCR versus culture-based testing. A total of 222 IMD cases were identified: 11 (42%) of 26 fatal cases had been misdiagnosed or undiagnosed and were reclassified as IMD after rPCR showed meningococcal DNA in all available specimens taken postmortem. Of the samples tested with both rPCR and culture, 58% were diagnosed by using rPCR alone. The underestimation factor associated with the use of culture alone was 3.28. In countries such as Italy, where rPCR is in limited use, IMD incidence may be largely underestimated; thus, assessments of benefits of meningococcal vaccination may be prone to error.

The Role of DNA Amplification and Cultural Growth in Complicated Acute Appendicitis

Bacterial growth of peritoneal fluid specimens obtained during surgical procedures for acute appendicitis may be useful to optimize further antibiotic therapy in complicated cases. DNA amplification represents a fast technique to detect microbial sequences. We aimed to compare the potential of DNA amplification versus traditional bacterial growth culture highlighting advantages and drawbacks in a surgical setting. Peritoneal fluid specimens were collected during surgery from 36 children who underwent appendectomy between May and December 2012. Real-time polymerase chain reaction (RT-PCR) and cultures were performed on each sample. RT-PCR showed an amplification of 16S in 18/36 samples, Escherichia coli (in 7 cases), Pseudomonas aeruginosa (3), Fusobacterium necrophorum (3), Adenovirus (2), E.coli (1), Klebsiella pneumoniae (1), Serratia marcescens/Enterobacter cloacae (1). Bacterial growth was instead observed only in four patients (3 E.coli and 1 P.aeruginosa and Bacteroides ovatus). Preoperative C-reactive protein and inflammation degree, the most reliable indicators of bacterial translocation, were elevated as expected. DNA amplification was a quick and useful method to detect pathogens and it was even more valuable in detecting aggressive pathogens such as anaerobes, difficult to preserve in biological cultures; its drawbacks were the lack of biological growths and of antibiograms. In our pilot study RT-PCR and cultures did not influence the way patients were treated.

Vertical Hepatitis C Virus Transmission is not Related to Mother-Child Class-1 HLA Concordance

Mother-child human leukocyte antigen (HLA) diversity is protective for vertical transmission of some viruses. The aim of this study is to evaluate the role of mother-child HLA diversity on hepatitis C virus (HCV) vertical transmission. Forty consecutive HCV infected and 46 consecutive control uninfected children born to HCV-RNA positive mothers were evaluated for HLA class-1 type concordance with their mothers. No significant difference in the degree of HLA concordance was found between HCV infected and uninfected children both when A, B, C ( p=0.30) and when only A and B alleles were evaluated ( p=0.59). Mother-infant HLA concordance does not affect HCV vertical transmission.

Diagnostic Value of Three Different Latex Extracts

The diagnosis of latex allergy is made on clinical history, but a confirmatory skin prick test (SPT) or a serological assay based on a commercial latex extract is always recommendable. Different raw materials can be used in the preparation of commercial latex extracts. Such extracts can consequently show both different qualitative profiles and a different diagnostic potential. Therefore, the selection of a proper latex extract is essential for in vitro and in vivo diagnosis of latex allergy. In the present study three different latex extracts, prepared from different raw materials (ammoniated -AL-, serum -SL-, or rubber particles -RPE- latex), are compared by in vitro techniques using sera from twenty patients with latex allergy. SDS-PAGE technique was used to compare the antigenic profile of the three latex extracts. Subsequently, their allergenic profiles were evaluated by immunoblotting technique using the individual sera from the twenty latex allergic patients. The diagnostic potential of the three latex extracts was also evaluated using direct Radio-Allergo-Sorbent Test (RAST) as well as skin prick tests (SPTs). In order to establish the more appropriate latex extract in a perspective of in vivo diagnosis of latex sensitization, the same latex extracts were subsequently compared by an in vivo SPT involving ten of the above subjects. The SDS-PAGE profiles of the three latex extracts examined were quite different. SL extract showed numerous bands comprised between 10–100 kDa. RPE extract was characterized by two intense bands at 14 and 20 kDa while AL extract showed the poorer antigenic composition. Analogously, immunoblotting analysis evidenced a different profile in relation to both different patients and extracts. For only two out of the twenty sera, direct RAST results showed a same positive class in relation to the different latex extracts used. SPT with SL extract showed, in respect to the other extracts (AL, RPE), a significantly higher wheal. This study showed that SL extract is able to express the best in vitro and in vivo diagnostic potential. Thus, its use should be preferred for the diagnosis of patients affected by latex allergy.

Altered natural killer cells subsets distribution in children with hepatitis C following vertical transmission

BACKGROUND

Natural killer (NK) cells number, phenotypes and function have been evaluated in many studies in adults with hepatitis C as compared with healthy controls or dynamically during interferon-based and interferon-free treatments. Overall, in adults with chronic infection number of circulating NK cells has been reported to be lower when compared to spontaneous resolvers and healthy subjects. Different studies yielded inconsistent findings due to patient and virus heterogeneity.

AIM

To evaluate NK cells in children according to the different outcomes of the infection.

METHODS

In this cross-sectional study, we examined numbers and phenotypes of circulating NK cells from a homogenous cohort of Italian children with vertically acquired hepatitis C.

RESULTS

We compared 31 children who developed chronic infection with nine who presented spontaneous clearance and 13 controls. CD56(+) CD3(-) NK cell numbers were consistently lower in the persistently infected group (P = 0.03 and 0.04). This decrease was due to depletions of CD56(dim) NK cells (P = 0.03 chronic infection vs. spontaneous clearance), while CD56(bright) NK cells were expanded (P = 0.03). No significant difference was found in the frequencies of CD56(+) CD16(+) and CD56(dim) CD16(-) cells. Perforin expression was higher in children with chronic infection (P = 0.03 vs. spontaneous clearance).

CONCLUSIONS

Altered NK cells number and phenotypes could impact the outcome of HCV infection in children following vertical transmission. This study suggests for the first time that NK cells cytolytic function, featured by CD56(dim) cells, contributes to the elimination of HCV in children presenting spontaneous clearance.

Subcutaneous immunoglobulin replacement therapy in patients with primary immunodeficiency in routine clinical practice: the VISPO prospective multicenter study

Background and Objectives

Subcutaneous immunoglobulin (SCIG) therapy is becoming increasingly popular as self-administration is possible because intravenous access is unnecessary, and there is a lower frequency of systemic adverse events. The aim of this study was to evaluate the shifting from intravenous immunoglobulins (IVIGs) replacement therapy to SCIG in patients with primary immunodeficiency (PID) in a routine real-life situation.

Methods

In a multicenter prospective observational study, we enrolled 50 patients suffering from PID who were monitored for 24 months; 44 patients switched from IVIG and six from different SCIG preparations. The study preparation (human IgG 16 %, Vivaglobin^®, CSL Behring GmbH, Germany) was subcutaneously infused weekly (maximum volume 15 mL/site; maximum infusion rate 22 mL/h). The study endpoints were: annual rate of severe bacterial infections (SBIs), local adverse reactions, quality of life, days off school/work, and days of hospitalization.

Results

Thirty-three of 39 (84.6 %) patients who completed the study experienced an infection or signs thereof. Only five SBIs were observed, corresponding to an annual rate of 0.056 episodes per patient in 44 subjects [intention-to-treat (ITT) population]. A significant decrease in both days of hospitalization (1.93 ± 4.08 vs. 0.64 ± 2.94) and days off school/work (15.27 ± 23.17 vs. 2.26 ± 4.45) was recorded at 24 months. Local reactions were observed in 14/50 (28 %) patients, mainly consisting of skin manifestations at the injection site. Only three (6.8 %) patients discontinued due to infusion site reactions. In patients shifting from IVIG to SCIG, the total mean score of Life Quality Index (LQI) improved from 76.9 ± 16.8 to 90.7 ± 11.6 (P < 0.01) at 6 months; there was an improvement also in the overall patients’ evaluation.

Conclusions

A total of 93.2 % patients tolerated the new route of administration and reported a significant improvement in their LQI. Our results from a routine clinical practice in a real-life population are consistent with those of phase III clinical studies.

The burden of bacteremia and invasive diseases in children aged less than five years with fever in Italy

Background

Invasive diseases (ID) caused by Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae (H. influenzae), and Neisseria meningitidis are a major public health problem worldwide. Comprehensive data on the burden of bacteremia and ID in Italy, including data based on molecular techniques, are needed.

Methods

We conducted a prospective, multi-centre, hospital-based study (GSK study identifier: 111334) to assess the burden of bacteremia and ID among children less than five years old with a fever of 39 °C or greater. Study participation involved a single medical examination, collection of blood for polymerase chain reaction (PCR) and blood culture, and collection of an oropharyngeal swab for colonization analysis by PCR.

Results

Between May 2008 and June 2009, 4536 patients were screened, 944 were selected and 920 were enrolled in the study. There were 225 clinical diagnoses of ID, 9.8 % (22) of which were bacteremic. A diagnosis of sepsis was made for 38 cases, 5.3 % (2) of which were bacteremic. Among the 629 non-ID diagnoses, 1.6 % (10) were bacteremic. Among the 34 bacteremic cases, the most common diagnoses were community-acquired pneumonia (15/34), pleural effusion (4/34) and meningitis (4/34). S. pneumoniae was the most frequently detected bacteria among bacteremic cases (29/34) followed by H. influenzae (3/34). Ninety percent (27/30) of bacteremic patients with oropharyngeal swab results were colonized with the studied bacterial pathogens compared to 46.1 % (402/872) of non-bacteremic cases (p < 0.001). PCV7 (7-valent pneumococcal conjugate vaccine) vaccination was reported for 55.9 % (19/34) of bacteremic cases. S. pneumoniae serotypes were non-vaccine serotypes in children who had been vaccinated. Mean duration of hospitalization was longer for bacteremic cases versus non-bacteremic cases (13.6 versus 5.8 days).

Conclusions

These results confirm that S. pneumoniae is one of the pathogens frequently responsible for invasive disease.

Development and validation of a 2nd tier test for identification of purine nucleoside phosphorylase deficiency patients during expanded newborn screening by liquid chromatography-tandem mass spectrometry

BACKGROUND

Purine nucleoside phosphorylase (PNP) deficiency has been recently introduced in the newborn screening program in Tuscany. In order to improve the PNP screening efficiency, we developed a 2nd tier test to quantify PNP primary markers deoxyguanosine (dGuo) and deoxyinosine (dIno).

METHODS

Dried blood spots (DBS) samples were extracted with 200 μL of methanol and 100 μL of water (by two steps). Internal standards were added at a final concentration of 10 μmol/L. After extraction, samples were analysed by LC-MS/MS. The chromatographic run was performed in gradient mode by using a Synergi Fusion column.

RESULTS

The assay was linear over a concentration range of 0.05-50 μmol/L (R2>0.999) for dGuo and 0.5-50 μmol/L (R2>0.998) for dIno. Intra- and interassay imprecision (mean CVs) for dIno and dGuo ranged from 2.9% to 12%. Limit of quantitaion (LOQ) were found to be 0.05 μmol/L and 0.5 μmol/L for dGuo and dIno, respectively. The reference ranges, obtained by measuring dGuo and dIno concentrations on DBS, were close to zero for both biomarkers. Moreover, DBS samples from seven patients with confirmed PNP were retrospectively evaluated and correctly identified.

CONCLUSIONS

The LC-MS/MS method can reliably measure dIno and dGuo in DBS for the diagnosis of PNP. Validation data confirm the present method is characterised by good reproducibility, accuracy and imprecision for the quantitation of dIno and dGuo. The assay also appears suitable for use in monitoring treatment of PNP patients.

Broad-spectrum antibodies against self-antigens and cytokines in RAG deficiency

Patients with mutations of the recombination-activating genes (RAG) present with diverse clinical phenotypes, including severe combined immune deficiency (SCID), autoimmunity, and inflammation. However, the incidence and extent of immune dysregulation in RAG-dependent immunodeficiency have not been studied in detail. Here, we have demonstrated that patients with hypomorphic RAG mutations, especially those with delayed-onset combined immune deficiency and granulomatous/autoimmune manifestations (CID-G/AI), produce a broad spectrum of autoantibodies. Neutralizing anti-IFN-α or anti-IFN-ω antibodies were present at detectable levels in patients with CID-G/AI who had a history of severe viral infections. As this autoantibody profile is not observed in a wide range of other primary immunodeficiencies, we hypothesized that recurrent or chronic viral infections may precipitate or aggravate immune dysregulation in RAG-deficient hosts. We repeatedly challenged Rag1S723C/S723C mice, which serve as a model of leaky SCID, with agonists of the virus-recognizing receptors TLR3/MDA5, TLR7/-8, and TLR9 and found that this treatment elicits autoantibody production. Altogether, our data demonstrate that immune dysregulation is an integral aspect of RAG-associated immunodeficiency and indicate that environmental triggers may modulate the phenotypic expression of autoimmune manifestations.

Histopathology of hepatitis C in children, a systematic review: implications for treatment

Chronic hepatitis C in children is usually considered a clinically mild and slowly progressive disease. Few pediatric studies focused on histopathology of children with hepatitis C are available. Those available show, overall, a wide spectrum of findings ranging from normal liver to cirrhosis and hepatocellular carcinoma. The present systematic review provides a comprehensive overview of the studies that explored histopathology in children with hepatitis C. Factors affecting the presence and the degree of necroinflammation, fibrosis and steatosis and the risk of progression to advanced liver disease were extensively evaluated. Insights on the possible role of histopathology findings in the decision-making process of whether or not to treat children with hepatitis C are provided.

Investigation on the Origin of Sperm DNA Fragmentation: Role of Apoptosis, Immaturity and Oxidative Stress

Sperm DNA fragmentation (sDF) represents a threat to male fertility, human reproduction and the health of the offspring. The causes of sDF are still unclear, even if apoptosis, oxidative assault and defects in chromatin maturation are hypothesized. Using multicolor flow cytometry and sperm sorting, we challenged the three hypothesized mechanisms by simultaneously evaluating sDF and signs of oxidative damage (8-hydroxy, 2'-deoxyguanosine [8-OHdG] and malondialdehyde [MDA]), apoptosis (caspase activity and cleaved poly[ADP-ribose] polymerase [cPARP]) and sperm immaturity (creatine phosphokinase [CK] and excess of residual histones). Active caspases and c-PARP were concomitant with sDF in a high percentage of spermatozoa (82.6% ± 9.1% and 53.5% ± 16.4%, respectively). Excess of residual histones was significantly higher in DNA-fragmented sperm versus sperm without DNA fragmentation (74.8% ± 17.5% and 37.3% ± 16.6%, respectively, p < 0.005), and largely concomitant with active caspases. Conversely, oxidative damage was scarcely concomitant with sDF in the total sperm population, at variance with live sperm, where 8-OHdG and MDA were clearly associated to sDF. In addition, most live cells with active caspase also showed 8-OHdG, suggesting activation of apoptotic pathways in oxidative-injured live cells. This is the first investigation on the origin of sDF directly evaluating the simultaneous presence of the signs of the hypothesized mechanisms with DNA breaks at the single cell level. The results indicate that the main pathway leading to sperm DNA breaks is a process of apoptosis, likely triggered by an impairment of chromatin maturation in the testis and by oxidative stress during the transit in the male genital tract. These findings are highly relevant for clinical studies on the effects of drugs on sDF and oxidative stress in infertile men and for the development of new therapeutic strategies.

[Universal vaccination against varicella in Italy: the same opportunity for all children]

Varicella is an infectious disease still frequent in Italy, where 8 out 20 Regions have adopted universal vaccination programs starting from 2003. Accordingly to National Vaccination Plan, all Regions should introduce universal varicella vaccination in 2015. An independent multidisciplinary group of experts met to discuss some debated questions. The available evidence of varicella vaccine efficacy in the 8 Regions was evaluated and the evidence of safety of monovalent and combined varicella vaccines are presented. The strategy for introducing universal varicella vaccine in the pediatric immunization schedule is discussed. The expert group concludes that available evidence supports the active offer of varicella vaccine in all Italian Regions and that catch up programs for susceptible cohorts should be encouraged.

Human papillomavirus prevalence in paired urine and cervical samples in women invited for cervical cancer screening

With the introduction of Human papillomavirus (HPV) vaccination in young girls in 2007, it is important to monitor HPV infections and epidemiological changes in this target population. The present study has evaluated the detection of human papillomavirus DNA in paired cervical and urine samples to understand if HPV testing in urine could be used as non-invasive method to monitor HPV status in young women. The study enrolled 216 twenty five-year-old women, resident in Florence and invited for the first time to the cervical cancer Screening Program within a project evaluating the impact of HPV vaccination. HPV genotyping was performed on 216 paired urine and cervical samples. The overall concordance between cervix and urine samples, investigated by HPV genotyping (INNO-LiPA HPV Genotyping Extra), was: 85.6% (184/215), 84.6% (182/215), 80% (172/215) when the same HPV, at least the same HR HPV and all HR HPV, respectively, were detected. HPV type specific concordance in paired urine and cervical samples was observed in 85.8% (175/204) of women with normal cytology and in seven out of nine women with abnormal cytology. Urine seems to be a suitable and reliable biological material for HPV DNA detection as evidenced by the high concordance with HPV detected in cervical samples. These results suggest that urine could be a good noninvasive tool to monitor HPV infection in vaccinated women.

Pertussis

Pertussis continues to be an important public-health issue. The high immunization coverage rates achieved, mainly in industrialized countries, have certainly decreased the spread of the pathogen. However, as immunity wanes, adolescents and adults play an important role in the dynamics of the infection. The surveillance system has several limitations and the underestimation of pertussis in adolescents, young adults and adults is mainly related to the atypical clinical characteristics of cases and the lack of lab confirmation. The real epidemiological impact of pertussis is not always perceived. The unavailability of comprehensive data should not hamper the adoption of active prophylactic measures designed to avoid the impact of waning immunity against pertussis. Different immunization strategies have been suggested and/or already adopted such as immunization of newborns, pre-school and school children, adolescents, adults, healthcare workers, childcare workers, pregnant women, cocoon strategy. Prevention of pertussis requires an integrated approach and the adoption of different immunization strategies, with the objective of achieving and maintaining high coverage rates.

A retrospective analysis of hospital discharge records for S. pneumoniae diseases in the elderly population of Florence, Italy, 2010-2012

Invasive pneumococcal diseases (IPD) and community acquired pneumonia (CAP) represent two of the major causes of out-patient visits, hospital admissions and deaths in the elderly. In Tuscany (Italy), in the Local Health Unit of Florence, a project aimed at implementing an active surveillance of pneumococcal diseases in the hospitalized elderly population started in 2013. The aim of this study is to show the results of the retrospective analysis (2010-2012) on hospital discharge records (HDRs) related to diseases potentially due to S. pneumoniae, using a selection of ICD9-CM codes. All ordinary hospitalizations (primary and secondary diagnoses) of the elderly population were included (11 245 HDRs). Among a population of about 200 000 inhabitants ≥65 y, the hospitalization rate (HR) increased with increasing age and was higher in males in all age groups. Almost all hospitalizations (95%) were due to CAP, only 5% were invasive diseases. Only few cases of CAP were specified as related to S. pneumoniae, the percentage was higher in case of meningitis (100%) or septicemia (22%). In-hospital deaths over the three-year period were 1703 (case fatality rate: 15%). The risk of dying, being hospitalized for a disease potentially attributable to pneumococcus (as primary diagnosis) increased significantly with age (P < 0.001), the odds ratio (OR) per increasing age year was 1.06 (95% CI 1.05-1.07) and was higher in patients with co-existing medical conditions with respect to patients without comorbidities. Currently, an active surveillance system on S. pneumoniae diseases with the inclusion of bio-molecular tests (RT-PCR), is a key step to assess the effectiveness of the PCV13 vaccine (13-valent pneumococcal conjugate vaccine) in the elderly population after implementation of vaccination policies. The results of this study will provide the comparator baseline data for the evaluation of a possible immunization programme involving one or more cohorts of the elderly in Tuscany.

Can Hexavalent Vaccines Be Simultaneously Administered with Pneumococcal or Meningococcal Conjugate Vaccines?

BACKGROUND

Local immunization programs may include hexavalent and conjugate pneumococcal or meningococcal vaccines administered in the same vaccination visit. Information based on evidence is necessary for correctly planning schedules and for parents who often fear the administration of too many vaccines. We reviewed the available literature to assess the effects on immunogenicity and safety of simultaneous administration of hexavalent and conjugate pneumococcal and meningococcal C vaccines in healthy children.

METHODS

We searched for papers including a comparison of coadministration and single administration of hexavalent with conjugate pneumococcal or meningococcal C vaccines. Data sources included Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE. Immunogenicity and safety results were extracted and compared. We calculated the absolute risk increase of being a non responder to any antigen and of experiencing common adverse events.

RESULTS

Four relevant articles were included in the review. Immunogenicity of components included in the hexavalent vaccines was maintained with coadministration of conjugate pneumococcal and meningococcal C vaccines. However individuals who received hexavalent vaccine with conjugate pneumococcal vaccines were 18% more likely to have anti-PRP < 1 microg/mL after the third dose although this difference disappeared after the fourth dose, and titres against meningococcal C antigens were higher when vaccines were administered separately. Children who received simultaneous administration of hexavalent vaccines with conjugate pneumococcal vaccines had a 13-17% additional risk of experiencing fever compared with single administration.

CONCLUSION

Few studies deal with coadministration of vaccines. Hexavalent and conjugate pneumococcal or meningococcal vaccines may however be administered simultaneously without noteworthy negative effects on immunogenicity or safety profile. Parents of vaccinees should be appropriately informed on the effects of coadministration to improve their compliance. Studies on vaccine coadministration should be promoted and unpublished studies realized for vaccine registration should be made available.

Polymorphisms in the IFNL3/IL28B gene and hepatitis C: from adults to children

The purpose of the present review is to summarise the current knowledge on the association between single nucleotide polymorphisms (SNPs) in the interferon L3 (IFNL3) gene and hepatitis C virus (HCV) infection in children. Many studies in adults have demonstrated that genetic variation in IFNL3 is a strong predictor of the virological response in treatment-naive patients with HCV genotype 1 who were treated with Pegylated-IFN-α and ribavirin. Genetic variation in IFNL3 is also associated with the spontaneous clearance of HCV. Thus far, few paediatric studies have explored the association between variations in the IFNL3 gene and either spontaneous or treatment-induced clearance of HCV. The CC genotype of the rs12979860 SNP is associated with the spontaneous clearance of HCV in children independently of HCV genotype. Four paediatric studies have shown that both the CC genotype of the rs12979860 SNP and the TT genotype of the rs8099917 SNP are associated with the treatment-induced (IFN monotherapy and Pegylated-IFN-α and ribavirin association) clearance of HCV, while the rs12980275 SNP did not affect the virological response. The possible role of IFNL3 gene variation as a pre-treatment and on-treatment predictor of virological response in children is highly attractive but still undetermined. Further paediatric studies are needed to evaluate if testing for SNPs in IFNL3, either alone or together with other predictors of response to treatment, could be used to direct treatment strategies, including an avoidance of unnecessary protease inhibitor therapy and the duration of treatment.