Anti-transglutaminase antibodies in non-coeliac children suffering from infectious diseases

Anti-transglutaminase antibodies are the diagnostic markers of coeliac disease. A role is suggested for infectious agents in the production of anti-transglutaminase antibodies. The aim was to measure positive anti-transglutaminase antibody levels in children with infectious diseases and to compare immunological and biological characteristics of the anti-transglutaminase antibodies derived from these children with that from coeliac patients. Two hundred and twenty-two children suffering from infectious diseases were enrolled prospectively along with seven biopsy-proven coeliacs. Serum samples were tested for anti-transglutaminase antibodies and anti-endomysium antibodies; positive samples were tested for coeliac-related human leucocyte antigen (HLA)-DQ2/8 and anti-viral antibodies. Purified anti-transglutaminase antibodies from the two study groups were tested for urea-dependent avidity, and their ability to induce cytoskeletal rearrangement and to modulate cell-cycle in Caco-2 cells, using phalloidin staining and bromodeoxyuridine incorporation assays, respectively. Nine of 222 children (4%) tested positive to anti-transglutaminase, one of whom also tested positive for anti-endomysium antibodies. This patient was positive for HLA-DQ2 and was diagnosed as coeliac following intestinal biopsy. Of the eight remaining children, two were positive for HLA-DQ8. Levels of anti-transglutaminase returned to normal in all subjects, despite a gluten-containing diet. Purified anti-transglutaminase of the two study groups induced actin rearrangements and cell-cycle progression. During an infectious disease, anti-transglutaminase antibodies can be produced temporarily and independently of gluten. The infection-triggered anti-transglutaminase antibodies have the same biological properties as that of the coeliacs, with the same in-vivo potential for damage.

The molecular epidemiology of influenza viruses: a lesson from a highly epidemic season

AIMS

To analyse the epidemiological and molecular features of a long-lasting epidemic (12 weeks) of influenza in north-eastern Italy during the 2004-05 season.

METHODS

Morbidity rates were analysed by time and age. Influenza virus isolates (93 strains) were submitted to antigenic evaluation by haemagglutination inhibition test and to molecular assessment by sequencing.

RESULTS

The incidence peak (16.4 per thousand) was the highest recorded over the last six years in north-eastern Italy. The epidemic was sustained by two subsequent waves of circulating viruses: an H3N2 variant and two type B variants, respectively. In addition, scattered isolation of an H1N1 variant occurred. Antigenic and molecular characterisation showed the emergence of an H3N2 virus drifted with respect to vaccine strain, which also had a substantial impact on morbidity in vaccinated subjects. Moreover, a single K145N substitution in the HA1 site of H3N2 was the starting point of two evolutionary branches. No change was observed in H1N1 isolates. B-type virus was mainly represented by Victoria-lineage strains, though Yamagata-lineage viruses were also identified. The fluctuating circulation of these two clades has characterised B virus epidemics in recent years.

CONCLUSIONS

The assessment of the H3N2 molecular change in this area was in line with results used for establishing the vaccine composition for the incoming season. The particular epidemiological features of two B virus clades, namely Yamagata-like and Victoria-like, may be considered for introduction into the influenza vaccine.

HBV, HCV, and TTV detection by in situ polymerase chain reaction could reveal occult infection in hepatocellular carcinoma: comparison with blood markers

OBJECTIVE

To report a retrospective analysis on the presence of hepatitis B virus (HBV), hepatitis C virus (HCV), and transfusion transmitted virus (TTV) sequences in formalin fixed, paraffin embedded liver biopsies from eight patients with hepatocellular carcinoma, in comparison with blood markers.

METHODS

A direct in situ polymerase chain reaction (PCR) technique was developed for the detection and localisation of genomic signals in the liver tissue. Conventional serological and molecular methods were used for blood evaluation.

RESULTS

In situ PCR showed the presence of one of the three viruses (four HCV, two HBV, and one TTV) in seven of the eight patients. In addition, a co-infection with HBV and HCV was detected in one patient. HCV and HBV sequences were located in the cytoplasm and the nucleus, respectively. When compared with blood markers, these findings were compatible with one occult HBV and two occult HCV infections.

CONCLUSIONS

These findings provide further evidence for occult HBV and HCV infections in cancerous tissues from patients with hepatocellular carcinomas. In situ PCR could be an additional tool for evaluating the viral aetiology of hepatocellular carcinoma alongside conventional diagnostic procedures.

A population based seroepidemiological survey of Chlamydia pneumoniae infections in schoolchildren

AIM

A serosurvey was carried out in schoolchildren from a northeastern area of Italy to define the burden of Chlamydia pneumoniae infection.

METHODS

A sample of 649 schoolchildren underwent a simplified version of the International Study of Asthma and Allergies in Childhood questionnaire and IgG and IgA antibodies were investigated using an enzyme immunoassay, followed by a microimmunofluorescence assay in reactive sera.

RESULTS

Of the children examined, 29% and 19.7% had IgG and IgA antibodies, respectively. The IgG prevalence increased with age. No other sociodemographical variable was related to C pneumoniae infection. An association was established between IgA prevalence and previous otitis media.

CONCLUSIONS

A mesoendemic (intermediate between high and low endemic level) pattern of C pneumoniae infection is present in schoolchildren from this area and the prevalence rate is related to age. Moreover, this is the first epidemiological evidence of the role of C pneumoniae in otitis.

Three-year (1999-2002) of epidemiological and virological surveillance of influenza in north-east Italy

The results of the epidemiological and virological surveillance of influenza performed during the 1999/2000, 2000/2001 and 2001/2002 seasons in the northeastern Italy were presented and the relationship between age-specific morbidity rates and circulating strains were discussed.The epidemiological findings pointed out a change in age distribution. During the 1999/2000 season, characterized by a circulation of viruses antigenically close to the vaccine strain, a similar incidence rate in the 0-14 and 15-64-year-old groups was observed, while during the 2001/ 2002 winter the virus infected mostly children. During 2001/2002 season, B type viruses predominated with at least three distinguishable molecular variants. In particular, B/Victoria/2/87-like viruses re-emerged after more than a decade, and the antibodies elicited by the vaccine strain and by the strains circulating in previous seasons were poor or not protecting. The accumulation of susceptible subjects in young age group during the 1990s, due to the lack of circulation of B/Victoria/2/87-like viruses, was responsible for the unusual morbidity in the 0-14 year group. No circulation of B/Victoria/2/87-like viruses was observed in > 64-year-old group during 2001/2002 epidemic, probably due to a long-lasting immunity against viruses belonging to this lineage.

[Vertical transmission of HGV and outcome of the infected babies]

To assess the risk of HGV mother-to-infant transmission and the clinical outcome of infected babies, we investigated 103 mother-infant couples and followed-up the infected children for 4-72 months. Twenty (19.4%) mothers were HGV-RNA positive and transmission occurred in ten (50%) babies; only one child acquired HGV and HCV infection. Maternal factors, such as history of intravenous drug use, HCV-RNA positivity, HIV coinfection, type of delivery and type of feeding were not related to HGV transmission. One HGV infected baby showed a mild hepatitis when he was also infected by Cytomegalovirus. Two babies cleared HGV within the first year of life. The HGV transmission rate is elevated but HGV infection seems to be benign, at least in a short-term follow-up.

[HHV-6, new perspectives]

HHV-6 is the etiological agent of Exanthema subitum, and its role in human infection is well known. Recently, molecular diagnostics tools showed for HHV-6 new pathogenetic features and new clinical implication. The present paper highlights recent knowledge on HHV-6 infection and presents a number of results concerning HHV-6 infection in children who had undergone BMT and concerning the roles of endothelial cells as viral reservoir.

In situ polymerase chain reaction detection of transfusion-transmitted virus in liver biopsy

The potential role of transfusion-transmitted virus (TTV) infection in determining liver damage is poorly understood and no information exists about TTV replication within hepatocytes. In this study, we assess TTV in situ PCR in liver tissue. Twenty-one patients with different degrees of liver damage were studied by both serum TTV-DNA detection and in situ TTV PCR analysis and extractive PCR in liver biopsy paraffin sections (FFPE). Extractive PCR and in situ PCR detected TTV-DNA both in serum and liver tissue of five patients. The presence of TTV in serum matched with that found in the liver and TTV sequences were never found independently in liver or serum. Four out of five TTV-DNA-positive patients have not other known cause of liver damage while in one a coinfection from HCV was observed. Our data indicate that in situ PCR appears to be a reliable tool for the detection of TTV-DNA in FFPE, and may help detecting unknown origin of liver damage.

Seroprevalence of Chlamydia pneumoniae antibodies in a young adult population sample living in Verona. European Community Respiratory Health Survey (ECRHS) Verona

The aim of the study was to evaluate the prevalence of antibodies to Chlamydia pneumoniae in a random population sample of 369 young adults (aged 20-44 years), living in Verona, Italy. IgG and IgM titers were measured by micro-immunofluorescence. IgG antibodies, greater or equal to 16, were found in 104/177 (58.8%) men and 76/192 (39.6%) women (p < 0.001). No relationship was found between IgG seropositivity, age, social class, education and family size. Factors positively associated with IgG seropositivity included smoking (p < 0.001), occupational status (employed vs unemployed: p = 0.02; students vs unemployed: p < 0.01) and living area (suburban [65.0%] vs urban area [45.3%]: p = 0.03). The geometric mean of IgG titers was higher in students (GM: 26.05) than in both employed (GM: 11.02) and unemployed persons (GM: 4.80) (p < 0.01 and p < 0.001, respectively). IgG titres > or = 512 and/or IgM titers > or = 16 (suggestive of a recent C. pneumoniae infection) were found in 39 subjects (10.6%). Recent infection was more frequent in spring (14.9%), with no significant variation in the other seasons (mean prevalence 6.7%) (p < 0.01). Recent infection was also associated with cigarette smoking. On the other hand, no significant association was found between respiratory symptoms and serologic evidence of recent infection.

IN CONCLUSION

1) the prevalence of antibodies to C. pneumoniae in young adults from Verona is similar to that found in European countries, and therefore, in Europe, it seems not related to latitude or climate; 2) male sex, tobacco smoking, employment status and living in a suburban area are independent risk factors of infection; 3) the infection is subclinical in most cases.

Serologic response to Bartonella henselae in patients with cat scratch disease and in sick and healthy children

Indirect fluorescent antibody assay (IFA) is the most reliable test for detecting antibody to Bartonella henselae in the diagnosis of cat scratch disease (CSD). Recently, an ELISA test has been proposed, but conflicting results are reported. We compared IgG-IFA and IgG-IgM ELISA methods in CSD patients and in healthy children. We also tested ELISA specificity in a large group of healthy controls and in children with lymphoma-associated lymphadenopathy and with pyogenic lymphadenitis. The ELISA procedure was positive in 69/78 patients with CSD (sensitivity 89.6%), in 5/100 healthy children (specificity 95%), in 2/51 patients with non-Hodgkin's lymphoma or pyogenic lymphadenitis (specificity 96%) and in 27/296 blood donors (specificity 91.6%). In 34 patients with CSD, ELISA IgM and IgG responses decreased significantly between time of diagnosis of the disease and recovery. We found significantly higher IgG-ELISA titres in cat-owners, whether blood donors or healthy children, than in non-cat-owners. The IgG-IFA test gave positive results in 69/78 patients with CSD (sensitivity 89.6%) and in 5/62 healthy controls (specificity 92.5%). The ELISA method is a cheap, sensitive method for determining antibody response to Bartonella henselae infection and is also important for evaluating the clinical course of the disease and the efficacy of antibiotic therapy. The high specificity of ELISA in patients with non-Hodgkin's lymphoma will help the clinician to exclude a potentially life-threatening disease associated with lymphadenopathy.

[Infection of Chlamydia trachomatis and dysplasia lesions of the cervix uteri (CIN)]

With the aim of evaluating the correlation between dysplastic lesions of the uterine cervix associated or not with condylomatosis and Chlamydia T. infection, we carried out a serological study of anti-Chlamydia species-specific antibodies and a direct and/or a cultural investigation on a sample of 320 women who performed a Pap-test. The serological examination showed positivity (titer greater than or equal to 1:32) in 49 control subjects (with negative cytology) (23.7%); in 27 cases (43.5%) with actual diagnosis of condylomatosis/CIN associated or not with condylomatosis and in 28 cases (54.9%) with previous diagnosis of condylomatosis/CIN associated or not with condylomatosis. The cultural investigation did not show any significant difference among the groups above mentioned. Finally, the frequency of positive cases for anti-Chlamydia antibodies was estimated for each grade of actual or previous CIN: a greater frequency of positivity was noted in cases with CIN 3 (75%).

[Retrospective study of coxsackie B virus infections and congestive cardiomyopathy]

Thirty patients with congestive cardiomyopathy (C.C.) have been studied for the prevalence of neutralizing antibodies to coxsackie B viruses in comparison with age and sex matched controls. Seropositivity toward each antigen was similar in cases and controls: an exception was coxsackie B5 virus, where a significantly seropositivity was found in the control group. As a whole, high antibody titers to any antigen were observed more frequently on sera of cardiopathic patients; however the difference between cases and controls of g.m.t. to each antigen tested was not statistically significant, with the exception of coxsackie B1 virus. The absence of a clear relationship between C.C. and viral infections might be explained through biological as well as epidemiological considerations; of particular relevance, the long duration of cardiac disease (average length 71 months, median 54). Final considerations are offered regarding the methodologic approach for a better understanding of the etiology of this elusive disease.