European Sero-Epidemiology Network 2: standardisation of immunoassay results for pertussis requires homogeneity in the antigenic preparations.

A standardisation process, already developed during the earlier European Sero-Epidemiology Network (ESEN) project, was employed with a more robust algorithm to harmonise results of pertussis serological assays performed in 12 European and non-European countries. Initially, results from each country's own assay were compared with those obtained at the reference laboratory by means of an in-house pertussis toxin (PT)-based ELISA: seven countries used in-house or commercial PT-ELISAs; the other countries used assays based on Bordetella pertussis whole cell extracts (WCE) (three countries) or on combined PT-FHA (filamentous haemagglutinin) antigenic preparations (two countries). The WCE assays, although admitted for diagnostic purposes, confirmed their low correlation with the PT-ELISAs and their results could not be used for standardisation; the PT-FHA ELISAs gave results that were suitable for standardisation in one country but unsatisfactory in the other; the use of purified PT in serological assays confirmed its better reliability than other preparations and all PT-ELISAs results could be calibrated against those of the reference centre. In the standardisation process two high-titre cut-offs indicative of likelihood of recent infection (from within 4 weeks of disease onset up to 1 year after) were included for evaluations as they are suggested to be more useful, for the sero-epidemiological assays of immunity to pertussis, than the cut-off of protection, commonly employed, but still not defined for pertussis. Providing PT-ELISAs are used, standardisation of pertussis assay results is always possible and, when standardisation is performed, evaluation and comparison of the impact of different interventions can be also allowed, by measuring at the distribution of high antibody titres in the populations.

[Rupture of the atherosclerotic plaque: is Chlamydia pneumoniae a possible agent?]. / Studio osservazionale la chlamydia pneumoniae è correlabile con la rottura della placca aterosclerotica?

BACKGROUND: The natural history of atherosclerosis has not clearly been elucidated yet. Some works reported that flogosis plays a role in plaque instability. Why does this inflammatory process start? We investigated the correlation between Chlamydia pneumoniae acute infection and plaque rupture. METHODS: We compared blood concentrations of IgM anti-Chlamydia pneumoniae in patients affected by acute myocardial infarction (AMI) and in patients affected by stable angina. RESULTS: Our results showed a minimal statistical difference, with a more positive value in patients with AMI. Subsequently, the group affected by AMI was divided into two subgroups with and without plaque rupture: the subgroup with plaque rupture showed a higher blood concentration of Chlamydia antibodies. This subgroup was also divided into two other subgroups according to blood white cell concentration: the subgroup with normal concentration of white blood cells showed the highest value of Chlamydia antibodies. CONCLUSIONS: Chlamydia pneumoniae could play an important role in atherosclerotic plaque instability