Validation and application of a SEC-HPLC method for the determination of total protein in therapeutic immunoglobulins as an alternative to the European Pharmacopoeia methods.

Several analytical procedures are described in the European Pharmacopoeia (Ph. Eur.) to determine total protein content. However, the method for the determination of protein content in therapeutic immunoglobulins prescribed in the Ph. Eur. monographs is the Kjeldahl method. The Kjeldahl method is time-consuming and requires the use of large amounts of hazardous reagents, which also results in the production of a large amount of hazardous chemical waste. The purpose of this work was to validate an alternative chromatographic method that requires no hazardous reagents and saves time, using the same instrumental conditions specified in the Ph. Eur. for the human immunoglobulin size-exclusion high-performance liquid chromatography (SEC-HPLC) molecular-size distribution assay. The chromatographic separation was achieved with a TSKgel G3000SW (600 × 7.5 mm, 10 µm) column, using an isocratic elution, with detection at 280 nm wavelength. The mobile phase consisted of an aqueous solution of 0.03 M disodium hydrogen phosphate dehydrate, 0.01 M sodium dihydrogen phosphate monohydrate, 0.2 M sodium chloride and 1 mM sodium azide. The protein content of the test samples was determined referring to a standard with a known protein concentration (i.e. Human immunoglobulin (molecular size) Biological Reference Preparation). The method was validated evaluating the characteristics precision and trueness according to the ICH Q2 guideline, and the goodness of linear fit for the signal response was assessed (given for information only). In addition, the equivalence of methods was evaluated with two one-sided t-tests (TOST) analysis with the Kjeldahl method mentioned in Ph. Eur. monographs on therapeutic immunoglobulins, and with Bland-Altman analysis of SEC-HPLC and manufacturers' data (Kjeldahl and biuret methods). The uncertainty of measurement was also calculated in order to evaluate the accuracy and quality of the results, thus facilitating a reliable compliance/non-compliance decision. Based on the outcome, the method is proposed as a suitable and convenient alternative for the determination of protein content in human immunoglobulins.

Sporadic isolation of sabin-like polioviruses and high-level detection of non-polio enteroviruses during sewage surveillance in seven Italian cities, after several years of inactivated poliovirus vaccination.

Sewage surveillance in seven Italian cities between 2005 and 2008, after the introduction of inactivated poliovirus vaccination (IPV) in 2002, showed rare polioviruses, none that were wild-type or circulating vaccine-derived poliovirus (cVDPV), and many other enteroviruses among 1,392 samples analyzed. Two of five polioviruses (PV) detected were Sabin-like PV2 and three PV3, based on enzyme-linked immunosorbent assay (ELISA) and PCR results. Neurovirulence-related mutations were found in the 5'noncoding region (5'NCR) of all strains and, for a PV2, also in VP1 region 143 (Ile>Thr). Intertypic recombination in the 3D region was detected in a second PV2 (Sabin 2/Sabin 1) and a PV3 (Sabin 3/Sabin 2). The low mutation rate in VP1 for all PVs suggests limited interhuman virus passages, consistent with efficient polio immunization in Italy. Nonetheless, these findings highlight the risk of wild or Sabin poliovirus reintroduction from abroad. Non-polio enteroviruses (NPEVs) were detected, 448 of which were coxsackievirus B (CVB) and 294 of which were echoviruses (Echo). Fifty-six NPEVs failing serological typing were characterized by sequencing the VP1 region (nucleotides [nt] 2628 to 2976). A total of 448 CVB and 294 Echo strains were identified; among those strains, CVB2, CVB5, and Echo 11 predominated. Environmental CVB5 and CVB2 strains from this study showed high sequence identity with GenBank global strains. The high similarity between environmental NPEVs and clinical strains from the same areas of Italy and the same periods indicates that environmental strains reflect the viruses circulating in the population and highlights the potential risk of inefficient wastewater treatments. This study confirmed that sewage surveillance can be more sensitive than acute flaccid paralysis (AFP) surveillance in monitoring silent poliovirus circulation in the population as well as the suitability of molecular approaches to enterovirus typing.

Detection and distribution of culturable Human Enteroviruses through environmental surveillance in Milan, Italy.

AIMS: Human Enteroviruses (HEVs) infections have a significant impact on public health, being implicated in outbreaks of meningitis, encephalitis, hand-foot-mouth disease and other acute and chronic manifestation. In the strategic plan for poliomyelitis eradication, the environmental surveillance of poliovirus (PV) has been identified by the World Health Organization (WHO) as an activity that can complement the surveillance of polio. Having wastewater samples available for PV surveillance allows us to study nonpolio enteroviruses (NPEVs) circulating in the study population, which are widely spread. METHODS AND RESULTS: This study was carried out according to the WHO guidelines for environmental surveillance of PV and analysed the circulation of PV and NPEVs through the isolation of viruses in cell cultures in Milan area; from 2006 to 2010, 321 wastewater samples were collected, regularly over time, at the inlet of three diverse waste water treatment plants (WWTPs). Culturable HEVs were isolated in 80% of sewage samples: all isolates belonged to the HEV-B group and those circulating more intensely were CVB5 and Echo 6, while CVB4 was the predominant serotype found in 2010. In this study, two type 2 PVs were isolated, both characterized as Sabin like. CONCLUSION: Environmental monitoring of HEVs in Milan has proved to be an interesting tool to investigate the circulation and distribution of viruses. SIGNIFICANCE AND IMPACT OF THE STUDY: The detection of PV and other NPEV could be predictive of possible re-emergence of these viruses with an impact on public health. NPEV monitoring could also be a powerful public health tool to investigate the possible role of NPEV in different clinical manifestations.

Massive outbreak of viral gastroenteritis associated with consumption of municipal drinking water in a European capital city.

On 24 August 2008, an outbreak alert regarding cases of acute gastroenteritis in Podgorica triggered investigations to guide control measures. From 23 August to 7 September, 1699 cases were reported in Podgorica (population 136 000) and we estimated the total size of the outbreak to be 10 000-15 000 corresponding to an attack rate of approximately 10%. We conducted an age- and neighbourhood-matched case-control study, microbiologically analysed faecal and municipal water samples and assessed the water distribution system. All cases (83/83) and 90% (80/90) [corrected] of controls drank unboiled chlorinated municipal water [matched odds ratio (mOR) 11.2, 95% confidence interval (CI), 1.6-infinity]. Consumption of bottled water was inversely associated with illness (mOR 0.3, 95% CI 0.1-0.8). Analyses of faecal samples identified six norovirus genotypes (21/38 samples) and occasionally other viruses. Multiple defects in the water distribution system were noted. These results suggest that the outbreak was caused by faecally contaminated municipal water. It is unusual to have such a large outbreak in a European city especially when the municipal water supply is chlorinated. Therefore, it is important to establish effective multiple-barrier water-treatment systems whenever possible, but even with an established chlorinated supply, sustained vigilance is central to public health.