Efficacy of individual nucleic acid amplification testing in reducing the risk of transfusion-transmitted hepatitis B virus infection in Switzerland, a low-endemic region

BACKGROUND

The risk of transfusion-transmitted hepatitis B virus (HBV) in Switzerland by testing blood donors for hepatitis B surface antigen (HBsAg) alone has been historically estimated at 1:160,000 transfusions. The Swiss health authorities decided not to introduce mandatory antibody to hepatitis B core antigen (anti-HBc) testing but to evaluate the investigation of HBV nucleic acid testing (NAT).

STUDY DESIGN AND METHODS

Between June 2007 and February 2009, a total of 306,000 donations were screened routinely for HBsAg and HBV DNA by triplex individual-donation (ID)-NAT (Ultrio assay on Tigris system, Gen-Probe/Novartis Diagnostics). ID-NAT repeatedly reactive donors were further characterized for HBV serologic markers and viral load by quantitative polymerase chain reaction. The relative sensitivity of screening for HBsAg, anti-HBc, and HBV DNA was assessed. The residual HBV transmission risk of NAT with or without anti-HBc and HBsAg was retrospectively estimated in a mathematical model.

RESULTS

From the 306,000 blood donations, 31 were repeatedly Ultrio test reactive and confirmed HBV infected, of which 24 (77%) and 27 (87%) were HBsAg and anti-HBc positive, respectively. Seven HBV-NAT yields were identified (1:44,000), two pre-HBsAg window period (WP) donations (1:153,000) and five occult HBV infections (1:61,000). Introduction of ID-NAT reduced the risk of HBV WP transmission in repeat donors from 1:95,000 to 1:296,000.

CONCLUSIONS

Triplex NAT screening reduced the HBV WP transmission risk approximately threefold. NAT alone was more efficacious than the combined use of HBsAg and anti-HBc. The data from this study led to the decision to introduce sensitive HBV-NAT screening in Switzerland. Our findings may be useful in designing more efficient and cost-effective HBV screening strategies in low-prevalence countries.

Evaluation of cytochrome P450 inhibition assays using human liver microsomes by a cassette analysis /LC-MS/MS

In vitro inhibition assays are used to screen new chemical entities (NCEs) for inhibition studies by using human liver microsomes. High-throughput inhibition assays using pooling methods have been developed to keep pace with screening requirements at the lead ADME stage. This method can determine IC(50) NCEs using microsomes from various organs from any species. A cassette analysis inhibition assay for five of the major CYP enzymes (phenacetin for CYP1A2, diclofenac for CYP2C9, (S)-mephenytoin for CYP2C19, bufurarol for CYP2D6 and midazolam, nifedipine and atorvastatin for CYP3A4) in pooled human liver microsomes using ultraperformance liquid chromatography tandem mass spectrometry (LC/MS/MS) were developed. The major metabolites of seven CYP-specific probe substrates for the five P450 isoforms were monitored and quantified to determine IC(50) values. Human liver microsomal incubation samples at each test compound concentration were combined and analyzed simultaneously by the LC/MS/MS method. The incubation was performed using the selective CYP inhibitors for each isoform: fluvoxamine (CYP1A2), sulphaphenazole (CYP2C9), ticlopidine (CYP2C19), quinidine (CYP2D6), and Ketoconazole (CYP3A4). Similar IC(50) results were obtained using the cassette analysis and discrete analysis method. The IC(50) values determined for typical CYP inhibitors were reproducible and consistent with those reported in the literature. The assay was fully automated in 96 well plate formats using Microlab 4000 series (Hamilton) coupled with two termomixer comfort (Eppendorf). An overall 70% time savings was achieved by pooling four isoforms samples (1A2, 2C9, 2C19 and 2D6) into one sample and also by pooling three CYP 3A4 substrate samples (MDZ, ATR, NIF) into one sample. Cassette analysis minimized the number of injections on LC/MS/MS analysis which results in a decrease in the LC/MS/MS analysis time.

500 ml of blood loss does not decrease non-invasive tissue oxygen saturation (StO2) as measured by near infrared spectroscopy - A hypothesis generating pilot study in healthy adult women

Background

The goal when resuscitating trauma patients is to achieve adequate tissue perfusion. One parameter of tissue perfusion is tissue oxygen saturation (StO₂), as measured by near infrared spectroscopy. Using a commercially available device, we investigated whether clinically relevant blood loss of 500 ml in healthy volunteers can be detected by changes in StO₂ after a standardized ischemic event.

Methods

We performed occlusion of the brachial artery for 3 minutes in 20 healthy female blood donors before and after blood donation. StO₂ and total oxygenated tissue hemoglobin (O₂Hb) were measured continuously at the thenar eminence. 10 healthy volunteers were assessed in the same way, to examine whether repeated vascular occlusion without blood donation exhibits time dependent effects.

Results

Blood donation caused a substantial decrease in systolic blood pressure, but did not affect resting StO₂ and O₂Hb values. No changes were measured in the blood donor group in the reaction to the vascular occlusion test, but in the control group there was an increase in the O₂Hb rate of recovery during the reperfusion phase.

Conclusion

StO₂ measured at the thenar eminence seems to be insensitive to blood loss of 500 ml in this setting. Probably blood loss greater than this might lead to detectable changes guiding the treating physician. The exact cut off for detectable changes and the time effect on repeated vascular occlusion tests should be explored further. Until now no such data exist.

Identifying a higher throughput assay for metabolism dependent inhibition (MDI)

A higher throughput method of screening for the metabolism dependent inhibition of 56 marketed drugs was evaluated and compared data from the PHLM assay (using midazolam as probe) with Cypex assay (using diethoxyfluoresin (DEF) as probe) for CYP3A4 by using 96 well plate. Also 27 marketed drugs were selected to evaluate the reproducibility of Cypex assay using 7-benzyloxyquinoline (7-BQ) as second probe substrate for CYP3A4. Furthermore Cypex CYP2D6 was used to evaluate the reproducibility of this system using 4-methylaminomethyl-7-methoxycoumarin (MMC) as probe substrate with 15 marketed drugs. The fold change was estimated using the fold change obtained from triplicates experiments in same day or different days. All replicates in agreement (i.e. all positive or all negative) for >80% of compounds. The IC50 values for the two assays closely matched only for 13 compounds (23%). Only 5 of the variant 56 compounds had higher IC50 values with the recombinant enzymes, whereas 38 had lower IC50 values with the recombinant cypex CYP3A4 enzyme. The Cypex assay is comparable to PHLM assay in terms of predictivity and reproducibility. The Cypex assay therefore offers a higher throughput, reproducible alternative to PHLM for placement earlier in the lead optimisation process. In conclusion, the results obtained from a fluorescence-based method using Cypex CYP3A4 reflect mostly those obtained from conventional assay using human liver microsomes. This method provides more rapid and reliable detection of MDI inhibitors and may be useful in drug discovery.

Brain penetration of local anaesthetics in the rat: Implications for experimental neuroscience

Multiple experimental neuroscience techniques rely on the use of general anaesthesia to minimize the discomfort associated to animal restraint and to achieve a more effective control of relevant physiological parameters. In order to minimise potential interference on brain neuronal activity, such studies are typically conducted at low anaesthetic doses. This practice is often coupled to peripheral infiltration of local anaesthetics to provide supplementary analgesia and prevent sub-threshold activation of pain pathways that may confound central measurements of brain function. However, little is known of the effect of peripheral anaesthesia on central measurements of brain activity in small laboratory animal species. In order to begin to address this question, we measured total and free brain exposure of five different local anaesthetics following subcutaneous infiltration of analgesic doses in a surgical protocol widely used in rodent neuroimaging and electrophysiology studies. Notably, all the anaesthetics exhibited detectable total and free brain concentrations at all the time points examined. Lidocaine and mepivacaine showed the highest free brain exposures (>525 ng/g), followed by bupivacaine and ropivacaine (>70 ng/g). The ester-type local anaesthetic tetracaine produced the lowest free brain exposure (<8.6 ng/g). Our data suggest that peripheral administration of local anaesthetics in small laboratory animals could result in pharmacologically active brain exposures that might influence and confound central measurements of brain function. The use of the ester-type anaesthetic tetracaine produced considerably lower brain exposure, and may represent a viable experimental option when local anaesthesia is required.

Production of an egg yolk antibody against Parietaria judaica 2 allergen

Specific antibodies are essential tools for studying proteins as well as for diagnostic research in biomedicine. The egg yolk of immunized chicken is an inexpensive source of high-quality polyclonal antibodies. The 12-kDa Parietaria judaica 2 allergen was expressed as a fusion protein and was used to immunize Leghorn chickens. In this paper, we show, using 2-dimensional gel electrophoresis and immunoblotting, that chicken antibodies raised against a recombinant allergen can be used to recognize similar proteins from a pollen raw extract. Allergen identity was confirmed by nanoLC-nanospray-tandem mass spectrometry analysis. Our data demonstrate for the first time that a synergistic combination of molecular biology, 2-dimensional PAGE, and use of nonmammalian antibodies represents a powerful tool for reliable identification of allergens.

Implementation of the JACIE standards for a haematopoietic progenitor cell transplantation programme: a cost analysis

The purpose of the present project was to analyse the costs incurred by the implementation of JACIE standards at a University Hospital with 1000 beds, performing some 40 autologous transplants per year. The cost analysis was performed on the basis of a prospective assessment of the time spent by all staff members involved with the implementation over a 14-month period of the quality management system (QMS) required by the JACIE standards. Two physicians worked on JACIE Section A (management=82 h), one physician and two nurses for section Ba (clinical unit adults=125.75 h), two physicians and three nurses for section Bp (clinical unit paediatrics=206 h), one physician, two nurses and one technician for section C (progenitor cell collection facility=105.75 h), and one physician and two technicians for section D (progenitor cell processing facility=426 h). The total time spent on the project amounted to 945.5 h with a total salary cost of \[euro]150 000. We concluded that implementation of the JACIE standards was accomplished within a 14-month period with a financial impact of approximately \[euro]150 000. The impact on quality parameters (eg clinical and laboratory end points, side effects) on HPC transplantation will be assessed in a second report after the first year of practical implementation.

Prospective, Paired Crossover Comparison of the in vitro Quality of Red Blood Cells Collected by the Automate for Blood Collection Device or by a Conventional Method

BACKGROUND: The prevention of the citrate shock should improve the quality of red blood cells (RBCs). We compared a conventional whole blood donation method (CONV) with a 'Automate for Blood Collection' (ABC), enabling a metered addition of anticoagulant and hence a correct and constant RBC-to-anticoagulant ratio throughout donation. We evaluated the performance of the ABC device and the storage quality of RBC units. MATERIAL AND METHODS: The study was designed as prospective, paired crossover study with two groups of 20 donors donating first with the ABC or CONV and switching to the alternative method after 12 weeks. We measured the processing data of donations and the storage quality of RBCs on days 1, 28, and 42. RESULTS: ABC whole blood donations showed a slightly higher volume before and after filtration. ABC-derived RBC units revealed higher values for haematocrit, mean cellular volume, potassium and lower values for mean corpuscular haemoglobin concentration and sodium until day 42. They further showed faster glucose consumption and lactate production until day 28. CONCLUSION: The ABC device is suitable for whole blood collection. The quality of the obtained RBCs is comparable to that of CONV. Avoiding the citrate shock by the described method did not improve the investigated RBC storage quality parameters.

Molecular identification and genetic analysis of Norovirus genogroups I and II in water environments: comparative analysis of different reverse transcription-PCR assays

Noroviruses have received increased attention in recent years because their role as etiologic agents in acute gastroenteritis outbreaks is now clearly established. Our inability to grow them in cell culture and the lack of an animal model hinder the characterization of these viruses. More recently, molecular approaches have been used to study the genetic relationships that exist among them. In the present study, environmental samples from seawater, estuarine water, and effluents of sewage treatment plants were analyzed in order to evaluate the role of environmental surface contamination as a possible vehicle for transmission of norovirus genogroups I and II. Novel broad-range reverse transcription-PCR/nested assays targeting the region coding for the RNA-dependent RNA polymerase were developed, amplifying fragments of 516 bp and 687 bp in the nested reactions for genogroups II and I, respectively. The assays were evaluated and compared against widely used published assays. The newly designed assays provide long regions for high-confidence BLAST searches in public databases and therefore are useful diagnostic tools for molecular diagnosis and typing of human noroviruses in clinical and environmental samples, as well as for the study of molecular epidemiology and the evolution of these viruses.

Male breast cancer with mandibular metastasis. A case report

Female breast cancer is one of the major causes of death among women while male breast cancer is relatively uncommon and accounts for about 1% of all breast cancers in both sexes. Influencing factors are: gynecomasty, familiarity for male breast cancer, Jewish and African-American male population. From the histological point of view, it is not different from the female breast cancer, except for the infiltrant ductal carcinoma, but with a much severe prognosis. Breast cancer metastases to the jaws are rare, only 1%; the most common sites of metastases are: lungs(59-69%), liver (58-65%), bone (44-71%), pleura (23-37%), brain (9-22%) and kidney (4-17%). At present, based on a literature research (May 2006), there have been just two other case reports of male breast cancer metastasis to the maxillofacial region, both to the mandible. The case of a 69-year-old white man who in 2001 underwent a radical mastectomy due to ductal breast cancer is reported. In 2005 the patient was referred to our department by his oncologist for multiple oral fistula. A mandibular TC revealed osteolytic lesions and the patient underwent mandibular surgery to remove the lesions and clean up the area. The histological examination was consistent with that of a metastatic deposit of adenocarcinoma of the breast. In June 2006 the patient died due to worsening of the general clinical conditions, in particular due to ascites and hepatic insufficiency.

Prospective, paired crossover comparison of multiple, single-needle plateletpheresis procedures with the Amicus and Trima Accel cell separators

BACKGROUND

The Baxter Amicus Version 2.51 (A) and the Gambro BCT Trima Accel Version 5.0 (T) cell separators may produce multiple platelet (PLT) concentrates within a single donation.

STUDY DESIGN AND METHODS

The single-needle multiple plateletpheresis procedures of the two devices were compared in a prospective, randomized, paired crossover study in 60 donors. The 120 donations were compared for donor comfort, collection efficiency, residual white blood cell (WBC) count, and (in selected patients) corrected count increment (CCI).

RESULTS

The mean PLT yield and the resultant mean number of units per donation were significantly lower for A (6.06 x 10(11) vs. 7.48 x 10(11) and 2.57 vs. 3.19, respectively, both p < 0.001), in spite of a longer apheresis duration (89 min vs. 79 min; p < 0.001). This resulted in a higher collection rate of T (5.68 x 10(11) PLTs/hr vs. 4.10 x 10(11) PLTs/hr, p < 0.001). Residual WBC count of every unit was fewer than 5 x 10(6), but significantly fewer A-PLT donations contained more than 10(5) WBCs per unit (1 vs. 9, p = 0.008). Although the ACD-A consumption was slightly higher for A (489 mL vs. 469 mL, p = 0.04), a trend to a higher frequency of side effects was found for T (42.4% vs. 23.7%, p = 0.06). The 1-hour CCIs of 33 transfused A-PLT units were comparable with those of 43 T-PLT units (11.8 vs. 13.9, p = 0.480).

CONCLUSIONS

Both cell separators showed safe collections of up to 4 PLT units per donation with adequate CCI. T produced a higher PLT yield despite shorter apheresis duration, but with slightly higher residual WBC counts and a trend to a higher side-effect frequency.

Validation of RT-PCR Assays for Molecular Characterization of Porcine Teschoviruses and Enteroviruses

Porcine enteroviruses (PEVs) and teschoviruses (PTVs) are described as causative agents of neurological disorders, fertility disorders and dermal lesions of swine. Difficulties in the serological detection of these viruses may lead to a significant underestimation of infections with clinical symptoms. With the recent availability of genome sequence data for all the serotypes, molecular diagnosis is a possibility. The present study describes a new approach to molecular 'serotyping' of PTVs and PEV-B viruses, involving the amplification and sequencing of a genomic fragment of the VP1 coding region. A molecular characterization of Italian entero-teschovirus isolates was performed using a set of previously published and newly designed polymerase chain reaction primers. A total of 33 porcine isolates and 10 reference strains were analysed. Porcine enterovirus-B samples were first diagnosed as positive for enterovirus by amplification of the 5'-non-translated region. Samples were then typed by amplification and sequencing of a portion of the VP1 coding region. Porcine enterovirus-A and PTVs were detected by a published assay in the 5'-NC region that allows them to be differentiated according to the size of amplification product, using the same set of primers. For serotype characterization of PTV, we evaluated four different regions: the N terminus of the capsid protein VP2, the region encoding for RNA-dependent RNA polymerase, and the capsid VP1 and VP4 regions. The newly designed primers in the VP1 region was proved to be broad in range and suitable for serotype assessment and therefore constitute a useful diagnostic tool for molecular diagnosis of porcine teschovirus/enterovirus strains and for the study of molecular epidemiology and evolution of these viruses.