Serologic and molecular diagnosis of hepatitis B virus

Hepatotropic viral infection associated systemic vasculitides-hepatitis B virus associated polyarteritis nodosa and hepatitis C virus associated cryoglobulinemic vasculitis

Two hepatotropic viruses have been shown to have causal relationship with systemic vasculitis-hepatitis B with classical polyarteritis nodosa and hepatitis C with cryoglobulinemic vasculitis. The present paper provides an updated overview on the clinical presentations and management of these vasculitides. HBV associated PAN patients have higher weight loss, peripheral neuropathy, mononeuritis multiplex, abdominal pain, gastrointestinal manifestations requiring surgery, cardiomyopathy, orchitis, hypertension, and/or elevated transaminase levels. Microaneurysms are also more common in mesenteric artery. Skin manifestations, however are less common. These patients also have a severe disease as suggested by higher five factor score and higher BVAS. Though relapses are less common, mortality is higher in patients with HBV PAN as compared to non HBV PAN. Plasmapheresis has a role in treatment in clearing off immune complexes. The common clinical manifestations of HCV associated cryoglobulinemic vasculitis are skin lesions, peripheral neuropathy, glomerulonephritis, arthritis, and sicca symptoms. Though combination therapy comprising of pegylated interferon α and ribavirin is the first line of management, immunotherapy is needed for severe or life threatening manifestations. Recent randomized trials have shown the efficacy of rituximab in such situations.

Introduction of an automated system for the diagnosis and quantification of hepatitis B and hepatitis C viruses

Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infections pose major public health problems because of their prevalence worldwide. Consequently, screening for these infections is an important part of routine laboratory activity. Serological and molecular markers are key elements in diagnosis, prognosis and treatment monitoring for HBV and HCV infections. Today, automated chemiluminescence immunoassay (CLIA) analyzers are widely used for virological diagnosis, particularly in high-volume clinical laboratories. Molecular biology techniques are routinely used to detect and quantify viral genomes as well as to analyze their sequence; in order to determine their genotype and detect resistance to antiviral drugs. Real-time PCR, which provides high sensitivity and a broad dynamic range, has gradually replaced other signal and target amplification technologies for the quantification and detection of nucleic acid. The next-generation DNA sequencing techniques are still restricted to research laboratories.The serological and molecular marker methods available for HBV and HCV are discussed in this article, along with their utility and limitations for use in Chronic Hepatitis B (CHB) diagnosis and monitoring.

Hepatitis B viral breakthrough associated with inappropriate preservation of entecavir

If virologic breakthrough is observed during chronic hepatitis B treatment, drug resistance or compliance problem should be considered. But in some cases, breakthrough depends on drug preservation conditions. We report the case of a 30-years-old man, who experienced viral breakthrough due to wrong preservation conditions of the drug.

Label-free multiplexed virus detection using spectral reflectance imaging

We demonstrate detection of whole viruses and viral proteins with a new label-free platform based on spectral reflectance imaging. The Interferometric Reflectance Imaging Sensor (IRIS) has been shown to be capable of sensitive protein and DNA detection in a real time and high-throughput format. Vesicular stomatitis virus (VSV) was used as the target for detection as it is well-characterized for protein composition and can be modified to express viral coat proteins from other dangerous, highly pathogenic agents for surrogate detection while remaining a biosafety level 2 agent. We demonstrate specific detection of intact VSV virions achieved with surface-immobilized antibodies acting as capture probes which is confirmed using fluorescence imaging. The limit of detection is confirmed down to 3.5 × 10(5)plaque-forming units/mL (PFUs/mL). To increase specificity in a clinical scenario, both the external glycoprotein and internal viral proteins were simultaneously detected with the same antibody arrays with detergent-disrupted purified VSV and infected cell lysate solutions. Our results show sensitive and specific virus detection with a simple surface chemistry and minimal sample preparation on a quantitative label-free interferometric platform.

Use of preconditioned human phagocytes for extracorporeal adsorption of viruses

Conventional treatment of severe viral disease is limited by the narrow choice as well as the often-significant side effects or lack of clear efficacy of antiviral chemotherapy. At the same time, however, it is known that a reduction in viral load leads to significant clinical improvement in a number of important viral diseases. In this paper we discuss the possibility of using preconditioned human phagocytes in an extracorporeal biohybrid system for adsorption of viral pathogens. We present data from in vitro experiments testing adsorption of an enterovirus and of hepatitis B virus (HBV) by a preconditioned human promyelocytic cell line. While no clearance of HBV could be detected, the results revealed a near elimination of enterovirus with the cell line displaying robust viability. Enterovirus titers of 1000 (reciprocal) were reduced to a mean titer of 10(0.6) CCID(50) with no virus detectable after adsorption in two out of five samples. Titers of 10000 (reciprocal) were in turn reduced to a mean of 10(1.4) CCID(50). The kinetics of the process was remarkable with this near elimination of the pathogen occurring within only 15min. Extracorporeal viral adsorption by a cellular biohybrid system appears feasible. Pairing target pathogens with suitable cell lines may offer a versatile antiviral technology.

A paradigm of diagnostic criteria for polyarteritis nodosa: analysis of a series of 949 patients with vasculitides

OBJECTIVE

To establish a set of clinical and paraclinical criteria potentially useful as a diagnostic screening tool for polyarteritis nodosa (PAN).

METHODS

The abilities of individual descriptive items to predict a diagnosis of PAN were evaluated by screening available data from 949 patients from the French Vasculitis Study Group database, including 262 with PAN and 687 with control vasculitides. Selected items were tested in a logistic regression model to establish a minimal set of nonredundant PAN-predictive criteria. The discriminative accuracy of these items and of the American College of Rheumatology (ACR) 1990 criteria were assessed by reapplying them to the initial patient sample and a subgroup restricted to PAN and microscopic polyangiitis (MPA) patients. A computer simulation procedure was conducted on artificially generated patient data to evaluate the usefulness of these criteria in predicting a diagnosis of PAN.

RESULTS

The analysis resulted in the retention of 3 positive predictive parameters (hepatitis B virus antigen and/or DNA in serum, arteriographic anomalies, and mononeuropathy or polyneuropathy) and 5 negative predictive parameters (indirect immunofluorescence detection of antineutrophil cytoplasmic antibody; asthma; ear, nose, and throat signs; glomerulopathy; and cryoglobulinemia) for the criteria set. These criteria yielded 70.6% sensitivity for all control vasculitides and 89.7% for MPA controls, with 92.3% specificity for all controls and 83.1% for MPA controls. The discriminant abilities of this set of items outperformed the ACR 1990 criteria in all analytical situations, showing better robustness to variations in the prevalence of individual vasculitides.

CONCLUSION

The use of positive and negative discriminant criteria could constitute a sound basis for developing a diagnostic tool for PAN to be used by clinicians. Further prospective analyses and validations in different populations are needed to confirm these items as satisfactory diagnostic criteria.