New enzyme-linked immunosorbent assay for detection of antibodies against hepatitis delta virus using a hepatitis delta antigen derived from a Taiwanese clone and comparison to the Abbott radioimmunoassay

Assessing the diagnostic accuracy of serological tests for hepatitis delta virus diagnosis: a systematic review and meta-analysis

Hepatitis Delta Virus (HDV), a satellite virus of Hepatitis B virus, exacerbates liver damage in affected individuals. Screening for HDV antibodies in HBsAg positive patients is recommended, but the diagnostic accuracy of serological tests remains uncertain. This review aimed to assess the diagnostic accuracy of serological tests for HDV. We searched PubMed, Web of Science, Cochrane Central Register of Controlled Trials, Scopus etc. for relevant studies. Studies measuring the sensitivity and specificity of serological HDV tests against PCR as a reference standard were included. Pooled sensitivity and specificity for each test method and sero-marker were calculated. The review included six studies with 11 study arms, evaluating ARCHITECT immunoassay, EIA, ELISA, QMAC, RIA, and Western Blot test methods targeting Anti-HDV IgG, Total anti-HDV and Anti-HDV IgM. Sensitivities for Anti-HDV IgG, Total Anti-HDV and Anti-HDV IgM, tests were 97.4%, 51.9%, and 62.0%, respectively, with specificities of 95.3%, 80.0%, and 85.0%. Our findings, with its limited number of studies, suggest that HDV serological tests, particularly those identifying Anti IgG exhibit high accuracy and can serve as effective screening tools for HDV.

Improving Access to Anti-HDV Testing: Development and Validation of an Affordable In-House ELISA Assay

In certain low-income nations, the hepatitis Delta virus and hepatitis B virus (HBV) pose a serious medical burden, where the prevalence of hepatitis B surface antigen (HBsAg) is greater than 8%. Especially in rural places, irregular diagnostic exams are the main restriction and reason for underestimation. Utilizing serum samples from a Pakistani isolate, an internal ELISA for the quick identification of anti-HDV was created, and the effectiveness of the test was compared to a commercial diagnostic kit. HDV-positive serum samples were collected, and a highly antigenic domain of HDAg antigen was derived from them. This antigenic HDAg was expressed in a bacterial expression system, purified by Ni-chromatography, and confirmed by SDS-PAGE and Western blot analysis. The purified antigen was utilized to develop an in-house ELISA assay for anti-HDV antibody detection of the patient's serum samples at very low cost. Purified antigens and positive and negative controls can detect anti-HDV (antibodies) in ELISA plates. The in-house developed kit's efficiency was compared with that of a commercial kit (Witech Inc., USA) by the mean optical density values of both kits. No significant difference was observed (a P value of 0.576) by applying statistical analysis. The newly developed in-house ELISA is equally efficient compared to commercial kits, and these may be useful in regular diagnostic laboratories, especially for analyzing local isolates.

Long-term clinical outcomes in patients with chronic hepatitis delta: the role of persistent viraemia

BACKGROUND

Chronic hepatitis delta is a severe liver disease with rapid progression to cirrhosis. The impact of hepatitis delta virus (HDV)-RNA on disease progression and interferon treatment in a real-world cohort has been barely explored.

AIM

To assess the development of clinical events in a cohort of chronic hepatitis delta patients according to the presence or absence of HDV-RNA METHODS: Multicentre study at four academic hospitals in Spain included anti-HDV-positive patients with compensated liver disease with a follow-up ≥12 months.

RESULTS

Among 2888 HBsAg-positive subjects, 151 (5.2%) tested positive for anti-HDV, and 118 were included (58% men; median age, 49 years; 73% detectable HDV-RNA and 30% cirrhosis, most often in subjects with HDV-RNA). After a median follow-up of 8 years, subjects with initially detectable HDV-RNA were more prone to developing cirrhosis (31% vs 0%, P = .002) and/or liver decompensation (28% vs 3%, P = .019). Mortality rate was 0.44 per 1000 person-months. The probability of a clinical event was 6%, 25%, and 80% according to initial baseline-event-anticipation score. HDV-RNA became undetectable in 21 (24%) subjects either due to interferon or spontaneously (48% vs 52%, P = .29). Liver decompensation was reduced in interferon-treated patients (13% vs 38%, P = .026).

CONCLUSIONS

Subjects with persistently positive HDV-RNA had a worse prognosis in terms of clinical events. Baseline-event-anticipation score is useful in predicting the risk of developing liver decompensation and hepatocellular carcinoma. Interferon was beneficial in reducing liver decompensation, even in the absence of virological response.

Comparison of Enzyme Immunoassays for Detection of Antibodies to Hepatitis D Virus in Serum

Serology remains critical for diagnosing hepatitis D virus (HDV) infection, which affects 15 to 20 million people worldwide, but the literature on characterizing commercial enzyme immunoassays (EIAs) dates back to 15 years ago. We evaluated 2 commercial EIAs currently available for detecting anti-HDV antibodies. The DiaSorin assay demonstrated 100% sensitivity and specificity. Using a modified cutoff value, the Cusabio assay demonstrated a sensitivity of 81.3% and specificity of 90.9%. Our data show that recently developed EIAs are reliable for anti-HDV antibody detection.

Detection of serum anti-NV-F antibodies in the convalescent phase of severe hepatitis in patients positive for tissue NV-F antigen and novel virus-like particles

Previously, a non-human DNA fragment named NV-F was isolated from a patient with non-A-E fulminant hepatitis. This sequence encoded an incomplete open reading frame (the NV-F antigen). In this study, we developed a western blot assay to detect serum anti-NV-F antibodies. Serum samples from 347 patients with severe hepatitis (ALT > fivefold ULN) were analyzed to understand the prevalence and distribution of the NV-F associated virus (HnFV) infection. Of these patients, acute HnFV infection was diagnosed (by positive serum NV-F DNA) in 34 patients (9.8%). However, none of these 34 serum samples were positive for serum anti-NV-F antibodies. In the remaining patients negative for serum NV-F DNA, 62 (17.9%) were positive for serum anti-NV-F antibodies. Liver biopsy samples from 35 severe hepatitis patients were submitted for immunohistochemistry and electron microscopy examination. Of them, seven were positive for hepatic NV-F antigen expression. Electron microscopy identified a novel virus-like particle in all of the seven NV-F antigen-positive liver tissues but not in the remaining 28 NV-F antigen-negative liver tissues. Longitudinal serum sample analysis revealed transient positivity of serum NV-F DNA in three of the seven patients during the clinical courses. Seroconversion of anti-NV-F antibody from negative to positive was found in four of the seven patients and all positive anti-NV-F antibodies were detected in the convalescent phases. In conclusion, in patients with severe hepatitis, a novel hepatotropic virus, temporarily named HnFV, was found in liver tissues expressing the NV-F antigen. Serum anti-NV-F antibodies were detected in the convalescent serum samples.

Classical and modern approaches used for viral hepatitis diagnosis

CONTEXT

Viral hepatitis diagnosis is an important issue in the treatment procedure of this infection. Late diagnosis and delayed treatment of viral hepatitis infections can lead to irreversible liver damages and occurrence of liver cirrhosis and hepatocellular carcinoma. A variety of laboratory methods including old and new technologies are being applied to detect hepatitis viruses. Here we have tried to review, categorize, compare and illustrate the classical and modern approaches used for diagnosis of viral hepatitis.

EVIDENCE ACQUISITION

In order to achieve a comprehensive aspect in viral hepatitis detection methods, an extensive search using related keywords was done in major medical library and data were collected, categorized and summarized in different sections.

RESULTS

Analyzing of collected data resulted in the wrapping up the hepatitis virus detection methods in separate sections including 1) immunological methods such as enzyme immunoassay (EIA), radio-immunoassay (RIA) immuno-chromatographic assay (ICA), and immuno-chemiluminescence 2) molecular approaches including non-amplification and amplification based methods, and finally 3) advanced biosensors such as mass-sensitive, electrical, electrochemical and optical based biosensors and also new generation of detection methods.

CONCLUSIONS

Detection procedures in the clinical laboratories possess a large diversity; each has their individual advantages and facilities' differences.