Detection of HBsAg mutants in the blood donor population of Pakistan

Abstract

BackgroundInfection with the Hepatitis B virus (HBV) continues to be one of the leading healthcare issues in Pakistan, affecting over 6 million people. The existence of HBsAg mutants is well documented in many countries. In Pakistan, HBV screening in the majority of the blood banks is performed by Rapid Detection Devices or ELISA tests. These tests are designed to detect HBsAg, but may not detect the mutant HBsAg. Failure to detect the HBsAg mutant may result in the transmission of HBV infection from donor to recipient. Hence, there is a need to identify a HBsAg assay which can detect mutants in a country where simple and conventional HBsAg assays with varying sensitivity and specificity are used to detect HBV infections.Material and methodsThree routinely used diagnostic tests (Rapid Detection Devices, ELISA and CLIA) for HBsAg were compared with the LIAISON® XL Murex HBsAg Quant Assay to determine the prevalence of HBV mutants in the Pakistani blood donor population.The samples of blood donors from different cities of Pakistan were collected. The testing was performed using SD Bioline rapid assay (n = 1500), ELISA (n = 1500), and Abbott ARCHITECT®CLIA system (n = 1500) at the centers where the donations were collected. All samples (n = 4500) were re-tested for comparative analysis on the LIAISON® XL Murex HBsAg Quant assay (DiaSorin S.p.A.). PCR testing was performed as a gold standard on all discordant samples.Results119/4500 (2.64%) of the samples were positive for antibodies against HBsAg. The sensitivity of SD Bioline Rapid, GB HBsAg ELISA, Abbott ARCHITECT® and LIAISON® XL Murex HBsAg Quant assay was 17.24%, 43.75%, 90.91%and 100% respectively. The specificity of SD Bioline Rapid, GB HBsAg ELISA, Abbott ARCHITECT® and LIAISON® XL Murex HBsAg Quant Assay was 98.82%, 99.59%, 100% and 100%, respectively.ConclusionLIAISON® XL Murex HBsAg Quant assay is a highly sensitive, specific and accurate screening assay for detecting wild type as well as mutant HBsAg.

Systematic review of the validity of the hepatitis B virus detection tests in blood banks from 2000 to 2018

“…Only two studies evaluated the diagnostic validity of detecting anti-HBc [3,9] and only one study evaluated both HBsAg and anti-HBc detections simultaneously [3]. The other studies evaluated immunological tests for the detection of HbsAg, using as standard a third-generation ELISA test, and only three studies did the index test with a PCR assay [2,5,9]. All studies presented high methodological quality by meeting more than 90% of the criteria of the QUADAS guide, the least applied were those related to the use of thresholds report of indeterminate results and, the appropriate time between the application of the test and the standard, which were applied in 92% of studies.…”

“…Hepatitis B virus (HBV) remains one of the main public health problems worldwide and an important cause for the development of chronic hepatitis, cirrhosis and hepatocellular carcinoma [1-3]. It is estimated that about two billion people are serologically positive for HBV [4] and according to data from the World Health Organization (WHO) in 2017, approximately 325 million people suffer from chronic infection [1]; This situation is aggravated if it is considered that diseases such as cirrhosis and carcinoma cost more than 650,000 lives each year [2].…”

“…HBV transmission occurs through blood transfusion, direct contact with blood, sexual intercourse and/or through intravenous injections [2,5-7]. WHO estimated that in 2001, unsafe blood transfusions generated 8-16 million HBV infections [6].…”

“…WHO estimated that in 2001, unsafe blood transfusions generated 8-16 million HBV infections [6]. Although the current treatment and vaccination options are helping to decrease this burden, especially the increased childhood vaccination coverage between 1980 and 2000 [1,4], the presence of mutations in the virus associated with selective pressure for vaccination and treatment, often makes it difficult to control this infection [2]. Furthermore, the poor availability of prevention programs, and the existence of individuals that do not respond adequately to the vaccine, means that almost 257 million people born before the modern vaccination regimes have an increased risk of infection.…”

“…Some previous studies have documented a high heterogeneity in the validity data of HBV screening tests. For example, Farooq et al , in 2017 compared three routinely diagnostic tests for HBsAg (SD Bioline rapid assay, GB HBsAg ELISA and Abbott ARCHITECT ® CLIA system) with a quantitative determination of hepatitis B surface antigen (HBsAg) (LIAISON ® XL Murex HBsAg Quant assay - chemiluminescence immunoassay), in which they found sensitivities of 17.2%, 43.7%, 90.9% and 100% respectively, and positive probability ratios between 38 and 100 [2]. In addition, Mutocheluh et al in 2014 evaluated the performance of the most common immunochromatographic (ICT) kits (Wondfo, Rapid Care, Core TM, Accul-Tell and Abon) used for screening blood donors in some blood bank facilities in the northern part of Ghana.…”