Realtime hbv assay

A minimum of three recordings of liver biochemistry for patients with normal levels and two recordings for those with elevated levels were required. The median number of ALT tests performed pre liver biopsy was 5 (interquartile range [IQR] 4–8), and these were sampled over a median period of 21 months (IQR 8–46). Serum biochemical and haematological values prior to the liver biopsy were recorded. Routine liver biochemical tests were performed using commercially available autoanalysers and hepatitis serological markers were assayed using commercially available enzyme-linked immunoassays. Patients with HBV DNA <20,000 IU/mL were classified as low-replicative while those with HBV DNA ≥20,000 IU/mL were classified as high-replicative. A minimum of three HBV DNA recordings was required and the reference value utilized for analysis was based on the pre biopsy level. Serum HBV DNA level was expressed in IU/mL (1 IU/mL = 5.6 copies/mL) [7 (link)]. Quantitative HBV DNA levels were measured by a COBAS TaqMan System (Roche Diagnostics, Indianapolis, IN, USA), which has a lower detection limit of 15 IU/mL, or Abbott Real-Time HBV assay (Abbott Molecular, Inc., Des Plaines, IL, USA), with a lower detection limit of 10 IU/mL. The median duration between the first and pre liver biopsy HBV DNA was 12 months (IQR 6–20).

HBsAg screening was completed using the Genescreen HBsAg 3.0 EIA assay (Bio-Rad Laboratories, Redmond, WA). To confirm the presence of HBV and to quantify DNA, we performed in vitro PCR using the Abbott RealTime HBV assay (Abbott Molecular, Des Plaines, IL). Participants who tested positive for HBsAg with detectable HBV DNA were considered HBV-infected.
Whole blood was tested for HIV using a parallel series of rapid tests (Alere Determine, Waltham, MA and Trinity biotech Uni-Gold HIV, Wicklow, Ireland). In cases of discordance, a 3rd rapid test (Chembio Diagnostics HIV-1/2 Stat Pak test, Medford, NY) was used to confirm or exclude HIV infection as outlined by the parallel testing algorithm for at-risk individuals in Nigeria [27 ]. For participants living with HIV, HIV RNA was quantified using the Ampliprep/COBAS TaqMan HIV-1 Test (Roche Molecular Diagnostics, Pleasanton, CA) and CD4 counts using the Partec CyFlow Counter (Sysmex, Kobe, Japan). Voided urine and rectal swabs were tested for Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) using the Aptima Combo 2 CT/ NG Assay (Hologic, San Diego, CA). All participants testing positive for HIV or other STIs were offered appropriate treatment regardless of CD4 count.