2.2 Data/sample collection and laboratory procedure
A structured questionnaire was used to collect demographic data such as
age, gender, place of residence, level of education completed,
occupation, and marital status. An estimated volume of 5 mL of blood
sample was collected from all participants and placed in tubes
containing ethylenediamine tetraacetic acid (EDTA) for serological
(HBsAg) and biochemical (AST and ALT) screening. Additional screening
for other sexually transmitted diseases was performed, to rule out HCV,
HIV, and syphilis infections. For this study, donors with a negative
result for HBsAg were considered the control group, while the group with
a positive result for HBsAg was considered the test group. All the
serological screening was performed with the ARCHITECT PLUS i2000SR
immunoassay analyzer (ARCHITECT, Abbott Laboratories) using the HBsAg
QUAL II detection kit (Abbott Laboratories, Ltd.) to screen for the
current presence of HBsAg, while the biochemical screening was performed
with the automatic biochemical analyzer Cobas C111 (Roche), using the
AST (Roche, Germany) and ALT (Roche, Germany) detection kits, for
evaluation of possible liver damage resulting from HBV infection.
Positive and negative controls were added during all laboratory
procedures following the manufacturer’s instructions. All laboratory
processing as well as the interpretation of the results were carried out
according to the manufacturer’s instructions. Patients reactive to the
HBsAg biomarker were classified as positive for HBV infection. For
purposes of this study, the reference range for AST was considered to be
8-48 U/L while for ALT it was 7-55 U/L. Furthermore, AST/ALT ratios less
than one were assigned to donors with acute or non-alcoholic liver
disease, while an AST/ALT ratio greater than or equal to 1, was assigned
to donors with suspected chronic liver disease, viral hepatitis, or
liver toxicity.