Methods:
For the study, patients who came for routine control between September
2020 and March 2021 in Ankara City Hospital Liver Transplant outpatient
clinic were screened. All patients were older than 18 years of age and
had undergone LT in the past. The ethics committee approved the study of
Ankara Bilkent City Hospital (Approval number: E2-21-280 ). The study
was conducted in accordance with good clinical practice principles and
the Declaration of Helsinki.
Study enrolment was performed when patients presented for scheduled
routine follow-up. Among all patients, patients whose serum COVID-19 IgM
+ IgG antibody was tested were recorded. Sars-Cov-2 polymerase chain
reaction (PCR) test was performed with a nasopharyngeal-oropharyngeal
swab in each patient with a positive antibody test within the first
three days the results. All participants completed a questionnaire
querying information including common clinical symptoms (fever, cough,
diarrhea, myalgia, nausea, and vomiting) in the last six months.
Additionally, we questioned all participants for a history of contact
with a covid-19 positive patient or hospitalization.
We evaluated the performance of COVID-19 serology testing on
chemiluminescent immunoassay (CLIA) per manufacture’s protocol (ADVIA
Centaur®) SARS-CoV-2 Total (COV2T) (Siemens Healthcare Diagnostics Inc.,
NY, USA) (Siemens Test). These serological tests use the SARS-CoV-2
Spike protein (S protein) as a viral labeling protein to detect
anti-SARS-CoV-2 antibodies. Test results were interpreted as positive if
the signal value of the Siemens Test (index) ≥1.0 of total antibodies.
All serum Anti-SARS-CoV-2 Total results of all patients were collected
before the vaccination for COVİD-19.
The statistical analyses were performed with IBM SPSS Statistics for
Windows, Version 26.0 software (IBM Corp., Armonk, NY, USA). Continuous
variables were expressed as median and range. Categorical variables were
summarized as count and percentage. Between-group comparisons were
performed using the Mann-Whitney U test for continuous variables and a
chi-squared test (or Fisher’s exact test where appropriate) for
categorical variables. P values are given as indicated using the
x2 test or a non-parametric t-test. A p-value
<0.05 was considered to indicate statistical significance.