SARS-CoV-2 Seroprevalence and Clinical Features of COVID-19 in a German Liver Transplant Recipient Cohort: A Prospective Serosurvey Study

Abstract

Background: In liver transplant (LT) recipients with severe coronavirus disease 2019 (COVID-19), fatal outcome has been reported in a substantial subset of patients. Whether LT recipients are at increased risk for severe COVID-19 compared with the general population is controversial. Here we report the results of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurvey in a large LT recipient cohort.

Methods: A total of 219 LT recipients were enrolled between May 5, 2020, and August 6, 2020, at the University Hospital Heidelberg. Serum blood samples were collected and tested for anti-SARS-CoV-2 IgG. SARS-CoV-2 RNA was detected in nasopharyngeal swabs using reverse transcription-polymerase chain reaction assays.

Results: Taking into account known risk factors of arterial hypertension, obesity, diabetes, or leukopenia, LT recipients a priori represented a high-risk cohort for severe COVID-19 with 101 of 219 (46.1%) presenting with more than 2 risk factors for severe COVID-19. Out of 219 LT recipients, 8 (3.7%) either had a positive test result for nasopharyngeal SARS-CoV-2 RNA or anti-SARS-CoV-2 serum IgG. Five of eight (62.5%) did not show any clinical signs of infection, three of eight (37.5%) had self-limited disease, and none required hospitalization for COVID-19. Two of eight (25%) had known exposure to infected health care staff as the probable source of infection.

Conclusions: In summary, LT recipients showed a SARS-CoV-2 seroconversion rate similar to that of the general population with a substantial percentage of unrecognized infections.

Fig 1

The course of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Germany. (A) Map of the Federal Republic of Germany indicating RNA-proven SARS-CoV-2 cases per capita in different federal states. Data as of August 15, 2020: red, >300 cases per 100,000; orange, 200-300 cases/100,000; yellow, 100-200 cases/100,000; green, <100 cases/100,000. Black dots indicate residence of enrolled LT recipients. (B) Number (7-day gliding average) of RNA-proven SARS-CoV-2 cases per day in the German state of Baden-Württemberg from February 25 until August 8, 2020. Below: Sample accrual time frame for nasopharyngeal RNA swab (upper black bar) and blood serum sample (lower black bar).

Fig 2

Anti–severe acute respiratory syndrome coronavirus 2 (anti–SARS-CoV-2) serum titers in patients 1 and 7 over time.

Fig 3

(A-G) Survey of self-protection measurements and behavior adjustments among liver transplant recipients during the severe acute respiratory syndrome coronavirus 2 pandemic. COVID-19, coronavirus disease 2019.