Abstract
COVID 19 (SARS-COV-2) disease expression remains uncertain. Immunocompromised individuals may be at particular risk of increased mortality. Lung transplant recipients provide a unique phenotype because the allograft is a preferred host location for the SARS-COV-2.
We conducted a single centre review of all lung transplant recipients SARS-COV-2 PCR positive between 17th March and June 2020. 7 of a total of 266 lung transplant recipients were SARS-COV-2 positive. 4 cases had a descriptive analysis of the immune microenvironment.
There was no association between COVID 19 disease severity and time from transplant. The most prevalent comorbidities were chronic kidney disease (86%), hypertension (71%) and diabetes mellitus (42%). One case died and 6 recovered. Forty-two percent of cases had established chronic allograft dysfunction. Six patients were receiving Azithromycin 500mg, 3 times per week prior COVID 19. Immunosuppression was altered in the three severe cases with calcineurin inhibitor (CNI) reduction and antimetabolite withdrawal.
The frequency of both CD4 and CD8 T cell subtypes were low in all 4 patients analysed. In the 2 severe cases CD8 subpopulations responsible for cellular antiviral response were profoundly diminished. The recipient requiring mechanical ventilation demonstrated an increased CD4/CD8 ratio of 5.9 and significantly reduced NK cells. NK cell reduction corresponded with disease severity.
The indirect potential COVID 19 prophylaxis with Azithromycin may have mitigated disease expression and mortality. Decreased anti-viral immune surveillance associated with a reduction in CD8 positive cytotoxic lymphocytes and raised CD4/CD8 ratio was associated with disease severity and may be a tool to identify high risk cases.
Footnotes
Cite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA3493.
This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2021