**5. Results**

During the study period, there were 18 episodes of SARS-CoV-2 infection among the LTRs, all of which were community-acquired. The lung function data are shown in Table 1 (mild COVID-19) and Table 2 (moderate COVID-19). The mean age was 49.9 (22–68) years; 12 of the LTRs (67%) were male.

In the group of patients with mild COVID-19, the mean C-reactive protein level (CRP) was 29.8 (4–77) mg/L; while in moderate COVID-19, the mean CRP was 58.2 (4.8–140) mg/L. In mild COVID-19, the mean creatinine level (119 μmol/L, range 60–166) was less than in moderate COVID-19 (mean creatinine 231 μmol/L, range 17–809). In both the mild and moderate COVID-19 patients, there was no obesity (mean body mass index 22.4 and 26.3 kg/m2, respectively) observed. All patients were under chronic triple immunosuppressive therapy, including prednisone in all (100%) of the patients. In the mild COVID-19 patients, this included cyclosporine A in one (14%), tacrolimus in six (86%) rapamycin in one

(14%), and mycophenolate mofetil in six (86%) of the patients. In the moderate COVID-19 patients, the immunosuppression included cyclosporine A in three (33%), tacrolimus in four (44%), and everolimus in one (11%) of the patients. During the active infection with SARS-CoV-2, in all patients mycophenolate mofetil was then discontinued as part of our standard practice.

Although we discontinued mycophenolate mofetil, most patients did not develop donor-specific antibodies (DSA), as shown in Tables 3 and 4.

The pre-transplant diagnosis was cystic fibrosis (CF) in four (57%), chronic obstructive pulmonary disease (COPD) in one (14%), and interstitial lung disease (ILD) in two (29%) patients in the group of patients with mild COVID-19, while in the group of moderate COVID-19 patients, this was CF in two (22%), COPD in four (44%), ILD in two (22%), and pulmonary arterial hypertension in one (11%) of the patients.

Two LTRs died due to severe COVID-19; these patients were intubated and therefore there were no post-COVID lung function data available. Since the only two patients with severe COVID-19 did not survive the infection, they are not shown in a separate table. The median age was 58.5 years (range 56–61); both were male with a mean BMI of 31.2 kg/m2. Both patients had very high CRP levels (mean 302 mg/L, range 199–406) and chronic kidney failure (mean creatinine 208, μmol/L, range 202–213). Both had interstitial lung disease as the pre-transplant diagnosis. Empiric antibiotic treatment was standard in all patients, both ambulatory and hospitalized. As the evolution of COVID-19 was favorable in most patients, additional microbiology samples were not indicated. Only in severe cases were additional samples performed; these patients were intubated and finally died.
