Tixagevimab-cilgavimab as an early treatment for COVID-19 in kidney transplant recipients (preprint)

Objective This single-center retrospective study evaluated the use of tixagevimab-cilgavimab as an early treatment for COVID-19 in kidney transplant recipients (KTRs) during the omicron wave. Methods KTRs were deemed at high risk for moderate-to-severe COVID-19 in presence of at least one comorbidity (age >60 years, diabetes, obesity, or cardiovascular disease) associated with a weak humoral response (<264 BAU/mL). All other KTRs were considered at low risk. The two groups were stratified according to the administration of tixagevimab-cilgavimab and compared in terms of COVID-19-related hospitalization, oxygen need, ICU admission, and mortality. Results Of the 61 KTRs at high risk, 26 received tixagevimab-cilgavimab. COVID-19-related hospitalizations (3.8% versus 34%, p=0.006) and oxygen need (3.8% versus 23%, p=0.04) were significantly less frequent in patients who received tixagevimab-cilgavimab. In addition, non-significant trends towards a lower number of ICU admissions (3.8% versus 14.3% p=0.17) and deaths (0 versus 3, p=0.13) were observed after administration of tixagevimab-cilgavimab. Ten of the 73 low-risk KTRs received tixagevimab-cilgavimab, and no significant clinical benefit was observed in this subgroup. Conclusion Early administration of tixagevimab-cilgavimab may be clinically useful in high-risk KTRs with COVID-19; however, no major benefit was observed for low-risk patients.

Weak anti-SARS-CoV-2 antibody response after the first injection of an mRNA COVID-19 vaccine in kidney transplant recipients (preprint)

Data concerning the anti-SARS-CoV-2 antibody response after mRNA COVID-19 vaccine in kidney transplant recipients (KTRs) are currently lacking. Here, we sought to examine this issue by analyzing the serological response observed in 241 KTRs after a first vaccine injection. Our results indicate that KTRs have a weak anti-SARS-CoV-2 antibody response, ultimately resulting in a low seroconversion rate (26/241, 10.8%). This phenomenon likely stems from a high immunosuppression burden in this clinical population.

In-depth virological assessment of kidney transplant recipients with COVID-19 (preprint)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread widely, causing coronavirus disease 2019 (COVID-19) and significant mortality. However, data on viral loads and antibody kinetics in immunocompromised populations are lacking. We aimed to determine nasopharyngeal and plasma viral loads via RT-PCR and SARS-CoV-2 serology via ELISA and study their association with severe forms of COVID-19 and death in kidney transplant recipients. In this study we examined hospitalized kidney transplant recipients with non-severe (n = 21) and severe (n =19) COVID-19. SARS-CoV-2 nasopharyngeal and plasma viral load and serological response were evaluated based on outcomes and disease severity. Ten recipients (25%) displayed persistent viral shedding 30 days after symptom onset. The SARS-CoV-2 viral load of the upper respiratory tract was not associated with severe COVID-19, whereas the plasma viral load was associated with COVID-19 severity (p=0.0087) and mortality (p=0.024). All patients harbored antibodies the second week after symptom onset that persisted for two months. We conclude that plasma viral load is associated with COVID-19 morbidity and mortality, whereas nasopharyngeal viral load is not. SARS-CoV-2 shedding is prolonged in kidney transplant recipients and the humoral response to SARS-CoV-2 does not show significant impairment in this series of transplant recipients.