Safety and efficacy of mycophenolate in COVID-19

Immunosuppressive drugs are used to prevent and treat the high-inflammation phase of COVID-19. However, immunosuppressive drugs also suppress the host's immune response to the virus. The study by Sajgure and colleagues assessed the effect of mycophenolate on COVID-19 mortality and length of hospital stay.¹ Although their study revealed that mycophenolate reduces mortality and length of hospital stay in COVID-19 patients and is safe, there are several concerns about this study.

First, although it is a non-randomised study, the characteristics of the two groups of patients were comparable. Hence, the possibility of selection bias affecting the study cannot be ruled out. In addition, the vaccination and previous infection history of the patients were not considered, which are important factors affecting the patients’ prognosis. Second, due to the lack of double-blind treatment, the treatment of the patients was determined by the doctor independently, and the comparability of the treatment of two groups patients could not be guaranteed. In study group, more antibiotics were used, whether prophylactic or therapeutic, indicating that immunosuppressant use is likely to lead to more secondary infections. Third, the study group received daily oral mycophenolate. But what about the patients who progressed to severe disease and who were unable to receive mycophenolate orally? The median hospitalisation time of patients was 7–8 days. Furthermore, it was not discussed whether it was necessary to take mycophenolate for one month or not. Fourth, multivariate regression showed that mycophenolate was a protective factor, while the use of methylprednisolone, also an immunosuppressant, was a risk factor, which needs to be explained.

Contributors

XL and GZ initiated and conceptualised the idea. GZ wrote the initial draft, XW and HL revised the draft.

Declaration of interests

None.