Results varied from patient to patient, but common signs spotted in all participants were higher levels of immune cells linked to cell death, epithelial damage and tissue repair.
The team noted that all the Covid patients had suffered a severe infection, which they had to be hospitalised for.
It, therefore, remains to be seen whether the results of the study are applicable to patients with less severe disease.
The study was also unable to determine whether any of the patients had any of the signs prior to their infection.