CD27 and acute respiratory distress syndrome: However, such cells may be involved in autoreactive effects post-infection, as was found by Vijayakumar et al., who showed that patients who experienced acute respiratory distress syndrome (ARDS) as part of the post-COVID-19 respiratory syndrome had an increased number of airway IgD–CD27+ memory B cells that correlated with CT scan-detected respiratory abnormalities (87).