In the new coronavirus (COVID-19), it is generally considered that impaired immune responses triggers unfavourable outcomes.
A group of Univ. of Pavia, Italy, suggests that the depletion of IgM Memory B cells is related to severe disease.
https://www.nature.com/articles/s41598-020-77945-8
A median value of IgM Memory B cell numbers was 65.0/uL (IQR: 51.0 – 85.0/uL) in healthy people, whereas a median vale was 5.9/uL (IQR: 2.1 – 13.9/uL) in COVID-19 patients. Although the number of COVID-19 patients assessed was as small as 66, but the depletion in IgM Memory B cells was correlated with severe disease.
There was no correlation between age, sex, and the depletion in IgM Memory B cells.
