[Relation of Circulating Follicular Helper T Cell Changes with B Cell Dysfunction in MDS Patients]

To explore the relation of circulating follicular helper T cell (c Tfh) changes with B cell dysfunction in MDS patients.

20 patients diagnosed as MDS from Auguct 2015 to October 2017 were enrolled in MDS group, and 20 healthy valuntears matching in age and sex were enrolled in healthy control (HC) group. The perepheral blood in 2 groups were collected, the mononuclear cells (PBMC) from which were isolated by densily gradient contrifugation, at the same time, the serum left in isolation process was reserved for further study. The flow cytometry was used to detect the ratio of cTfh such as CD4⁺CXCR5⁺ T cells and its subset CD4⁺CXCR5⁺ICOS⁺ T cells, CD4⁺CXCR5⁺PD-1⁺ T cells in PBMC, as well as the ratio of plasmablast CD19⁺CD20^-CD38⁺ B cells. The ELISA was used to detect the concentration of IgA, IgM and IgG. The differences in ratio of cTfh cells and plasmablast B cells, as well as the concentration of IgA, IgM and IgG between MDS and HC groups were compared, at the same time, the correlation of cTfh cell ratio with the plasmablast B cell ratio and the concentration of IgA, IgM and IgG in MDS patient was analyzed.

The ratio of CD4⁺CXCR5⁺T, CD4⁺CXCR5⁺ICOS⁺T cells and CD19⁺CD20^-CD38⁺B cells and the concentration of IgA, IgM and IgG decreased in MDS patients, while the ratio of CD4⁺CXCR5⁺PD-1⁺T cells increased in MDS patients. The ratio of CD4⁺CXCR5⁺T cells, CD4⁺CXCR5⁺ICOS⁺T cells positively correlated with the ratio of CD19⁺CD20^-CD38⁺B cells, as well as with the concentration of IgA, IgM and IgG in MDS patients. However, the ratio of CD4⁺CXCR5⁺PD-1⁺T cells negatively correlated with the ratio of CD19⁺CD20^-CD38⁺B cells, as well as with the concentration of IgA, IgM and IgG.

The ratio of circulating Tfh cells and their subsets showed significant changes, that correlate with B cell dysfunction in MDS patients.