To study the correlation between the expression of Fcgamma receptor II b (FcgammaRII b) on B cells and rheumatoid arthritis (RA) patients of Shen deficiency syndrome (SDS).
There were 43 RA patients, including 26 of SDS and 17 of non-SDS. The expression levels of FcgammaRII b on naive B cells, memory B cells, and plasma blasts in the peripheral blood were detected by flow cytometry. The numbers of tender joints, numbers of swollen joints, erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), and disease activity score (DAS28), the correlation between the distribution of B cells and the expression level of FcgammaRII b in RA patients were analyzed. Besides, another 21 healthy volunteers were recruited as the control group.
The expression level of FcgammaRII b was 49.65% +/- 15.86% on memory B cells and 43.69% +/- 22.57% on plasma blasts in RA patients of SDS, significantly down-regulated when compared with those of the control group (64.03% +/- 6.01%, 66.59% +/- 10.18%, P < 0.01). The expression level of FcgammaRII b on memory B cells of RA patients of non-SDS was down-regulated more obviously when compared with that of the control group (52.70% +/- 9.52% versus 64.03% +/- 6.01%, P < 0.01). The expression level of FcgammaRII b on plasma blasts was obviously lower in RA patients of SDS than in RA patients of non-SDS (56.10% +/- 17.05%, P < 0.05). The expression level of FcgammaRII b on memory B cells was not correlated with numbers of tender joints, numbers of swollen joints, ESR, RF, or DAS28.
The defective immunological tolerance of B cells in RA patients of SDS might be closely correlated with down-regulation of FcgammaRII b on memory B cells and plasma blasts. There might exist genetic abnormality of FcgammaRII b gene in RA patients of SDS, thus inducing loss of autoimmunity tolerance.