Selective IgM deficiency (SIgMD) is a rare immunodeficiency characterized by serum IgM below two standard of mean, and normal IgG and IgA levels. Both in human and mice with selective IgM deficiency, germinal centers cells are decreased. The development of germinal center and humoral immunity are regulated in part by follicular helper T (T_FH) and follicular regulatory T (T_FR) cells. However, the analysis of circulating T_FH (cT_FH) and T_FR (cT_FR) cells in the pathogenesis of SIgMD has not been explored. We observed lower percentage of cT_FR cells in SIgMD patients than in control group. However, we did not observe any significant difference in the percentage of cT_FH cells and their subsets between both experimental groups. When data were analyzed according to specific antibody response to pneumococcal polysaccharide, we observed a higher percentage of cT_FH cells in SIgMD patients with specific antibody deficiency than in SIgMD patients with normal specific antibody response. Our results suggest that cT_FH cells and their subsets are preserved in SIgMD patients. However, the role of lower percentage of cT_FR cells in the pathogenesis of this immunodeficiency is not clear.

选择性IgM缺乏症（SIgMD）是一种罕见的免疫缺陷，其特征在于血清IgM低于均值和正常IgG和IgA两种标准水平。在人类和患有选择性IgM缺乏症的小鼠中，生发中心细胞均减少。生发中心和体液免疫的发育部分受卵泡辅助性T（T _FH）和卵泡调节性T（T _FR）细胞的调节。但是，尚未探讨在SIgMD发病机理中循环T _FH（cT _FH）和T _FR（cT _FR）细胞的分析。我们观察到较低的cT _FR百分比SIgMD患者中的细胞比对照组中的多。但是，我们没有观察到两个实验组之间的cT _FH细胞百分比及其亚组的任何显着差异。根据针对肺炎球菌多糖的特异性抗体反应分析数据时，我们观察到特异性抗体缺乏的SIgMD患者的cT _FH细胞百分比高于特异性抗体反应正常的SIgMD患者。我们的结果表明，在SIgMD患者中，cT _FH细胞及其亚群得以保留。但是，较低百分比的cT _FR细胞在这种免疫缺陷的发病机理中的作用尚不清楚。