[The role of serum B cell activation factor in the diagnosis and phenotypes of chronic rhinosinusitis with nasal polyps].

To investigate the changes of serum B cell activating factor（BAFF） levels in chronic rhinosinusitis with nasal polyps（CRSwNP） patients and its predictive value in phenotypes. Forty healthy volunteers（control group） and 77 patients with CRSwNP were recruited in the present study, all CRSwNP patients were divided into eosinophilic（neCRSwNP group, =40） and non-eosinophilic（eCRSwNP group, =37） according to the degree of eosinophil infiltration in postoperative histological sections. Serum samples were collected from all subjects, and serum BAFF levels were detected by ELISA, and the relationships between BAFF levels and clinical variables were evaluated. The predictive value of serum BAFF in distinguishing eCRSwNP was evaluated by receiver operating curve（ROC） and Logistic regression. BAFF concentrations in the serum of CRSwNP patients were（1.2±0.4） ng/mL, which were higher than control group（[0.8±0.3]ng/mL）. In addition, serum BAFF levels in eCRSwNP group were （1.3±0.5） ng/mL, which were higher than neCRSwNP group（[1.1±0.2]ng/mL）, and both groups were higher than control groupt（<0.05）. The elevated serum BAFF levels in CRSwNP patients were positively correlated with the tissue eosinophil percentage（=0.629, <0.001） and counts（=0.563, <0.001）, peripheral blood eosinophil percentage（=0.411, =0.002） and counts（=0.501, <0.001）, and serum total IgE（=0.178, =0.021）. Multivariate Logistic regression showed that serum BAFF level was an independent factor associated with CRSwNP phenotypes（=3.652, =0.001）. ROC analysis suggested that serum BAFF exhibited a good predictive value for eCRSwNP（AUC=0.885）. Serum BAFF levels were increased in CRSwNP patients and associated with the degree of systemic and polyp eosinophilic inflammation. Preoperative evaluation of serum BAFF level maybe clinically meaningful for distinguishing CRSwNP phenotypes.