OBJECTIVETo observe the effect of Xinfeng Capsule (XFC) on ankylosing spondylitis (AS) patients' symptoms and signs, serum immunoglobulin levels, peripheral blood lymphocyte autophagy protein, autophagy gene, and to explore its mechanism.

METHODSTotally 59 AS patients were assigned to the treatment group (39 cases) and the control group (20 cases) according to random digit table. Patients in the treatment group received XFC, 0.5 g each pill, three pills each time, 3 times per day, while those in the control group received sulfasalazine (SASP), 0.25 g per tablet, 4 tablets each time, twice per day. Three months consisted of one therapeutic course. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) were statistically calculated. Serum immunoglobulins (IgG1, IgG2, IgG3, IgG4, IgA , SIgA, and IgM) were detected using ELISA. Changes of Beclin1, LC3-II, phosphatidylinositol 3-kinase (PI3K), Akt, the mammalian target of rapamycin (mTOR) were detected using Western blot. Serum autophagy related genes such as Atg1, Atg5, Atg12, Atg13, and Atg17 were detected using the polymerase chain reaction (PCR). The correlation between immunoglobulin subtypes and autophagy gene in AS patients using Spearman correlation.

RESULTSCompared with before treatment, BASDAI, IgG1, lgG3, and IgA decreased (P < 0.01); PI3K, Akt, and mTOR protein expressions decreased (P < 0.01); ATG1, ATG12, ATG13, and ATG17 mRNA expressions decreased, ATG5 mRNA expression increased (P < 0.01) in the treatment group. But BASDAI, IgG1, and IgA levels decreased (P < 0.05, P < 0.01); PI3K, Akt, and mTOR protein expressions decreased (P < 0.05); ATG1 and ATG13 mRNA expressions decreased (P < 0.05, P < 0.01) in the control group. Compared with the control group, BASDAI, IgG1, and IgA levels decreased (P < 0.05); PI3K, Akt, mTOR protein expressions decreased (P < 0.01); ATG12 and ATG17 mRNA expression decreased, ATG5 mRNA expression increased (P < 0.01) in the XFC group. Correlation analysis showed AS patients' IgG1, IgG2, IgG3, IgA, SIgA, IgM had negative correlation with ATG17; IgG4 and ATG17 were positively correlated (P < 0.05, P < 0.01).

CONCLUSIONXFC could elevate clinical efficacy of AS patients and enhance their autophagy, which might be achieved by acting on PI3K/Akt/mTOR signal, affecting autophagy gene and autophagy protein expression, taking part in the regulation of proliferation and differentiation of lymphocyte B, and strengthen humoral immunity.