Purpose:There are limited studies on the intestinal microbiome in patients with wheat-dependent exercise-induced anaphylaxis (WDEIA), and changes in the gut microbiome in WDEIA patients after wheat-free diet have not been studied. Methods:This is a cross-sectional analysis. Fecal samples and clinical data were collected from 26 non-wheat-free patients with WDEIA, 11 wheat-free patients with WDEIA, and 24 healthy controls (HCs). The gut microbiota was evaluated through metagenomic sequencing. Results:The sequencing revealed differences in the gut microbiome between patients with WDEIA on a non-wheat-free diet and HCs; more specifically, the non-wheat-free group exhibited a downregulation of two families (Rikenellaceae and Odoribacteraceae), three genera (Alistipes, Odoribacter, and Catenibacterium), and four species (Bacteroides_stercoris, Alistipes_putredinis, Bacteroides_intestinalis, and Bacteroides_cellulosilyticus). A wheat-free diet is associated with intestinal flora more similar to the structure of healthy individuals. The species Bacteroides_stercoris was negatively correlated with T-IgE, and the genus Catenibacterium was negatively correlated with T-IgE, as well as wheat, gluten, or gliadin-specific IgE. The genus Catenibacterium was positively correlated with the healthy control-enriched "Apoptosis (ko04210)" pathway and negatively correlated with the non-wheat-free WDEIA group-enriched "Thyroid hormone signaling pathway (ko04919)" pathway. Conclusion:Patients with WDEIA exhibit a specific gut microbiota signature and function, which demonstrated the potential association between the gut microbiome and WDEIA development. WDEIA patients on a wheat-free diet exhibit a gut microbiome composition more similar to healthy individuals.

Eosinophils have long been recognized as terminal effector cells in type 2 immunity; however, emerging evidence positions them as central regulators of intestinal homeostasis, immune modulation, and tissue adaptation. This review provides a comprehensive overview of gastrointestinal eosinophils, integrating recent advances in their development, regulatory mechanisms, functional subsets, and pleiotropic roles across tissues. The developmental and homing pathways that guide eosinophils to the gut are first discussed, with an emphasis on niche-derived signals that control their survival and localization. The functional heterogeneity of intestinal eosinophils is then highlighted, revealing marked transcriptional and spatial diversification. The diverse functions of gut eosinophils are further summarized, including their contributions to pathogen defense, tissue repair, mutual regulation with the microbiota, anti-tumor, and interactions with immune cells. Finally, the cross-tissue orchestration of eosinophil behavior is examined, with a focus on the gut–immune axis. By synthesizing current knowledge, this review aims to present a holistic picture of gastrointestinal eosinophil biology and to inspire new perspectives for understanding and treating eosinophil-associated intestinal disorders.

To investigate the clinical outcomes of patients with a history of iodinated contrast medium (ICM)-induced hypersensitivity reactions (HSR) undergoing re-exposure to ICM. Medical records of inpatients who received allergy consultations in Peking Union Medical College Hospital from January 1, 2019 to July 31, 2024 were retrospectively reviewed. Patients with prior ICM-related HSR who subsequently underwent ICM re-administration were enrolled. Of 997 patients referred for allergy consultation, 65 met inclusion criteria, including 47 males (72.3

Eosinophilic gastroenteritis (EGE) is a rare, immune-mediated disorder characterized by pathological eosinophilic infiltration of the gastrointestinal tract. Corticosteroids are the primary treatment for EGE, but managing patients who are corticosteroid-dependent can be challenging. This report describes a 33-year-old female patient with EGE and severe hypereosinophilia, who was corticosteroid-dependent and had been on long-term oral corticosteroids for 5 years with an increasing maintenance dose. The patient achieved effective treatment with omalizumab without adverse reactions. This case provides evidence for the efficacy and safety of omalizumab in patients with corticosteroid-dependent eosinophilic gastroenteritis and severe hypereosinophilia.

The composition of the gut microbiome is associated with the development of wheat-dependent exercise-induced anaphylaxis (WDEIA); however, no studies to date have investigated changes in the gut microbiome in patients with WDEIA who have adhered to a wheat-free diet. Thus, the aim of this study was to compare the gut microbiota of patients with WDEIA with wheat-free and non-wheat-free diets through metagenomic sequencing.

Background:Eosinophilic gastrointestinal disorders (EGIDs) are chronic immune-mediated conditions characterized by pathological eosinophilic infiltration. The clinical features and therapies for eosinophilic esophagitis (EoE) vary between children and adults. However, there is limited comparison of non-EoE EGIDs across different ages of disease onset. Methods:We retrospectively analyzed data that included 94 patients (12 juveniles, 57 young adults, and 23 older adults) with a history of non-EoE EGIDs managed in a tertiary hospital. Results:The study included patients with a mean onset age of 36.6 years, 52.1% of whom had allergic comorbidities. Diarrhea was more common in young adults (18-49 years), while nausea and vomiting were predominant in juveniles (0-17 years) compared to older adults (≥50 years). Reduced flatulence and/or defecation were less common in young adults. Ascites were less frequent in older adults. Notably, patients with the same affected gastrointestinal site also exhibited varying manifestations across age groups: young adults with gastric or ileal involvement had higher diarrhea rates (64% and 68.4%, respectively, p < 0.05), while juveniles with gastric/duodenal involvement exhibited higher nausea, vomiting, and ascites, and those with ileal involvement showed higher ascites (p =0.031). Young adults with colonic involvement had reduced flatulence/defecation less frequently (p = 0.005). Juveniles had significantly higher peripheral eosinophil counts (p = 0.040), and higher total serum IgE levels (p =0.002) compared to older adults. Serum albumin levels were significantly higher, and erythrocyte sedimentation rate (ESR) was significantly lower in the juvenile group compared to the young adult group (p = 0.004, p = 0.045) and the older adult group (p = 0.002, p = 0.002). Conclusion:Clinical phenotypes of patients with non-EoE EGIDs vary by age of onset. A comprehensive understanding of the features in symptoms and therapies across different age groups can help accelerate diagnosis and enhance patient care.

Background Eosinophilic gastritis (EoG) has rarely been reported in conjunction with gluten-sensitive enteropathy (GSE). When this does occur, patients typically present with gastrointestinal symptoms. To our knowledge, hypoproteinemia has not been reported as the primary manifestation. Anti-IgE therapy, such as omalizumab, lowers eosinophil counts in the blood, lungs, and gut. Its efficiency in treating active EoG remain unknown. Case presentation We report a 33-month-old boy with a history of food allergy and atopic dermatitis who developed recurrent edema, hypoproteinemia, and eosinophilia at the age of 14 months. The diagnoses of EoG and GSE were confirmed based on the clinical presentation and results of gastrointestinal biopsies and serological testing. Although prednisone and dietary intervention were initially effective, the boy developed prednisone-related facial swelling. After stopping prednisone, his symptoms relapsed. Subsequent treatment with omalizumab, combined with dietary intervention, showed good efficacy and safety. Conclusions To our knowledge, this is the first case of concurrent EoG and GSE that presented primarily with hypoproteinemia. We highlight the rare manifestations of these two diseases to raise clinical suspicion and prevent missed and delayed diagnoses. The pathogenesis of EoG is heterogeneous and complex. Omalizumab showed good efficacy, indicating that IgE-mediated processes may be involved in the pathogenesis of this patient’s diseases.

BACKGROUND Eosinophilic gastroenteritis (EGE) is a chronic recurrent disease with abnormal eosinophilic infiltration in the gastrointestinal tract. Glucocorticoids remain the most common treatment method. However, disease relapse and glucocorticoid dependence remain notable problems. To date, few studies have illuminated the prognosis of EGE and risk factors for disease relapse. AIM To describe the clinical characteristics of EGE and possible predictive factors for disease relapse based on long-term follow-up. METHODS This was a retrospective cohort study of 55 patients diagnosed with EGE admitted to one medical center between 2013 and 2022. Clinical records were collected and analyzed. Kaplan-Meier curves and log-rank tests were conducted to reveal the risk factors for long-term relapse-free survival (RFS). RESULTS EGE showed a median onset age of 38 years and a slight female predominance (56.4%). The main clinical symptoms were abdominal pain (89.1%), diarrhea (61.8%), nausea (52.7%), distension (49.1%) and vomiting (47.3%). Forty-three (78.2%) patients received glucocorticoid treatment, and compared with patients without glucocorticoid treatments, they were more likely to have elevated serum immunoglobin E (IgE) (86.8% vs 50.0%, P = 0.022) and descending duodenal involvement (62.8% vs 27.3%, P = 0.046) at diagnosis. With a median follow-up of 67 mo, all patients survived, and 56.4% had at least one relapse. Six variables at baseline might have been associated with the overall RFS rate, including age at diagnosis < 40 years [hazard ratio (HR) 2.0408, 95% confidence interval (CI): 1.0082-4.1312, P = 0.044], body mass index (BMI) > 24 kg/m(2) (HR 0.3922, 95%CI: 0.1916-0.8027, P = 0.014), disease duration from symptom onset to diagnosis > 3.5 mo (HR 2.4725, 95%CI: 1.220-5.0110, P = 0.011), vomiting (HR 3.1259, 95%CI: 1.5246-6.4093, P = 0.001), total serum IgE > 300 KU/L at diagnosis (HR 0.2773, 95%CI: 0.1204-0.6384, P = 0.022) and glucocorticoid treatment (HR 6.1434, 95%CI: 2.8446-13.2676, P = 0.003). CONCLUSION In patients with EGE, younger onset age, longer disease course, vomiting and glucocorticoid treatment were risk factors for disease relapse, whereas higher BMI and total IgE level at baseline were protective.

To analyze the predictors of response to omalizumab in chronic spontaneous urticaria (CSU). Clinical data were collected from patients, who were diagnosed with CSU and received administration of omalizumab (300mg/4weeks) for 3 sessions. At weeks 0, 1, and 12, urticaria activity score over 7 days(UAS7)was used to evaluate clinical symptoms of patients. Clinical characteristics between the response group and the non-response group were compared. A total of 78 patients with CSU were enrolled. 80.8% of the patients responded to omalizumab. 51.3% patients responded completely to omalizumab treatment, 29.5% patients showed late partial response, while 19.2% patients showed no response. The baseline total IgE level in the response group was significantly higher than that in the non-response group (127kUA/L vs 41.95 kUA/L, P=0.006). The area under the ROC curve for the total IgE level to predict the efficacy of omalizumab was 0.741 (95% CI: 0.564-0.917, P=0.006). The best cut-off value of total IgE was 56.1 kUA/L, the sensitivity was 84.2%, and the specificity was 71.4%. In addition, the positive rate of ANA in the non-response group was significantly higher than that in the response group (5.13% vs 37.5%, P=0.029). The baseline total IgE level of CSU patients may be a predictor of response to omalizumab. Elevated baseline total IgE level(>56.1 kUA/L)indicates better efficacy of omalizumab. CSU patients with positive ANA show poor response to omalizumab treatment.

Background: Wheat-induced anaphylaxis (WIA) is a serious and potentially life-threatening wheat allergy, more common in adults than in children. Little is known about the differences in clinical profiles in WIA among patients of various ages in China.Methods: We analyzed data retrospectively from an allergy department in a tertiary hospital that included 248 patients (208 adults and 40 children and adolescents) with a history of WIA.Results: We found that alcohol was more frequent in patients aged >50 years [older adults] (19.0%, 4/21) than in those aged 12-17 years [adolescents] (0%, 0/33; p = 0.019). The frequency of NSAID use in older adults (42.9%, 9/21) was significantly higher than that in adolescents (0%, 0/ 33; p < 0.001), and patients aged 18-49 years [young adults] (2.8%, 5/178; p < 0.001). During WIA, cardiovascular symptoms in children were less frequent than those in other age groups (children, 28.6%; adolescents, 87.9%; young adults, 93.0%; older adults, 95.2%; p < 0.001). The consciousness loss rate in adults (both age groups; p < 0.001) and the hypotension rate in older adults (p = 0.006) were higher than those in other age groups. Compared with adults (young and older adults), children had a higher rate of allergic comorbidities (p = 0.004, 0.001, respectively) and a higher rate of other food allergies (p < 0.001, <0.001, respectively). Compared with the mild-to-moderate anaphylaxis group, the severe anaphylaxis group had a higher onset age (p = 0.001), higher cofactor prevalence (p = 0.004), lower allergic comorbidity rate (p = 0.014), and higher positive rate of specific IgE to omega-5 gliadin (u-5 gliadin) (p = 0.023).Conclusion: Clinical profiles of patients with WIA are different among various onset age/severity groups. An improved understanding of WIA symptoms in various age/severity groups could help accelerate diagnosis, suggest preventive measures, and contribute to improved patient care.

Background Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a serious and potentially life-threatening form of wheat allergy. Further episodes can only be prevented by avoiding wheat ingestion or avoiding exercise after wheat intake. Anaphylaxis may recur in some patients post-diagnosis. This study aimed to analyze the clinical features and management/outcomes of WDEIA in China. Methods We retrospectively analyzed the clinical characteristics, and laboratory testing of 197 patients with WDEIA. After diagnosis, the patients were followed up as outpatients to evaluate dietary/exercise choice and clinical outcomes. Results Among the 197 WDEIA patients (median age, 37 years), 53.8% were male and 28.4% had other allergic disorders. The median duration of anaphylaxis before diagnosis was 16 months. Significant delays in diagnosis (> 1 years) were recorded in 52.7% of the patients, which has not decreased by years ( P = 0.064). Exercise (83.8%), alcohol (12.2%), and nonsteroidal anti-inflammatory drugs (7.1%) were the most common cofactors. The most common clinical features were urticaria (100%), loss of consciousness (82.7%), dyspnea (50.8%), and hypotension (47.2%). Of the 197 eligible patients, 155 responded (78.7%), and 124 (80.0%) of which had no anaphylaxis post-diagnosis. A wheat-free diet prevented future anaphylaxis in 91.7% of the patients, followed by the avoidance of wheat combined with exercise (87%) and reduced wheat intake combined with exercise avoidance (80.5%). Conclusion The diagnosis of WDEIA is frequently delayed. Therefore, when patients present with unexplained anaphylaxis, the possibility of WDEIA should be considered. A wheat-free diet or avoiding wheat combined with exercise or reduced wheat combined with exercise avoidance helps to significantly reduce the onset of future anaphylaxis. However, approximately one-fifth of patients continue to experience anaphylaxis post-diagnosis. Thus, these patients must always carry epinephrine autoinjectors.

由中国医师协会、中国医师协会变态反应医师分会(以下简称分会)主办的"中国医师协会第五届变态反应医师分会年会(CCAA2021)"于2021年12月17日至19日以线上线下相结合形式召开.目前疫情虽尚未结束,但分会推广变态反应专科建设、过敏专科医生培训体系建设的脚步没有停下,在尹佳会长的领导下,分会为全国同道精心准备了一场学术盛宴,同时创造了安全而高效的学习、交流渠道.

食物过敏是一种由食物变应原引起的异常免疫反应.食物过敏的发生和发展是遗传因素与环境因素的共同作用,其中环境因素发挥重要作用,但其发病机制尚不明确.多项研究表明,肠道菌群与食物过敏的发生和发展密切相关,肠道菌群失衡可通过增强Th2型免疫应答,干扰免疫成熟,减少Treg细胞,破坏肠道黏膜屏障等机制导致机体出现食物过敏.本文针对肠道菌群紊乱与食物过敏的关系及其潜在机制进行综述,为食物过敏的早期预防及病因治疗提供依据.

BACKGROUND Inactivated vaccines against coronavirus disease-2019 (COVID-19) offer an effective public health intervention to mitigate this devastating pandemic. However, little is known about their safety in patients with wheat-dependent exercise-induced anaphylaxis (WDEIA). METHODS We recruited 72 WDEIA patients and 730 healthy matched controls who received an inactivated COVID-19 vaccine. Participants were monitored for 4 weeks after each immunization for adverse reactions and completed questionnaires regarding local and systemic reactions at 7 and 28 days after each vaccination. For those who had received the COVID-19 vaccine prior to enrollment, adverse event data were obtained retrospectively. RESULTS Local and systemic adverse events occurred at similar rates in the WDEIA group and the control group. In both groups, injection-site pain and fatigue were the most common local and systemic reactions, respectively. Compared with healthy controls, more allergic events were reported in the WDEIA group (after dose 1, 0.5% vs. 4.2%, p=0.019; after dose 2, 0% vs. 1.4%, p=0.089). Allergic reactions mainly manifested as rash, urticaria, and edema, which were mild and controllable. No serious allergic events were reported. CONCLUSIONS The adverse event profile of inactivated COVID-19 vaccine did not differ between WDEIA patients and healthy controls. The risk of allergic reactions in patients with WDEIA seems higher, but no anaphylaxis was reported, and the allergic reactions were controllable. Inactivated COVID-19 vaccines appear to be well-tolerated in WDEIA patients, but patients with potential allergy risks should be cautious.

目的 评价皮下免疫治疗(subcutaneous immunotherapy,SCIT)在过敏性鼻炎和过敏性哮喘中的疗效及安全性.方法 采用多中心、横断面调查研究方法对2020年1月至2020年12月11家医疗机构的患者进行问卷调查,比较SCIT治疗前后过敏性鼻炎患者鼻结膜炎症状及用药评分,哮喘患者用药情况、哮喘控制测试(asthma control test,ACT)评分和哮喘急性加重次数.总结分析SCIT过程中的局部及全身不良反应.结果 246例过敏性鼻炎和/或过敏性哮喘患者纳入研究,96.7％患者经SCIT治疗后自觉临床症状改善,SCIT治疗的中位起效时间为1(1,2)年.SCIT治疗前后,鼻结膜炎症状[1.8(1.3,2.5)vs.1(0.5,1.3)]、鼻结膜炎用药评分[2(1,2)vs.1(0,2)]、ACT评分[(16.0±4.6)vs.(21.4±3.3)]差异有统计学意义(P<0.001).SCIT治疗后,口服抗组胺药、抗组胺喷鼻剂、抗组胺药滴眼液、激素类喷鼻剂、激素类滴眼液、口服白三烯受体拮抗剂和口服茶碱类药物的用药时间缩短(P<0.05).哮喘患者在SCIT后停用吸入激素的比例较治疗前增加[(52例(34.2％)vs.72例(47.4％)],因急性加重急诊就诊次数减少(P<0.001).共89例患者出现注射局部不良反应;24例患者出现27例次全身不良反应,占全部总注射次数的0.035％(27次/77000次);22例次在注射30 min内发生,92.5％(25/27)与注射花粉变应原相关.结论 应用皮下注射免疫治疗可安全、有效的治疗过敏性鼻炎和过敏性哮喘.

To evaluate the efficacy and safety of subcutaneous immunotherapy (SCIT) for allergic asthma with summer and autumn pollen mixed allergen extracts. Clinical data of 25 allergic asthma patients were collected and analyzed. Self-assessment of asthma control, asthma control test (ACT), medication scores, and the percentage of forced expiratory volume in the first second to predicted value (FEV1%) were evaluated pre- and after SCIT. Adverse reactions were also recorded. Among the 25 patients with allergic asthma, 13 were prescribed with single summer and autumn pollen allergen mixed extracts, and 12 with pollen and dust mite allergen combined extracts. After SCIT, asthma symptoms improved in all patients, of which 52% (13/25) patients' asthma symptoms improved significantly. The asthma control rate increased from 52% to 92%, 36% (9/25) patients completely discontinued asthma medication, and 32% (8/25) patients' asthma medication dose was significantly reduced. The average effective time of SCIT was 20.5±9.6 months. Compared with the baseline level, the ACT score of the two groups of patients increased significantly (P <0.05), FEV1% was increased significantly (P <0.05), and the total score of asthma medication was reduced significantly (P <0.01). Twelve patients had local adverse reactions caused by injection, and 4 patients had a total of 4 systemic adverse reactions. All patients' adverse reactions relieved within a short period. The application of summer and autumn pollen allergen mixed allergen can treat summer and autumn pollen-induced allergic asthma effectively and safely.

按惯例,中国医师协会变态反应医师分会在12月25日首先举行了青年论坛, 由中国医师协会变态反应医师分会青年委员会副主任委员、 中国医学科学院北京协和医院变态反应科关凯副教授主持(图1). 中国医师协会变态反应医师分会会长、 中国医学科学院北京协和医学院变态反应学系主任尹佳教授向全体青年委员及嘉宾致开幕辞, 勉励青年医师夯实基础医学知识, 紧跟临床指南更新, 关注科研成果进展, 为中国变态反应学事业的明天而奋斗 (图2).

Background: Patients with pollinosis are often multi-sensitized to diverse pollen allergens. However, little is known about pollen allergy types among Chinese pollinosis patients. This study is aimed to characterize clinical manifestations of food allergy among patients with different types of pollen allergy. Methods: We retrospectively analyzed 402 pollinosis patients from an outpatient allergy department of the Peking Union Medical College Hospital who had been diagnosed by experienced allergists. All included patients who answered a questionnaire regarding seasonal pollinosis and clinical symptoms after ingestion of food and underwent intradermal skin tests. Total IgE and specific IgE levels were quantified by ImmunoCAP, using 0.35 kUA/L as a threshold for positivity. Results: The patients were divided into 3 groups, based on the season during which they experienced symptoms and the 2 peaks of Chinese airborne pollen: spring-tree pollen symptoms group (SG), autumn-weed pollen symptoms group (AG), and a combined spring and autumn pollen symptoms group (CG). Birch pollen (83%) and ash pollen (74%) were common allergens among patients with spring symptoms, while mugwort pollen (87%) was a common allergen among patients with autumn symptoms. In total, 30% of the study population experienced pollen-related food allergy. Pollen-related food allergies were more prevalent among the single-season symptom groups (68% and 50% for the SG and AG, respectively) than among the CG (20%). All patients with pollen-related food-induced anaphylaxis exhibited autumn weed pollen symptoms. Except for 2 patients, all patients with food-induced anaphylaxis were allergic to mugwort pollen. In the SG, all patients with food allergy were sensitive to birch pollen, with birch and Bet v 1-specific IgE levels higher in this group than in the group without food allergy (p < 0.001). In the AG, Art v 3 was more prevalent among patients with pollen-related food allergy than without food allergy (79% vs. 33%, p < 0.001), a proportion similar to the one in the CG (67% vs. 48%, p = 0.01). Meanwhile, the Art v 3-specific IgE levels among patients with pollen-related food allergy were higher than among tolerant patients in the AG (p < 0.001) and CG (p = 0.02). Unexpectedly, the Art v 3-specific IgE levels were higher in patients with food-induced anaphylaxis than with oral allergy syndrome only in the CG. Conclusions: Bet v 1 (a Pathogenesis-related 10 protein) and Art v 3 (a non-specific lipid transfer protein; nsLTP) are candidate molecular biomarkers for the diagnosis of food allergies in patients with season-specific pollen-related allergies. Measuring pollen allergen component-specific IgE levels might be an effective tool for the management of pollinosis in clinical practice in China.

The intestinal microbiota plays a critical role in food allergy development. However, little is known regarding the structure and composition of the intestinal microbiota in patients with wheat-dependent exercise-induced anaphylaxis (WDEIA). We examined the gut microbiota alterations in patients with WDEIA and the microbiota's association with WDEIA. Fecal samples were collected from 25 patients with WDEIA and 25 healthy controls. Environmental exposure factors were obtained, serum total IgE, IgE specific to wheat, gluten, and omega-5 gliadin were measured. Fecal samples were profiled using 16S rRNA gene sequencing. The relative abundances of the bacterial genera Blautia (P < 0.05), Erysipelatoclostridium (P < 0.01), Akkermansia (P < 0.05) and Lachnospiraceae_NK4A136_group (P < 0.05) were significantly increased, while those of Lactobacillus (P = 0.001) and Dialister (P < 0.05) were significantly decreased in subjects with WDEIA. The microbial diversity did not differ between WDEIA patients and healthy controls. IgE specific to omega-5 gliadin was positively associated with the Oscillospira (r = 0.48, P < 0.05) and negatively associated with Leuconostoc (r = - 0.49, P < 0.05). Total IgE levels were significantly negatively correlated with Bifidobacterium (P < 0.05). The gut microbiome compositions in WDEIA patients differed from those of healthy controls. We identified a potential association between the gut microbiome and WDEIA development. Our findings may suggest new methods for preventing and treating WDEIA.

Objective: To explore the effect of cathepsin (Cat) S in primary biliary cholangitis (PBC). Methods: The serum of PBC patients and Hepatitis B virus (HBV) patients were collected in Peking Union Medical College Hospital from August 2016 to July 2017 and the liver tissue of PBC were collected from March 2010 to July 2013. Indirect enzyme-linked immunosorbent assay (ELISA) was used to detect the serum concentrations of total-and pro-Cat S respectively in 24 PBC patients, 24 Hepatitis B patients and 24 healthy controls. The relation between the serum levels of Cat S and cholestasis biochemical indexes and the serum levels of immunoglobulin (Ig) M, G were analyzed. Immunofluorescence analysis of liver tissue was performed to detect macrophage infiltration and Cat S expression. The data was analyzed by student's t-test, spearman correlation analysis, and receiver operating characteristic (ROC) curve was used to obtain an optimal cutoff value. Results: The serum levels of total-Cat S, pro-Cat S and active-Cat S in PBC group were significantly higher than those in healthy controls and HBV controls (P<0.05). There was a correlation between serum total-Cat S and ALP and GGT in patients with PBC (P<0.05). There was a moderate correlation between pro-Cat S and ALP and GGT (P<0.05) and total Cat S was associated with IgG (P<0.05). The area under ROC curve (AUC) of total-Cat S, pro-Cat S and active-Cat S was 0.85(P<0.01), 0.65(P<0.05) and 0.77(P<0.01), respectively. The optimal cut-off value was 11.30、7.81 and 5.93 pg/L, respectively, with the sensitivity of 0.81, 0.53 and 0.53 and specificity of 0.82, 0.81 and 0.96. Liver tissue immunofluorescence revealed macrophage infiltration in the liver of PBC patients. The average percentage of macrophages and Cat S co-expressed cells in mononuclear cells was 23.77%. Conclusion: The expression of Cat S in serum of patients with PBC is significantly higher than that of healthy controls and HBV patients, and is related to IgG and serum ALP, r-GT levels. Liver tissue macrophages were co-expressed with Cat S. Cat S may participate in the process of antigen presentation in the pathogenesis of PBC.