Objective To explore the effects and mechanisms of human umbilical cord mesenchymal stem cell (HUC-MSC)-derived exosomes (Exo) pretreated with Huangkui capsules on renal ischemia-reperfusion injury (IRI). Methods HUC-MSCs were cultured in media containing different concentrations of Huangkui capsules for 24 hours to determine cell viability and select an appropriate concentration for subsequent experiments. HUC-MSCs were pretreated with 50 μg/mL Huangkui capsules for 24 hours, and Exo were extracted using an exosome extraction kit. The morphology was observed under a transmission electron microscope, particle size was measured by nanoparticle tracking analysis, and the expression of exosomal membrane surface marker proteins was detected by Western blot. Human renal tubular epithelial cells (HK-2 cells) were randomly divided into hypoxia/reoxygenation group (M group), hypoxia/reoxygenation + Exo group (E group), and hypoxia/reoxygenation + Huangkui capsules pretreated Exo group (H group). Western blotting was used to measure the expression of endoplasmic reticulum stress (ERS)-related proteins, and real-time fluorescent quantitative reverse transcription polymerase chain reaction was used to measure the expression of ERS-related gene messenger RNA (mRNA). Mice were randomly divided into sham operation group (Sham group), ischemia-reperfusion group (I/R group), ischemia-reperfusion + Exo group (E group), and ischemia-reperfusion + Huangkui capsules pretreated Exo group (H group). Renal histological assessment, serum creatinine (Scr), blood urea nitrogen (BUN) measurement and inflammatory factor detection were performed 24 hours later. Results Both Exo and Huangkui capsules prereated Exo had a bilayer membrane structure and a cup-shaped morphology; their average particle sizes were 116.8 nm and 81.3 nm, respectively. Both expressed CD9, CD63, TSG101. Compared with the M group, the E group had decreased relative expression of transcription factor 6 (ATF6) and protein kinase R-like endoplasmic reticulum kinase (PERK) proteins, increased mRNA relative expression, increased relative expression of C/EBP homologous protein (CHOP) protein, and decreased mRNA relative expression. Compared with the E group, the H group had decreased relative expression of ATF6, PERK, CHOP proteins, and decreased mRNA relative expression of ATF6 and PERK (all P<0.05). Animal experimental results showed that compared with the Sham group, the I/R group had increased renal tubular injury scores, Scr, BUN, interleukin (IL)-1β, IL-10, IL-18, tumor necrosis factor (TNF)-α levels. Compared with the I/R group, the E and H groups had decreased renal tubular injury scores and Scr, BUN, IL-1β, IL-10, IL-18, TNF-α levels. Compared with the E group, the H group had decreased renal tubular injury scores and Scr, BUN, IL-1β, IL-10, IL-18, TNF-α levels (all P<0.05). Conclusions Huangkui capsules pretreatment HUC-MSC-derived Exo may alleviate renal IRI by inhibiting ERS.

Objective To analyze the relationship between 15 immunophenotypes of peripheral blood T cells and age and gender in healthy adults in the Dalian area. Methods A total of 277 healthy adults admitted to the physical examination center of the Second Affiliated Hospital of Dalian Medical University from October 2022 to June 2023 were selected as the research subjects,including 154 males and 123 females. They were divided into three groups according to age:young group(18～44 years,n=103),middle-aged group(45～60 years,n=114) and old age group(>60 years,n=60). Flow cytometry was used to determine immunophenotypes of T cells,including the absolute count and proportion of na?ve cells (N),central memory (CM),effector memory (EM),terminal effector memory (TEM),activation (HLA-DR+) and senescence (CD28-) CD4+and CD8+T cells,and the differences of them among age and gender were analyzed. Spearman correlation analysis was also used to evaluate the correlation between age and immunophenotypes of T cells. Results Compared with the young group,the absolute count and proportion of CD8+TEM,CD4+HLA-DR+,CD8+HLA-DR+and CD8+CD28-T lymphoaytes cells were increased in the middle-aged group and old age group (Z=2.009～6.607),while the absolute count and proportion of CD8+N T cells were decreased in the middle-aged group (Z=5.574～7.999) and old age group,and the differences were statistically significant (all P<0.05),respectively. Compared with the female group,the absolute count and proportion of CD8+CM,CD8+HLA-DR+and CD8+CD28-T cells were increased in the female group (Z=2.945～6.131),while the absolute count and proportion of CD3+,CD4+and CD8+N T cells were decreased in the male group (Z=2.075～4.225),and the differences were statistically significant(all P<0.05),respectively. Spearman correlation analysis showed that age was positively correlated with the absolute count and proportion of CD4+CM,CD4+HLA-DR+,CD4+CD28-,CD8+TEM,CD8+HLA-DR+and CD8+CD28-T lymphocytes cells (r=0.125～0.479,all P<0.05),while negatively correlated the absolute count and proportion of CD4+N and CD8+N T lymphocytes cells (r=-0.538～-0.148,all P<0.05). Conclusion The 15 immunophenotypes of peripheral blood T lymphocytes cells in healthy adults from Dalian area are affected by age and gender,so it is necessary to establish a suitable local reference interval to provide a more accurate reference for immune function assessment.

BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes are involved in multiple injury repair processes,and the effects and the specific mechanisms of renal ischemia/reperfusion injury have not been fully elucidated.OBJECTIVE:To investigate the molecular mechanism of human umbilical cord mesenchymal stem cell-derived exosomes in the treatment of renal ischemia/reperfusion injury.METHODS:(1) Human umbilical cord mesenchymal stem cells were cultured and exosomes were obtained and identified using an exosome extraction kit.(2) The distribution of exosomes in the kidney of mice with renal ischemia/reperfusion injury was examined by intravital fluorescence imaging.(3) Thirty C57/BL6 male mice were divided into five groups according to the random number table method:sham operation group,renal ischemia/reperfusion group,sham operation group+Compound C group,renal ischemia/reperfusion+exosome group (exosome group),and renal ischemia/reperfusion+exosome+Compound C group (exosome+Compound C group),with 6 mice in each group.Except the sham operation group,bilateral renal pedicles were clamped for 45 minutes and a mouse model of renal ischemia/reperfusion injury was established after 24 hours of reperfusion.In sham operation+Compound C group and exosome+Compound C group,AMPK inhibitor Compound C was intraperitoneally injected 30 minutes before model establishment.In the exosome group and exosome+Copmpound C group,exosomes were injected through the tail vein 15 minutes before renal pedicle clipping.The levels of serum creatinine and urea nitrogen,interleukin 6,and tumor necrosis factor α in renal tissue,and the expression of apoptosis-related factors in renal tissue were detected after 24 hours of reperfusion in each group.RESULTS AND CONCLUSION:(1) Human umbilical cord mesenchymal stem cell exosomes had the typical tea tray morphology,with the diameter distribution in the range of 40-160 nm,and expressed the specific marker membrane protein of exosome surface.(2) Murine kidneys after renal ischemia/reperfusion injury were more likely to gather human umbilical cord mesenchymal stem cell exosomes compared with the sham operation group.(3) Exosome pretreatment reduced renal injury and the level of renal cell apoptosis in mice treated with renal ischemia/reperfusion injury.Moreover,this protective effect could be reversed by AMPK inhibitors.These findings verify that human umbilical cord mesenchymal stem cell-derived exosomes exerting a protective effect on renal ischemia/reperfusion injury may be related to the activation of the AMPK/YAP1 pathway to antiapoptosis.

This study aims to investigate the changes in blood biochemical indicators of tongue roll-ing(TR)behavior in cattle and their correlation with changes in oral microbiota,laying a founda-tion for further exploring the relationship between animal oral microbiota,biochemical indicators,and behavioral changes.It also provides theoretical basis for preventing and treating TR behavior through regulating oral microbiota.This study intends to analyze and compare the blood biochemi-cal indicators and changes in oral microbiota of cattle with TR behavior and healthy cattle without TR behavior(healthy control,H),in order to explore the blood biochemical indicators of TR cattle and their correlation with changes in oral microbiota.Blood samples from the caudal vein of cattle in each group were collected for the detection of blood biochemical indicators and stress-related hormone indicators.Oral swabs from cattle in each group were collected for 16S rRNA gene se-quencing to analyze the composition,structure,and functional changes of their oral microbiota.The results of blood biochemical indicators in H and TR groups showed that the concentrations of al-bumin(ALB),aspartate aminotransferase(AST),calcium ion(Ca2+),and cortisol in TR group were significantly higher than those in H group(P＜0.05).There were significant differences in beta diversity of oral microbiota between TR and H groups(P＜0.05).At the genus level,the rela-tive abundances of Pseudomonas,Enterobacter,Xanthomonas,and other genera in the oral micro-biota of TR group were significantly higher than those in H group(P＜0.05).However,the rela-tive abundances of Tessaracoccus,Turicibacter,Monoglobus,Dietzia,Bifidobacterium,and other genera in the oral microbiota of TR group were significantly lower than those in H group(P＜0.05).In the KEGG metabolic pathway at the third level,the relative abundances of thiamine me-tabolism,lipoate metabolism,cysteine and methionine metabolism in the oral microbiota of TR group were significantly lower than those in H group(P＜0.05).Spearman correlation analysis showed that ALB and AST were significantly positively correlated with the relative abundances of Pseudomonas and Stenotrophomonas.Therelative abundances of Pseudomonas,Stenotrophomonas,and Sphingomonas were significantly positively correlated with fatty acid metabolism,phosphate and phosphonate metabolism,and lipoate metabolism.ALB was significantly positively correlated with inositol phosphate metabolism and phosphate and phosphonate metabolism.The study found that there were significant differences in blood biochemical indicators and oral microbiota between TR and H groups.In addition,there is a certain correlation between the composition,structure,and function of oral microbiota and the biochemical function of the host.This indicates that TR behav-ior may be associated with changes in the biochemical indicators of the host and the composition,structure,and function of oral microbiota.

This study aims to investigate the changes in blood biochemical indicators of tongue roll-ing(TR)behavior in cattle and their correlation with changes in oral microbiota,laying a founda-tion for further exploring the relationship between animal oral microbiota,biochemical indicators,and behavioral changes.It also provides theoretical basis for preventing and treating TR behavior through regulating oral microbiota.This study intends to analyze and compare the blood biochemi-cal indicators and changes in oral microbiota of cattle with TR behavior and healthy cattle without TR behavior(healthy control,H),in order to explore the blood biochemical indicators of TR cattle and their correlation with changes in oral microbiota.Blood samples from the caudal vein of cattle in each group were collected for the detection of blood biochemical indicators and stress-related hormone indicators.Oral swabs from cattle in each group were collected for 16S rRNA gene se-quencing to analyze the composition,structure,and functional changes of their oral microbiota.The results of blood biochemical indicators in H and TR groups showed that the concentrations of al-bumin(ALB),aspartate aminotransferase(AST),calcium ion(Ca2+),and cortisol in TR group were significantly higher than those in H group(P＜0.05).There were significant differences in beta diversity of oral microbiota between TR and H groups(P＜0.05).At the genus level,the rela-tive abundances of Pseudomonas,Enterobacter,Xanthomonas,and other genera in the oral micro-biota of TR group were significantly higher than those in H group(P＜0.05).However,the rela-tive abundances of Tessaracoccus,Turicibacter,Monoglobus,Dietzia,Bifidobacterium,and other genera in the oral microbiota of TR group were significantly lower than those in H group(P＜0.05).In the KEGG metabolic pathway at the third level,the relative abundances of thiamine me-tabolism,lipoate metabolism,cysteine and methionine metabolism in the oral microbiota of TR group were significantly lower than those in H group(P＜0.05).Spearman correlation analysis showed that ALB and AST were significantly positively correlated with the relative abundances of Pseudomonas and Stenotrophomonas.Therelative abundances of Pseudomonas,Stenotrophomonas,and Sphingomonas were significantly positively correlated with fatty acid metabolism,phosphate and phosphonate metabolism,and lipoate metabolism.ALB was significantly positively correlated with inositol phosphate metabolism and phosphate and phosphonate metabolism.The study found that there were significant differences in blood biochemical indicators and oral microbiota between TR and H groups.In addition,there is a certain correlation between the composition,structure,and function of oral microbiota and the biochemical function of the host.This indicates that TR behav-ior may be associated with changes in the biochemical indicators of the host and the composition,structure,and function of oral microbiota.

Objective To analyze the relationship between 15 immunophenotypes of peripheral blood T cells and age and gender in healthy adults in the Dalian area. Methods A total of 277 healthy adults admitted to the physical examination center of the Second Affiliated Hospital of Dalian Medical University from October 2022 to June 2023 were selected as the research subjects,including 154 males and 123 females. They were divided into three groups according to age:young group(18～44 years,n=103),middle-aged group(45～60 years,n=114) and old age group(>60 years,n=60). Flow cytometry was used to determine immunophenotypes of T cells,including the absolute count and proportion of na?ve cells (N),central memory (CM),effector memory (EM),terminal effector memory (TEM),activation (HLA-DR+) and senescence (CD28-) CD4+and CD8+T cells,and the differences of them among age and gender were analyzed. Spearman correlation analysis was also used to evaluate the correlation between age and immunophenotypes of T cells. Results Compared with the young group,the absolute count and proportion of CD8+TEM,CD4+HLA-DR+,CD8+HLA-DR+and CD8+CD28-T lymphoaytes cells were increased in the middle-aged group and old age group (Z=2.009～6.607),while the absolute count and proportion of CD8+N T cells were decreased in the middle-aged group (Z=5.574～7.999) and old age group,and the differences were statistically significant (all P<0.05),respectively. Compared with the female group,the absolute count and proportion of CD8+CM,CD8+HLA-DR+and CD8+CD28-T cells were increased in the female group (Z=2.945～6.131),while the absolute count and proportion of CD3+,CD4+and CD8+N T cells were decreased in the male group (Z=2.075～4.225),and the differences were statistically significant(all P<0.05),respectively. Spearman correlation analysis showed that age was positively correlated with the absolute count and proportion of CD4+CM,CD4+HLA-DR+,CD4+CD28-,CD8+TEM,CD8+HLA-DR+and CD8+CD28-T lymphocytes cells (r=0.125～0.479,all P<0.05),while negatively correlated the absolute count and proportion of CD4+N and CD8+N T lymphocytes cells (r=-0.538～-0.148,all P<0.05). Conclusion The 15 immunophenotypes of peripheral blood T lymphocytes cells in healthy adults from Dalian area are affected by age and gender,so it is necessary to establish a suitable local reference interval to provide a more accurate reference for immune function assessment.

BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes are involved in multiple injury repair processes,and the effects and the specific mechanisms of renal ischemia/reperfusion injury have not been fully elucidated.OBJECTIVE:To investigate the molecular mechanism of human umbilical cord mesenchymal stem cell-derived exosomes in the treatment of renal ischemia/reperfusion injury.METHODS:(1) Human umbilical cord mesenchymal stem cells were cultured and exosomes were obtained and identified using an exosome extraction kit.(2) The distribution of exosomes in the kidney of mice with renal ischemia/reperfusion injury was examined by intravital fluorescence imaging.(3) Thirty C57/BL6 male mice were divided into five groups according to the random number table method:sham operation group,renal ischemia/reperfusion group,sham operation group+Compound C group,renal ischemia/reperfusion+exosome group (exosome group),and renal ischemia/reperfusion+exosome+Compound C group (exosome+Compound C group),with 6 mice in each group.Except the sham operation group,bilateral renal pedicles were clamped for 45 minutes and a mouse model of renal ischemia/reperfusion injury was established after 24 hours of reperfusion.In sham operation+Compound C group and exosome+Compound C group,AMPK inhibitor Compound C was intraperitoneally injected 30 minutes before model establishment.In the exosome group and exosome+Copmpound C group,exosomes were injected through the tail vein 15 minutes before renal pedicle clipping.The levels of serum creatinine and urea nitrogen,interleukin 6,and tumor necrosis factor α in renal tissue,and the expression of apoptosis-related factors in renal tissue were detected after 24 hours of reperfusion in each group.RESULTS AND CONCLUSION:(1) Human umbilical cord mesenchymal stem cell exosomes had the typical tea tray morphology,with the diameter distribution in the range of 40-160 nm,and expressed the specific marker membrane protein of exosome surface.(2) Murine kidneys after renal ischemia/reperfusion injury were more likely to gather human umbilical cord mesenchymal stem cell exosomes compared with the sham operation group.(3) Exosome pretreatment reduced renal injury and the level of renal cell apoptosis in mice treated with renal ischemia/reperfusion injury.Moreover,this protective effect could be reversed by AMPK inhibitors.These findings verify that human umbilical cord mesenchymal stem cell-derived exosomes exerting a protective effect on renal ischemia/reperfusion injury may be related to the activation of the AMPK/YAP1 pathway to antiapoptosis.

Objective:To detect the immunophenotype of B cell subsets in peripheral blood of patients with primary Sjogren′s syndrome (pSS) and explore the clinical significance of B cell subsets in pSS.Methods:This is a retrospective case-control study. A total of 25 pSS patients treated in the Second Affiliated Hospital of Dalian Medical University from March 1st 2023 to February 28th 2024 were enrolled (pSS group). The mean age of the pSS group was 62.0±11.9 years old, including 25 female. Besides, 25 female healthy subjects were selected as the control group (HC group) during the tudy period, with a mean age of 57.6±11.2 years old. Flow cytometry was used to detect the proportion of B cell subsets in peripheral blood. In our study, pSS patients were divided into<60 years old group (15 cases) and≥60 years old group (10 cases). pSS patients were divided into ESSDAI score<5 group (9 cases) and ESSDAI score≥5 group (16 cases) according to ESSDAI score. Besides, they were further divided into no system damage group (7 cases) and combined system damage group (18 cases). According to the expression of anti-SSA and anti-SSB antibodies, pSS patients were divided into anti-SSA antibody negative group (7 cases), anti-SSA antibody positive group (18 cases), anti-SSB negative group (17 cases) and anti-SSB positive group (8 cases). Mann-Whitney U test was used to compare the distribution difference of B cell subsets between the two groups, and Spearman correlation analysis was performed to analyze the correlation between B cell subsets and laboratory indicators and ESSDAI scores of pSS patients. Results:In comparison to the HC group, the pSS group exhibited a statistically significant increase in the proportions of na?ve B cells, CD19 +CD20 +B cells and plasmablast cells, alongside a decrease in the proportions of unswitched memory B cells, switched memory B cells and regulatory B cells, and the differences were statistically significant (all P<0.05). The proportion of plasmablast cells was significantly higher in the ESSDAI score≥5 group than that in the ESSDAI score<5 group [1.20% (1.00%, 1.38%) vs. 0.5% (0.38%, 0.65%), Z=2.416, P<0.05]. Conversely, the proportion of regulatory B cells was lower in the ESSDAI score≥5 group compared to the ESSDAI score<5 group [2.50% (2.00%, 2.78%) vs. 5.55% (3.58%, 7.10%), Z=2.775, P<0.05]. The proportion of unswitched memory B cells was significantly lower in the group with systemic injury compared to the group without systemic injury [1.50% (0.85%, 1.70%) vs. 2.45% (1.73%, 2.78%), Z=2.122, P<0.05]. Spearman correlation analysis showed that the ESSDAI score was positively correlated with the proportion of plasmablast cells in patients with pSS (r=0.431, P<0.05), while negatively correlated with the proportion of regulatory B cells in pSS patients ( r=-0.413, P<0.05). Conclusions:There is an increased proportion of plasmablast cells and a reduced proportion of regulatory B cells in the peripheral blood of patients with pSS, and these alterations are strongly correlated with the disease activity of pSS. Consequently, plasmablast cells and regulatory B cells may play a crucial role in the pathogenesis of pSS.

Objective:To evaluate the role of nuclear factor E2-related factor 2 (Nrf2)/heme oxidase-1 (HO-1) in reduction of renal ischemia-reperfusion (I/R) injury by the human umbilical cord mesenchymal stem cells (hucMSCs)-derived exosomes (hucMSCs-exo) in mice.Methods:The hucMSCs were cultured, and exosomes were extracted and identified by transmission electron microscopy, nanoparticle tracking analysis and Western blot. Thirty-six male SPF-grade C57BL/6 mice, weighing 20-25 g, were used. Thirty mice were selected and divided into 5 groups ( n=6 each) by a random number table method: sham operation group (Sham group), sham operation + Nrf2 inhibitor ML385 group (Sham + ML385 group), renal I/R group (I/R group), renal I/R + exosome group (I/R+ EXO group), and renal I/R + exosome + Nrf2 inhibitor ML385 group (I/R+ EXO+ ML385 group). A model of renal I/R injury was prepared by clamping the bilateral renal pedicles for 45 min followed by perfusion in anesthetized animals. ML385 30 mg/kg was intraperitoneally injected at 45 min before preparing the model in Sham+ ML385 group and I/R+ EXO+ ML385 group, and hucMSCs-exo 100 μg was injected via the tail vein at 15 min before reperfusion in I/R+ EXO group and I/R+ EXO+ ML385 group. Serum blood urea nitrogen (BUN) and creatinine (Cr) concentrations were detected at 24 h of reperfusion. The renal tissues were obtained for examination of the pathological changes and for determination of contents of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA), superoxide dismutase (SOD) activity and reactive oxygen species (ROS) levels and expression of Nrf2 and HO-1 protein and mRNA (by Western blot and quantitative real-time polymerase chain reaction). The left 6 mice were allocated to sham operation group (Sham-IM group, n=3) and renal I/R group (I/R-IM group, n=3) by a random number table method for VISQUE in living imaging observation. Results:The exosomes showed a typical cup-shaped morphology with a transmission electron microscope, the nanoparticles tracked and analyzed the average diameter of the exosome, with an average diameter of 96.7 nm, and the positive expression of surface markers CD9, CD63 and TSG101 was detected using Western blot. The renal fluorescence intensity value was significantly increased in I/R-IM group as compared with Sham-IM group ( P<0.05). Compared with Sham group, the serum BUN and Cr concentrations were significantly increased, the contents of IL-6, TNF-α and MDA and ROS levels were increased, the activity of SOD was decreased, the expression of Nrf2 and HO-1 protein and mRNA was down-regulated ( P<0.05), and the pathological changes of renal tissues were aggravated in I/R group, and no significant change was found in serum BUN and Cr concentrations in Sham+ ML385 group ( P>0.05). Compared with I/R group, the serum BUN and Cr concentrations were significantly decreased, the contents of IL-6, TNF-α and MDA and ROS levels were decreased, the activity of SOD was increased, the expression of Nrf2 and HO-1 protein and mRNA was up-regulated ( P<0.05), and the pathological changes of renal tissues were significantly attenuated in I/R+ EXO group. Compared with I/R+ EXO group, the serum BUN and Cr concentrations were significantly increased, the contents of IL-6, TNF-α and MDA and ROS levels were increased, the activity of SOD was decreased, the expression of Nrf2 and HO-1 protein and mRNA was down-regulated ( P<0.05), and the pathological changes of renal tissues were aggravated in I/R+ EXO+ ML385 group. Conclusions:The mechanism by which hucMSCs-exo reduces renal I/R injury may be related to activation of the Nrf2/HO-1 signaling pathway in mice.

Objective:To detect the immunophenotype of B cell subsets in peripheral blood of patients with primary Sjogren′s syndrome (pSS) and explore the clinical significance of B cell subsets in pSS.Methods:This is a retrospective case-control study. A total of 25 pSS patients treated in the Second Affiliated Hospital of Dalian Medical University from March 1st 2023 to February 28th 2024 were enrolled (pSS group). The mean age of the pSS group was 62.0±11.9 years old, including 25 female. Besides, 25 female healthy subjects were selected as the control group (HC group) during the tudy period, with a mean age of 57.6±11.2 years old. Flow cytometry was used to detect the proportion of B cell subsets in peripheral blood. In our study, pSS patients were divided into<60 years old group (15 cases) and≥60 years old group (10 cases). pSS patients were divided into ESSDAI score<5 group (9 cases) and ESSDAI score≥5 group (16 cases) according to ESSDAI score. Besides, they were further divided into no system damage group (7 cases) and combined system damage group (18 cases). According to the expression of anti-SSA and anti-SSB antibodies, pSS patients were divided into anti-SSA antibody negative group (7 cases), anti-SSA antibody positive group (18 cases), anti-SSB negative group (17 cases) and anti-SSB positive group (8 cases). Mann-Whitney U test was used to compare the distribution difference of B cell subsets between the two groups, and Spearman correlation analysis was performed to analyze the correlation between B cell subsets and laboratory indicators and ESSDAI scores of pSS patients. Results:In comparison to the HC group, the pSS group exhibited a statistically significant increase in the proportions of na?ve B cells, CD19 +CD20 +B cells and plasmablast cells, alongside a decrease in the proportions of unswitched memory B cells, switched memory B cells and regulatory B cells, and the differences were statistically significant (all P<0.05). The proportion of plasmablast cells was significantly higher in the ESSDAI score≥5 group than that in the ESSDAI score<5 group [1.20% (1.00%, 1.38%) vs. 0.5% (0.38%, 0.65%), Z=2.416, P<0.05]. Conversely, the proportion of regulatory B cells was lower in the ESSDAI score≥5 group compared to the ESSDAI score<5 group [2.50% (2.00%, 2.78%) vs. 5.55% (3.58%, 7.10%), Z=2.775, P<0.05]. The proportion of unswitched memory B cells was significantly lower in the group with systemic injury compared to the group without systemic injury [1.50% (0.85%, 1.70%) vs. 2.45% (1.73%, 2.78%), Z=2.122, P<0.05]. Spearman correlation analysis showed that the ESSDAI score was positively correlated with the proportion of plasmablast cells in patients with pSS (r=0.431, P<0.05), while negatively correlated with the proportion of regulatory B cells in pSS patients ( r=-0.413, P<0.05). Conclusions:There is an increased proportion of plasmablast cells and a reduced proportion of regulatory B cells in the peripheral blood of patients with pSS, and these alterations are strongly correlated with the disease activity of pSS. Consequently, plasmablast cells and regulatory B cells may play a crucial role in the pathogenesis of pSS.