Objective To evaluate the safety of the 13-valent pneumococcal polysaccharide conjugate vaccine (tetanus toxoid/diphtheria toxoid) (PCV13-TT/DT) among age-eligible children in Tianjin through a combination of active and passive surveillance methods. Methods From July 15, 2023, to August 31, 2024, active surveillance for adverse events following immunization (AEFI) was conducted among recipients of PCV13-TT/DT at 18 selected vaccination clinics in Tianjin. Recipients were monitored through on-site observation or telephone follow-up within 30 minutes after vaccination and on days 1, 3, 7, and 28. Passive surveillance for AEFI was conducted among recipients of PCV13-TT/DT at other vaccination clinics across the city. The incidence of AEFI was analyzed using descriptive epidemiological methods. Results A total of 24 916 recipients of PCV13-TT/DT were observed, with 440 AEFI cases reported, resulting in an overall incidence rate of 176.59 per 10 000. The incidence rate of AEFI in active surveillance was 813.79 per 10 000, significantly higher than that in passive surveillance (20.49 per 10 000; P< 0.001). The incidence rates of general reactions, abnormal reactions, and coincidental cases in active surveillance were 744.44 per 10 000, 8.16 per 10 000, and 61.19 per 10 000, respectively, all of which were higher than those in passive surveillance (18.49 per 10 000, 0.50 per 10 000, and 1.50 per 10 000), with P values < 0.05. General reactions were mainly characterized by fever, local redness, and local induration. Abnormal reactions included angioedema and allergic rash. Coincidental cases were mainly infections. No severe adverse reactions occurred. Conclusion The large-scale vaccination of PCV13-TT/DT after its launch has good safety, and continuous strengthening of vaccine safety monitoring is needed.

ObjectiveTo systematically compare the differential regulation of the maternal-fetal interface cell lineages and communication networks in the CBA/J×DBA/2 mouse model of recurrent pregnancy loss （RPL） by the two classic therapeutic methods-tonifying the kidney to stabilize the fetus and invigorating the spleen to stabilize the fetus （Shoutai Wan， Juyuan Jian）-of traditional Chinese medicine （TCM） at the single-cell resolution and clarify their modern scientific connotations. MethodsFemale non-pregnant CBA/J mice were caged with male BALB/c （blank group） and DBA/2 （modeling group） mice separately. Pregnant mice in the modeling group were randomly grouped as follows： high/low-dose Shoutai Wan， high/low-dose Juyuan Jian， model （RPL）， and positive control （dydrogesterone）， with 10 mice in each group. Starting from the day after the detection of the vaginal plug， mice were administrated with drugs or an equal volume of normal saline by gavage for 10 consecutive days. After the intervention， the following indicators were measured. ① Macroscopic evaluation： general conditions， uterine wet weight， embryo loss rate， four coagulation parameters ［prothrombin time （PT）， activated partial thromboplastin time （APTT）， fibrinogen （FIB）， and thrombin time （TT）］， and peripheral blood estradiol （E₂） and progesterone （Pg） levels. The decidua with embryos was stained with hematoxylin-eosin （HE） and evaluated by transmission electron microscopy （TEM）. The expression of B-cell lymphoma-2 （Bcl-2）， vascular endothelial growth factor （VEGF）， angiotensin Ⅱ （AngⅡ）， matrix metalloproteinase-2 （MMP-2）， interleukin-6 （IL-6）， leukemia inhibitory factor （LIF）， CXC chemokine ligand 12 （CXCL12）， and microtubule-associated protein 1 light chain 3 homolog （LC3）Ⅰ/Ⅱ was quantified by Western blot. ② Mechanism analysis at the single-cell level： The decidua with embryos from the blank， model， high-dose Shoutai Wan， and high-dose Juyuan Jian groups （6 mice per group， with 3 single-cell samples per group， totaling 24 mice） were analyzed by the BD Rhapsody™ platform， and the whole-cell atlas was drawn by uniform manifold approximation and projection （UMAP） dimensionality reduction clustering combined with the single-cell mouse cell atlas （scMCA）. The differentially expressed genes （DEGs） and cell interaction networks were analyzed via Gene Ontology （GO）， Kyoto Encyclopedia of Genes and Genomes （KEGG）， and CellChat， and the protein-protein interaction （PPI） map of subtype cells was constructed. The CytoTRACE pseudo-temporal analysis was performed to explore the developmental trajectories of core immune cells （natural killer cells， NK cells） from maternal and fetal sources. Results① Pathological and Western blot results indicated that compared with the blank group， the RPL group showed an increase in the embryo loss rate （P<0.01）， down-regulated expression of Bcl-2， LIF， MMP-2， and Vegf in the decidua with embryos （P<0.05）， up-regulated protein levels of CXCL-12， AngⅡ， and IL-6 （P<0.05）， blocked angiogenesis， apoptosis-inflammation imbalance， and coagulation dysfunction. Both prescriptions dose-dependently reduced the abortion rate and restored the angiogenesis-inflammation balance， and Shoutai pill showed superior performance in restoring the E₂ level to the Pg level （P<0.05）. ② Single-cell transcriptome analysis indicated that compared with the blank group， the RPL group showed differences in multiple key cell populations such as decidual cells， trophoblast cells， endothelial cells， erythroblasts， NK cells， and macrophages at the maternal-fetal interface. Immunity and angiogenesis were the key links in RPL. Compared with the RPL group， high-dose Shoutai Wan reversed the changes of NK cells in the embryonic layer （upregulating the mRNA levels of 17 genes and downregulating the mRNA levels of 29 genes） and macrophages （upregulating the mRNA levels of 117 genes and downregulating the mRNA levels of 53 genes） through the regulation of gene expression. High-dose Shoutai pill regulated the immune cells to affect unfolded proteins， cell adhesion， and programmed cell death， thereby promoting decidualization and angiogenesis and modulating embryo-membrane development. High-dose Juyuan Jian regulated the key subgroups of NK cells （up-regulating the mRNA levels of 9 genes and down-regulating the mRNA levels of 17 genes） and macrophages （up-regulating the mRNA levels of 110 genes and down-regulating the mRNA levels of 81 genes）， which affected decidual inflammation and apoptosis and intervened in glycolysis. ③ The pseudo-temporal analysis and communication network indicated that the communication frequency of the RPL group decreased. High-dose Shoutai Wan restored maternal-fetal tolerance through pathways such as NKG2D， CDH5， GDF， and FASLG. High-dose Juyuan Jian enhanced the IL-6/LIFR/JAK/signal transducer and activator of transcription 3 （STAT3） and desmosome/SEMA6/tumor necrosis factor-like weak inducer of apoptosis （TWEAK） signaling to improve endometrial receptivity. The RPL group showed an increased proportion of toxic dNK7， a decreased proportion of reparative dNK4， and blocked embryo fNK1. High-dose Shoutai Wan down-regulated dNK7 and up-regulated dNK4. High-dose Juyuan Jian inhibited the terminal differentiation of dNK7 and up-regulated LILRB1， thus restoring the balance of cytotoxicity and repair. ConclusionBoth the kidney-tonifying and spleen-invigorating methods are effective in treating RPL. NK and macrophages are the key immune cells in the interaction between the embryo and the membrane. The kidney-tonifying method （Shoutai Wan） has an advantage in regulating the phenotypes of unfolded protein， cell adhesion， and programmed cell death， and shows expression characteristics closer to the physiological state in the regulation of NKG2D and CDH5 signals. The spleen-invigorating method （Juyuan Jian） has an advantage in regulating epithelial-mesenchymal transition （EMT）， angiogenesis， and glycolysis and shows higher communication intensity in the IL-6 and LIFR pathways.

Abstract The prevention and control of myopia in children and adolescents has become a national health strategy in China, and its prevention and management are transitioning from experience driven approaches to precise and intelligent strategies. Understanding the role of artificial intelligence (AI) in myopia prevention and control can provide a foundation for a comprehensive myopia prevention and control system. AI, with its powerful capabilities in data analysis and pattern recognition, shows significant potential in myopia risk prediction, screening and diagnosis, intervention support and behavior monitoring in children and adolescents. The article systematically summarizes the scientific evidence and consensus on the application of AI for myopia prevention and control in children and adolescents. From the perspective of public health practice, it proposes hierarchical expert recommendations for multiple scenarios including schools, families, communities and medical institutions, as well as policy and research with development. Furthermore, it discusses current challenges and future directions, aiming to provide a reference for building an intelligent, precise and fully covered comprehensive myopia prevention and control system in children and adolescents.

Objective: To investigate the stability of plasma from blood donors cryopreserved at-80℃for two months in ELISA and NAT detection (HBV, HCV, and HIV), and to provide a reference for the preservation, transportation, and retrospective testing of samples collected in remote areas or during emergency blood collection. Methods: Three sets of experimental designs were adopted, each including ELISA (HBsAg, anti-HCV, HIV Ag-Ab) and NAT (HBV DNA, HCV RNA, HIV-1 RNA) testing. Stability validation test: 136 positive and 150 negative donor samples were selected, retested with the original reagents after cryopreservation at-80℃for two months, and the ELISA S/CO values, NAT Ct values, and result concordance rates before and after freezing were compared. Limit of detection validation test: Standard substances with known concentrations were diluted into three gradients of weakly reactive samples (ELISA S/CO values of 0.8-5, NAT Ct values of 35-42). Each was tested six times before and after freezing, the mean values were calculated, and the ELISA S/CO values and NAT Ct values were compared. Real-world validation test: 300 randomly selected donor samples were subjected to plasma separation after initial testing and cryopreserved for two months. The reactive detection rates of ELISA and NAT before and after freezing were compared. Results: Stability validation test: In ELISA testing, 3 samples converted from weak-positive to negative, and 3 samples converted from weak-positive to gray zone, yielding a concordance rate of 97.9%. In NAT testing, 2 samples converted from weak-positive to gray zone, yielding a concordance rate of 99.30%. Significant differences were observed in both ELISA S/CO values and NAT Ct values after freezing (P<0.05). Limit of detection validation test: No significant differences were found in ELISA S/CO values or NAT Ct values for the three concentrations of weakly reactive samples before and after freezing (P>0.05); only the anti-HCV ELISA result for the 0.5 NCU/mL sample converted from positive to the gray zone. Real-world validation test: The ELISA reactive detection rates before and after freezing were 1.67% vs 1.00%, and the NAT reactive detection rates were 0.33% vs 0.33%, with no significant differences (P≥0.05). Conclusion: After cryopreservation of donor plasma at-80℃for two months, the overall concordance rates for ELISA and NAT testing are extremely high. Although weak-positive samples are susceptible to freezing effects, the overall qualitative results remain stable, demonstrating that deep-low temperature cryopreservation can effectively maintain the stability of viral marker detection.

Objective:To prepare a nano-barium titanate@gold Schottky junction (nano-BaTiO 3@Au) coating and investigate its effects on the adhesion, proliferation, and osteogenic differentiation of bone marrow stem cells (BMSCs), aiming to explore a titanium surface modification strategy with superior osteogenic activity. Methods:Pure titanium specimens served as the control group (Ti group). Titanium dioxide coatings were prepared on their surfaces via anodic oxidation. Nano-barium titanate (nBTO group) was further synthesized using the hydrothermal method. Gold nanoparticles were grown in situ on the nano-BaTiO 3 via high-temperature reduction of chloroauric acid using sodium citrate, yielding the nano-barium titanate@gold Schottky junction coating (nBTO@Au group). Surface morphology was observed by scanning electron microscopy (SEM). Elemental composition was analyzed using X-ray energy dispersive spectrum (EDS) and X-ray photoelectron spectroscopy (XPS). Crystal structure was analyzed using X-ray diffraction (XRD) and Raman spectroscopy. Hydrophilicity was assessed via water contact angle measurement. Specimens were co-cultured with BMSCs to evaluate biocompatibility and osteogenic properties. Cell proliferation on days 1, 3, 5, and 7 was assessed using the cell counting kit-8 (CCK-8) assay. Cytotoxicity towards BMSCs was assessed using live/dead cell staining. Cell morphology and adhesion were observed using cytoskeleton staining. Alkaline phosphatase (ALP) expression in BMSCs after 7 days was quantified using an ALP activity assay and ALP staining. Extracellular matrix mineralization after 7 days was evaluated using alizarin red staining and quantification assay. Each experiment was performed using three specimens per group. Results:Scanning electron microscopy revealed that gold nanoparticles with the diameter of(14.838±0.718) nm, uniform in size and homogeneously distributed, were successfully grown in situ on the surface of the nBTO coating. EDS and XPS confirmed the presence of Ba, Ti, O, and Au elements in the nBTO@Au composite coating. XRD and Raman spectroscopy analysis indicated that the nanostructured barium titanate (nBTO) coating was synthesized via a hydrothermal method.Water contact angle measurements showed that the contact angle was 66.8°± 0.45° for the control group, 22.55°±0.42° for the nBTO group, and 26.78°±1.15° for the nBTO@Au group, indicating good hydrophilicity of both nBTO and nBTO@Au coatings. On day 1 and day 3 of culture, the cell proliferation in the nBTO group was significantly lower than that in the control group ( P<0.05). In contrast, no significant differences were observed between the nBTO@Au group and either the control group or the nBTO group (all P>0.05). By day 5, the cell proliferation of nBTO@Au groups was significantly lower than that of the control group ( P<0.05), and the cell proliferation of nBTO group was significantly lower than that of the control group and that of the nBTO@Au group ( P<0.05). By day 7, there were no statistically significant differences in cell proliferation among all experimental groups ( F=1.62, P>0.05).Live/dead cell staining demonstrated that the cell survival rate exceeded 90% in all groups, with normal morphology and few dead cells, indicating good biocompatibility of the nBTO@Au coating. Compared to the control group, both nBTO and nBTO@Au groups promoted cell adhesion and spreading, although no significant difference in cell morphology was noted between the two modified groups. ALP staining revealed a larger stained area and deeper coloration in the nBTO@Au group. Quantitative results showed that ALP activity in the nBTO@Au group was significantly higher than that in both the nBTO and control groups ( P<0.05), and the nBTO group also exhibited significantly higher activity than the control group( P<0.05). Alizarin red staining indicated the deepest coloration in the nBTO@Au group, followed by the nBTO group, and the lightest in the control group. Quantitative analysis further confirmed that the amount of calcium nodule deposition in the nBTO@Au group was significantly greater than that in the other two groups ( P<0.05), and the nBTO group also showed significantly more deposition than the control group( P<0.05). Conclusions:This study successfully prepared an nBTO@Au coating possessing good biocompatibility and enhanced osteogenic properties.

The global aging population has intensified the incidence of degenerative bone diseases and the therapeutic demand for traumatic bone injuries, thereby making bone regenerative medicine a research focus. There is a close connection and interaction between the skeletal system and the nervous system, and innervation plays an indispensable regulatory role in the process of bone regeneration: the sympathetic nervous system exerts a negative regulatory effect during bone regeneration, while the parasympathetic nervous system plays a positive regulatory role in this process. Nerve fibers within bones are distributed alongside blood vessels, with their density decreasing from the periosteum to the cancellous bone. Nerve signals regulate bone regeneration either by directly acting on target cell receptors or indirectly modulating the metabolism of the local microenvironment (such as the levels of inflammatory factors and the supply of nutrients). A variety of neuropeptides (e.g., calcitonin gene-related peptide, substance P, neuropeptide Y, vasoactive intestinal peptide, etc.) play a crucial role in bone tissue, constructing a "neuro-osseous" regulatory axis, which in turn regulates the osteoblast-osteoclast balance, angiogenesis, and the homeostasis of the local microenvironment. This review focuses on the neural regulatory mechanisms in bone regeneration, with an emphasis on sorting out the functions of key neuropeptides and related neurotransmitters. Neuropeptides are the core mediators of neuro-osseous interaction; however, the interaction network among neuropeptides remains to be further clarified, which requires the application of advanced in vitro models such as three-dimensional bioprinted bone models and organoid technology, as well as cutting-edge techniques like single-cell sequencing for analysis. In the future, the integration of neural regulation strategies with traditional bone regeneration technologies, along with the expansion into interdisciplinary fields such as neuro-vascular and neuro-muscular fields, is expected to provide new directions for the treatment of bone defects and large maxillofacial tissue defects, and promote the transformation of regenerative medicine from prosthetic treatment to functional and neurotized tissue regeneration.

Objective:To compare the efficacy and safety of crisaborole ointment 2% versus pimecrolimus cream 1% in the treatment of mild to moderate atopic dermatitis in children aged 2 years or older.Methods:A multicenter, randomized, open-label, controlled clinical trial was conducted. A total of 120 pediatric patients aged 2 - 17 years with mild to moderate atopic dermatitis were enrolled from departments of dermatology of 8 hospitals in China between March 2022 and February 2023. The participants were randomly assigned in a 1∶1 ratio to the crisaborole group and the pimecrolimus group, and received the treatment with crisaborole ointment 2% and pimecrolimus cream 1% respectively, twice a day for 4 weeks. Visits were scheduled at baseline/on day 1, as well as on days 8, 15, and 29. The primary efficacy outcome was the percentage of patients achieving the Investigator's Static Global Assessment (ISGA) success (defined as clear [0] or almost clear [1] on the ISGA scale, combined with ≥ 2‐grade improvement from baseline) on day 29. The secondary efficacy outcomes included changes in the Eczema Area and Severity Index (EASI) total scores from baseline to day 29, percentages of patients achieving ISGA improvement (defined as clear [0] or almost clear [1] on the ISGA scale), as well as changes in the Peak Pruritus Numerical Rating Scale (NRS) scores, Dermatology Life Quality Index (DLQI) /Infants' Dermatology Life Quality Index (IDLQI) /Children's Dermatology Life Quality Index (CDLQI) scores, and in the Dermatitis Family Impact (DFI) scores. Drug safety was evaluated according to the incidence of adverse events. Categorical data were compared using the chi-square test. Since measurement data did not follow a normal distribution, the rank sum test was used for comparisons of measurement data between groups.Results:A total of 106 children with mild to moderate atopic dermatitis were included in the per-protocol analysis set, with 52 in the crisaborole group (26 males and 26 females) and 54 in the pimecrolimus group (27 males and 27 females). There were no significant differences in age, disease duration, ISGA and EASI scores at baseline between the two groups (all P > 0.05). On day 29, 22 patients (42.31%) in the crisaborole group and 25 (46.30%) in the pimecrolimus group achieved ISGA success, with no significant difference between the two groups ( χ2 = 0.17, P = 0.68) ; 35 patients (67.31%) in the crisaborole group and 45 (83.33%) in the pimecrolimus group achieved ISGA improvement, also with no significant difference between the two groups ( χ2 = 3.68, P = 0.06) ; additionally, there were no significant differences in the EASI, pruritus NRS, DLQI/IDLQI/CDLQI, or DFI scores between the two groups (all P > 0.05). Adverse reactions to the two topical agents were mainly local reactions such as mild to moderate pain, itching, or worsening of itching, and no obvious systemic adverse reactions occurred. The incidence of drug-related adverse reactions was 46.15% (24 cases) in the crisaborole group and 37.04% (20 cases) in the pimecrolimus group, with no significant difference between the two groups ( χ2 = 0.91, P = 0.34) . Conclusion:The efficacy of crisaborole ointment 2% was comparable to that of pimecrolimus cream 1% in the treatment of mild to moderate atopic dermatitis in children aged ≥ 2 years, and it yielded early and rapid improvement in the quality of life of patients and their families, with good safety and tolerability profiles.

Objective:To investigate factors influencing frequent episodes (≥ 4 episodes within 1 year) in children with moderate-to-severe atopic dermatitis (AD) in China.Methods:A national multicenter cross-sectional study was conducted. Patients under the age of 18 years diagnosed with moderate-to-severe AD were enrolled at dermatology clinics in 18 medical institutions across 12 provinces and municipalities in China between June 12 and August 8, 2023. At the time of the visit, their guardians completed a structured questionnaire covering demographic characteristics, clinical features of AD, personal and family history, factors associated with frequent episodes of moderate-to-severe AD, compliance with treatment, and disease awareness. Statistical analyses included t tests, one-way analysis of variance, rank-sum tests, and chi-square tests, with multiple-response analysis applied for multiple-choice questions. Results:A total of 965 valid questionnaires were collected, and 965 children with moderate-to-severe AD were included. Among them, there were 531 males and 434 females, 678 (70.3%) were aged 2 - < 12 years, 837 (86.7%) were from urban areas, the age at onset was 2.47 ± 3.03 years, and the median frequency of AD episodes in the past year was 4 times. These children were divided into 2 groups based on the median episode frequency: < 4-episode group (439 cases, 45.5%) and ≥ 4-episode group (526 cases, 54.5%). Compared with the < 4-episode group, children in the ≥ 4-episode group showed younger ages at onset (2.22 ± 2.98 years vs. 2.76 ± 3.06 years, P = 0.006) and higher proportions of patients with comorbid allergic diseases in both the children themselves (82.9% [436/526] vs. 69.7% [306/439], χ2 = 23.42, P < 0.001) and their relatives (66.0% [347/526] vs. 57.4% [252/439], χ2 = 7.46, P = 0.006). Children in the ≥ 4- episode group also had higher monthly usage of moisturizers (150 [30, 300] g vs. 60 [6, 200] g) and daily frequency of moisturizer use, greater disease awareness, but more severe fear of medication use (all P < 0.05). The region and the human development index level were both significantly associated with the episode frequency (both P < 0.001), with the highest proportion of children from South China in the ≥ 4- episode group (36.3%, 191/526). Children in the ≥ 4-episode group also had a longer duration of topical glucocorticoid use than those in the < 4-episode group ( Z = -2.21, P = 0.027). External triggers associated with AD episodes mainly included heat exposure (50.36%, 486/965), hot water bathing (40.73%, 393/965), seafood (23.52%, 227/965), and dust mites (33.37%, 322/965) . Conclusion:In children with moderate-to-severe AD in China, factors influencing frequent episodes may include residence in southern or economically developed regions, earlier age at onset, having a personal or family history of allergic diseases, and fear of medication use.

Objective:To evaluate the diagnostic performance of fecal calprotectin (FC) in predicting endoscopic activity of ulcerative colitis (UC), and to compare it with high-sensitivity C reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR) .Methods:A cross-sectional stydy was conducted. UC patients diagnosed at Peking Union Medical College Hospital between May 2023 and July 2025 were retrospective enrolled. Patients were divided into the endoscopically active group and endoscopic remission group according to endoscopic activity. FC levels were measured using latex-enhanced turbidimetric immunoassay (LETIA). Receiver operating characteristic (ROC) curves and logistic regression models were used to assess diagnostic efficacy. Subgroup analyses were conducted according to disease extent.Results:A total of 166 UC patients were enrolled, including 92 males and 74 females with the age of 40.00 (32.00, 52.00) years old and disease course 5.00 (2.00, 10.75) years. Forty-six patients were assigned to the active group, while the remaining 120 were assigned to the remission group. FC levels were significantly higher in the active group than in the remission group (620.72 μg/g vs. 29.00 μg/g, P < 0.001), with an AUC of 0.894 at a cutoff value of 122.54 μg/g. hsCRP and ESR had lower AUC (0.712 and 0.736, respectively). The combination of FC, hsCRP, and ESR slightly improved specificity (AUC 0.898). FC was strongly correlated with the endoscopic activity ( r =0.669, P < 0.001) but not with disease extent. Conclusions:FC measured by latex-enhanced turbidimetric immunoassay had comparable diagnostic accuracy to ELISA-based methods commonly used abroad, and provided a reference cutoff value of 122.54 μg/g. FC outperforms hsCRP and ESR in assessing intestinal inflammation in UC and it is less affected by disease extent, making it a reliable non-invasive biomarker for UC monitoring.

Objective:To evaluate the predictive efficacy of fecal calprotectin (FC) for endoscopic activity in patients with Crohn's disease (CD) .Methods:A cross-sectional study was conducted and patients diagnosed as CD at Peking Union Medical College Hospital from June 2023 to September 2025 were enrolled consecutively. Data was collected including general information, laboratory tests [hemoglobin (HGB), platelet (PLT), FC, high-sensitivity C-reactive protein (hsCRP), erythrocyte sedimentation rate (ESR) and so on], and endoscopic results. FC levels were measured by latex-enhanced turbidimetric immunoassay (LETIA). Endoscopic activity was defined as the simplified endoscopic score for Crohn's disease (SES-CD) > 2. Patients were divided into the endoscopically active group and endoscopic remission group according to endoscopic activity, and the differences in clinical data between the two groups were compared. Spearman correlation analysis was used to assess the correlation between FC and endoscopic activity, and receiver operating characteristic (ROC) curve was used to evaluate the predictive efficacy of FC, hsCRP and ESR for endoscopic activity, and the differences were compared.Results:A total of 90 CD patients were enrolled, including 65 males and 25 females with the age of 30 (22, 41) years old and disease course 4.0 (0.5, 8.0) years. Seventy-one patients (78.9%) had ileocolonic disease involvement (L3), and 55 patients (61.1%) were using biologics. Sixty-nine patients in endoscopic active phase were assigned to the endoscopically active group, while the remaining 21 were assigned to the endoscopic remission group. There were no statistically significant differences in general characteristics such as age and gender between the two groups (all P > 0.05). Compared with endoscopic remission group, HGB was significantly lower in the endoscopically active group, while PLT, hsCRP, ESR, and FC were moderataly higher (all P < 0.05). Among the 90 CD patients, FC levels were moderatly correlated with endoscopic activity (ρ = 0.494). ROC curve analysis indicated that the area under the curve for FC in predicting endoscopic activity was 0.836 (95% CI: 0.737-0.935), with a sensitivity of 0.725, specificity of 0.952, and accuracy of 0.778 at the optimal FC cutoff value of 153.8 μg/g. FC outperformed hsCRP and ESR. Conclusion:FC measured by LETIA demonstrates certain efficacy in predicting endoscopic activity in CD and will assist in efficient clinical monitoring of CD patients.