Mycophenolic acid (MPA), the active moiety of both mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS), serves as a primary immunosuppressant for maintaining solid organ transplants. Therapeutic drug monitoring (TDM) enhances treatment outcomes through tailored approaches. This study aimed to develop an evidence-based guideline for MPA TDM, facilitating its rational application in clinical settings. The guideline plan was drawn from the Institute of Medicine and World Health Organization (WHO) guidelines. Using the Delphi method, clinical questions and outcome indicators were generated. Systematic reviews, Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evidence quality evaluations, expert opinions, and patient values guided evidence-based suggestions for the guideline. External reviews further refined the recommendations. The guideline for the TDM of MPA (IPGRP-2020CN099) consists of four sections and 16 recommendations encompassing target populations, monitoring strategies, dosage regimens, and influencing factors. High-risk populations, timing of TDM, area under the curve (AUC) versus trough concentration (C₀), target concentration ranges, monitoring frequency, and analytical methods are addressed. Formulation-specific recommendations, initial dosage regimens, populations with unique considerations, pharmacokinetic-informed dosing, body weight factors, pharmacogenetics, and drug‍-‍drug interactions are covered. The evidence-based guideline offers a comprehensive recommendation for solid organ transplant recipients undergoing MPA therapy, promoting standardization of MPA TDM, and enhancing treatment efficacy and safety.
Mycophenolic Acid/administration & dosage* ; Drug Monitoring/methods* ; Humans ; Organ Transplantation ; Immunosuppressive Agents/administration & dosage* ; Delphi Technique

Objective To explore the pharmacokinetic(PK)characteristics of desloratadine tablets and reference drugs in healthy subjects,and evaluate their bioequivalence and safety.Methods The random,open,two-period,cross-over pharmacokinetic study method was adopted,each subject received a single oral dose of desloratadine tablets test drug(T)or reference drug(R)for 5 mg.The concentrations of desloratadine and 3-hydroxy desloratadine in plasma were determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS);and the PK parameters were calculated by WinNonlin 8.1 software to evaluate the bioequivalence.Results The main PK parameters of T and R of desloratadine were as follows:the fasting condition Cmax were respectively(3 809.82±1 016.54)and(3 642.36±777.07)pg·mL-1;AUC0-120h were respectively(5.75 ×104±5.03 ×104)and(5.51 × 104±4.00 × 104)pg·h·mL-1;AUC0-∞ were respectively(6.85× 104±1.03× 104)and(6.37 × 104±7.92 × 104)pg·h·mL-1.The fed condition Cmax were respectively(4 398.98±1 191.22)and(4 744.4±1 511.97)pg·mL-1;AUC0-120h were respectively(5.25 × 104±1.82 × 104)and(5.55 × 104±1.98 × 104)pg·h·mL-1;AUC0-∞ were respectively(5.37 × 104±1.86 × 104)and(5.68 × 104±2.04 × 104)pg·h·mL-1.The 90％confidence interval of Cmax,AUC0-t and AUC0-∞ of desloratadine were all within 80.00％～125.00％.Conclusion There was no significant difference in the main PK parameters between T tablets and R under fasting or high-fat postprandial conditions,and desloratadine tablets were bioequivalent,safe and well tolerated.

Objective:To examine the long-term efficacy and complications of fecal microbiota transplantation (FMT) for the treatment of diseases related to intestinal dysbiosis.Methods:This was a retrospective descriptive study. Relevant data were collected from the records of 15 000 patients who had undergone FMT and been followed up for more than 3 months during the period from May 2017 to September 2024. The patient cohort comprised 3746 male and 11 254 female patients aged (45.3±12.2) years. The inclusion criterion was meeting the indications for FMT. Application of this criterion yielded 8258 patients with constipation, 684 with Clostridium difficile infection, 1730 with chronic diarrhea, 510 with inflammatory bowel disease, 432 with radiation enteritis, 1940 with irritable bowel syndrome, 365 with autism, 870 with postoperative gastrointestinal dysfunction, and 211 with neurodegenerative diseases. The three routes of delivering FMT comprised infusion of an enterobacterial solution through a nasoenteric tube into the jejunum for 6 consecutive days (upper gastrointestinal FMT group, 11 125 patients), oral intake of enterobacterial capsules for 6 consecutive days (oral capsule FMT, 3597 patients), and a single injection of a bacterial solution into the colon via colonoscopy (lower gastrointestinal FMT group, 278 patients). Other treatments were discontinued during the treatment and follow-up period and administration of other medications was not recommended unless absolutely necessary. The primary outcomes were the efficacy of FMT after 3, 12 and 36 months of treatment, and improvement in chronic constipation, C. difficile infection, chronic diarrhea, inflammatory bowel disease, radiation enteritis, irritable bowel syndrome, post-surgery gastrointestinal dysfunction, and autism. Other outcomes included the occurrence of short-term (within 2 weeks after treatment) and long-term (within 36 months after treatment) adverse reactions.Results:At 3, 12 and 36 months after treatment, the overall rates of effectiveness of treatment were 71.8% (10 763/15 000), 64.4% (7600/11 808) and 58.8% (3659/6218), respectively. Specifically, the rates of clinical improvement were 70.3% (5805/8258), 62.6% (3970/6345), and 56.5% (1894/3352), respectively, for constipation; 85.8% (587/684), 72.3% (408/564), and 67.3% (218/324), respectively, for C.difficile infection; 81.0% (1401/1730), 78.1% (1198/1534), and 72.3% (633/876), respectively, for chronic diarrhea; 64.3% (328/510), 52.3% (249/476), and 46.6 % (97/208), respectively, for inflammatory bowel disease; 77.3% (334/432), 65.4% (212/324), and 53.6% (82/153), respectively, for radiculitis; 70.6% (1370/1940), 64.5% (939/1456), and 60.4% (475/786), respectively, for irritable bowel syndrome; 75.3% (275/365), 70.0% (201/287), and 63.6% (112/176), respectively, for autism; 65.3% (568/870), 54.3% (355/654), and 46.5% (114/245), respectively, for post-surgical gastrointestinal dysfunction; and 45.0% (95/211), 40.5% (68/168), and 34.7% (34/98), respectively, for neurodegenerative diseases. At 3, 12, and 36 months post-treatment, clinical improvement rates were 77.1% (8580/11 125), 67.1% (6437/9595), and 62.1% (3196/5145), respectively, in the upper gastrointestinal route group; and 57.3% (2062/3597), 53.6% (1115/2081), and 45.0% (453/1006), respectively, in the oral capsule group; and 43.5% (121/278) , 36.4% (48/132) and 14.9% (10/67), respectively, in the lower gastrointestinal route group. No serious adverse reactions occurred during treatment or follow-up. The most common adverse reactions in the upper gastrointestinal route group, oral capsule group, and lower gastrointestinal route group were respiratory discomfort (20.4%, 2269/11 125), nausea and vomiting on swallowing the capsule (7.6%, 273/3597), and diarrhea (47.5%, 132/278), respectively; these symptoms resolved at the end of treatment. At 36 months of follow-up, 19 patients reported exacerbation of symptoms of pre-existing diseases and there had been 16 deaths that were not directly related to FMT. Additionally, no systemic diseases had developed after FMT.Conclusion:FMT for the treatment of intestinal dysfunction associated with disorders of the intestinal flora and related extraintestinal diseases is effective and not associated with serious adverse events.

Objective:In this study, we aimed to investigate the short-term efficacy and safety of perioperative administration of the PD-1 inhibitor tislelizumab combined with the SOX regimen (oxaliplatin plus S-1) in patients with locally advanced gastric cancer, and to identify factors influencing therapeutic outcomes.Methods:In this retrospective cohort study, we analyzed clinical data of 166 patients who had undergone perioperative therapy and D2 radical gastrectomy in the Department of General Surgery, First Medical Center of Chinese PLA General Hospital between September 2021 and September 2023. The cohort comprised 140 men and 26 women, of median age 62 years (range: 30-75). The patients were allocated to two groups: 62 receiving tislelizumab plus SOX (combination therapy group), and 104 SOX alone (chemotherapy-only group). Primary outcomes included pathological complete response rate, treatment-related adverse events, and complications of surgery. Secondary outcomes comprised major pathological response rate, tumor regression grade (Grades 1-2 denoting favorable response, Grade 3 moderate, and Grades 4-5 poor response), R0 resection rate, and short-term survival outcomes (1-year disease-free and overall survivals). Risk factors associated with pCR in the combination group were also analyzed.Results:The combination therapy group exhibited significantly higher rates of pCR (25.8% vs. 8.7%, χ 2=8.93, P=0.003) and Grade 1 tumor regression (25.8% vs. 16.3%, χ 2=15.32, P=0.001) than the chemotherapy-only group. There were no statistically significant differences in major pathological response rates (41.9% vs. 39.4%), R0 resection rates (96.8% vs. 97.1%,), treatment- related adverse events (48.4% vs. 42.3%,), surgical complications (9.7% vs. 12.5%), 1-year disease-free survival (82.3% vs. 78.8%), or 1-year overall survival (93.5% vs. 91.3%), There were no statistically significant differences (all P>0.05). Multivariate logistic analysis identified neural invasion as an independent risk factor for reduced pCR in the combination group (OR=0.10, 95%CI:0.01-0.85, P=0.035). Conclusions:Perioperative tislelizumab combined with SOX chemotherapy improves pathological response rates in patients with locally advanced gastric cancer and has favorable short-term efficacy and safety profiles. Neural invasion may diminish the therapeutic efficacy of immunotherapy.

Objective To explore the protective effects of genetically modified porcine erythrocyte suspension as a subnormothermic normoxic mechanical perfusate on hypoxic-ischemic brain injury in cynomolgus monkeys caused by traumatic hemorrhage.Methods Cynomolgus monkeys were randomly divided into positive and negative control groups(a total of 3 monkeys,with 3 left cerebral hemispheres as the positive control group and 3 right cerebral hemispheres as the negative control group)and the subnormothermic perfusion group(n=3).The positive control group was directly sampled 1 hour after circulatory arrest,while the negative control group was placed at subnormothermic conditions for 6 hours after circulatory arrest.The subnormothermic perfusion group underwent 6 hours of subnormothermic normoxic mechanical perfusion of the bilateral common carotid arteries of the cynomolgus monkey hypoxic-ischemic brain injury model using genetically modified porcine erythrocyte suspension 1 hour after circulatory arrest.Before perfusion,cross-matching experiments were conducted between the six genetically modified pig and the cynomolgus monkeys.After the start of perfusion,the levels of routine blood indicators in the perfusate were detected at 0,1,2,3,4,5 and 6 hours.Blood oxygen saturation was recorded,and the levels of Na+,K+,Ca2+,glucose and blood pH in the perfusate were measured,as well as the levels of IgG and IgM in the perfusate.After 6 hours of perfusion,the water content of the brain tissue was measured.Nissl staining was performed on the frontal cortex and hippocampal regions,and immunofluorescence staining was used to detect the expression of glial fibrillary acidic protein(GFAP),ionized calcium-binding adapter molecule 1(Iba1)and neuronal nuclear antigen(NEUN).Results The cross-matching results between the six genetically modified pig and the cynomolgus monkeys were negative.The number of red blood cells in the perfusate decreased significantly at 3 hours of perfusion,and the hemoglobin level showed a downward trend at 1,3,5 and 6 hours.The number of white blood cells and platelets decreased at all time points.The blood oxygen saturation in the subnormothermic perfusion group remained stable at 95%-98%,and the levels of blood oxygen saturation,Na+,Ca2+,glucose and pH were stable,while the K+level first increased and then decreased.There was no significant difference in the levels of IgG and IgM before and after perfusion.The water content of brain tissue at the end of perfusion in the subnormothermic perfusion group was significantly higher than that in the positive control group(P<0.001).Nissl staining results showed that compared with the positive control group,the pyramidal neurons in the prefrontal cortex of the subnormothermic perfusion group maintained better morphological integrity,with no significant increase in enlarged and deformed cells.In the hippocampal CA1 region,there was a slight increase in enlarged and deformed cells,and a few cells with undamaged structures showed reduced cell size.In the hippocampal dentate gyrus,fewer granule neurons had compromised structural integrity,with increased cell edema.NEUN immunofluorescence staining showed that compared with the positive control group,the pyramidal neurons in the prefrontal cortex and hippocampal CA1 region of the subnormothermic perfusion group had better morphological states,with clear axons.The granule cells in the hippocampal dentate gyrus were well preserved,but the nuclei were less well protected.GFAP immunofluorescence staining showed that compared with the positive control group,the subnormothermic perfusion group had sparser protrusions that were more tightly associated with neurons.Iba1 immunofluorescence staining showed that compared with the positive control group,the subnormothermic perfusion group had thicker and fewer protrusions.Conclusions Compared with the positive control group,subnormothermic normoxic mechanical perfusion with genetically modified porcine erythrocyte perfusate increases brain tissue edema in cynomolgus monkeys,but better preserves the morphological integrity of neurons and glial cells.The protective effects may be related to the continuous oxygen and energy supply,maintenance of ion homeostasis and perfusate pH,reduced rejection,and low metabolic state of the whole brain.

Objective To explore the pharmacokinetic(PK)characteristics of desloratadine tablets and reference drugs in healthy subjects,and evaluate their bioequivalence and safety.Methods The random,open,two-period,cross-over pharmacokinetic study method was adopted,each subject received a single oral dose of desloratadine tablets test drug(T)or reference drug(R)for 5 mg.The concentrations of desloratadine and 3-hydroxy desloratadine in plasma were determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS);and the PK parameters were calculated by WinNonlin 8.1 software to evaluate the bioequivalence.Results The main PK parameters of T and R of desloratadine were as follows:the fasting condition Cmax were respectively(3 809.82±1 016.54)and(3 642.36±777.07)pg·mL-1;AUC0-120h were respectively(5.75 ×104±5.03 ×104)and(5.51 × 104±4.00 × 104)pg·h·mL-1;AUC0-∞ were respectively(6.85× 104±1.03× 104)and(6.37 × 104±7.92 × 104)pg·h·mL-1.The fed condition Cmax were respectively(4 398.98±1 191.22)and(4 744.4±1 511.97)pg·mL-1;AUC0-120h were respectively(5.25 × 104±1.82 × 104)and(5.55 × 104±1.98 × 104)pg·h·mL-1;AUC0-∞ were respectively(5.37 × 104±1.86 × 104)and(5.68 × 104±2.04 × 104)pg·h·mL-1.The 90％confidence interval of Cmax,AUC0-t and AUC0-∞ of desloratadine were all within 80.00％～125.00％.Conclusion There was no significant difference in the main PK parameters between T tablets and R under fasting or high-fat postprandial conditions,and desloratadine tablets were bioequivalent,safe and well tolerated.

Objective To explore the protective effects of genetically modified porcine erythrocyte suspension as a subnormothermic normoxic mechanical perfusate on hypoxic-ischemic brain injury in cynomolgus monkeys caused by traumatic hemorrhage.Methods Cynomolgus monkeys were randomly divided into positive and negative control groups(a total of 3 monkeys,with 3 left cerebral hemispheres as the positive control group and 3 right cerebral hemispheres as the negative control group)and the subnormothermic perfusion group(n=3).The positive control group was directly sampled 1 hour after circulatory arrest,while the negative control group was placed at subnormothermic conditions for 6 hours after circulatory arrest.The subnormothermic perfusion group underwent 6 hours of subnormothermic normoxic mechanical perfusion of the bilateral common carotid arteries of the cynomolgus monkey hypoxic-ischemic brain injury model using genetically modified porcine erythrocyte suspension 1 hour after circulatory arrest.Before perfusion,cross-matching experiments were conducted between the six genetically modified pig and the cynomolgus monkeys.After the start of perfusion,the levels of routine blood indicators in the perfusate were detected at 0,1,2,3,4,5 and 6 hours.Blood oxygen saturation was recorded,and the levels of Na+,K+,Ca2+,glucose and blood pH in the perfusate were measured,as well as the levels of IgG and IgM in the perfusate.After 6 hours of perfusion,the water content of the brain tissue was measured.Nissl staining was performed on the frontal cortex and hippocampal regions,and immunofluorescence staining was used to detect the expression of glial fibrillary acidic protein(GFAP),ionized calcium-binding adapter molecule 1(Iba1)and neuronal nuclear antigen(NEUN).Results The cross-matching results between the six genetically modified pig and the cynomolgus monkeys were negative.The number of red blood cells in the perfusate decreased significantly at 3 hours of perfusion,and the hemoglobin level showed a downward trend at 1,3,5 and 6 hours.The number of white blood cells and platelets decreased at all time points.The blood oxygen saturation in the subnormothermic perfusion group remained stable at 95%-98%,and the levels of blood oxygen saturation,Na+,Ca2+,glucose and pH were stable,while the K+level first increased and then decreased.There was no significant difference in the levels of IgG and IgM before and after perfusion.The water content of brain tissue at the end of perfusion in the subnormothermic perfusion group was significantly higher than that in the positive control group(P<0.001).Nissl staining results showed that compared with the positive control group,the pyramidal neurons in the prefrontal cortex of the subnormothermic perfusion group maintained better morphological integrity,with no significant increase in enlarged and deformed cells.In the hippocampal CA1 region,there was a slight increase in enlarged and deformed cells,and a few cells with undamaged structures showed reduced cell size.In the hippocampal dentate gyrus,fewer granule neurons had compromised structural integrity,with increased cell edema.NEUN immunofluorescence staining showed that compared with the positive control group,the pyramidal neurons in the prefrontal cortex and hippocampal CA1 region of the subnormothermic perfusion group had better morphological states,with clear axons.The granule cells in the hippocampal dentate gyrus were well preserved,but the nuclei were less well protected.GFAP immunofluorescence staining showed that compared with the positive control group,the subnormothermic perfusion group had sparser protrusions that were more tightly associated with neurons.Iba1 immunofluorescence staining showed that compared with the positive control group,the subnormothermic perfusion group had thicker and fewer protrusions.Conclusions Compared with the positive control group,subnormothermic normoxic mechanical perfusion with genetically modified porcine erythrocyte perfusate increases brain tissue edema in cynomolgus monkeys,but better preserves the morphological integrity of neurons and glial cells.The protective effects may be related to the continuous oxygen and energy supply,maintenance of ion homeostasis and perfusate pH,reduced rejection,and low metabolic state of the whole brain.

Objective:To examine the long-term efficacy and complications of fecal microbiota transplantation (FMT) for the treatment of diseases related to intestinal dysbiosis.Methods:This was a retrospective descriptive study. Relevant data were collected from the records of 15 000 patients who had undergone FMT and been followed up for more than 3 months during the period from May 2017 to September 2024. The patient cohort comprised 3746 male and 11 254 female patients aged (45.3±12.2) years. The inclusion criterion was meeting the indications for FMT. Application of this criterion yielded 8258 patients with constipation, 684 with Clostridium difficile infection, 1730 with chronic diarrhea, 510 with inflammatory bowel disease, 432 with radiation enteritis, 1940 with irritable bowel syndrome, 365 with autism, 870 with postoperative gastrointestinal dysfunction, and 211 with neurodegenerative diseases. The three routes of delivering FMT comprised infusion of an enterobacterial solution through a nasoenteric tube into the jejunum for 6 consecutive days (upper gastrointestinal FMT group, 11 125 patients), oral intake of enterobacterial capsules for 6 consecutive days (oral capsule FMT, 3597 patients), and a single injection of a bacterial solution into the colon via colonoscopy (lower gastrointestinal FMT group, 278 patients). Other treatments were discontinued during the treatment and follow-up period and administration of other medications was not recommended unless absolutely necessary. The primary outcomes were the efficacy of FMT after 3, 12 and 36 months of treatment, and improvement in chronic constipation, C. difficile infection, chronic diarrhea, inflammatory bowel disease, radiation enteritis, irritable bowel syndrome, post-surgery gastrointestinal dysfunction, and autism. Other outcomes included the occurrence of short-term (within 2 weeks after treatment) and long-term (within 36 months after treatment) adverse reactions.Results:At 3, 12 and 36 months after treatment, the overall rates of effectiveness of treatment were 71.8% (10 763/15 000), 64.4% (7600/11 808) and 58.8% (3659/6218), respectively. Specifically, the rates of clinical improvement were 70.3% (5805/8258), 62.6% (3970/6345), and 56.5% (1894/3352), respectively, for constipation; 85.8% (587/684), 72.3% (408/564), and 67.3% (218/324), respectively, for C.difficile infection; 81.0% (1401/1730), 78.1% (1198/1534), and 72.3% (633/876), respectively, for chronic diarrhea; 64.3% (328/510), 52.3% (249/476), and 46.6 % (97/208), respectively, for inflammatory bowel disease; 77.3% (334/432), 65.4% (212/324), and 53.6% (82/153), respectively, for radiculitis; 70.6% (1370/1940), 64.5% (939/1456), and 60.4% (475/786), respectively, for irritable bowel syndrome; 75.3% (275/365), 70.0% (201/287), and 63.6% (112/176), respectively, for autism; 65.3% (568/870), 54.3% (355/654), and 46.5% (114/245), respectively, for post-surgical gastrointestinal dysfunction; and 45.0% (95/211), 40.5% (68/168), and 34.7% (34/98), respectively, for neurodegenerative diseases. At 3, 12, and 36 months post-treatment, clinical improvement rates were 77.1% (8580/11 125), 67.1% (6437/9595), and 62.1% (3196/5145), respectively, in the upper gastrointestinal route group; and 57.3% (2062/3597), 53.6% (1115/2081), and 45.0% (453/1006), respectively, in the oral capsule group; and 43.5% (121/278) , 36.4% (48/132) and 14.9% (10/67), respectively, in the lower gastrointestinal route group. No serious adverse reactions occurred during treatment or follow-up. The most common adverse reactions in the upper gastrointestinal route group, oral capsule group, and lower gastrointestinal route group were respiratory discomfort (20.4%, 2269/11 125), nausea and vomiting on swallowing the capsule (7.6%, 273/3597), and diarrhea (47.5%, 132/278), respectively; these symptoms resolved at the end of treatment. At 36 months of follow-up, 19 patients reported exacerbation of symptoms of pre-existing diseases and there had been 16 deaths that were not directly related to FMT. Additionally, no systemic diseases had developed after FMT.Conclusion:FMT for the treatment of intestinal dysfunction associated with disorders of the intestinal flora and related extraintestinal diseases is effective and not associated with serious adverse events.

Objective:In this study, we aimed to investigate the short-term efficacy and safety of perioperative administration of the PD-1 inhibitor tislelizumab combined with the SOX regimen (oxaliplatin plus S-1) in patients with locally advanced gastric cancer, and to identify factors influencing therapeutic outcomes.Methods:In this retrospective cohort study, we analyzed clinical data of 166 patients who had undergone perioperative therapy and D2 radical gastrectomy in the Department of General Surgery, First Medical Center of Chinese PLA General Hospital between September 2021 and September 2023. The cohort comprised 140 men and 26 women, of median age 62 years (range: 30-75). The patients were allocated to two groups: 62 receiving tislelizumab plus SOX (combination therapy group), and 104 SOX alone (chemotherapy-only group). Primary outcomes included pathological complete response rate, treatment-related adverse events, and complications of surgery. Secondary outcomes comprised major pathological response rate, tumor regression grade (Grades 1-2 denoting favorable response, Grade 3 moderate, and Grades 4-5 poor response), R0 resection rate, and short-term survival outcomes (1-year disease-free and overall survivals). Risk factors associated with pCR in the combination group were also analyzed.Results:The combination therapy group exhibited significantly higher rates of pCR (25.8% vs. 8.7%, χ 2=8.93, P=0.003) and Grade 1 tumor regression (25.8% vs. 16.3%, χ 2=15.32, P=0.001) than the chemotherapy-only group. There were no statistically significant differences in major pathological response rates (41.9% vs. 39.4%), R0 resection rates (96.8% vs. 97.1%,), treatment- related adverse events (48.4% vs. 42.3%,), surgical complications (9.7% vs. 12.5%), 1-year disease-free survival (82.3% vs. 78.8%), or 1-year overall survival (93.5% vs. 91.3%), There were no statistically significant differences (all P>0.05). Multivariate logistic analysis identified neural invasion as an independent risk factor for reduced pCR in the combination group (OR=0.10, 95%CI:0.01-0.85, P=0.035). Conclusions:Perioperative tislelizumab combined with SOX chemotherapy improves pathological response rates in patients with locally advanced gastric cancer and has favorable short-term efficacy and safety profiles. Neural invasion may diminish the therapeutic efficacy of immunotherapy.

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.