Objective:To investigate the association of regulatory T cell (Treg) levels in peripheral blood with bronchopulmonary dysplasia (BPD) in preterm infants and its predictive value for BPD.Methods:In this case-control study, a total of 102 infants with gestational age ≤32 weeks who were hospitalized in the Neonatal Intensive Care Unit of the First Affiliated Hospital of Xinxiang Medical University from April 2022 to April 2024 were included.They were divided into a BPD group (31 cases) and a non-BPD group (71 cases) based on the diagnostic criteria of BPD.Peripheral blood samples were collected on 0 day, 7 days, 14 days, 21 days and 28 days after birth.Differences in Treg levels between the 2 groups and the relationship between Treg levels and BPD were analyzed.The independent sample t test or χ2 test was used to analyze differences between the 2 groups.One-Way ANOVA was used to compare data between groups.Multivariate Logistic regression was used to analyze the risk factors of BPD.The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of Treg levels on 7 days after birth for early diagnosis of BPD. Results:Gestational age[(28.1±1.4) weeks vs.(30.9±1.0) weeks], birth weight[(1 024±243) g vs.(1 301±188) g], Apgar score at 1 minute after birth[(4.3±1.9) points vs.(7.8±1.9) points], Apgar score at 5 minutes after birth[(7.2±1.7) points vs.(9.1±1.3) points], proportion of invasive mechanical ventilation time ≥7 days [87.1%(27/31) vs.45.1%(32/71)] and oxygen inhalation time[(45.1±11.7) days vs.(19.7±7.3) days] were statistically significantly different between BPD and non-BPD groups (all P<0.05).The Treg level in the peripheral blood of preterm infants increased first and then decreased after birth, with the peak observed on 7 days after birth.On 7 days after birth, the BPD group had a significantly higher Treg level than the non-BPD group[(10.4±1.2)% vs.(8.7±1.7)%] ( P<0.05).The multivariate Logistic regression analysis showed increased Treg levels in peripheral blood on 7 days after birth ( OR=3.320, 95% CI: 1.057-10.427, P=0.040), gestational age ( OR=0.040, 95% CI: 0.003-0.446, P=0.009), invasive mechanical ventilation time ≥7 days ( OR=4.126, 95% CI: 1.301-14.125, P=0.002), and oxygen inhalation time ( OR=1.716, 95% CI: 1.317-3.933, P=0.041) were risk factors of BPD in preterm infants.The ROC curve analysis showed that the area under the curve of Treg levels on 7 days after birth for BPD prediction was 0.794, the best cut-off value was 9.35%, the sensitivity was 90.3%, and the specificity was 66.2%. Conclusions:Treg levels in the peripheral blood of preterm infants increase first and then decrease in the early stage after birth, peaking at 7 days after birth.Elevated Treg levels at 7 days after birth may have early predictive value for the occurrence of BPD in preterm infants.

Objective:To investigate the association of regulatory T cell (Treg) levels in peripheral blood with bronchopulmonary dysplasia (BPD) in preterm infants and its predictive value for BPD.Methods:In this case-control study, a total of 102 infants with gestational age ≤32 weeks who were hospitalized in the Neonatal Intensive Care Unit of the First Affiliated Hospital of Xinxiang Medical University from April 2022 to April 2024 were included.They were divided into a BPD group (31 cases) and a non-BPD group (71 cases) based on the diagnostic criteria of BPD.Peripheral blood samples were collected on 0 day, 7 days, 14 days, 21 days and 28 days after birth.Differences in Treg levels between the 2 groups and the relationship between Treg levels and BPD were analyzed.The independent sample t test or χ2 test was used to analyze differences between the 2 groups.One-Way ANOVA was used to compare data between groups.Multivariate Logistic regression was used to analyze the risk factors of BPD.The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of Treg levels on 7 days after birth for early diagnosis of BPD. Results:Gestational age[(28.1±1.4) weeks vs.(30.9±1.0) weeks], birth weight[(1 024±243) g vs.(1 301±188) g], Apgar score at 1 minute after birth[(4.3±1.9) points vs.(7.8±1.9) points], Apgar score at 5 minutes after birth[(7.2±1.7) points vs.(9.1±1.3) points], proportion of invasive mechanical ventilation time ≥7 days [87.1%(27/31) vs.45.1%(32/71)] and oxygen inhalation time[(45.1±11.7) days vs.(19.7±7.3) days] were statistically significantly different between BPD and non-BPD groups (all P<0.05).The Treg level in the peripheral blood of preterm infants increased first and then decreased after birth, with the peak observed on 7 days after birth.On 7 days after birth, the BPD group had a significantly higher Treg level than the non-BPD group[(10.4±1.2)% vs.(8.7±1.7)%] ( P<0.05).The multivariate Logistic regression analysis showed increased Treg levels in peripheral blood on 7 days after birth ( OR=3.320, 95% CI: 1.057-10.427, P=0.040), gestational age ( OR=0.040, 95% CI: 0.003-0.446, P=0.009), invasive mechanical ventilation time ≥7 days ( OR=4.126, 95% CI: 1.301-14.125, P=0.002), and oxygen inhalation time ( OR=1.716, 95% CI: 1.317-3.933, P=0.041) were risk factors of BPD in preterm infants.The ROC curve analysis showed that the area under the curve of Treg levels on 7 days after birth for BPD prediction was 0.794, the best cut-off value was 9.35%, the sensitivity was 90.3%, and the specificity was 66.2%. Conclusions:Treg levels in the peripheral blood of preterm infants increase first and then decrease in the early stage after birth, peaking at 7 days after birth.Elevated Treg levels at 7 days after birth may have early predictive value for the occurrence of BPD in preterm infants.

Objective:To evaluate the correlation between peri-implant probing depth (PPD) and radiographic bone level (rBL) in implants with peri-implantitis.Methods:From January 2019 to December 2022, 24 patients with 30 implants who suffered from peri-implantitis at the Department of Periodontology, Peking University School and Hospital of Stomatology were included in the present research. SPSS 26.0 software was used to simple random sampling select 30 healthy implants from which with electronic examination records in Department of Periodontology, Peking University School and Hospital of Stomatology from January 2007 to June 2023 as the control group. On the premise of retaining the implant prosthesis, PPD (distance between pocket bottom and peri-implant soft tissue margin) was examined using a Williams periodontal probe with a light force (about 0.2 N), and a total of 4 sites were recorded for each implant. Periapical radiography and cone beam CT were applied to measure the rBL (distance between the reference point at the neck of the implant and the apical point of the bone defect) and the width of the bone defect (DW), and the type of the bone defect was recorded. The correlation and consistency between the diagnosis of PPD and rBL were analyzed.Results:PPD was significantly correlated with rBL in a total of 60 implants in 180 sites ( r=0.64, P<0.001). The chi-square test showed an 8.15-fold increase in the detection rate of PD≥6 mm at sites with rBL≥1 mm ( P<0.001). Multivariate logistic regression analysis showed that rBL was still statistically associated with PPD after adjustment for jaw position and examination position of implants. Take rBL <1 mm as reference, the odds ratios ( OR) of 1 mm≤rBL<2 mm, 2 mm≤rBL<3 mm and rBL≥3 mm group with PPD were 6.23 ( P=0.014), 2.77 ( P=0.183) and 10.87 ( P=0.001), respectively. Conclusions:There is a positive correlation between PPD and rBL in implants with peri-implantitis. PPD can be used as a clinical examination index to assist in estimating the level of peri-implant bone under the premise of retaining the prosthesis.