Objective:To assess the status of undernutrition and appropriate catch-up growth in extremely preterm infants within 24 months of corrected age (CA).Methods:A retrospective cohort study was conducted. A total of 422 extremely preterm infants born at Shenzhen Maternity and Child Healthcare Hospital, Women and Children's Medical Center, Southern Medical University from January 2017 to December 2022 and followed up until 24 months of CA were enrolled. The extremely preterm infants were grouped by gestational age at birth (<25, 25-26, 27 weeks), birth weight (<500, 500-749, 750-999,≥1 000 g), weight for gestational age (large for gestational age (LGA), appropriate for gestational age (AGA), small for gestational age (SGA)) and sex. Weight data within 24 months of CA were collected every 3 months. Nutritional insufficiency, growth rate, and achievement of adequate catch-up growth were analyzed during the period from 0 to 24 months of CA. Z-score method was used to analyze data. Fenton 2013 preterm growth charts (Fenton 2013) were used before 40 weeks of corrected gestational age, and World Health Organization child growth standards (2009) fitted Z-scores were applied from 40 weeks of CA. Changes in weight Z-scores of extremely preterm infants from 0 to 24 months of CA were observed and compared, the occurrence of moderate to severe malnutrition and growth retardation was determined, nutritional insufficiency was assessed, and growth rate as well as the achievement of appropriate catch-up growth were analyzed. The Lambda-mu-sigma method combined with the Z-score fitting model was used to fit and analyze the distribution characteristics of weight percentiles in extremely preterm infants. The Chi-square test was used to compare differences among groups.Results:A total of 422 extremely preterm infants were included, with a gestational age at birth of 26.3(25.4, 27.2) weeks and a birth weight of (880±177) g. Among them, 238 were males and 184 were females; 36 cases (8.5%) were LGA, and 16 cases (3.8%) were SGA. During follow-up within 24 month of CA, 89 cases (21.1%) developed moderate to severe malnutrition. When compared separately among different birth weight and gestational age at birth groups, there had both statistically differences in the incidence of moderate to severe malnutrition ( χ2=42.94 and 9.17, both P<0.05). The incidence was the highest in the birth weight of CA<500 g group and the <25 weeks gestational age at birth group, while it was the lowest in the birth weight of CA≥1 000 g group and the 27 weeks gestational age at birth group in their respective groups. Growth retardation occurred in 5.2% (22/422). However, there had statistically differences in the incidence of growth retardation among different birth weight and gestational age at birth groups, in each grouped time interval ( χ2=21.61 and 4.30, both P<0.05). The proportions of rapid growth were relatively high in the 0-3 months and 3-6 months of CA groups, which were 96 cases (27.4%) and 98 cases (26.6%), respectively. Overall, appropriate catch-up growth was achieved in 341 cases (80.8%) from 0 to 24 months of CA. There had statistically differences in the completion rate of appropriate catch-up growth among different birth weight and gestational age at birth groups ( χ2=23.65 and 7.08, both P<0.05). The completion rate was the highest in the birth weight of CA<500 g group and the <25 weeks of gestational age at birth group, while it was the lowest in the birth weight of CA≥1 000 g group and the 27 weeks of gestational age at birth group. Conclusions:The lower the birth weight and gestational age of extremely preterm infants, the higher the incidence of moderate to severe malnutrition and the lower the achievement rate of adequate catch-up growth within 24 months of CA. The period of 0-6 months of CA is the critical window for catch-up in extremely preterm infants.

Objective:To assess the status of undernutrition and appropriate catch-up growth in extremely preterm infants within 24 months of corrected age (CA).Methods:A retrospective cohort study was conducted. A total of 422 extremely preterm infants born at Shenzhen Maternity and Child Healthcare Hospital, Women and Children's Medical Center, Southern Medical University from January 2017 to December 2022 and followed up until 24 months of CA were enrolled. The extremely preterm infants were grouped by gestational age at birth (<25, 25-26, 27 weeks), birth weight (<500, 500-749, 750-999,≥1 000 g), weight for gestational age (large for gestational age (LGA), appropriate for gestational age (AGA), small for gestational age (SGA)) and sex. Weight data within 24 months of CA were collected every 3 months. Nutritional insufficiency, growth rate, and achievement of adequate catch-up growth were analyzed during the period from 0 to 24 months of CA. Z-score method was used to analyze data. Fenton 2013 preterm growth charts (Fenton 2013) were used before 40 weeks of corrected gestational age, and World Health Organization child growth standards (2009) fitted Z-scores were applied from 40 weeks of CA. Changes in weight Z-scores of extremely preterm infants from 0 to 24 months of CA were observed and compared, the occurrence of moderate to severe malnutrition and growth retardation was determined, nutritional insufficiency was assessed, and growth rate as well as the achievement of appropriate catch-up growth were analyzed. The Lambda-mu-sigma method combined with the Z-score fitting model was used to fit and analyze the distribution characteristics of weight percentiles in extremely preterm infants. The Chi-square test was used to compare differences among groups.Results:A total of 422 extremely preterm infants were included, with a gestational age at birth of 26.3(25.4, 27.2) weeks and a birth weight of (880±177) g. Among them, 238 were males and 184 were females; 36 cases (8.5%) were LGA, and 16 cases (3.8%) were SGA. During follow-up within 24 month of CA, 89 cases (21.1%) developed moderate to severe malnutrition. When compared separately among different birth weight and gestational age at birth groups, there had both statistically differences in the incidence of moderate to severe malnutrition ( χ2=42.94 and 9.17, both P<0.05). The incidence was the highest in the birth weight of CA<500 g group and the <25 weeks gestational age at birth group, while it was the lowest in the birth weight of CA≥1 000 g group and the 27 weeks gestational age at birth group in their respective groups. Growth retardation occurred in 5.2% (22/422). However, there had statistically differences in the incidence of growth retardation among different birth weight and gestational age at birth groups, in each grouped time interval ( χ2=21.61 and 4.30, both P<0.05). The proportions of rapid growth were relatively high in the 0-3 months and 3-6 months of CA groups, which were 96 cases (27.4%) and 98 cases (26.6%), respectively. Overall, appropriate catch-up growth was achieved in 341 cases (80.8%) from 0 to 24 months of CA. There had statistically differences in the completion rate of appropriate catch-up growth among different birth weight and gestational age at birth groups ( χ2=23.65 and 7.08, both P<0.05). The completion rate was the highest in the birth weight of CA<500 g group and the <25 weeks of gestational age at birth group, while it was the lowest in the birth weight of CA≥1 000 g group and the 27 weeks of gestational age at birth group. Conclusions:The lower the birth weight and gestational age of extremely preterm infants, the higher the incidence of moderate to severe malnutrition and the lower the achievement rate of adequate catch-up growth within 24 months of CA. The period of 0-6 months of CA is the critical window for catch-up in extremely preterm infants.

Objective:To explore the genotype and the clinical phenotype of SCN2A-related developmental delay in children. Methods:A case series study was adopted. Collect clinical data from 10 cases of children with SCN2A gene variants diagnosed with global developmental delay/intellectual disability who were admitted to the Children′s Hospital between July 2019 and March 2023. Summarize the clinical phenotype and genotype based on clinical data such as general information, clinical manifestations, imaging examinations, laboratory tests, genetic testing results, and comprehensive pediatric neuropsychological development assessment. Results:A total of 10 patients were recruited, including 7 males and 3 females, with an age range of 27 days to 5 years and 9 months. 9 patients underwent children′s neuropsychological and behavioral assessments, and the results were consistent with global developmental delay, including 2 mild cases, 4 moderate cases, and 3 severe cases. 3 cases had autism spectrum disorder, and 2 cases had epilepsy. 6 patients underwent complete head MRI examination, and 4 of them showed abnormalities, including delayed myelination, widening of the local extra brain space in the frontal lobe, and abnormal frontal lobe morphology. All 10 cases had point variants. Among them, 9 cases are de novo and 1 case is maternal inheritance. Out of 10 cases, there were 5 cases with copy number variations, but all of them were of unknown significance. Among the 10 variants, 8 have been reported and 2 have not been reported, namely c.4145A>T(p.N1382I) and c.4937T>A(p.I1646N). In this study, 4 out of 10 patients with SCN2A variants had variation sites located in the S4 segment of domain which constitute Nav1.2, the sodium ion channel encoded by SCN2A. The developmental quotient level was lower when the variation sites were located in the S4 segment of domain, and the difference was statistically significant ( t=-3.101, P=0.017), indicating that the severity of developmental delay may be related to the localization of amino acids corresponding to variant sites within the protein domain. Conclusion:SCN2A mutations are strongly associated with diverse neurodevelopmental disorders. In this study, the phenotypic spectrum of SCN2A variants encompassed epilepsy, global developmental delay, and autism spectrum disorder. Affected individuals exhibited early-onset developmental delays, predominantly moderate to severe in severity. Voltage-sensing domain dysfunction in sodium channels may constitute a critical pathomechanism underlying neurodevelopmental impairments. Further electrophysiological characterization and molecular mechanistic studies are warranted todelineate the genotype-phenotype correlations between specific variant loci and clinical severity.

Objective:To analyze the epidemiological and clinical characteristics of respiratory pathogens in China.Methods:This study was a cross-sectional study, which encompassed 19 core units of the clinical pathogen network and established a three-tiered clinical pathogen surveillance system. Thirty respiratory samples were collected every two weeks from various units from January to December 2024, and the clinical and pathogen diagnostic information were gathered. A total of 11 864 samples were tested using this system. The tier-1 clinical pathogen surveillance system covered influenza A virus (Flu-A), influenza B virus (Flu-B), respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The tier-2 clinical pathogen surveillance system focused on 18 key respiratory pathogens. The tier-3 clinical pathogen surveillance system further clarified whether any emerging infectious diseases had occurred.Results:The tier-1 clinical pathogen surveillance system showed Flu-A predominated in December, Flu-B predominated in January, SARS-CoV-2 peaked in March and August, whereas RSV circulated sporadically throughout the year. Geographic trends were broadly consistent across the seven major regions, although Flu-A detection in December was notably higher in Northeast China (48.1%(111/231)) and East China (36.2%(148/409)), and RSV detection was concentrated in the Northwest and South China from January to March. Data from the tier-2 clinical pathogen surveillance system indicated that Streptococcus pneumoniae, Mycoplasma pneumoniae, rhinovirus, and adenovirus were detected year-round, of these, Streptococcus pneumoniae and rhinovirus showed elevated positive detection rates from August to September, while adenovirus peaked in January. Legionella pneumophila was not detected throughout the year, and other pathogens fluctuated throughout the year without a consistent pattern. The predominant etiologic agents of pediatric pneumonia were Mycoplasma pneumoniae (35.0%(105/300)), rhinovirus (25.7%(77/300)), and adenovirus (17.3%(52/300)), whereas adult pneumonia was mainly caused by Streptococcus pneumoniae (10.5%(29/277)), Staphylococcus aureus (6.9%(19/277)), Mycoplasma pneumoniae (6.9%(19/277)), and Flu-A (6.1%(17/277)). The tier-3 clinical pathogen surveillance system did not identify any emerging respiratory pathogens. Conclusion:Respiratory pathogens in China in 2024 exhibit distinct temporal and spatial distribution patterns and vary among different populations.

Objective Estimating the residual risk of transfusion-transmitted diseases in voluntary blood donors is crucial for monitoring blood safety.and to analyze the evolution trend over a five-year period in Yantai,Shandong Province.Methods This study retrospectively reviewed screening data from Yantai Central Blood Station between 2018 and 2022.We compared the positivity rates between first-time and repeat donors,calculated the prevalence of each virus,and estimated the residual risk using the prevalence-window period model.Meanwhile,the age characteristics of all positive donors were analyzed.Results Over the five-year period,a total of 320 016 individuals donated blood.The overall reaction rate of transfusion-transmitted diseases was 0.165%,with HBV(0.129%)being the most common.The positivity rate among first-time donors[P(FTDs)](0.310%)was significantly higher than that among repeat donors[P(RDs)](0.054%)(χ2=312.783,P<0.05).The serological residual risks for HBV,HCV,and HIV were 1∶188 090,1∶1 042 805,and 1∶392 995,respectively.During the five-year period,they decreased from 1∶129 495 to 1∶390 011,from 1∶697 002 to 1∶1 145 826,and from 1∶684 109 to 1∶1 067 317,respectively.The residual risks of HCV and HIV after NAT were 1∶22 369 329 and 1∶6 639 965,respectively,which were significantly reduced by 21.5-fold and 16.9-fold,and decreased steadily during the study period.Among the HBV-DNA(+)donors,61.8%(68/110)were RDs,and the residual risk was 1∶65 350.Conclusion This study demonstrates the remarkable effectiveness of introducing nucleic acid amplification technology(NAT)in reducing the residual risk of HBV,HCV,and HIV,particularly for HCV and HIV.The residual risk for HBV remains higher compared to HCV and HIV due to the discovery of occult HBV infections(OBI).Therefore,a crucial step toward further reducing this residual risk is the use of more sensitive reagents and detection platforms.Furthermore,implementing effective long-term incentive mechanisms and strategic planning to increase the proportion of repeat donors(RDs)is critical for enhancing transfusion safety.

Objective Estimating the residual risk of transfusion-transmitted diseases in voluntary blood donors is crucial for monitoring blood safety.and to analyze the evolution trend over a five-year period in Yantai,Shandong Province.Methods This study retrospectively reviewed screening data from Yantai Central Blood Station between 2018 and 2022.We compared the positivity rates between first-time and repeat donors,calculated the prevalence of each virus,and estimated the residual risk using the prevalence-window period model.Meanwhile,the age characteristics of all positive donors were analyzed.Results Over the five-year period,a total of 320 016 individuals donated blood.The overall reaction rate of transfusion-transmitted diseases was 0.165%,with HBV(0.129%)being the most common.The positivity rate among first-time donors[P(FTDs)](0.310%)was significantly higher than that among repeat donors[P(RDs)](0.054%)(χ2=312.783,P<0.05).The serological residual risks for HBV,HCV,and HIV were 1∶188 090,1∶1 042 805,and 1∶392 995,respectively.During the five-year period,they decreased from 1∶129 495 to 1∶390 011,from 1∶697 002 to 1∶1 145 826,and from 1∶684 109 to 1∶1 067 317,respectively.The residual risks of HCV and HIV after NAT were 1∶22 369 329 and 1∶6 639 965,respectively,which were significantly reduced by 21.5-fold and 16.9-fold,and decreased steadily during the study period.Among the HBV-DNA(+)donors,61.8%(68/110)were RDs,and the residual risk was 1∶65 350.Conclusion This study demonstrates the remarkable effectiveness of introducing nucleic acid amplification technology(NAT)in reducing the residual risk of HBV,HCV,and HIV,particularly for HCV and HIV.The residual risk for HBV remains higher compared to HCV and HIV due to the discovery of occult HBV infections(OBI).Therefore,a crucial step toward further reducing this residual risk is the use of more sensitive reagents and detection platforms.Furthermore,implementing effective long-term incentive mechanisms and strategic planning to increase the proportion of repeat donors(RDs)is critical for enhancing transfusion safety.

Objective:To explore the genotype and the clinical phenotype of SCN2A-related developmental delay in children. Methods:A case series study was adopted. Collect clinical data from 10 cases of children with SCN2A gene variants diagnosed with global developmental delay/intellectual disability who were admitted to the Children′s Hospital between July 2019 and March 2023. Summarize the clinical phenotype and genotype based on clinical data such as general information, clinical manifestations, imaging examinations, laboratory tests, genetic testing results, and comprehensive pediatric neuropsychological development assessment. Results:A total of 10 patients were recruited, including 7 males and 3 females, with an age range of 27 days to 5 years and 9 months. 9 patients underwent children′s neuropsychological and behavioral assessments, and the results were consistent with global developmental delay, including 2 mild cases, 4 moderate cases, and 3 severe cases. 3 cases had autism spectrum disorder, and 2 cases had epilepsy. 6 patients underwent complete head MRI examination, and 4 of them showed abnormalities, including delayed myelination, widening of the local extra brain space in the frontal lobe, and abnormal frontal lobe morphology. All 10 cases had point variants. Among them, 9 cases are de novo and 1 case is maternal inheritance. Out of 10 cases, there were 5 cases with copy number variations, but all of them were of unknown significance. Among the 10 variants, 8 have been reported and 2 have not been reported, namely c.4145A>T(p.N1382I) and c.4937T>A(p.I1646N). In this study, 4 out of 10 patients with SCN2A variants had variation sites located in the S4 segment of domain which constitute Nav1.2, the sodium ion channel encoded by SCN2A. The developmental quotient level was lower when the variation sites were located in the S4 segment of domain, and the difference was statistically significant ( t=-3.101, P=0.017), indicating that the severity of developmental delay may be related to the localization of amino acids corresponding to variant sites within the protein domain. Conclusion:SCN2A mutations are strongly associated with diverse neurodevelopmental disorders. In this study, the phenotypic spectrum of SCN2A variants encompassed epilepsy, global developmental delay, and autism spectrum disorder. Affected individuals exhibited early-onset developmental delays, predominantly moderate to severe in severity. Voltage-sensing domain dysfunction in sodium channels may constitute a critical pathomechanism underlying neurodevelopmental impairments. Further electrophysiological characterization and molecular mechanistic studies are warranted todelineate the genotype-phenotype correlations between specific variant loci and clinical severity.

Objective:To analyze the epidemiological and clinical characteristics of respiratory pathogens in China.Methods:This study was a cross-sectional study, which encompassed 19 core units of the clinical pathogen network and established a three-tiered clinical pathogen surveillance system. Thirty respiratory samples were collected every two weeks from various units from January to December 2024, and the clinical and pathogen diagnostic information were gathered. A total of 11 864 samples were tested using this system. The tier-1 clinical pathogen surveillance system covered influenza A virus (Flu-A), influenza B virus (Flu-B), respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The tier-2 clinical pathogen surveillance system focused on 18 key respiratory pathogens. The tier-3 clinical pathogen surveillance system further clarified whether any emerging infectious diseases had occurred.Results:The tier-1 clinical pathogen surveillance system showed Flu-A predominated in December, Flu-B predominated in January, SARS-CoV-2 peaked in March and August, whereas RSV circulated sporadically throughout the year. Geographic trends were broadly consistent across the seven major regions, although Flu-A detection in December was notably higher in Northeast China (48.1%(111/231)) and East China (36.2%(148/409)), and RSV detection was concentrated in the Northwest and South China from January to March. Data from the tier-2 clinical pathogen surveillance system indicated that Streptococcus pneumoniae, Mycoplasma pneumoniae, rhinovirus, and adenovirus were detected year-round, of these, Streptococcus pneumoniae and rhinovirus showed elevated positive detection rates from August to September, while adenovirus peaked in January. Legionella pneumophila was not detected throughout the year, and other pathogens fluctuated throughout the year without a consistent pattern. The predominant etiologic agents of pediatric pneumonia were Mycoplasma pneumoniae (35.0%(105/300)), rhinovirus (25.7%(77/300)), and adenovirus (17.3%(52/300)), whereas adult pneumonia was mainly caused by Streptococcus pneumoniae (10.5%(29/277)), Staphylococcus aureus (6.9%(19/277)), Mycoplasma pneumoniae (6.9%(19/277)), and Flu-A (6.1%(17/277)). The tier-3 clinical pathogen surveillance system did not identify any emerging respiratory pathogens. Conclusion:Respiratory pathogens in China in 2024 exhibit distinct temporal and spatial distribution patterns and vary among different populations.

Objective:To investigate clinical characteristics of and genetic variants in the NF1 gene in children with neurofibromatosis type 1 (NF1) .Methods:Clinical data were collected from 22 children with NF1, who were admitted to the Department of Dermatology, Children's Hospital, Capital Institute of Pediatrics from January 2022 to September 2023, and were analyzed. Next-generation sequencing was performed to detect NF1 mutations in the probands, and the variants were verified in the family members by Sanger sequencing. A homology modeling software was used to predict the three-dimensional protein structure, and analyze the characteristics of gene mutations.Results:Among the 22 children with NF1, there were 14 males and 8 females, and they were aged from 3 months to 12 years at the clinic visit. All the 22 children presented with multiple café-au-lait spots, and their age at onset ranged from birth to 2 years. Nine patients were accompanied by freckles in the axillary or inguinal regions, 2 by cutaneous neurofibromas, 2 by juvenile xanthogranuloma, 2 by learning disabilities, and Lisch nodules of the iris, central precocious puberty and scoliosis occurred in 1 case each; 5 cases showed characteristic manifestations of neurofibroma on brain magnetic resonance imaging. A total of 5 types of NF1 gene variants were identified in the 22 patients, including complete heterozygous deletion of the NF1 gene (1 patient), missense variants (4 patients, one of whom carried 2 types of missense variants), frameshift variants (8 patients), nonsense variants (6 patients), and classical splicing variants (3 patients). Among the 22 variants, 7 were unreported variants, including c.758T>A (p.Val253Glu), c.2360dupC (p.Thr788Asnfs*5), c.5513T>G (p.Leu1838*), c.2774dupT (p.Leu925Phefs*11), c.6894dupT (p.Val2299Cysfs*7), c.6882_6883delCT (p.Phe2295Leufs*10), and c.6448A>T (p.Lys2150*). Of the unreported variants, 6 were frameshift or nonsense variants leading to different degrees of truncated protein expression, and severely affecting protein function; based on the three-dimensional protein structure prediction analysis, it was uncertain if the missense variant c.758T>A (p.Val253Glu) affected protein conformation. In 2 children, the NF1 variants were inherited from their mothers; 1 child carried 2 NF1 missense variants, 1 of which was a spontaneous mutation potentially causing the disease, while the other one with unknown pathogenicity was inherited from the phenotypically normal father; the remaining 19 children all carried spontaneous mutations.Conclusions:Children with NF1 mainly present with multiple café-au-lait spots at the early stage, and some characteristic manifestations such as cutaneous neurofibroma, juvenile xanthogranuloma, and Lisch nodules of the iris can also occur. NF1 gene pathogenic variants are complex and diverse, and 22 variants were identified in this study, enriching the spectrum of NF1 gene variants.

Objective:To analyze the clinical characteristics, muscle imaging and pathological features of patients with anti-signal recognition particle positive immune-mediated necrotizing myopathy (SRP-IMNM).Methods:Nine patients with SRP-IMNM were collected in the Neuromuscular Disease Center of Jiaozuo People′s Hospital from May 2018 to May 2023, who were confirmed by skeletal muscle pathology and myositis-specific autoantibodies detection, and their clinical manifestations, muscle imaging and muscle pathology characteristics were systematically summarized.Results:Among the 9 patients with SRP-IMNM, there were 7 females and 2 males. The age of onset ranged from 18 to 59 years. All the patients presented proximal muscle weakness. Seven patients experienced neck weakness, and dysphagia was present in 5 patients. Laboratory examinations showed elevated serum creatine kinase levels in all 9 patients (1 866-6 725 U/L). Eight patients were combined with other antibodies positivity, except for anti-SRP antibody. Among them, 7 patients were combined with anti-Ro-52 antibody positivity, 4 patients combined with anti-Ro-52 antibody positivity alone, and 3 patients combined with 3 or more positive antibodies simultaneously. Those patients who presented with interstitial lung disease and cardiac involvement were all combined with other antibodies positivity. Seven patients completed thigh muscle magnetic resonance imaging (MRI), which showed diffuse skeletal muscle oedema, partial muscle atrophy and fatty replacement, primarily affecting the posterior thigh muscle group. Two patients underwent shank muscle MRI. The soleus involvement was evident, while the tibialis anterior muscle and gastrocnemius muscles were involved in 1 patient. All 9 patients showed varying degrees of scattered muscle fiber necrosis and regeneration on muscle biopsies. In 1 patient, a small amount of inflammatory cell infiltration was observed. Pipestem capillaries were observed in 4 patients. Immunohistochemical staining revealed a small number of CD68-positive lymphocytes in 8 patients. Additionally, 5 patients showed upregulation of major histocompatibility complex Ⅰ expression on the muscle fiber membrane, while 6 patients showed deposition of membrane attack complex (C5b-9) on non-necrotic muscle fibers and capillaries. P62 staining showed homogeneous fine-granular in sarcoplasm in 6 patients.Conclusions:In addition to proximal muscle weakness, patients with SRP-IMNM often experience neck weakness and dysphagia. Those with multiple antibodies are more likely to develop interstitial lung disease and cardiac involvement. SRP-IMNM patients have diffuse oedema in the affected muscles, and the posterior thigh muscles are more prone to atrophy and fatty tissue formation. C5b-9 deposition and pipestem capillaries are significant pathological features of SRP-IMNM, which provide additional evidence for clinical diagnosis.