PURPOSE: To investigate the protective effect of sub-hypothermic mechanical perfusion combined with membrane lung oxygenation on ischemic hypoxic injury of yorkshire brain tissue caused by traumatic blood loss. METHODS: This article performed a random controlled trial. Brain tissue of 7 yorkshire was selected and divided into the sub-low temperature anterograde machine perfusion group (n = 4) and the blank control group (n = 3) using the random number table method. A yorkshire model of brain tissue injury induced by traumatic blood loss was established. Firstly, the perfusion temperature and blood oxygen saturation were monitored in real-time during the perfusion process. The number of red blood cells, hemoglobin content, NA⁺, K⁺, and Ca²⁺ ions concentrations and pH of the perfusate were detected. Following perfusion, we specifically examined the parietal lobe to assess its water content. The prefrontal cortex and hippocampus were then dissected for histological evaluation, allowing us to investigate potential regional differences in tissue injury. The blank control group was sampled directly before perfusion. All statistical analyses and graphs were performed using GraphPad Prism 8.0 Student t-test. All tests were two-sided, and p value of less than 0.05 was considered to indicate statistical significance. RESULTS: The contents of red blood cells and hemoglobin during perfusion were maintained at normal levels but more red blood cells were destroyed 3 h after the perfusion. The blood oxygen saturation of the perfusion group was maintained at 95% - 98%. NA⁺ and K⁺ concentrations were normal most of the time during perfusion but increased significantly at about 4 h. The Ca²⁺ concentration remained within the normal range at each period. Glucose levels were slightly higher than the baseline level. The pH of the perfusion solution was slightly lower at the beginning of perfusion, and then gradually increased to the normal level. The water content of brain tissue in the sub-low and docile perfusion group was 78.95% ± 0.39%, which was significantly higher than that in the control group (75.27% ± 0.55%, t = 10.49, p < 0.001), and the difference was statistically significant. Compared with the blank control group, the structure and morphology of pyramidal neurons in the prefrontal cortex and CA1 region of the hippocampal gyrus were similar, and their integrity was better. The structural integrity of granulosa neurons was destroyed and cell edema increased in the perfusion group compared with the blank control group. Immunofluorescence staining for glail fibrillary acidic protein and Iba1, markers of glial cells, revealed well-preserved cell structures in the perfusion group. While there were indications of abnormal cellular activity, the analysis showed no significant difference in axon thickness or integrity compared to the 1-h blank control group. CONCLUSIONS Mild hypothermic machine perfusion can improve ischemia and hypoxia injury of yorkshire brain tissue caused by traumatic blood loss and delay the necrosis and apoptosis of yorkshire brain tissue by continuous oxygen supply, maintaining ion homeostasis and reducing tissue metabolism level.
Animals ; Perfusion/methods* ; Disease Models, Animal ; Brain Injuries/etiology* ; Swine ; Male ; Hypothermia, Induced/methods*

Gene regulation relies on the precise binding of transcription factors (TFs) at regulatory elements, but simultaneously detecting hundreds of TFs on chromatin is challenging. We developed cFOOT-seq, a cytosine deaminase-based TF footprinting assay, for high-resolution, quantitative genome-wide assessment of TF binding in both open and closed chromatin regions, even with small cell numbers. By utilizing the dsDNA deaminase SsdAtox, cFOOT-seq converts accessible cytosines to uracil while preserving genomic integrity, making it compatible with techniques like ATAC-seq for sensitive and cost-effective detection of TF occupancy at the single-molecule and single-cell level. Our approach enables the delineation of TF footprints, quantification of occupancy, and examination of chromatin influences on TF binding. Notably, cFOOT-seq, combined with FootTrack analysis, enables de novo prediction of TF binding sites and tracking of TF occupancy dynamics. We demonstrate its application in capturing cell type-specific TFs, analyzing TF dynamics during reprogramming, and revealing TF dependencies on chromatin remodelers. Overall, cFOOT-seq represents a robust approach for investigating the genome-wide dynamics of TF occupancy and elucidating the cis-regulatory architecture underlying gene regulation.
Transcription Factors/genetics* ; Humans ; Chromatin/genetics* ; Animals ; Binding Sites ; Mice ; DNA Footprinting/methods*

Objective:To compare the protective effects of the static cold storage (SCS) and normothermic machine perfusion (NMP) on the skeletal muscle of the amputated limbs of pigs.Methods:Four Landrace pigs were selected, from which eight limbs were amputated and divided into SCS group ( n=5) and NMP group ( n=3) according to the random number table method. After blood collection from the carotid artery, an amputated limb model was established by amputating the limbs at the scapulohumeral joints. The limbs in the SCS group were wrapped in sterile cloth and stored at 4 ℃ for 24 hours. In the NMP group, the limbs were mechanically perfused with a red blood cell-containing perfusion fluid at 37 ℃ for 24 hours, with 70% of the perfusion fluid replaced every 6 hours. Before the experiment, cross-matching tests with the saline medium were conducted between donor and recipient pigs to evaluate blood coagulation and blood safety in the NMP group. An allogeneic red blood cell perfusion fluid was prepared and the levels of pH, Na +, K +, Cl -, Ca 2+, glucose (Glu), hematocrit (Hct), lactic acid (Lac) and osmotic pressure of the perfusion fluid were measured. At 0, 6, 12, 18, and 24 hours after perfusion, the skin temperature and oxyhemoglobin saturation (SaO 2) levels in the NMP group were monitored and the levels of pH, Glu, creatine kinase (Ck), K +, Ca 2+, and Na +levels of the perfusion fluid were analyzed to evaluate the metabolism of the skeletal muscle in the amputated limbs. The mean intercellular distance and apoptosis index of the myocytes were quantitatively analyzed and histopathological changes were observed by performing HE staining and TUNEL staining on the skeletal muscle of the amputated limbs in both groups at 0 and 24 hours after perfusion. After perfusion was ended, the weight gain rate and swelling degree of the amputated limbs were compared between the two groups and the overall state of the amputated limbs was evaluated. Results:The result of the cross-matching test between donor and recipient pig blood was negative. The parameters in the prepared red blood cell-containing perfusion fluid generally maintained within a normal range: pH 7.38±0.04, Na + concentration (138.30±4.48)mmol/L, K + concentration (3.50±0.26)mmol/L, Glu concentration (6.11±2.08)mmol/L, and osmotic pressure (305.67±3.79)mmol/L. However, slightly higher Cl - and Ca 2+ concentrations [(118.34±12.00)mmol/L and (2.00±0.15)mmol/L] and lower Hct and lactate concentrations [0.30±0.03 and (1.54±0.38)mmol/L] were detected when compared with the reference range. During the perfusion, the average skin temperature of the amputated limbs in the NMP group was (36.13±0.98)℃, with the skin temperatures at 6, 12, 18, and 24 hours after perfusion being significantly higher than that at 0 hour ( P<0.01), while no significant difference among the skin temperatures at 6, 12, 18, and 24 hours after perfusion was observed ( P>0.05). The SaO 2 levels in the skin of the amputated limbs in the NMP group averaged over 95%, which showed no significant difference at 0, 12, 18, and 24 hours after perfusion ( P>0.05), while a significant elevation was observed at 6 hours compared with that at 0 hour ( P<0.05). There were no significant differences in pH, Glu, Na +, and Ca 2+ levels in the NMP group at 0, 6, 12, 18, and 24 hours after perfusion ( P>0.05), while the Ck levels at 18 and 24 hours were both significantly higher than that at 6 hours after perfusion ( P<0.05), and the Ck levels at 6, 12, 18, and 24 hours were all significantly higher than that at 0 hour ( P<0.05). The K + level progressively increased with the perfusion time, with significant elevations at 18 and 24 hours after perfusion compared with that at 0 hour ( P<0.05). HE staining revealed well-preserved muscle fiber continuity and regular arrangement in the NMP group and the SCS group at 0 hour, with an intercellular distance of (8.95±0.60)μm. At 24 hours, the NMP group exhibited slight skeletal muscle fiber rupture and swelling, with a slightly increased intercellular distance of (14.75±0.90)μm, significantly greater than that at 0 hour ( P<0.01). At 24 hours, the SCS group showed marked skeletal muscle fiber rupture and swelling, with a significantly increased intercellular distance of (23.51±1.49)μm, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). TUNEL immunofluorescence staining indicated a tiny amount of apoptotic cells in the skeletal muscle in both groups at 0 hour, with an apoptotic index of (4.26±1.62)%. There was a small number of apoptotic cells in the skeletal muscle in the NMP group at 24 hours, with an apoptotic index of (25.94±2.69)%, significantly larger than that in the same group at 0 hour ( P<0.01). The SCS group exhibited a large number of apoptotic cells at 24 hours, with an apoptotic index of (62.97±3.22)%, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). In comparison with the SCS group at 24 hours, the amputated limbs in the NMP group showed red color in the appearance, no symptoms of ischemic muscle contracture and good joint movement despite slight edema in the subcutaneous layer. At 24 hours, the weight gain rate of the amputated limbs was (15.82±0.89)% in the NMP group, significantly higher than (0.97±0.28)% in the SCS group ( P<0.01). Conclusion:Compared with SCS, NMP with the red blood cell-containing perfusion fluid prepared with the allogeneic blood for the amputated limbs of pigs can alleviate the ischemic injury of the muscle fibers and inhibit the apoptosis of the muscle cells by sustaining stable energy and oxygen supply and balancing ion homeostasis and pH of the perfusion fluid.

Objective:To observe the efficacy of eculizumab in children with atypical hemolytic uremic syndrome.Methods:It was a single-center observational study. The clinical data of children diagnosed with atypical hemolytic uremic syndrome and treated with eculizumab in Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2023 to May 2024 were retrospectively collected. Eculizumab was used at the conventional dose based on the children 's weight. Event-free survival (no death or end-stage renal disease) rate, complete remission rate and recurrence rate of thrombotic microangiopathy in children with atypical hemolytic uremic syndrome after eculizumab treatment were analyzed. The complete remission time of estimated glomerular filtration rate, hemoglobin, platelet, lactic dehydrogenase, urine routine and the adverse reactions during the treatment were observed. Whole exome sequencing was used to conduct genetic testing based on blood samples of the children and their parents.Results:There were 4 children enrolled in the study. Four children were all Han Chinese, including 3 males and 1 female. The median age of onset was 8 years (ranging from 7 to 10 years). Two patients had complement gene abnormalities, both of which were homozygous deletions of complement factor H-related 1 and complement factor H-related 3. All the patients were free of plasma exchange or perfusion after treatment with eculizumab, and the 6-month event-free survival rate and thrombotic microangiopathy complete remission rate were both 4/4. The complete remission time was 19 (14-28) days. The time for the complete recovery of platelets, lactate dehydrogenase, estimated glomerular filtration rate and hemoglobin in 4 children was 4 (1-5), 19 (14-28), 10 (5-14) and 29 (20-42) days, respectively. Except for 1 patient whose urine routine fluctuated between negative and weakly positive expression, the other 3 patients had normal urine routine. All the patients discontinued eculizumab. Two patients without gene mutations discontinued eculizumab after 7 doses, and there was no recurrence during the 1-year follow-up after drug withdrawal. Two patients with genetic abnormalities discontinued eculizumab after 26 weeks of treatment, and no recurrence was found during the 3-month follow-up after drug withdrawal. One patient developed rash approximately 7 days after receiving the third dose of eculizumab. The rash was relieved after anti-allergic treatment, and there was no recurrence after the continued use of eculizumab.Conclusion:Eculizumab is effective and safe in the treatment of children with atypical hemolytic uremic syndrome. Discontinuation of eculizumab can be considered in patients without gene mutations when their condition is stable, but close monitoring and follow-up are needed after drug withdrawal.

As a cheap and effective antibiotic,sulfonamides are often used in animal husbandry.However,their residues in animal-derived foodstuffs will threaten human health.Consequently,a high-performance liquid chromatography(HPLC)method integrated with supramolecular solvent microextraction was successfully established for simultaneous quantification of sulfonamide residues sulfachlorpyridazine,sulfamethoxazole,sulfamethoxypyridazine and sulfadimethoxine in milk matrices.This approach exhibited prominent characteristics of operational simplicity,environmental sustainability,and high extraction efficiency.The supramolecular solvents prepared by tributyl octylphosphine tetrafluoroborate and tetrahydrofuran were employed as extraction solvents.The analytes underwent isolation and concentration via dispersive liquid-liquid microextraction(DLLME)prior to quantitative determination using high-performance liquid chromatography(HPLC).The composition and microscopic morphology of the supramolecular solvent were characterized through a series of analytical techniques,including phase diagram,Fourier transform infrared spectroscopy,scanning electron microscopy,and inverted fluorescence microscopy and so on.The density and pH value of supramolecular solvents were determined.The extraction conditions were optimized through the one-factor experiments.The experimental results demonstrated that under the optimal extraction conditions,the four kinds of sulfonamide antibiotics exhibited excellent linearity within respective detection range(R2 ≥ 0.9998)and the limits of detection(LOD)were 0.67-1.45 μg/L.Compared with literature methods,this approach offered some advantages such as simplicity of operation and less reagent consumption,and could be used for analysis and detection of sulfonamide antibiotic residues in milk samples.The present method provided technical support for food safety regulation and paved a new way for the application of supramolecular solvents in the field of extraction and separation.

Objective:To explore the effects of Qingre Qudu Decoction for fumigation combined with three-gap drainage on wound healing and serum inflammatory factors in patients with acute perianal abscess.Methods:Randomized controlled trial was conducted. A total of 117 patients with acute perianal abscess in the hospital were enrolled as the observation objects between August 2022 and May 2024. According to random number table method, they were divided into observation group (59 cases) and control group (58 cases). Both groups received three-gap drainage therapy. On basis of three-gap drainage, control group was given potassium permanganate, while observation group was given Qingre Qudu Decoction for fumigation. All patients were treated for 14 d. The growth of granulation tissue and wound secretions before and after treatment was evaluated. VAS scale was used to evaluate the degree of incision pain, and Wexner score was used to assess incontinence; ELISA was used to detect serum activator A (ACTA), immunoturbidimetry was used to detect serum CRP, and radioimmunoassay was used to detect serum IL-6 levels. The occurrence of complications and abscess recurrence during treatment was recorded, and clinical efficacy was evaluated.Results:The total effective rate of the observation group was 96.61% (57/59), while that of the control group was 82.76% (48/58), with statistical significance ( χ2=6.10, P=0.014). After treatment, scores of granulation tissue growth and wound secretions in observation group, and scores of VAS and Wexner incontinence in observation group were lower than those in the control group ( t=9.66, 5.00, 7.98, 3.65, P<0.001), and wound healing time was shorter than that in control group ( t=8.41, P<0.001). After treatment, levels of serum ACTA, CRP and IL-6 in observation group were lower than those in control group ( t=15.30, 2.08, 19.34, P<0.01 or P<0.05). The incidence of postoperative complications in the observation group was 6.78% (4/59), while in the control group it was 27.59% (16/58), with statistical significance ( χ2=8.93, P=0.003). Conclusion:Qingre Qudu Decoction for fumigation combined with three-gap drainage can relieve postoperative incision pain, inhibit inflammatory response, accelerate the recovery of wound and promote the recovery of anal function and improve clinical efficacy.

OBJECTIVE: To evaluate the clinical significance of a hemizygous c.1042-10G>C variant of the SLC9A7 gene NM_001257291.2) previously identified in individuals with neurodevelopmental disorders, and to provide an evidence-based guidance for prenatal genetic counseling. METHODS: Four families presented at the Medical Genetics Center of Henan Provincial People's Hospital between December 2022 and July 2024 were included in this study. Phenotypic information and biological samples were collected from family members. Genomic DNA was extracted and subjected to whole-exome sequencing and copy number variation analysis to identify candidate pathogenic variants. Sanger sequencing was performed for familial co-segregation analysis. Reverse-transcription PCR was used to assess the RNA splicing pattern of the variant in peripheral blood samples. Quantitative PCR was employed to analyze the expression profiles of various SLC9A7 transcripts in fetal brain tissue and peripheral blood samples. Pathogenicity of the variant was classified based on guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of Henan Provincial People's Hospital (Ethics No.: 2021-171). RESULTS: Six hemizygous males carrying the SLC9A7 c.1042-10G>C variant were identified among the four families, which included three adult males and two male infants with normal phenotypes. Only one affected male from family 3 exhibited global developmental delay, short neck, webbed neck, ocular dysplasia, and congenital corneal leukoma. He also had a history of perinatal asphyxia and carried an additional hemizygous variant HUWE1 c.12283C>G. Reverse-transcription PCR showed no aberrant splicing in heterozygous or hemizygous carriers compared to healthy controls, suggesting that the variant does not affect RNA splicing. Quantitative PCR revealed that NM_001257291.2 is the predominant transcript expressed in fetal brain tissue and peripheral blood. CONCLUSION The SLC9A7 c.1042-10G>C variant does not alter RNA splicing and is present in multiple phenotypically normal males, which supported its classification as a benign variant.
Humans ; Male ; Female ; Genetic Counseling ; Pedigree ; Adult ; DNA Copy Number Variations/genetics* ; Sodium-Hydrogen Exchangers/genetics* ; Exome Sequencing

OBJECTIVE: To investigate the clinical phenotype and genetic characteristics of an infertile woman carrying a novel PADI6 gene variant. METHODS: An infertile woman who visited the Medical Genetics Center of Henan Provincial People's Hospital on April 29, 2024 was selected as the study subject. Clinical data of the proband and her family members were collected. Peripheral blood samples were obtained from the proband and her husband for genomic DNA extraction. Whole-exome sequencing (WES) was performed. Candidate variant was verified among the family members by Sanger sequencing. The pathogenicity of candidate variant was classified according to the American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines for the Interpretation of Sequence Variants. Relevant literature on the pathogenic variants of the PADI6 gene was reviewed for genotype-phenotype correlation analysis. This study was approved by the Medical Ethics Committee of Henan Provincial People's Hospital (Ethics No.: 2021-171). RESULTS: The proband was a 35-year-old woman who underwent two oocyte retrieval cycles, yielding a total of five oocytes, with all embryos arrested at day 3 post-fertilization. WES identified a homozygous PADI6 variant, c.367+4_367+7del. In vitro splicing assay confirmed that this variant can cause skipping of exon 3, leading to a frameshift and alterations in the protein structure or premature termination of translation. Literature review identified 12 relevant publications, and the PADI6 c.367+4_367+7del was determined to be a novel variant. CONCLUSION The homozygous PADI6 c.367+4_367+7del variant probably underlay the pathogenesis of infertility in the proband.
Humans ; Female ; Infertility, Female/genetics* ; Adult ; Protein-Arginine Deiminase Type 6/genetics* ; Pedigree ; Exome Sequencing ; Mutation

Objective:To compare the protective effects of the static cold storage (SCS) and normothermic machine perfusion (NMP) on the skeletal muscle of the amputated limbs of pigs.Methods:Four Landrace pigs were selected, from which eight limbs were amputated and divided into SCS group ( n=5) and NMP group ( n=3) according to the random number table method. After blood collection from the carotid artery, an amputated limb model was established by amputating the limbs at the scapulohumeral joints. The limbs in the SCS group were wrapped in sterile cloth and stored at 4 ℃ for 24 hours. In the NMP group, the limbs were mechanically perfused with a red blood cell-containing perfusion fluid at 37 ℃ for 24 hours, with 70% of the perfusion fluid replaced every 6 hours. Before the experiment, cross-matching tests with the saline medium were conducted between donor and recipient pigs to evaluate blood coagulation and blood safety in the NMP group. An allogeneic red blood cell perfusion fluid was prepared and the levels of pH, Na +, K +, Cl -, Ca 2+, glucose (Glu), hematocrit (Hct), lactic acid (Lac) and osmotic pressure of the perfusion fluid were measured. At 0, 6, 12, 18, and 24 hours after perfusion, the skin temperature and oxyhemoglobin saturation (SaO 2) levels in the NMP group were monitored and the levels of pH, Glu, creatine kinase (Ck), K +, Ca 2+, and Na +levels of the perfusion fluid were analyzed to evaluate the metabolism of the skeletal muscle in the amputated limbs. The mean intercellular distance and apoptosis index of the myocytes were quantitatively analyzed and histopathological changes were observed by performing HE staining and TUNEL staining on the skeletal muscle of the amputated limbs in both groups at 0 and 24 hours after perfusion. After perfusion was ended, the weight gain rate and swelling degree of the amputated limbs were compared between the two groups and the overall state of the amputated limbs was evaluated. Results:The result of the cross-matching test between donor and recipient pig blood was negative. The parameters in the prepared red blood cell-containing perfusion fluid generally maintained within a normal range: pH 7.38±0.04, Na + concentration (138.30±4.48)mmol/L, K + concentration (3.50±0.26)mmol/L, Glu concentration (6.11±2.08)mmol/L, and osmotic pressure (305.67±3.79)mmol/L. However, slightly higher Cl - and Ca 2+ concentrations [(118.34±12.00)mmol/L and (2.00±0.15)mmol/L] and lower Hct and lactate concentrations [0.30±0.03 and (1.54±0.38)mmol/L] were detected when compared with the reference range. During the perfusion, the average skin temperature of the amputated limbs in the NMP group was (36.13±0.98)℃, with the skin temperatures at 6, 12, 18, and 24 hours after perfusion being significantly higher than that at 0 hour ( P<0.01), while no significant difference among the skin temperatures at 6, 12, 18, and 24 hours after perfusion was observed ( P>0.05). The SaO 2 levels in the skin of the amputated limbs in the NMP group averaged over 95%, which showed no significant difference at 0, 12, 18, and 24 hours after perfusion ( P>0.05), while a significant elevation was observed at 6 hours compared with that at 0 hour ( P<0.05). There were no significant differences in pH, Glu, Na +, and Ca 2+ levels in the NMP group at 0, 6, 12, 18, and 24 hours after perfusion ( P>0.05), while the Ck levels at 18 and 24 hours were both significantly higher than that at 6 hours after perfusion ( P<0.05), and the Ck levels at 6, 12, 18, and 24 hours were all significantly higher than that at 0 hour ( P<0.05). The K + level progressively increased with the perfusion time, with significant elevations at 18 and 24 hours after perfusion compared with that at 0 hour ( P<0.05). HE staining revealed well-preserved muscle fiber continuity and regular arrangement in the NMP group and the SCS group at 0 hour, with an intercellular distance of (8.95±0.60)μm. At 24 hours, the NMP group exhibited slight skeletal muscle fiber rupture and swelling, with a slightly increased intercellular distance of (14.75±0.90)μm, significantly greater than that at 0 hour ( P<0.01). At 24 hours, the SCS group showed marked skeletal muscle fiber rupture and swelling, with a significantly increased intercellular distance of (23.51±1.49)μm, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). TUNEL immunofluorescence staining indicated a tiny amount of apoptotic cells in the skeletal muscle in both groups at 0 hour, with an apoptotic index of (4.26±1.62)%. There was a small number of apoptotic cells in the skeletal muscle in the NMP group at 24 hours, with an apoptotic index of (25.94±2.69)%, significantly larger than that in the same group at 0 hour ( P<0.01). The SCS group exhibited a large number of apoptotic cells at 24 hours, with an apoptotic index of (62.97±3.22)%, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). In comparison with the SCS group at 24 hours, the amputated limbs in the NMP group showed red color in the appearance, no symptoms of ischemic muscle contracture and good joint movement despite slight edema in the subcutaneous layer. At 24 hours, the weight gain rate of the amputated limbs was (15.82±0.89)% in the NMP group, significantly higher than (0.97±0.28)% in the SCS group ( P<0.01). Conclusion:Compared with SCS, NMP with the red blood cell-containing perfusion fluid prepared with the allogeneic blood for the amputated limbs of pigs can alleviate the ischemic injury of the muscle fibers and inhibit the apoptosis of the muscle cells by sustaining stable energy and oxygen supply and balancing ion homeostasis and pH of the perfusion fluid.

Objective:To observe the efficacy of eculizumab in children with atypical hemolytic uremic syndrome.Methods:It was a single-center observational study. The clinical data of children diagnosed with atypical hemolytic uremic syndrome and treated with eculizumab in Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2023 to May 2024 were retrospectively collected. Eculizumab was used at the conventional dose based on the children 's weight. Event-free survival (no death or end-stage renal disease) rate, complete remission rate and recurrence rate of thrombotic microangiopathy in children with atypical hemolytic uremic syndrome after eculizumab treatment were analyzed. The complete remission time of estimated glomerular filtration rate, hemoglobin, platelet, lactic dehydrogenase, urine routine and the adverse reactions during the treatment were observed. Whole exome sequencing was used to conduct genetic testing based on blood samples of the children and their parents.Results:There were 4 children enrolled in the study. Four children were all Han Chinese, including 3 males and 1 female. The median age of onset was 8 years (ranging from 7 to 10 years). Two patients had complement gene abnormalities, both of which were homozygous deletions of complement factor H-related 1 and complement factor H-related 3. All the patients were free of plasma exchange or perfusion after treatment with eculizumab, and the 6-month event-free survival rate and thrombotic microangiopathy complete remission rate were both 4/4. The complete remission time was 19 (14-28) days. The time for the complete recovery of platelets, lactate dehydrogenase, estimated glomerular filtration rate and hemoglobin in 4 children was 4 (1-5), 19 (14-28), 10 (5-14) and 29 (20-42) days, respectively. Except for 1 patient whose urine routine fluctuated between negative and weakly positive expression, the other 3 patients had normal urine routine. All the patients discontinued eculizumab. Two patients without gene mutations discontinued eculizumab after 7 doses, and there was no recurrence during the 1-year follow-up after drug withdrawal. Two patients with genetic abnormalities discontinued eculizumab after 26 weeks of treatment, and no recurrence was found during the 3-month follow-up after drug withdrawal. One patient developed rash approximately 7 days after receiving the third dose of eculizumab. The rash was relieved after anti-allergic treatment, and there was no recurrence after the continued use of eculizumab.Conclusion:Eculizumab is effective and safe in the treatment of children with atypical hemolytic uremic syndrome. Discontinuation of eculizumab can be considered in patients without gene mutations when their condition is stable, but close monitoring and follow-up are needed after drug withdrawal.