Background::Growth retardation is a common complication of chronic kidney disease in children, which can be partially relieved after renal transplantation. This study aimed to develop and validate a predictive model for growth patterns of children with end-stage renal disease (ESRD) after kidney transplantation using machine learning algorithms based on genomic and clinical variables.Methods::A retrospective cohort of 110 children who received kidney transplants between May 2013 and September 2021 at the First Affiliated Hospital of Zhengzhou University were recruited for whole-exome sequencing (WES), and another 39 children who underwent transplant from October 2021 to March 2022 were enrolled for external validation. Based on previous studies, we comprehensively collected 729 height-related single-nucleotide polymorphisms (SNPs) in exon regions. Seven machine learning algorithms and 10-fold cross-validation analysis were employed for model construction.Results::The 110 children were divided into two groups according to change in height-for-age Z-score. After univariate analysis, age and 19 SNPs were incorporated into the model and validated. The random forest model showed the best prediction efficacy with an accuracy of 0.8125 and an area under curve (AUC) of 0.924, and also performed well in the external validation cohort (accuracy, 0.7949; AUC, 0.796). Conclusions::A model with good performance for predicting post-transplant growth patterns in children based on SNPs and clinical variables was constructed and validated using machine learning algorithms. The model is expected to guide clinicians in the management of children after renal transplantation, including the use of growth hormone, glucocorticoid withdrawal, and nutritional supplementation, to alleviate growth retardation in children with ESRD.

Objective:To explore the clinical characteristics of pediatric kidney transplant recipients reinfected with SARS-CoV-2.Method:The relevant clinical data were retrospectively reviewed for 191 pediatric kidney transplant recipients at a single center. Based upon whether or not there was a reinfection of SARS-CoV-2, they were assigned into two groups of single infection (group A, 127 cases) and reinfection (group B, 64 cases). Baseline profiles, clinical symptoms, diagnostic and therapeutic strategies, markers of disease progression, immune status, respiratory support modalities, comorbidities and transplantation-related data were collected for comparing the inter-group differences during primary infection and between two infections in reinfected group.Result:As compared with group A, group B recipients had a higher proportion of age <12 years (71.9% vs 54.3%) ,unvaccinated (81.2% vs 66.1%) and such symptoms as high fever (34.4% vs 12.6% ), dry cough (43.8% vs 23.6% ) and chest tightness (14.1% vs 3.9 %) during primary infection (all P<0.05). During primary infection, the levels of IL-6 and CRP were higher in group B than in group A and inter-group difference was statistically significant (both P<0.01). The levels of IL-6 ( P<0.01), CRP ( P<0.01) and PCT ( P= 0.023) were lower in group B during reinfection than those during primary infection and the difference was statistically significant. During primary infection, the counts of CD3+, CD4+, CD8+, NK and B lymphocyte of group B were lower than those of group A. And inter-group differences were statistically significant (all P<0.01). During reinfection, the levels of CD3+, CD4+, CD8+, NK and B lymphocyte counts of group B spiked as compared with those of group A during primary infection and the differences were statistically significant (all P<0.01). The levels of SCr and UA in group B differed insignificantly before and after primary infection with SARS-CoV-2. However, the differences before and after reinfection were statistically significant (both P<0.01) . Conclusion:Symptomatic and immunocompromised pediatric KT recipients during primary infection with SARS-CoV-2 are more prone to reinfection during subsequent epidemics. Though mildly symptomatic, reinfection may exacerbate impairments of graft kidney function in pediatric KT recipients.

Objective:To explore the characteristic pathological manifestations of non-HLA antibodies after kidney transplantation (KT) and examine the differences of MFT values of non-HLA antibodies in different pathological manifestations.Methods:The study was conducted on KT recipients at the First Affiliated Hospital of Zhengzhou University from February 2021 to June 2023 with unexplained elevated serum creatinine. Patients undergoing pathological puncture and concurrent HLA antibody testing were included, focusing on those with DSA (MFI>4 000) and non-HLA antibody negativity. According to the detection results of non-HLA and HLA antibodies, they were assigned into two groups of non-HLA antibody positive (45 cases) and HLA-DSA positive (28 cases). Both non-HLA and HLA antibodies were detected by luminex single antigen microbeads, χ2, t or Mann-Whitney U nonparametric tests were utilized for examining the inter-group differences in pathological manifestations. The recipients with positive non-HLA antibodies were grouped according to the differential pathological features[microvascular inflammation group (22 cases) and non-microvascular inflammation group (23 cases), interstitial fibrosis group (39 cases) and non-interstitial fibrosis (9 cases) ]. MFI values of non-HLA antibodies were standardized and heat map was generated with R language ComplexHeatmap package. The differences of response values of non-HLA antibodies with different pathological manifestations were examined by rank-sum test. Results:The positive rates of microvascular inflammation were 48.9% (22/45) and 82.1% (23/28) in HLA-DSA positive and non-HLA antibody positive groups with statistical significance ( χ2=8.073, P=0.006). The positive rates of interstitial fibrosis in two groups were 80.8% (36/45) and 53.6% (15/28) and the difference was statistically significant ( χ2=5.726, P=0.021). The relative levels of anti-arachnotoxin receptor 1 (Latrophilin 1, LPHN1), keratin 8 (KRT8), keratin 18 (KRT18) and Sjogren's syndrome antigen B (SSB) were higher in microvascular inflammation group than those in non-microvascular inflammation group. The differences were statistically significant [559.50 (262.00, 801.25) vs 285.00 (183.00, 460.00), P=0.024; 504.50 (369.5, 725.25) vs 317.00 (231.50, 458.00), P=0.014; 672.50 (454.50, 969.50) vs 399.00 (246.50, 772.50), P=0.030; 967.50 (482.00, 2 066.50) vs 399.00 (246.50, 772.50), P=0.033]. The relative levels of anti-cyclic citrullinate peptide (CCP), colony-stimulating factor 2 (CSF2), intercellular adhesion molecule 1 (ICAM1) and collagen Ⅳ antibody were higher in interstitial fibrosis group than those in non-interstitial fibrosis group with statistical significance [100.00 (79.88, 167.50) vs 64.50 (37.00, 89.00), P=0.016; 146.25 (93.38, 244.75) vs 87.00 (66.00, 105.00), P=0.041; 132.50 (106.38, 229.50) vs 95.00 (55.00, 125.00), P=0.037; 432.50 (280.75, 653.75) vs 208.00 (192.00, 301.00), P=0.028]. Conclusions:As compared with HLA-DSA, the characteristic pathological manifestations of non-HLA antibodies post-KT include a lower incidence of microvascular inflammation and a higher incidence of interstitial fibrosis. For non-HLA antibody response values of characteristic pathological manifestations, the expressions of different non-HLA antibodies vary statistically.