BACKGROUND: The primary limitation to kidney transplantation is organ shortage. Recent progress in gene editing and immunosuppressive regimens has made xenotransplantation with porcine organs a possibility. However, evidence in pig-to-human xenotransplantation remains scarce, and antibody-mediated rejection (AMR) is a major obstacle to clinical applications of xenotransplantation. METHODS: We conducted a kidney xenotransplantation in a brain-dead human recipient using a porcine kidney with five gene edits (5GE) on March 25, 2024 at Xijing Hospital, China. Clinical-grade immunosuppressive regimens were employed, and the observation period lasted 22 days. We collected and analyzed the xenograft function, ultrasound findings, sequential protocol biopsies, and immune surveillance of the recipient during the observation. RESULTS: The combination of 5GE in the porcine kidney and clinical-grade immunosuppressive regimens prevented hyperacute rejection. The xenograft kidney underwent delayed graft function in the first week, but urine output increased later and the single xenograft kidney maintained electrolyte and pH homeostasis from postoperative day (POD) 12 to 19. We observed AMR at 24 h post-transplantation, due to the presence of pre-existing anti-porcine antibodies and cytotoxicity before transplantation; this AMR persisted throughout the observation period. Plasma exchange and intravenous immunoglobulin treatment mitigated the AMR. We observed activation of latent porcine cytomegalovirus toward the end of the study, which might have contributed to coagulation disorder in the recipient. CONCLUSIONS 5GE and clinical-grade immunosuppressive regimens were sufficient to prevent hyperacute rejection during pig-to-human kidney xenotransplantation. Pre-existing anti-porcine antibodies predisposed the xenograft to AMR. Plasma exchange and intravenous immunoglobulin were safe and effective in the treatment of AMR after kidney xenotransplantation.
Transplantation, Heterologous/methods* ; Kidney Transplantation/methods* ; Heterografts/pathology* ; Immunoglobulins, Intravenous/administration & dosage* ; Graft Survival/immunology* ; Humans ; Animals ; Sus scrofa ; Graft Rejection/prevention & control* ; Kidney/pathology* ; Gene Editing ; Species Specificity ; Immunosuppression Therapy/methods* ; Plasma Exchange ; Brain Death ; Biopsy ; Male ; Aged

Humans ; Immunoglobulins, Intravenous/therapeutic use* ; Child ; Consensus ; Autoimmune Diseases of the Nervous System/drug therapy* ; Autoimmune Diseases/drug therapy* ; Nervous System Diseases/drug therapy*

To prepare antibodies that specifically recognize the conserved domain in the large extracellular loop of the CD63 protein, we expressed anti-CD63 single-chain variable fragment (scFv) antibody in Pichia pastoris in a secreted form. The purified expression product was found to bind specifically with CD63 protein and recognize CD63 on the surface of SK-MEL-28 cells. The variable region of the anti-CD63 monoclonal antibody in an anti-CD63-positive cell line was sequenced. The anti-CD63 scFv consisted of a variable heavy chain and a variable light chain linked by a flexible peptide was then designed. After codon optimization, the gene was synthesized and cloned into the expression plasmid pPICZα-A. The SacI-linearized plasmid was electroporated into P. pastoris X33, and 1% methanol were used to induce the expression of scFv. The fermentation supernatant was purified by Ni column. Anti-CD63 scFv was identified by SDS-PAGE and Western blotting, and its biological activities were analyzed by immunoblotting, immunofluorescence, cell-based ELISA, and flow cytometry. A P. pastoris strain capable of expressing and secreting anti-CD63 scFv was successfully obtained. The antibody had a molecular weight of approximately 30 kDa and specifically recognized CD63 protein. The expression of anti-CD63 scFv in P. pastoris paves the way for the production of anti-CD63 antibodies on a large-scale, which is undoubtedly an economical and effective way of antibody acquisition.
Single-Chain Antibodies/immunology* ; Humans ; Tetraspanin 30/immunology* ; Recombinant Proteins/immunology* ; Pichia/genetics* ; Saccharomycetales/metabolism*

This study is designed to address the development, synthesis, and screening of non-animal-derived nanoantibody libraries. Furthermore, it seeks to elucidate the impact of framework region selection and complementarity-determining region (CDR) design on the characteristics of synthesized nanoantibody libraries. These investigations aim to establish a robust theoretical and technical foundation for enhancing the efficacy, diversity, and practical applicability of synthetic nanoantibody libraries. In this study, a new framework (IGHV3S65*01-IGHJ4*01) was identified based on the high-throughput sequencing results of natural nanobodies, and degenerate primers were designed based on the frequency of amino acids at each position in the complementarity-determining region (CDR) region to synthesize the coding fragments of nanobodies by overlap PCR. After 40 times of electro-transformation, a single-frame synthesized nanobody library (SS-Library) containing 6×10⁹ clones was obtained, and the titer of the library was demonstrated to be 10¹³ PFU/mL after rescue by the helper phage M13K07. Random 48 single colonies were picked for PCR, which revealed an insertion rate of 95.8%. Sanger sequencing results showed that 38 clones had complete sequences, none of which showed cysteines or stop codons, and no identical sequences appeared, suggesting that the library had higher diversity. The library was screened and validated with three antigens, including bovine serum albumin (BSA), acetylcholinesterase (AchE), and immunoglobulin G (IgG). Finally, 2 nanobodies against BSA, 10 against AchE, and 15 against IgG were obtained. One positive clone of each antigen was singled out for recombinant expression, and the results showed that all the three nanobodies were expressed in a soluble form. The binding activity of recombinantly expressed nanobodies was evaluated using indirect enzyme-linked immunosorbent assay (ELISA) and bio-layer interferometry (BLI). The results demonstrated that the anti-AChE and anti-IgG nanobodies exhibited specific binding to their respective antigens, with affinity constants (KD) of 294 nmol/L and 250 nmol/L, respectively. The nanobody synthetic library preparation method proposed in this study is simple and easy to use with low preference, and it is expected to be a universal nanobody discovery platform for the preparation and development of lead specific nanobodies.
Single-Domain Antibodies/biosynthesis* ; Peptide Library ; Complementarity Determining Regions/immunology* ; Animals

INTRODUCTION: Acute severe ulcerative colitis (ASUC) is a significant cause of disease morbidity. One-third of patients with ASUC are steroid refractory. Rescue therapy may not successfully induce remission, necessitating colectomy. We aimed to identify predictors of rescue therapy and colectomy in ASUC assessed within 24 h of admission for early risk stratification. METHODS: We conducted a retrospective cohort study of 58 admissions for ASUC among 47 patients from August 2002 to January 2022. Serum biomarkers assessed were measured on admission. Primary outcomes were the need for rescue therapy during the same admission and colectomy within 1 year of admission. RESULTS: Rescue therapy (all with infliximab) was given in 20 (34.5%) of the admissions. Colectomy was done within 1 year for nine (15.5%) of the admissions. An elevated C-reactive protein (CRP) of >30 mg/L (relative risk [RR] 1.63), a CRP-albumin ratio of >0.85 (RR 1.63), and a composite factor of both CRP > 30 mg/L and age ≥60 years (RR 2.37) were significantly associated with the need for rescue therapy. Hypoalbuminaemia ≤ 25 g/L (RR 4.35) and the use of biologics at presentation (RR 1.54) were significantly associated with colectomy within 1 year of admission, while a CRP of ≥ 80 mg/L was a significant protective factor (RR 0.70). CONCLUSION Patients with ASUC who have elevated CRP or CRP-albumin ratio on admission should be considered at risk for steroid-refractory disease. Those with hypoalbuminaemia on admission and using biologics at presentation are more likely to require colectomy in the first year after admission for ASUC.
Humans ; Colitis, Ulcerative/therapy* ; Colectomy ; Retrospective Studies ; Male ; Female ; Middle Aged ; Adult ; C-Reactive Protein/metabolism* ; Infliximab/therapeutic use* ; Biomarkers/blood* ; Acute Disease ; Aged ; Severity of Illness Index ; Treatment Outcome

OBJECTIVE: To investigate the effectiveness of tibial transverse transport (TTT) in treating Wagner grade 3-4 type 2 diabetic foot ulcers and analyze dynamic changes in immunoglobulin levels. METHODS: The clinical data of 68 patients with Wagner grade 3-4 type 2 diabetic foot ulcers treated with TTT between May 2022 and September 2023 was retrospectively analyzed. The cohort included 49 males and 19 females, aged 44-91 years (mean, 67.3 years), with 40 Wagner grade 3 and 28 grade 4 ulcers. The duration of type 2 diabetes ranged from 5 to 23 years, with an average of 10 years. The number of wound healing cases, healing time, amputation cases, death cases, and complications were observed and recorded. Serum samples were collected at 6 key time points [1 day before TTT and 3 days, 7 days (the first day of upward transverse transfer), 14 days (the first day of downward transverse transfer), 21 days (the first day after the end of transfer), 36 days (the first day after the removal of the transfer device)], and the serum immunoglobulin levels were detected by flow cytometry including immunoglobulin G (IgG), IgA, IgM, IgE, complement C3 (C3), C4, immunoglobulin light chain κ (KAP), immunoglobulin light chain λ (LAM). RESULTS: All the 68 patients were followed up 6 months. Postoperative pin tract infection occurred in 3 cases and incision infection in 2 cases. Amputation occurred in 5 patients (7.4%) at 59-103 days after operation, and 8 patients (11.8%) died at 49-77 days after operation; the wounds of the remaining 55 patients (80.9%) healed in 48-135 days, with an average of 80 days. There was no recurrence of ulcer, peri-osteotomy fracture, or local skin necrosis during follow-up. The serum immunoglobulin levels of 55 patients with wound healing showed that the levels of IgG and IgM decreased significantly on the 3rd and 7th day after operation compared with those before operation ( P<0.05), and gradually returned to the levels before operation after 14 days, and reached the peak on the 36th day. IgA levels continued to decrease with time, and there were significant differences at all time points when compared with those before operation ( P<0.05). The level of IgE significantly decreased at 21 days after operation compared with that before operation ( P<0.05), while it was higher at other time points than that before operation, but the difference was not significant ( P>0.05). The level of C3 showed a clear treatment-related increase, which was significantly higher on the 7th, 14th, and 21st days after operation than that before operation ( P<0.05), and the peak appeared on the 14th day. The change trend of C4 level was basically synchronous with that of C3, but the amplitude was smaller, and the difference was significant at 7 and 14 days after operation compared with that before operation ( P<0.05). There was no significant difference in KAP/LAM between different time points before and after operation ( P>0.05). CONCLUSION TTT can accelerate wound healing, effectively treat diabetic foot ulcer, and reduce amputation rate, and has definite effectiveness. The potential mechanisms of TTT in the treatment of diabetic foot ulcers include the dynamic regulation of IgG, IgA, IgM, and IgE levels to balance the process of inflammation and repair, and the periodic increase of C3 and C4 levels may promote tissue cleaning, angiogenesis, and anti-infection defense.
Humans ; Male ; Female ; Middle Aged ; Aged ; Diabetic Foot/immunology* ; Wound Healing ; Adult ; Retrospective Studies ; Aged, 80 and over ; Treatment Outcome ; Tibia/transplantation* ; Diabetes Mellitus, Type 2/complications* ; Amputation, Surgical ; Immunoglobulins/blood* ; Immunoglobulin G/blood*

Objective To construct a library of human-derived anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) single-chain variable fragments (scFv) and screen for broad-spectrum neutralizing antibodies to identify candidate molecules for the development of diagnostic and therapeutic agents. Methods Peripheral blood mononuclear cells (PBMCs) were isolated from the peripheral blood of patients who had recovered from novel coronavirus infection. Total RNA was extracted from these PBMCs and reverse transcribed into cDNA, which was used as a template for constructing a human anti-SARS-CoV-2 scFv library. Phage display technology was used to screen for scFv antibodies specific to the SARS-CoV-2 S protein. Full-length IgG antibodies were synthesized through sequence analysis and human IgG expression, and their binding capacity and neutralizing activity against SARS-CoV-2 were evaluated. Results A human-derived scFv antibody library against SARS-CoV-2 with a capacity of 1.56×10⁷ CFU was successfully constructed. Two specific scFv antibodies were screened from this library and expressed as full-length IgG antibodies (IgG-A10 and IgG-G6). IgG-A10 exhibited strong neutralizing activity against both the original SARS-CoV-2 strain (WT) and the XBB subvariant of the Omicron variant. However, the neutralizing activity of this antibody against the JN.1 sub lineage of the Omicron BA.2.86 variant was moderate. Conclusion This study has successfully constructed a human anti-SARS-CoV-2 scFv antibody library from the peripheral blood of recovered patients, and screened and expressed anti-SARS-CoV-2 IgG antibodies with neutralizing activity, laying a foundation for the prevention, diagnosis, and treatment of SARS-CoV-2 infection.
Humans ; Single-Chain Antibodies/genetics* ; SARS-CoV-2/immunology* ; COVID-19/immunology* ; Immunoglobulin G/genetics* ; Antibodies, Viral/genetics* ; Peptide Library ; Spike Glycoprotein, Coronavirus/immunology* ; Antibodies, Neutralizing/immunology* ; Leukocytes, Mononuclear/immunology* ; Broadly Neutralizing Antibodies/immunology*

OBJECTIVES: To explore the predictive factors for non-response to intravenous immunoglobulin (IVIG) in children with Kawasaki disease (KD) and to establish an IVIG non-response prediction scoring model for the Sichuan region. METHODS: A retrospective study was conducted by collecting clinical data from children with KD admitted to four tertiary hospitals in Sichuan Province between 2019 and 2023. Among them, 940 children responded to IVIG, while 74 children did not respond. Multivariate logistic regression analysis was used to identify the predictive factors for non-response to IVIG and to establish a predictive scoring model. The model's effectiveness was assessed using the receiver operating characteristic curve (ROC) and validated with an independent dataset. RESULTS: Multivariate logistic regression analysis showed that the platelet-to-lymphocyte ratio (PLR), hemoglobin (Hb), serum creatinine, aspartate aminotransferase (AST), and platelet count (PLT) were closely related to non-response to IVIG in children with KD (P<0.05). Based on these indicators, a predictive scoring model was established: PLR > 199, 0.4 points; Hb ≤ 116 g/L, 4 points; AST > 58 U/L, 0.2 points; serum creatinine > 38 µmol/L, 3.9 points; PLT count ≤ 275 × 10⁹/L, 0.3 points. Using this model, children with KD were scored, and a total score greater than 4.3 was considered high risk of non-response to IVIG. The sensitivity of the model in predicting non-response to IVIG was 77.0%, specificity was 65.7%, and the area under the ROC curve was 0.746 (95%CI: 0.688-0.805). CONCLUSIONS The predictive scoring model based on PLR, Hb, serum creatinine, AST, and PLT demonstrates good predictive performance for non-response to IVIG in children with KD in the Sichuan region and can serve as a reference for clinical decision-making.
Humans ; Mucocutaneous Lymph Node Syndrome/blood* ; Immunoglobulins, Intravenous/therapeutic use* ; Male ; Female ; Retrospective Studies ; Child, Preschool ; Infant ; Logistic Models ; Child ; Platelet Count ; ROC Curve

OBJECTIVES: To study the impact of different induction remission therapies on the nutritional status of children with Crohn's disease (CD). METHODS: A retrospective analysis was conducted on the medical data of 188 children with CD who received induction remission therapy at the Children's Hospital, Zhejiang University School of Medicine from January 2013 to May 2023. The effects of three induction remission therapies-exclusive enteral nutrition (EEN), corticosteroids, and infliximab (IFX)-on height, weight, hemoglobin, and trace elements were compared. RESULTS: After induction remission therapy, the weight-for-age Z scores and serum levels of hemoglobin and albumin in all three groups significantly increased (P<0.05), while the height-for-age Z scores showed no change (P>0.05). The levels of folic acid, 25-hydroxy vitamin D, serum iron, and total calcium increased, and serum copper levels decreased in the EEN and IFX groups (P<0.05). Vitamin B₁₂ levels improved in the EEN group (P<0.05). CONCLUSIONS EEN, corticosteroids, and IFX may effectively improve the weight-for-age Z scores and serum levels of hemoglobin and albumin in children with CD. EEN and IFX seem to be superior to corticosteroid therapy in improving 25-hydroxy vitamin D, folic acid, serum iron, and total calcium levels.
Humans ; Crohn Disease/blood* ; Child ; Male ; Female ; Retrospective Studies ; Adolescent ; Nutritional Status ; Infliximab/therapeutic use* ; Child, Preschool ; Enteral Nutrition ; Adrenal Cortex Hormones/therapeutic use*

OBJECTIVES: To investigate the clinical efficacy and safety of low-dose rituximab (RTX) (<375 mg/m²) maintenance therapy in children with primary nephrotic syndrome (PNS). METHODS: A retrospective analysis was conducted on the clinical data of PNS children who received low-dose RTX therapy at the Department of Renal Immunology, Children's Hospital of Soochow University from July 2016 to March 2024. Remission rate, recurrence frequency, corticosteroid and tacrolimus usage, and adverse reactions before and after RTX treatment were analyzed. RESULTS: Compared with before treatment, low-dose RTX maintained remission in PNS, reduced the relapse frequency, and decreased the dosage of corticosteroids and tacrolimus (P<0.05). IgG levels did not significantly decrease, and no additional preventive anti-infective treatment was required. CONCLUSIONS Low-dose RTX therapy is effective and safe for treating PNS in children.
Humans ; Nephrotic Syndrome/drug therapy* ; Rituximab/adverse effects* ; Male ; Female ; Child ; Retrospective Studies ; Child, Preschool ; Adolescent ; Infant