Transplantation of chemically induced pluripotent stem-cell-derived islets under abdominal anterior rectus sheath in a type 1 diabetes patient.

We report the 1-year results from one patient as the preliminary analysis of a first-in-human phase I clinical trial (ChiCTR2300072200) assessing the feasibility of autologous transplantation of chemically induced pluripotent stem-cell-derived islets (CiPSC islets) beneath the abdominal anterior rectus sheath for type 1 diabetes treatment. The patient achieved sustained insulin independence starting 75 days post-transplantation. The patient's time-in-target glycemic range increased from a baseline value of 43.18% to 96.21% by month 4 post-transplantation, accompanied by a decrease in glycated hemoglobin, an indicator of long-term systemic glucose levels at a non-diabetic level. Thereafter, the patient presented a state of stable glycemic control, with time-in-target glycemic range at >98% and glycated hemoglobin at around 5%. At 1 year, the clinical data met all study endpoints with no indication of transplant-related abnormalities. Promising results from this patient suggest that further clinical studies assessing CiPSC-islet transplantation in type 1 diabetes are warranted.

Author Correction: Inducible degradation of lncRNA Sros1 promotes IFN-γ-mediated activation of innate immune responses by stabilizing Stat1 mRNA.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Multi-omics blood atlas reveals unique features of immune and platelet responses to SARS-CoV-2 Omicron breakthrough infection.

Although host responses to the ancestral SARS-CoV-2 strain are well described, those to the new Omicron variants are less resolved. We profiled the clinical phenomes, transcriptomes, proteomes, metabolomes, and immune repertoires of >1,000 blood cell or plasma specimens from SARS-CoV-2 Omicron patients. Using in-depth integrated multi-omics, we dissected the host response dynamics during multiple disease phases to reveal the molecular and cellular landscapes in the blood. Specifically, we detected enhanced interferon-mediated antiviral signatures of platelets in Omicron-infected patients, and platelets preferentially formed widespread aggregates with leukocytes to modulate immune cell functions. In addition, patients who were re-tested positive for viral RNA showed marked reductions in B cell receptor clones, antibody generation, and neutralizing capacity against Omicron. Finally, we developed a machine learning model that accurately predicted the probability of re-positivity in Omicron patients. Our study may inspire a paradigm shift in studying systemic diseases and emerging public health concerns.

Inducible degradation of lncRNA Sros1 promotes IFN-γ-mediated activation of innate immune responses by stabilizing Stat1 mRNA.

Interferon-γ (IFN-γ) is essential for the innate immune response to intracellular bacteria. Noncoding RNAs and RNA-binding proteins (RBPs) need to be further considered in studies of regulation of the IFN-γ-activated signaling pathway in macrophages. In the present study, we found that the microRNA miR-1 promoted IFN-γ-mediated clearance of Listeria monocytogenes in macrophages by indirectly stabilizing the Stat1 messenger RNA through the degradation of the cytoplasmic long noncoding RNA Sros1. Inducible degradation or genetic loss of Sros1 led to enhanced IFN-γ-dependent activation of the innate immune response. Mechanistically, Sros1 blocked the binding of Stat1 mRNA to the RBP CAPRIN1, which stabilized the Stat1 mRNA and, consequently, promoted IFN-γ-STAT1-mediated innate immunity. These observations shed light on the complex RNA-RNA regulatory networks involved in cytokine-initiated innate responses in host-pathogen interactions.

Repeated Omicron exposures override ancestral SARS-CoV-2 immune imprinting.

The continuing emergence of SARS-CoV-2 variants highlights the need to update COVID-19 vaccine compositions. However, immune imprinting induced by vaccination based on the ancestral (hereafter referred to as WT) strain would compromise the antibody response to Omicron-based boosters1-5. Vaccination strategies to counter immune imprinting are critically needed. Here we investigated the degree and dynamics of immune imprinting in mouse models and human cohorts, especially focusing on the role of repeated Omicron stimulation. In mice, the efficacy of single Omicron boosting is heavily limited when using variants that are antigenically distinct from WT-such as the XBB variant-and this concerning situation could be mitigated by a second Omicron booster. Similarly, in humans, repeated Omicron infections could alleviate WT vaccination-induced immune imprinting and generate broad neutralization responses in both plasma and nasal mucosa. Notably, deep mutational scanning-based epitope characterization of 781 receptor-binding domain (RBD)-targeting monoclonal antibodies isolated from repeated Omicron infection revealed that double Omicron exposure could induce a large proportion of matured Omicron-specific antibodies that have distinct RBD epitopes to WT-induced antibodies. Consequently, immune imprinting was largely mitigated, and the bias towards non-neutralizing epitopes observed in single Omicron exposures was restored. On the basis of the deep mutational scanning profiles, we identified evolution hotspots of XBB.1.5 RBD and demonstrated that these mutations could further boost the immune-evasion capability of XBB.1.5 while maintaining high ACE2-binding affinity. Our findings suggest that the WT component should be abandoned when updating COVID-19 vaccines, and individuals without prior Omicron exposure should receive two updated vaccine boosters.

Imprinted SARS-CoV-2 humoral immunity induces convergent Omicron RBD evolution.

Continuous evolution of Omicron has led to a rapid and simultaneous emergence of numerous variants that display growth advantages over BA.5 (ref. 1). Despite their divergent evolutionary courses, mutations on their receptor-binding domain (RBD) converge on several hotspots. The driving force and destination of such sudden convergent evolution and its effect on humoral immunity remain unclear. Here we demonstrate that these convergent mutations can cause evasion of neutralizing antibody drugs and convalescent plasma, including those from BA.5 breakthrough infection, while maintaining sufficient ACE2-binding capability. BQ.1.1.10 (BQ.1.1 + Y144del), BA.4.6.3, XBB and CH.1.1 are the most antibody-evasive strains tested. To delineate the origin of the convergent evolution, we determined the escape mutation profiles and neutralization activity of monoclonal antibodies isolated from individuals who had BA.2 and BA.5 breakthrough infections2,3. Owing to humoral immune imprinting, BA.2 and especially BA.5 breakthrough infection reduced the diversity of the neutralizing antibody binding sites and increased proportions of non-neutralizing antibody clones, which, in turn, focused humoral immune pressure and promoted convergent evolution in the RBD. Moreover, we show that the convergent RBD mutations could be accurately inferred by deep mutational scanning profiles4,5, and the evolution trends of BA.2.75 and BA.5 subvariants could be well foreseen through constructed convergent pseudovirus mutants. These results suggest that current herd immunity and BA.5 vaccine boosters may not efficiently prevent the infection of Omicron convergent variants.

BA.2.12.1, BA.4 and BA.5 escape antibodies elicited by Omicron infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages BA.2.12.1, BA.4 and BA.5 exhibit higher transmissibility than the BA.2 lineage1. The receptor binding and immune-evasion capability of these recently emerged variants require immediate investigation. Here, coupled with structural comparisons of the spike proteins, we show that BA.2.12.1, BA.4 and BA.5 (BA.4 and BA.5 are hereafter referred collectively to as BA.4/BA.5) exhibit similar binding affinities to BA.2 for the angiotensin-converting enzyme 2 (ACE2) receptor. Of note, BA.2.12.1 and BA.4/BA.5 display increased evasion of neutralizing antibodies compared with BA.2 against plasma from triple-vaccinated individuals or from individuals who developed a BA.1 infection after vaccination. To delineate the underlying antibody-evasion mechanism, we determined the escape mutation profiles2, epitope distribution3 and Omicron-neutralization efficiency of 1,640 neutralizing antibodies directed against the receptor-binding domain of the viral spike protein, including 614 antibodies isolated from people who had recovered from BA.1 infection. BA.1 infection after vaccination predominantly recalls humoral immune memory directed against ancestral (hereafter referred to as wild-type (WT)) SARS-CoV-2 spike protein. The resulting elicited antibodies could neutralize both WT SARS-CoV-2 and BA.1 and are enriched on epitopes on spike that do not bind ACE2. However, most of these cross-reactive neutralizing antibodies are evaded by spike mutants L452Q, L452R and F486V. BA.1 infection can also induce new clones of BA.1-specific antibodies that potently neutralize BA.1. Nevertheless, these neutralizing antibodies are largely evaded by BA.2 and BA.4/BA.5 owing to D405N and F486V mutations, and react weakly to pre-Omicron variants, exhibiting narrow neutralization breadths. The therapeutic neutralizing antibodies bebtelovimab4 and cilgavimab5 can effectively neutralize BA.2.12.1 and BA.4/BA.5, whereas the S371F, D405N and R408S mutations undermine most broadly sarbecovirus-neutralizing antibodies. Together, our results indicate that Omicron may evolve mutations to evade the humoral immunity elicited by BA.1 infection, suggesting that BA.1-derived vaccine boosters may not achieve broad-spectrum protection against new Omicron variants.

Convergent evolution of SARS-CoV-2 XBB lineages on receptor-binding domain 455-456 synergistically enhances antibody evasion and ACE2 binding.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) XBB lineages have achieved dominance worldwide and keep on evolving. Convergent evolution of XBB lineages on the receptor-binding domain (RBD) L455F and F456L is observed, resulting in variants with substantial growth advantages, such as EG.5, FL.1.5.1, XBB.1.5.70, and HK.3. Here, we show that neutralizing antibody (NAb) evasion drives the convergent evolution of F456L, while the epistatic shift caused by F456L enables the subsequent convergence of L455F through ACE2 binding enhancement and further immune evasion. L455F and F456L evade RBD-targeting Class 1 public NAbs, reducing the neutralization efficacy of XBB breakthrough infection (BTI) and reinfection convalescent plasma. Importantly, L455F single substitution significantly dampens receptor binding; however, the combination of L455F and F456L forms an adjacent residue flipping, which leads to enhanced NAbs resistance and ACE2 binding affinity. The perturbed receptor-binding mode leads to the exceptional ACE2 binding and NAb evasion, as revealed by structural analyses. Our results indicate the evolution flexibility contributed by epistasis cannot be underestimated, and the evolution potential of SARS-CoV-2 RBD remains high.

Spatial transcriptomics reveals tumor-derived SPP1 induces fibroblast chemotaxis and activation in the hepatocellular carcinoma microenvironment.

BACKGROUND: The tumor microenvironment (TME) exerts profound effects on tumor progression and therapeutic efficacy. In hepatocellular carcinoma (HCC), the TME is enriched with cancer-associated fibroblasts (CAFs), which secrete a plethora of cytokines, chemokines, and growth factors that facilitate tumor cell proliferation and invasion. However, the intricate architecture of the TME in HCC, as well as the mechanisms driving interactions between tumor cells and CAFs, remains largely enigmatic. METHODS: We analyzed 10 spatial transcriptomics and 12 single-cell transcriptomics samples sourced from public databases, complemented by 20 tumor tissue samples from liver cancer patients obtained in a clinical setting. RESULTS: Our findings reveal that tumor cells exhibiting high levels of SPP1 are preferentially localized adjacent to hepatic stellate cells (HSCs). The SPP1 secreted by these tumor cells interacts with the CD44 receptor on HSCs, thereby activating the PI3K/AKT signaling pathway, which promotes the differentiation of HSCs into CAFs. Notably, blockade of the CD44 receptor effectively abrogates this interaction. Furthermore, in vivo studies demonstrate that silencing SPP1 expression in tumor cells significantly impairs HSC differentiation into CAFs, leading to a reduction in tumor volume and collagen deposition within the tumor stroma. CONCLUSIONS: This study delineates the SPP1-CD44 signaling axis as a pivotal mechanism underpinning the interaction between tumor cells and CAFs. Targeting this pathway holds potential to mitigate liver fibrosis and offers novel therapeutic perspectives for liver cancer management.

Cancer mortality among solid organ transplantation recipients: A systematic review and meta-analysis.

OBJECTIVES: To evaluate the cancer mortality risk among solid organ transplant recipients through a systematic review and meta-analysis. METHODS: Systematic searches were conducted in PubMed (starting from 1965), ISI Web of Science (starting from 1900), MEDLINE (starting from 1976), and Scopus (starting from 1968) from the inception of each database until July 15, 2024. Studies published in English reporting at least one type of cancer mortality risk among recipients of any type of solid organ transplantation were included. The main outcomes were the standardized mortality ratio (SMR) for cancer mortality in transplant recipients compared to the general population, and the hazard ratio (HR) for cancer mortality in transplant recipients versus cancer patients without prior transplantation. RESULTS: Solid organ transplant recipients had a 2.06-fold increased cancer mortality risk (SMR, 2.06 [95 % CI, 1.56-2.71]) than the general population. Risks were higher in kidney (SMR 1.92 [95 % CI: 1.30-2.84]), liver (SMR 3.07 [95 % CI: 1.80-5.24]), and lung/heart (SMR 4.87 [95 % CI: 3.33-7.12]) transplant recipients. Cancer patients with prior transplantation had a 1.47-fold increased cancer mortality risk (HR 1.47 [95 % CI: 1.29-1.68]) than those without. East Asia female transplant recipients exhibited higher mortality risks from breast, ovarian, cervix and uterus cancers than those from other regions (SMR 3.13 [95 % CI: 1.93-5.07] vs. 1.16 [95 % CI: 0.88-1.53], P < 0.01). CONCLUSIONS: Solid organ transplant recipients face significantly higher cancer mortality risks than the general population, highlighting the need for targeted cancer screening and interventions, especially for female solid organ transplant recipients from East Asia.

Cis-acting lnc-Cxcl2 restrains neutrophil-mediated lung inflammation by inhibiting epithelial cell CXCL2 expression in virus infection.

Chemokine production by epithelial cells is important for neutrophil recruitment during viral infection, the appropriate regulation of which is critical for restraining inflammation and attenuating subsequent tissue damage. Epithelial cell expression of long noncoding RNAs (lncRNAs), RNA-binding proteins, and their functional interactions during viral infection and inflammation remain to be fully understood. Here, we identified an inducible lncRNA in the Cxcl2 gene locus, lnc-Cxcl2, which could selectively inhibit Cxcl2 expression in mouse lung epithelial cells but not in macrophages. lnc-Cxcl2-deficient mice exhibited increased Cxcl2 expression, enhanced neutrophils recruitment, and more severe inflammation in the lung after influenza virus infection. Mechanistically, nucleus-localized lnc-Cxcl2 bound to Cxcl2 promoter, recruited a ribonucleoprotein La, which inhibited the chromatin accessibility of chemokine promoters, and consequently inhibited Cxcl2 transcription in cis However, unlike mouse lnc-Cxcl2, human lnc-CXCL2-4-1 inhibited multiple immune cytokine expressions including chemokines in human lung epithelial cells. Together, our results demonstrate a self-protecting mechanism within epithelial cells to restrain chemokine and neutrophil-mediated inflammation, providing clues for better understanding chemokine regulation and epithelial cell function in lung viral infection.

Construction and validation of a risk model of proteinuria in patients with omicron COVID-19: retrospective cohort study.

BACKGROUND: To explore the risk factors of proteinuria in Omicron variant patients and to construct and verify the risk predictive model. METHODS: 1091 Omicron patients who were hospitalized from August 2022 to November 2022 at Tianjin First Central Hospital were defined as the derivation cohort. 306 Omicron patients who were hospitalized from January 2022 to March 2022 at the same hospital were defined as the validation cohort. The risk factors of proteinuria in derivation cohort were screened by univariate and multivariate logistic regression analysis, and proteinuria predicting scoring system was constructed and the receiver operating characteristic(ROC)curve was drawn to test the prediction ability. The proteinuria risk model was externally validated in validation cohort. RESULTS: 7 factors including comorbidities, blood urea nitrogen (BUN), serum sodium (Na), uric acid (UA), C reactive protein (CRP) and vaccine dosages were included to construct a risk predictive model. The score ranged from -5 to 16. The area under the ROC curve(AUC) of the model was 0.8326(95% CI 0.7816 to 0.8835, p < 0.0001). Similarly to that observed in derivation cohort, the AUC is 0.833(95% CI 0.7808 to 0.9002, p < 0.0001), which verified good prediction ability and diagnostic accuracy in validation cohort. CONCLUSIONS: The risk model of proteinuria after Omicron infection had better assessing efficiency which could provide reference for clinical prediction of the risk of proteinuria in Omicron patients.

Impact of different ischemia times on biliary stricture after living donor liver transplantation with biliary atresia.

Biliary atresia (BA) is the most common indication for pediatric liver transplantation, and biliary stricture (BS) remains an Achilles' heel for pediatric living donor liver transplantation (LDLT). We investigated the impact of different ischemia times on BS after LDLT in patients with BA. We retrospectively analyzed patients (<18 y) with BA who underwent LDLT between January 2016 and December 2020. Cases with hepatic artery thrombosis, bile leakage, early BS (<2 wk), and early death (<3 mo) were excluded. In all, 572 cases were included. A total of 26 cases (4.55%, 26/572) developed BS: 25 patients with anastomotic stricture and 1 patient with anastomotic stricture combined with left hepatic duct stricture. In addition, the time to diagnosis of BS ranged from 1.8 to 53.0 months (mean, 13.0 mo and median, 8.2 mo) after transplantation. A multivariate logistic regression analysis showed that arterial ischemia time (AIT), per 10 minutes (OR=1.222, 95% CI: 1.007-1.438, p =0.04) was the only independent risk factor for the development of BS after LDLT in patients with BA. What is more, the 5-year cumulative risk of BS between the AIT ≥40 minutes and AIT <40 minutes groups was 2.79% versus 10.57%. AIT was the only independent risk factor for the development of BS after LDLT with BA, and AIT ≥40 minutes would increase the 5-year cumulative risk of BS in our study. A shorter AIT, especially AIT <40 minutes, should be kept to decrease BS.

Outcome of split-liver transplantation from pediatric donors weighing 25 kg or less.

The lower limit of body weight for "splitable" liver grafts remains unknown. To examine the outcome of split-liver transplantation (SLT) from pediatric donors ≤25 kg relative to conventional graft-type liver transplantation from deceased donors under corresponding conditions, a total of 158 patients who received primary liver transplantation, including 22 SLTs from donors ≤25 kg, 46 SLTs from donors >25 kg, 76 whole-liver transplantations, and 14 reduced-liver transplantations in donors ≤25 kg between January 2018 and December 2019, were included in the study. There was no significant difference in the complications, patient survival, and graft survival between each of the latter three groups and the SLT ≤25 kg group. Pediatric End-Stage Liver Disease (PELD) score was the independent predictor of graft loss (death or retransplantation). Graft weight was the independent predictor of hepatic artery thrombosis. SLT using well-selected pediatric donors ≤25 kg is an effective strategy to increase organ availability, especially for low-body-weight recipients, compared with conventional graft type from deceased donors under the condition of corresponding donor weight without increasing morbidity and mortality.

The pattern of cytokines expression and dynamic changes of renal function at 6 months in patients with Omicron COVID-19.

To analyze the dynamic changes of renal function longitudinally and investigate the cytokine profiles at 6 months in patients with Omicron COVID-19. Forty-seven patients with a proven diagnosis of Omicron COVID-19 from January to February 2022 attended a 6-month follow-up after discharge at Tianjin First Central Hospital. The demographic parameters, clinical features, and laboratory indexes were collected during hospitalization and 6 months after discharge. The serum cytokine levels at 6 months were also assessed. Patients were grouped according to with or without kidney involvement at admission. The levels of serum creatinine and estimated glomerular filtration rate (eGFR) were all normal both in the hospital and at follow-up. Whereas, compared with renal function in the hospital, serum creatinine levels at 6 months increased remarkably; meanwhile, eGFR decreased significantly in all patients. The serum levels of interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10, and TNF-α and IFN-γ significantly decreased and TGF-ß remarkably increased in the kidney involvement group. The serum levels of IL-2 and IL-5 were positively correlated with age; contrarily, TGF-ß showed a negative correlation with aging. The younger was an independent risk factor of the higher TGF-ß levels. Omicron patients showed a decline in renal function at follow-up, reflecting the trend of CKD. Serum cytokine profiles were characterized with the majority of cytokines decreased and TGF-ß increased in the kidney involvement group; the latter may be used as a sign of CKD. The tendency of CKD is one of the manifestations of long COVID and deserves attention.

Metabolic reprogramming of myeloid-derived suppressor cells in the context of organ transplantation.

Myeloid-derived suppressor cells (MDSCs) are naturally occurring leukocytes that develop from immature myeloid cells under inflammatory conditions that were discovered initially in the context of tumor immunity. Because of their robust immune inhibitory activities, there has been growing interest in MDSC-based cellular therapies for transplant tolerance induction. Indeed, various pre-clinical studies have introduced in vivo expansion or adoptive transfer of MDSC as a promising therapeutic strategy leading to a profound extension of allograft survival due to suppression of alloreactive T cells. However, several limitations of cellular therapies using MDSCs remain to be addressed, including their heterogeneous nature and limited expansion capacity. Metabolic reprogramming plays a crucial role for differentiation, proliferation and effector function of immune cells. Notably, recent reports have focused on a distinct metabolic phenotype underlying the differentiation of MDSCs in an inflammatory microenvironment representing a regulatory target. A better understanding of the metabolic reprogramming of MDSCs may thus provide novel insights for MDSC-based treatment approaches in transplantation. In this review, we will summarize recent, interdisciplinary findings on MDSCs metabolic reprogramming, dissect the underlying molecular mechanisms and discuss the relevance for potential treatment approaches in solid-organ transplantation.

Incidence and risk factors of subclinical rejection after pediatric liver transplantation, and impact on allograft fibrosis.

INTRODUCTION: Subclinical rejection (SCR) is a common injury in protocol biopsy after pediatric liver transplantation (pLT), but its effect on the recipient is not clearly understood. We herein investigated the incidence and risk factors involved in SCR and analyzed the relationship between SCR and allograft fibrosis (AF). METHODS: We retrospectively reviewed the biopsy results from 507 children between May 2013 and May 2019, and 352 patients underwent protocol biopsy 2 years after pLT, 203 underwent protocol biopsy 5 years after pLT, and 48 underwent protocol biopsy both 2 and 5 years after pLT. RESULTS: The incidence of SCR in the 5-year group was higher than that in the 2-year group (20.2% vs.13.4%, respectively, p = .033). The number of patients with mild and moderate SCR in the 5-year group was also higher than that in the 2-year group (p = .039). Logistic regression analysis showed that acute rejection before liver biopsy and deceased donor liver transplantation (DDLT) were independent risk factors for SCR in the two groups, and that the incidence and severity of AF in protocol biopsies at both periods in the SCR group were higher than those in the non-SCR group (p < .05). CONCLUSIONS: The incidence and severity of SCR increased with the prolongation of protocol biopsy time. We postulate that acute rejection and DDLT are independent risk factors for SCR after transplantation. As the occurrence of SCR also augmented the incidence and severity of AF.

A novel predictive model of microvascular invasion in hepatocellular carcinoma based on differential protein expression.

BACKGROUND: This study aims to construct and verify a nomogram model for microvascular invasion (MVI) based on hepatocellular carcinoma (HCC) tumor characteristics and differential protein expressions, and explore the clinical application value of the prediction model. METHODS: The clinicopathological data of 200 HCC patients were collected and randomly divided into training set and validation set according to the ratio of 7:3. The correlation between MVI occurrence and primary disease, age, gender, tumor size, tumor stage, and immunohistochemical characteristics of 13 proteins, including GPC3, CK19 and vimentin, were statistically analyzed. Univariate and multivariate analyzes identified risk factors and independent risk factors, respectively. A nomogram model that can be used to predict the presence of MVI was subsequently constructed. Then, receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were conducted to assess the performance of the model. RESULTS: Multivariate logistic regression analysis indicated that tumor size, GPC3, P53, RRM1, BRCA1, and ARG were independent risk factors for MVI. A nomogram was constructed based on the above six predictors. ROC curve, calibration, and DCA analysis demonstrated the good performance and the clinical application potential of the nomogram model. CONCLUSIONS: The predictive model constructed based on the clinical characteristics of HCC tumors and differential protein expression patterns could be helpful to improve the accuracy of MVI diagnosis in HCC patients.

The value of 18 F-FDG PET/CT quantitative indexes in the diagnosis of nondestructive posttransplant lymphoproliferative disorders after pediatric liver transplantation.

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) is a serious complication after pediatric liver transplantation (pLT), which may lead to death. 18 F-FDG PET/CT is rarely considered in PTLD after pLT and lacks clear diagnostic guidelines, especially in the differential diagnosis of nondestructive PTLD. The aim of this study was to find a quantifiable 18 F-FDG PET/CT index to identify nondestructive PTLD after pLT. METHODS: This retrospective study collected the data of patients who underwent pLT, postoperative lymph node biopsy, and 18 F-FDG PET/CT at Tianjin First Central Hospital from January 2014 to December 2021. Quantitative indexes were established using lymph node morphology and the maximum standardized uptake value (SUVmax). RESULTS: A total of 83 patients met the inclusion criteria and were included in this retrospective study. To distinguish between PTLD-negative cases and nondestructive PTLD cases, according to the receiver operating characteristic curve, (the shortest diameter of the lymph node at the biopsy site [SDL]/the longest diameter of the lymph node at the biopsy site [LDL])*(SUVmax at the biopsy site [SUVmaxBio]/SUVmax of the tonsils [SUVmaxTon]) had the maximum area under the curve (0.923; 95% confidence interval: 0.834-1.000), and the cutoff value was 0.264 according to the maximum value of Youden's index. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 93.6%, 94.7%, 97.8%, 85.7%, and 93.9%, respectively. CONCLUSIONS: (SDL/LDL)*(SUVmaxBio/SUVmaxTon) has good sensitivity, specificity, positive predictive and negative predictive values, and accuracy, and can be used as a good quantitative index for the diagnosis of nondestructive PTLD.

HBsAg seroconversion in de novo hepatitis B virus-infected paediatric liver transplant recipients with anti-viral therapy.

We investigated the clinical characteristics and therapeutic strategies for paediatric liver transplant (PLT) recipients who experienced de novo hepatitis B virus infection and the features of HBsAg seroconversion. A total of 821 PLT were performed in HBV-free recipients between January 2013 and January 2019 in Paediatric Organ Transplant Center, Tianjin First Central Hospital. Twenty-one recipients developed de novo HBV infection, the clinical data were analysed. The overall incidence of de novo HBV infection was 2.5%. Only one recipient received an HBcAb-negative graft, 20 recipients received HBcAb-positive grafts. The incidence of de novo HBV infection in HBcAb-negative and HBcAb-positive graft recipients were 0.2% and 6.3%, respectively. Fifteen de novo HBV-infected recipients showed HBsAg seroconversion, the incidence of HBsAg seroconversion was 71.4%. The median time from the diagnosis of de novo HBV infection to HBsAg seroconversion was 15 (1, 73) months. Recipients with hepatitis B surface antigen (HBsAg) titre <1000 IU/L and negative hepatitis B e antigen (HBeAg) at the time of de novo HBV infection diagnosis were more likely to achieve HBsAg seroconversion. Nucleotide analogues were effective in treating recipients with de novo HBV infection. De novo HBV infection does not impact liver graft function as well as recipient and graft survival rate. De novo HBV infection does not impact PLT recipient outcomes under close monitoring and appropriate treatment. High incidence of HBsAg seroconversion can be achieved after anti-viral therapy.