Objective:To explore the application of high-throughput second-generation gene sequencing technology based upon metagenomics in the diagnosis of pulmonary infection after organ transplantation.Methods:From June 2016 to January 2020, clinical records were retrospectively reviewed for 34 renal and liver transplant recipients hospitalized for pulmonary infection. From June 2016 to December 2018, they were assigned as group A (n=20) of traditional pathogen detections. From January 2019 to January 2020, 14 cases in group B were sequenced by high-throughput second-generation technology. The detection rate, sensitivity and specificity, the return time of detection results, the average length of stay and the mortality of 28 days between two groups were analyzed.Results:No significant inter-group difference existed in clinical data (age, gender, antibody induction method, immunosuppressant use, etc.). As compared with group A, the positive detection rate of etiology and the the sensitivity were higher in group B and the differences in specificity were statistically insignificant. The return time of test results in group B was significantly shorter than that in group A. And the difference was statistically significant. The average hospitalization stay and 28-day mortality of group B were lower than those of group A. And the differences were statistically significant.Conclusions:High-throughput second-generation gene sequencing technology can improve the detection rate of pulmonary infection after organ transplantation. Providing a " precise and accurate" direction for disease treatment, it is a useful supplement to traditional diagnostic methods.

Objective:To retrospectively summarize the clinical experiences of managing renal artery stenosis after donor kidney transplantation in children.Methods:From January 2018 to October 2021, 114 pediatric kidney transplants(donor/recipient aged <18 years)were performed.According to the findings of color Doppler ultrasonography, they were divided into two groups of normal( n=80)and rapid flow( n=34). Rapid flow group were assigned into symptomatic( n=13)and asymptomatic( n=21)sub-groups based upon clinical features of hypertension and renal instability. Results:Among them, there were 65 males and 49 females.A significant inter-gender difference existed in the proportion of higher arterial flow rate of transplanted kidney(38.5% and 18.4%, P=0.02). No significant difference existed in age or body weight of transplant recipients among all groups( P>0.05). The mean age(10.4 months)and body weight(9 kg)of donors were significantly lower in symptomatic group than those in normal group(65.3 months, 21 kg)and asymptomatic group(64.4 months, 21.2 kg). The mean velocity of symptomatic group was significantly higher than that of asymptomatic group(363.5 vs 228.8 cm/s)( P<0.001). In symptomatic group, 6 cases received medications and their clinical manifestations were completely relieved.Among 7 patients invasively treated, one percutaneous transluminal angioplasty(PTA)was offer once( n=2), twice( n=2)and triple( n=1)with clinical relief and stable renal function.One case of bleeding at puncture site during PTA had treatment failure with a gradual loss of graft function.One ineffective case of PTA was subsequently placed with an endovascular stent.However, repeated stent dilation failed due to restenosis.After surgical exploration, vascular stent removal and transplantation of renal artery clipping, clinical symptoms were relieved. Conclusions:Male recipient, low body weight or young donor may be risk factors for transplant renal artery stenosis(TRAS)during pediatric donor renal transplantation.A higher flow rate of transplanted renal artery on ultrasonography could not confirm the diagnosis of TRAS.Greater arterial flow and associated clinical manifestations often hint at a strong possibility of TRAS, requiring drug or invasive treatment interventions.If PTA efficacy is not satisfactory, multiple treatments should be performed.Nevertheless, stenting should be avoided as far as possible to prevent in-stent restenosis.

Objective:To explore the risk factors related to acute rejection (AR) after pediatric kidney transplantation (KT).Methods:Retrospective analysis was performed for 189 pediatric KT recipients from September 2011 to August 2022.They were divided into two groups of AR (n=33) and non-AR (n=156).Univariate and multivariate Logistic regression analyses were performed for identifying potential risk factors of AR.And the effects of AR on graft function and survival were also examined.Results:During follow-ups, a total of 33(17.5%) patients developed AR with a 1-year cumulative incidence of AR of 16.9%(32/189).Univariate analysis revealed that median time on dialysis was longer in AR group than that in non-AR group (19 vs. 11 months, P=0.034).Median age of donors (12 vs. 24 months, P=0.033), median weight of donors (9.5 vs. 12 kg, P=0.025) and median donor/recipient body weight ratio (0.36 vs. 0.50, P=0.005) were lower in AR group than those in non-AR group.And the proportion of subtherapeutic tacrolimus (TAC) trough level was higher in AR group than that in non-AR group (45.5% vs. 21.2%, P=0.004).Multivariate regression analysis indicated that subtherapeutic TAC trough level was an independent risk factor for AR ( OR=2.977, 95% CI: 1.314-6.743, P=0.009).At the last follow-up, serum creatinine and eGFR were (78.4±24.3) vs. (74.6±24.7) μmol/L and (85.3±26.3) vs. (89.5±24.2) ml·min -1·1.73 m -2 in AR and non-AR groups respectively.There were no significant differences.1/5-year patient survival rate was both 97% in AR group and both 99.4% in non-AR group; 1/5-year graft survival rate both 90.9% in AR group and was 98.1% and 97.4% in non-AR group.No significant inter-group differences existed in patient and graft survival. Conclusions:Although an occurrence of early AR does not negatively impact graft outcomes, the incidence of AR remains high after pediatric KT.Therefore prompt diagnosis and treatment of AR should be strengthened.

This review described the management of 11 recipients hospitalized with severe COVID-19 after kidney transplantation during the omicron variant epidemic in Shanghai from December 2022 to January 2023.After withdrawing oral immunosuppressants and starting immunoreplacement therapy, taking small molecule antiviral drugs and treating mixed infections, 10 recipients recovered and were discharged.One critically recipient died from a mixed bacterial and fungal infection after 80-day treatment.No overproduction of inflammatory cytokines was observed during treatment.And no rejection occurred during a cessation of oral immunosuppression.Delayed administration(>1 week of SARS-CoV-2 infection)of small molecule antiviral agents could effectively control viral replication.And there was simultaneous restoration of immune function.

Xenotransplantation is a potential solution to the shortage of human organs. In the previous 100 years, xenotransplantation has witnessed preliminary attempts and persistent progress. At present, it has entered a new stage of rapid development and achieved a series of results. Nevertheless, the management of xenotransplantation rejection is more challenging compared with that of allogeneic organ transplantation rejection. Therefore, researchers have developed a series of immunosuppressive strategies, such as use of genetically modified pig donors, use of traditional and novel immunosuppressants, and co-transplantation of donor pig thymus with donor organs, aiming to adjust the immune system response of recipients, mitigate the intensity of rejection and prolong the survival time of grafts. In this article, research progress in the mechanism, prevention and treatment strategies of xenotransplantation rejection was reviewed, aiming to provide reference for accelerating subsequent development of xenotransplantation.