Effects of Anti-COVID-19 Vaccination and Pre-Exposure Prophylaxis with Tixagevimab-Cilgavimab in Kidney and Liver Transplant Recipients

Background and Objectives: Underpowered immune response to vaccines against SARS-CoV-2 was observed in solid organ transplant (SOT) recipients. A novel combination of monoclonal antibodies tixagevimab-cilgavimab (TGM/CGM) received authorization as pre-exposure prophylaxis (PrEP) in those with reduced response to vaccine. We aimed to evaluate the response rate to COVID-19 vaccination in kidney transplant (KT), compared to liver transplant (LT) recipients, and the efficacy and safety of PrEP with TGM/CGM. Material and Methods: Between March and November 2022, adult KT and LT recipients who had completed the vaccination schedule (3 doses) were tested for anti-SARS-CoV-2 antibodies titer. SOT recipients with anti-SARS-CoV-2 titer ≥ 100 IU/mL were considered protected against infection, while those with titer < 100 UI/mL were defined non-protected. Patients with inadequate response were invited to PrEP. Results: In total, 306 patients were enrolled [KT:197 (64.4%), LT:109 (35.6%)]. After the complete scheme of vaccination, 246 (80.3%) patients developed a protective titer, while 60 (19.6%) did not have a protective titer. KT recipients had a lower rate of protective anti-COVID-19 titer compared to LT patients [149 (75.6%) vs. 97 (89.0%), p = 0.004]. Recipients with non-protective anti-COVID-19 titer received mainly tacrolimus-based regimen associated with mycophenolate mofetil (MMF) (70%) e steroids (46.7%) as maintenance immunosuppression, while those treated with everolimus were associated with higher protective titer. Of 35 (58.3%) patients who received PrEP, within 12 months, 6 (17.1%) (all KT) developed pauci-symptomatic COVID-19 disease, while 15/25 (60%) of non-responders, who did not receive the prophylaxis, developed COVID-19 disease. After PrEP, hospitalization rate was lower (2.8% vs. 16%), and no adverse events, neither graft loss nor rejection, were observed. Conclusions: Despite complete COVID-19 vaccination, SOT recipients might be not protected from the SARS-CoV-2 infection, especially after KT. In non-protected SOT patients, the subsequent pre-exposure prophylaxis with combination of monoclonal antibodies (TGM/CGM) might be an efficacy and safe strategy to prevent COVID-19 severe disease and hospitalization.

Vascular Involvements in Cholangiocarcinoma: Tips and Tricks

Cholangiocarcinoma (CCA) is an aggressive malignancy of the biliary tract. To date, surgical treatment remains the only hope for definitive cure of CCA patients. Involvement of major vascular structures was traditionally considered a contraindication for resection. Nowadays, selected cases of CCA with vascular involvement can be successfully approached. Intrahepatic CCA often involves the major hepatic veins or the inferior vena cava and might necessitate complete vascular exclusion, in situ hypothermic perfusion, ex situ surgery and reconstruction with autologous, heterologous or synthetic grafts. Hilar CCA more frequently involves the portal vein and hepatic artery. Resection and reconstruction of the portal vein is now considered a relatively safe and beneficial technique, and it is accepted as a standard option either with direct anastomosis or jump grafts. However, hepatic artery resection remains controversial; despite accumulating positive reports, the procedure remains technically challenging with increased rates of morbidity. When arterial reconstruction is not possible, arterio-portal shunting may offer salvage, while sometimes an efficient collateral system could bypass the need for arterial reconstructions. Keys to achieve success are represented by accurate selection of patients in high-volume referral centres, adequate technical skills and eclectic knowledge of the various possibilities for vascular reconstruction.

Liver transplantation for hepatitis D virus/hepatitis B virus coinfection in Italy: an intention-to-treat analysis of long-term outcomes

Patients with hepatitis D virus (HDV)/hepatitis B virus (HBV)-related end-stage liver disease candidates for liver transplantation (LT) have traditionally been regarded as a special population, although their outcomes are controversial. An intention-to-treat (ITT) analysis of long-term outcomes of HDV/HBV-coinfected patients waitlisted for LT in Italy, between 2011 and 2020, was performed and compared with HBV-monoinfected LT candidates. Of 1731 HBV-infected LT candidates, 1237 (71.5%) had HBV monoinfection and 494 (28.5%) HDV/HBV coinfection. At listing, HDV/HBV-coinfected patients were significantly younger, listed mainly for decompensated cirrhosis, and with fewer hepatocellular carcinoma (HCC) cases; (26% vs 65.8%; P <.0001) compared with HBV-monoinfected patients. HDV/HBV-coinfected patients showed better 5-year ITT survival (83.2%; 95% CI: 79.4%-83.4%, vs 71.6%; 95% CI: 68.8%-74.2%; P < .0001). ITT-multivariable analysis identified the presence of HCC, advanced recipient age, and high model for end-stage liver disease-Na scores as mortality risk factors. Five years after LT, 99.1% of HDV/HBV-coinfected patients received oral nucleos(t)ide analogs, with immunoglobulins against antigen of the hepatitis B virus in 91.8% of cases. HBV and HDV viral recurrences were 1.1% and 0.2%, respectively, whereas recurrent or de novo HCC were 8.9% and 0.3%, respectively. In Italy, HDV/HBV-coinfected patients waitlisted for LT showed more favorable outcomes compared with HBV-monoinfected patients, both before and after LT. These excellent results, from the largest cohort reported so far, suggest that HDV/HBV-coinfected LT recipients do not represent a risky population and may be considered for simpler long-term antiviral prophylactic strategies.

The Effects of Sustained Immunosuppression Withdrawal After Liver Transplantation on Metabolic Syndrome

BACKGROUND

Liver transplant (LT) recipients often experience adverse effects of immunosuppressive (IS) drugs, especially on metabolic profiles. Selected LT recipients can achieve successful IS withdrawal; however, its effects on metabolic syndrome (MS) are unknown.

METHODS

This is a retrospective single-center study investigating the incidence and/or regression of MS in 75 selected LT recipients who were previously enrolled in prospective IS withdrawal trials between 1999 and 2017. Patients who were transplanted due to nonalcoholic steatohepatitis/metabolic-associated fatty liver disease were excluded, as well as those with a follow-up <3 y after IS weaning.

RESULTS

Forty-four patients (58.7%) achieved sustained withdrawal or minimization of immunosuppression (WMIS) and 31 patients (41.3%) required reintroduction of immunosuppression (no-WMIS). Among LT recipients who were metabolically healthy (n = 52, 69.3%) before the start of IS weaning, there was a significantly lower rate of de novo MS in WMIS patients compared with no-WMIS patients after 5 y (8.3% and 47.8%, respectively, P  = 0.034). Of 23 LT recipients (30.7%) who had MS at the time of commencing IS withdrawal, complete regression of MS was observed in 47.1% of WMIS patients and in none (0%) of the no-WMIS patients after 5 y ( P  = 0.054). Furthermore, individual components of MS were better controlled in IS-weaned patients, such as arterial hypertension and abnormal serum lipids.

CONCLUSIONS

Achievement of sustained IS withdrawal reduces the incidence of de novo MS development in metabolically healthy patients and increases the likelihood of MS regression in patients with established MS. The foreseeable long-term beneficial effects of these favorable metabolic changes on morbidity and mortality of LT recipients require further investigation.

COVID-19 in a pregnant kidney transplant recipient - what we need to know: A case report

BACKGROUND

In the era of the coronavirus disease 2019 (COVID-19) pandemic, kidney tran splant recipients are more susceptible to severe acute respiratory syndrome co ronavirus (SARS-CoV-2) infection, developing severe morbidity and graft im pairment. Pregnant women are also more likely to develop severe COVID-19 di sease, causing pregnancy complications such as preterm births and acute kidney injury.

CASE SUMMARY

Herein, we report the case of a pregnant woman with a third kidney tran splantation who developed COVID-19 disease. The reduction of immunosuppressive drugs and strict monitoring of trough blood levels were needed to avoid severe SARS-CoV-2-related complications, and permitted to continue a healthy pregnancy and maintain good graft function. In such a complex scenario, the con comitance of COVID-19-related morbidity, the risk of acute rejection in the hype rimmune recipient, graft dysfunction and pregnancy complications make the management of immunosuppression a very difficult task and clinicians must be aware.

CONCLUSION

Tailoring the immunosuppressive regimen is a key factor affecting both the graft outcome and pregnancy safety.

Colorectal cancer in ulcerative colitis after liver transplantation for primary sclerosing cholangitis: a systematic review and pooled analysis of oncological outcomes

INTRODUCTION

Patients with ulcerative colitis (UC) receiving liver transplantation (LT) due to primary sclerosing cholangitis (PSC) have higher risk of developing colorectal cancers (CRC). Aim of this systematic review was to define the patients' features, immunosuppressive management, and oncological outcomes of LT recipients with UC-PSC developing CRC.

METHODS

Searches were conducted in PubMed (MEDLINE), Cochrane Library, Web of Science for all English articles published until September 2023. Inclusion criteria were original articles including patients specifying outcomes of interest. Primary endpoints comprised incidence of CRC, disease free survival (DFS), overall survival (OS) and cancer recurrence. Secondary endpoints were patient's and tumor characteristics, graft function, immunosuppressive management and PSC recurrence. PROSPERO CRD42022369190.

RESULTS

Fifteen studies included, 88 patients were identified. Patients (mean age: 50 years) had a long history of UC (20 years), mainly with active colitis (79%), and developed tumor within the first 3 years from LT, while receiving a double or triple immunosuppressive therapy. Cumulative incidence of tumor was 5.5%. At one, two and three years, DFS was 92%, 82% and 75%, while OS was 87%, 81% and 79% respectively. Disease progression rate was 15%. After CRC surgery, 94% of patients maintained a good graft functionality, with no reported cases of PSC recurrence.

CONCLUSIONS

After LT, patients with PSC and UC have an increased risk of CRC, especially in presence of long history of UC and active colitis. Surgical resection guarantees satisfactory mid-term oncological outcomes, but samples are limited, and long-term data are lacking. National and international registry are auspicial to evaluate long-term oncological outcomes and to optimize clinical management.

Combined endovascular-surgical treatment for complex congenital intrahepatic arterioportal fistula: A case report and review of the literature

BACKGROUND

Congenital intrahepatic arterioportal fistula (IAPF) is a rare vascular malformation in infants that causes severe portal hypertension (PH) with poor prognosis if untreated. Currently, radiological embolisation is considered the first-line therapy for simple IAPF; however, it might be not resolutive for complex hepatic vascular lesions. When endovascular embolization is not sufficient to completely obliterate the IAPF, surgical intervention is needed, but it has been associated with severe morbidity and mortality in small children. Furthermore, indications are not defined.

CASE SUMMARY

We present the first case of a 6-month-old girl with trisomy 21 affected by a complex congenital IAFP, which caused severe PH, successfully treated with an endovascular-surgical hybrid procedure. The novel technique comprised a multi-step endovascular embolisation, including a superselective transarterial embolisation of the afferent vessels and a direct transhepatic embolisation of the dilated portal vein segment, combined with selective surgical ligation of the arterial branches that supply the fistula, which were too small to be embolised. The complex IAPF was also associated with severe cholestasis and intra/extrahepatic biliary tree dilatation, which was successfully treated by a temporary biliary drainage. At 24-mo follow-up, the hybrid endovascular-surgical procedure achieved complete occlusion of the complex IAPF and resolution of the PH. A comprehensive review of the literature on congenital IAPF management, focussed on alternative treatment strategies, is also reported.

CONCLUSION

The combined radiological-surgical approach is a safe and effective treatment option for complex IAPF and avoids major invasive surgery.

Immunosuppression protocols for emerging oncological indications in liver transplantation: A systematic review and pooled analysis

The evolving field of liver transplant (LT) oncology calls for tailored immunosuppression protocols to minimize the risk of tumor recurrence. We systematically reviewed the available evidence from inception to May 2023 regarding immunosuppression protocols used in patients undergoing LT for cholangiocarcinoma, neuroendocrine tumors (NET), hepatic-endothelial hemangioendothelioma, and colorectal liver metastases (CRLM) to identify common practices and to evaluate their association with oncological outcomes. Studies not involving humans, case reports, and short case series (ie, n < 10) were excluded. Among 3374 screened references, we included 117 studies involving 6797 patients distributed as follows: cholangiocarcinoma (58.1%), NETs (18.8%), hepatic-endothelial hemangioendothelioma (7.7%), CRLM (6.8%), mixed neoplasms (6.8%), or others (1.7%). Only 41% of the studies disclosed details of the immunosuppression protocol, and 20.8% of studies provided drug trough concentrations during follow-up. The immunosuppression protocols described were heterogeneous and broadly mirrored routine practices for nontumoral indications. The only exception was CRLM, where tacrolimus minimization-or even withdrawal-in combination with inhibitors of the mammalian target of rapamycin (mTORi) were consistently reported. None of the studies evaluated the relationship between the immunosuppression protocol and oncological outcomes. In conclusion, based on low-quality and indirect scientific evidence, patients with tumoral indications for LT should receive the lowest tacrolimus level tolerated under close surveillance. The combination with mTORi titrated to achieve the top therapeutic range of trough concentrations could allow complete tacrolimus withdrawal. This approach may be particularly useful in patients with cholangiocarcinoma and CRLM, in whom tumor recurrence is the main cause of death. We propose a tool for reporting immunosuppression protocols, which could be implemented in future transplant oncology studies.

The impact of center volume on the utilization and outcomes of machine perfusion technology in liver transplantation: An international survey

INTRODUCTION

Machine perfusion (MP) was developed to expand the donor pool and improve liver transplantation (LT) outcomes. Despite optimal results in clinical trials, the real-world MP benefit in centers with low-/mid-volume activity (LVCs) is still being determined.

METHODS

Online survey on MP for LT, distributed to worldwide LT-centers representatives. Variables of interest included logistics, technicalities, and outcomes. Responders were grouped into high-volume centers (HVCs) (>60 LTs/year) and LVCs and results compared.

RESULTS

Sixty-seven centers were included, 36 HVCs and 31 LVCs. Significant differences in MP regarded: (I) existence of an established program (80.6% vs. 41.9%; p = 0.02), (II) presence of a dedicated perfusionist (58.3% vs. 22.6%; p = 0.006), (III) duration (>4 h: 47.2% vs. 16.1%; p = 0.01), (IV) routine use (20%-40% vs. 5%-20%; p = 0.002), (V) graft utilization (>50%: 75% vs. 51.6%; p = 0.009), (VI) 90-day patient-survival (90%-100% vs. 50%-90%; p = 0.001) and (VII) subjectively perceived benefit (always vs. only in selected ECD; p = 0.009). Concordance was found for indications, type, viability tests, graft-salvage, 90-day graft-loss, and major-complications.

CONCLUSIONS

This study captured a picture of MP in real-world LT-practice. Significant disparities have surfaced between LVCs and HVCs regarding logistics, utilization, and results. To close this gap, efforts should be made to more efficiently deliver dedicated support, training and mentoring to LVC teams adopting MP technology.