Donor with HLA-C2 is associated with acute rejection following liver transplantation in southern Chinese

Epidemiology of liver transplantation and post-LT complications in Germany: nationwide study (2005-2018)

BACKGROUND

To date, liver transplantation (LT) is the only curative treatment for cirrhosis and early-diagnosed progressive acute liver failure (ALF). However, LT results in morbidities and mortality even post-LT. Different comorbidities may follow and further increase mortality and morbidity. In this study, we investigated the outcomes and their trends over a period of 14 years among hospitalized patients evaluated for LT, transplant and post-LT in Germany.

METHODS

This German nationwide study investigated the number of admissions of patients hospitalized for evaluation of LT and post-LT on related comorbidities and complications between 2005 and 2018 based on the DRG system with ICD-10/OPS codes. 14 745 patients were put on the LT waiting list and 12 836 underwent LT during the observational period.

RESULTS

The LT number decreased by 2.3% over time, while the waiting list mortality rate increased by 5%. By contrast, the in-hospital mortality rate decreased by 3%, especially in ALF patients (decrease of 16%). Interestingly, admissions of post-LT patients for complications almost doubled, driven mainly by complications of immunosuppression (tripled). Importantly, post-LT patients with acute kidney injury (20.2%) and biliodigestive anastomosis (18.4%) showed the highest in-hospital mortality rate of all complications.

CONCLUSION

In conclusion, the decrease in LT leads most probably to the increased in-hospital mortality of patients on the waiting list. Interestingly, in-hospital mortality decreased in LT patients. Post-LT comorbidities requiring hospitalization increased in the observational period and management of patients post-LT with AKI or biliodigestive anastomosis should be addressed.

Immature and activated phenotype of blood NK cells is associated with acute rejection in adult liver transplant

Natural killer (NK) cells contribute to liver transplant (LTx) rejection. However, the blood-circulating NK-cell dynamics of patients who experience acute rejection (AR) are unclear. Herein, we longitudinally profiled the total NK cells and their subsets, along with the expression of activating and inhibitory receptors in sequential peripheral blood mononuclear cell samples, spanning from before LTx to the first year after LTx of 32 patients with AR and 30 patients under a steady immune status. Before transplantation, patients with AR (rejectors) contained a significantly higher proportion of the immature CD56 bright CD16 - subset and a lower cytolytic CD56 dim CD16 + in the total blood-circulating NK cells than patients with steady immunity. Both subsets contained a high NKp30-positive population, and CD56 dim CD16 + additionally exhibited a high NKp46-positive ratio. The NKp30-positive ratio in CD56 dim CD16 + subset showed the most prominent AR predictive ability before LTx and was an independent risk factor of LTx AR. After transplantation, the blood-circulating NK cells in rejectors maintained a higher CD56 bright CD16 - and lower CD56 dim CD16 + composition than the controls throughout the first year after LTx. Moreover, both subsets maintained a high NKp30-positive ratio, and CD56 dim CD16 + retained a high NKp46-positive ratio. The blood-circulating NK cell subset composition was consistent during AR, while the expressions of NKp30 and NKp46 were augmented. Collectively, a more immature CD56 bright CD16 - subset composition and an activated phenotype of high NKp30 expression were the general properties of blood-circulating NK cells in rejected LTx recipients, and the NKp30-positive ratio in CD56 dim CD16 + NK subset before LTx possessed AR predictive potential.

Importance of human leukocyte antigen antibodies and leukocyte antigen/killer-cell immunoglobulin-like receptor genes in liver transplantation

Many mechanisms have been proposed to explain the hypothetical state of hepatic tolerance, which is described by eventual imbalances or deregulation in the balance of cytokines, mediators, effectors, and regulatory cells in the complex milieu of the liver. In this section, we will comment on the importance of donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) as well as the compatibility and pairings of HLA and killer-cell immunoglobulin-like receptor (KIR) genotypes in the evolution of liver transplantation. Thus, HLA compatibility, viral infections, and HLA-C/KIR combinations have all been linked to liver transplant rejection and survival. There have been reports of increased risk of acute and chronic rejection with ductopenia, faster graft fibrosis, biliary problems, poorer survival, and even de novo autoimmune hepatitis when DSAs are present in the recipient. Higher mean fluorescence intensity (MFI) values of the DSAs and smaller graft size were associated with poorer patient outcomes, implying that high-risk patients with preformed DSAs should be considered for selecting the graft placed and desensitization methods, according to the investigators. Similarly, in a combined kidney-liver transplant, a pretransplant with a visible expression of several DSAs revealed that these antibodies were resistant to treatment. The renal graft was lost owing to antibody-mediated rejection (AMR). The HLA antigens expressed by the transplanted liver graft influenced antibody elimination. Pathologists are increasingly diagnosing AMR in liver transplants, and desensitization therapy has even been employed in situations of AMR, particularly in patients with DSAs in kidney-hepatic transplants and high-class II MFI due to Luminex. In conclusion, after revealing the negative impacts of DSAs with high MFI, pretransplant virtual crossmatch techniques may be appropriate to improve evolution; however, they may extend cold ischemia periods by requiring the donor to be typed.