Presence of donor specific HLA class 2 antibodies (DSA class 2) is associated with development of graft fibrosis more than 10 years after liver transplantation-a retrospective single center study

BSHI and BTS UK guideline on the detection of alloantibodies in solid organ (and islet) transplantation

Solid organ transplantation represents the best (and in many cases only) treatment option for patients with end-stage organ failure. The effectiveness and functioning life of these transplants has improved each decade due to surgical and clinical advances, and accurate histocompatibility assessment. Patient exposure to alloantigen from another individual is a common occurrence and takes place through pregnancies, blood transfusions or previous transplantation. Such exposure to alloantigen's can lead to the formation of circulating alloreactive antibodies which can be deleterious to solid organ transplant outcome. The purpose of these guidelines is to update to the previous BSHI/BTS guidelines 2016 on the relevance, assessment, and management of alloantibodies within solid organ transplantation.

Long-term Outcome of Pediatric Liver Transplant Recipients Who Have Reached Adulthood: A Single-center Experience

BACKGROUND

As long-term survival of pediatric liver transplant recipients increases, the assessment of physical, psychological, and social well-being becomes more important.

METHODS

In this retrospective analysis, 120 young adult patients (age ≥18 y) who underwent liver transplantation in childhood were studied. Patients with ideal outcome were defined as patients with perfect graft function, with no complications from the immunosuppressive medication, no late retransplantation, and no steroid treatment. Also, the patients' drug adherence and their psychosocial situation were assessed.

RESULTS

After a median follow-up of 19 y, only 16.7% of the patients (mean age: 26.5 y) were considered patients with ideal outcome. The main reasons precluding ideal outcome were chronic kidney disease (38.3%), elevated liver enzymes (33.3%), and arterial hypertension (31.7%). Ideal outcome decreased over time from 54% to 42%, 26%, and 8% at 10-, 15-, 20-, and 25-y follow-up, respectively. Reduced drug adherence was noted in 24.8% of patients and associated with a significantly higher prevalence of donor-specific antibodies class II ( P  = 0.015), elevated transaminases ( P  = 0.010), and chronic rejection ( P  < 0.001). Also, 15% of patients had a psychiatric disease, mainly depression.

CONCLUSIONS

The morbidity of young adults who underwent liver transplantation as children was high and increased over time. The majority developed complications from immunosuppression or chronic graft dysfunction. More than 1 in 7 patients had a psychiatric disease and 1 in 4 was not perfectly drug adherent. Therefore, immunosuppressive treatment and psychological care should be optimized for these particularly vulnerable patients.

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.

Progress and challenges in diagnosis and treatment of rejection following liver transplantation

PURPOSE OF REVIEW

Liver biopsy remains the most widely utilized method for diagnosis of allograft rejection following liver transplantation. However, associated risks and limitations present an opportunity for emerging noninvasive diagnostic techniques to improve upon the current standard of care. This review evaluates progress toward development of new noninvasive methods for the monitoring and diagnosing of allograft rejection.

RECENT FINDINGS

Recent studies investigate the potential of a variety of analytes. Quantification of dd-cfDNA and of DSA show potential to indicate status of allograft rejection and aid in immunosuppression modulation. Moreover, mRNA microarray profiling of differentially expressed genes, as well as characterization of cytokine responses and immunophenotypic shifts following liver transplantation, may predict and recognize rejection events.

SUMMARY

Noninvasive methods are not yet ready to replace liver biopsy as the standard of care for diagnosis of allograft rejection, though several assays and biomarkers have shown promising preliminary results. As noninvasive techniques become validated in clinical settings, their integration with current diagnostic methods is likely to foster increased sensitivity, specificity, and reliability of diagnosis.