Long-term liver allograft fibrosis: A review with emphasis on idiopathic post-transplant hepatitis and chronic antibody mediated rejection

Liver transplantation (LT) is a life-saving surgical procedure and the current standard of care for most patients with end stage liver disease. With improvements in organ preservation techniques, perioperative care, and immunosuppression, there is better patient and graft survival following LT, and assessment of the liver allograft in long-term survivors is becoming increasingly important. Recurrent or de novo viral or autoimmune injury remains the most common causes of chronic hepatitis and fibrosis following liver transplantation in adults. However, no obvious cause can be identified in many adults with controlled recurrent disease and the majority of pediatric LT recipients, as they have been transplanted for non-recurrent liver diseases. Serial surveillance liver biopsies post LT have been evaluated in several adult and pediatric centers to identify long-term pathological changes. Pathological findings are frequently present in liver biopsies obtained after a year post LT. The significance of these findings is uncertain as many of these are seen in protocol liver biopsies from patients with clinically good allograft function and normal liver chemistry parameters. This narrative review summaries the factors predisposing to long-term liver allograft fibrosis, highlighting the putative role of idiopathic post-LT hepatitis and chronic antibody mediated rejection in its pathogenesis.

Is the level of HLA eplet mismatch a risk factor for graft loss among kidney transplant recipients who have already formed de novo donor specific antibody?

Eplet mismatches are associated with de novo DSA (dnDSA) and antibody mediated rejection (ABMR) among the general kidney transplant population. However, it is unclear whether the level of eplet mismatch can be used for risk stratification among patients with dnDSA. We performed a retrospective observational study of kidney transplant recipients with dnDSA (n = 44) transplanted between 10/2007 and 5/2014 to evaluate eplet mismatch as a risk factor for ABMR and allograft loss among dnDSA patients. High resolution typing was inferred from by imputation based on ethnicity and NMDP haplotypes, and the eplet mismatch was calculated using the Epvix algorithm. Biopsies (N = 151) from 95.3%(42/44) of patients were reviewed. The mean (SD) eplet mismatch was 69.8(22.8). The ABMR incidence was 71.4% (30/42) and 5 year death censored allograft survival was 67.4% during the mean (SD) follow-up of 5.3 (3.1) years. ABMR and death-censored allograft survival were not correlated with eplet mismatch among dnDSA patients. However, medication adherence and dnDSA MFI < 3000 were associated with reduced ABMR incidence. Among patients with both of these favorable characteristics, only 35.7% (15/42) developed ABMR. In conclusion, the level of eplet mismatch does not correlate with ABMR or allograft loss among high risk kidney transplant patients with dnDSA.

[THE USE OF BORTEZOMIB FOR THE TREATMENT OF CHRONIC ANTIBODY MEDIATED REJECTION AFTER KIDNEY TRANSPLANTATION]

(Backgrounds) The efficacy of bortezomib for chronic antibody mediated rejection (CAMR) after kidney transplantation is still obscure. (Materials and methods) CAMR were persisted in 5 recipients who were treated with plasma exchange, low dose of IVIG, steroid pulse therapy, and rituximab. 1.3 mg/m² of bortezomib was administered on days 1, 4, 8, 11. Serum creatinine (sCr) levels, anti-HLA antibodies, and histology were analyzed. (Results) Stable sCr levels were obtained in 3 out of 5 recipients. No one lost renal graft function during follow-up periods. Anti-HLA class I antibodies were significantly decreased after bortezomib treatment, however anti-HLA class II antibodies were not changed. Histology showed no improvement at 6 months after bortezomib administration. Two recipients whose sCr levels increased during follow-up had already had interstitial fibrosis and tubular atrophy (IF/TA) in histology before bortezomib treatment. (Conclusions) The use of bortezomib after IF/TA could be detected in histology may not contribute to stabilize renal graft function in CAMR.