Subcapsular hepatic necrosis in orthotopic liver allografts

Allograft Necrosis in Liver Biopsy Is Predictive for Organ Outcome and Patient Survival

AIM

To evaluate if any association existed between the extent of allograft necrosis in liver biopsy and patient survival.

METHODS

Sixty-nine patients who had 70 liver transplantations with allograft necrosis were included in the study. Correlations of necrosis, the Model for End-Stage Liver Disease (MELD) score, and allograft survival were analyzed.

RESULTS

Allograft failure rate within 1 month after index biopsy was worse in patients with a higher extent of necrosis (2.5%, 12.5%, 25%, and 40% in groups with allograft necrosis of 1-25%, 26-50%, 51-75%, and >75%, respectively). Adequate biopsy with more than 50% necrosis is associated with significant allograft failure (P <.001). The MELD scores did not always accurately predict fatality that was caused by massive necrosis. In the absence of substantial clinical changes, repetition of allograft biopsy within a short period of time did not provide additional value. Among patients with more than 75% allograft necrosis, one who received an immediate second transplantation survived and 3 out of 9 patients who had not received those deceased within 1 month.

CONCLUSIONS

Allograft necrosis demonstrates strong predictive power in organ and patient survival. Additionally, biopsy-proven allograft necrosis unequivocally pinpoints ischemia as the direct cause of allograft failure, which facilitates clinical management. Immediate retransplantation is crucial for patients with substantial allograft necrosis.

Diagnosis in Pediatric Transplant Biopsies

Infant recipients have better survival after solid organ transplantation than older children and adults possibly due to immune tolerance. Over the past two decades, postsurgical complications have markedly decreased, and multidrug immunosuppressive regimens have become effective in preventing and treating rejection. Immunocompromised for life, these patients are susceptible to both the usual bacterial as well as opportunistic infections that often involve the lung. Post-transplant lymphoproliferative disease seems to be decreasing even further in frequency. This article focuses on the findings seen on biopsy, usually of the transplanted organ, and also of other sites affected by post-transplant complications.

Involvement of intrasinusoidal hemostasis in the development of concanavalin A-induced hepatic injury in mice

Concanavalin A (Con A) stimulation induces T-cell activation-associated hepatic injury. This study is designed to show the involvement of microcirculatory disturbance in the pathogenesis. Con A administration led to prominent intrasinusoidal hemostasis, which consisted of erythrocyte agglutination, lymphocyte/neutrophil sticking to endothelial cells, and platelet aggregation and degranulation, resulting in a marked decrease in the intrahepatic blood flow and elevation of portal perfusion pressure. After hemostasis, confluent hepatic necrosis occurred within the congested area of liver parenchyma. Reduction in the extent of hemostasis by the treatment with heparin (thrombin inhibitor) or cyproheptadine (serotonin inhibitor) decreased hepatic injury. Pretreatment with either anti-tumor necrosis factor alfa (TNF-alpha) or anti-interferon gamma (IFN-gamma) monoclonal antibody (MAb) moderately decreased hemostasis and hepatic injury, whereas combined use of two MAbs almost perfectly protected mice from these disorders. Complete obliteration of hemostasis and hepatic injury was also accomplished by the pretreatment with FK506 which suppressed TNF-alpha and IFN-gamma production. Intrasinusoidal accumulation of leukocytes and platelets was, however, not blocked by FK506, indicating that Con A activities other than the stimulation of cytokine production are responsible for this event. The administration of anti-CD3 MAb, a T-cell stimulant without agglutination activities, which elevated plasma cytokine levels in a comparable degree without inducing prominent leukocyte infiltration, did not induce hepatic congestion and injury. These findings indicate that the agglutination activities of Con A and T-cell activation mediated TNF-alpha/IFN-gamma production are both required for the induction of intrasinusoidal hemostasis, which is indispensable for the development of hepatic injury.

Evaluation of protocol before transplantation and after reperfusion biopsies from human orthotopic liver allografts: considerations of preservation and early immunological injury

Light microscopic, immunohistochemical and ultrastructural analysis of protocol before transplantation and after reperfusion biopsy specimens from 87 randomly selected patients was performed to assess the contribution of preservation and immunological injury to early graft failure. Most biopsy specimens were essentially normal by light microscopy before transplantation, and no particular feature could be relied on to predict function after transplantation. Ultrastructural examination of biopsy specimens before transplantation demonstrated preferential degeneration of sinusoidal lining cells, but no strict correlation was seen between ultrastructural sinusoidal integrity before transplantation and function after transplantation. The presence of zonal or severe focal necrosis and a severe neutrophilic exudate in biopsy specimens after reperfusion presaged a poor early postoperative course in most, but not all, patients. The presence of preformed lymphocytotoxic antibodies had no effect on the early clinical course, but was associated with Kupffer cell hypertrophy in needle biopsy specimens taken after transplantation. No definite evidence was seen of hyperacute rejection as a result of preformed lymphocytotoxic antibodies as detected in conventional assays. These findings suggest that preservation injury accounts for only a subset of grafts that fail to function after transplantation. Other perioperative or "recipient" factors may be of equal or greater importance in early graft dysfunction or failure.