Acute Liver Injury Is Independent of B Cells or Immunoglobulin M

Acute liver injury is a clinically important pathology and results in the release of Danger Associated Molecular Patterns, which initiate an immune response. Withdrawal of the injurious agent and curtailing any pathogenic secondary immune response may allow spontaneous resolution of injury. The role B cells and Immunoglobulin M (IgM) play in acute liver injury is largely unknown and it was proposed that B cells and/or IgM would play a significant role in its pathogenesis.Tissue from 3 models of experimental liver injury (ischemia-reperfusion injury, concanavalin A hepatitis and paracetamol-induced liver injury) and patients transplanted following paracetamol overdose were stained for evidence of IgM deposition. Mice deficient in B cells (and IgM) were used to dissect out the role B cells and/or IgM played in the development or resolution of injury. Serum transfer into mice lacking IgM was used to establish the role IgM plays in injury.Significant deposition of IgM was seen in the explanted livers of patients transplanted following paracetamol overdose as well as in 3 experimental models of acute liver injury (ischemia-reperfusion injury, concanavalin A hepatitis and paracetamol-induced liver injury). Serum transfer into IgM-deficient mice failed to reconstitute injury (p = 0.66), despite successful engraftment of IgM. Mice deficient in both T and B cells (RAG1-/-) mice (p<0.001), but not B cell deficient (μMT) mice (p = 0.93), were significantly protected from injury. Further interrogation with T cell deficient (CD3εKO) mice confirmed that the T cell component is a key mediator of sterile liver injury. Mice deficient in B cells and IgM mice did not have a significant delay in resolution following acute liver injury.IgM deposition appears to be common feature of both human and murine sterile liver injury. However, neither IgM nor B cells, play a significant role in the development of or resolution from acute liver injury. T cells appear to be key mediators of injury. In conclusion, the therapeutic targeting of IgM or B cells (e.g. with Rituximab) would have limited benefit in protecting patients from acute liver injury

The use of marginal heart beating donor livers for transplantation in the United kingdom.

BACKGROUND: This study investigated the use of deceased heart-beating donor livers offered for transplantation during a 10-year period, during which there has been an increasing disparity between organ supply and demand in the United Kingdom. METHODS: Summary data from the National Transplant Database were analyzed on all 7107 heart-beating cadaveric donor livers offered for transplantation in the United Kingdom between 1996 and 2006, with particular attention to livers that were not retrieved, not transplanted, or that subsequently failed to function after transplantation. RESULTS: The difference between the number of patients registered for liver transplantation in the United Kingdom and those transplanted increased from 132 in 1996 to 333 in 2006, leading to a 77% increase in the number of waiting list deaths. Mean donor age increased by 6.1 (5.7-6.6) years during the period studied, in part because of a reduction in the proportion of donors arising from road fatalities. Despite this, the rate of primary nonfunction remained low (1.7% during 1996-2006). The absolute risk increase of primary nonfunction arising from receipt of a moderately as opposed to mildly steatotic organ was 2.6%, which translates to a "number needed to harm" of 41 patients. CONCLUSIONS: The decline in both the number and the quality of livers offered for transplantation in the United Kingdom during the past 10 years has not been associated with a change in the rate of primary nonfunction. In these times of acute donor shortage, these data may justify a more liberal use of marginal grafts