Quantitative assessment of serum beta-2-microglobulin in liver transplant recipients and relationship to liver graft rejection

Objective: To investigate the usefulness of serum β2-microglobulin determination in the diagnosis of acute liver allograft rejection. Design: Prospective study. Setting: Liver transplant unit. Patients: Twenty consecutive patients who underwent liver transplantation because of a non-virus-related end-stage liver disease. Methods: Serum samples were collected before the transplant, at days 7, 30 and 90 and whenever a clinical complication developed after liver transplantation. β2-Microglobulin was quantified using a new quantitative automated microparticle enzyme immunoassay. Results: Serum β2-microglobulin levels increased significantly (P<0.05) during rejection episodes and correlated with the degree of hepatocyte injury as assessed using serum aspartate aminotransferase levels. Increased β2-microglobulin levels were also found in surgical or infectious post-transplant complications. A significant difference in β2-microglobulin values was recorded between patients with rejection and only those with bacterial sepsis. Conclusion: Although highly sensitive in recognizing damage to the graft, determination of β2-microglobulin was not sufficiently specific to differentiate between rejection and other post-transplantation complications. European Journal of Gastroenterology & Hepatology 1995, 7:1215–1219