MINI-MICROABSCESS SYNDROME IN LIVER-TRANSPLANT RECIPIENTS

Cytomegalovirus (CMV) is a significant cause of morbidity in immunosup pressed patients. It is characterized in the liver by parenchymal micr oabscesses, usually containing CMV-infected cells. However, not all he patic microabscesses are due to CMV infection. In 1992, we described ' 'mini'' microabscess (MMA) syndrome, a distinct clinical syndrome that occurs in transplanted livers. This report analyzes the clinical and laboratory features of 57 cases of MMA syndrome occurring in 52 patien ts and compares these with 19 biopsy-proven cases of CMV infection. Th e diagnosis of MMA syndrome can only be made histologically. The micro abscesses are smaller and more numerous than in CMV infection, and the re are no viral inclusions present. CMV DNA could not be detected in l iver biopsy specimens with MMAs by using ''nested'' polymerase chain r eaction (PCR), indicating that MMA syndrome is not caused by CMV infec tion. The pattern of liver enzyme and bilirubin elevation is predomina ntly hepatocellular, with transaminase levels elevated, on average, si x to eight times the upper limit of normal. The clinical features of M MA syndrome are that it predominantly affects female (40 of 52 patient s) orthotopic liver transplant (OLT) recipients of all ages (range, 11 months to 66.9 years). MMA syndrome is unrelated to the indication fo r initial OLT and tends to occur later after transplantation than CMV infection (median, 91 days post-OLT vs. 32 days for CMV hepatitis). Al though the etiology of MMA syndrome is not clear, it does not appear t o adversely affect graft or patient survival.