Graft-versus-host disease after orthotopic liver transplantation: multivariate analysis of risk factors.

Graft-versus-host disease (GVHD) is a rare, fatal complication following orthotopic liver transplantation (OLT). To date, several risk factors have been proposed, but reports on these factors have been inconclusive. This is a retrospective, case-control study of prospectively collected data from 2775 OLTs performed at our institution. Eight cases of GVHD after OLT were diagnosed on the basis of the patient's clinical characteristics, and the findings were confirmed with skin and colonic biopsies. Each case was matched to three controls based on the diagnosis of liver disease, recipient's age, and blood group. Univariate and multivariate analyses were performed to identify risk factors associated with the development of GVHD after OLT. The univariate and multivariate analyses identified two main risk factors associated with development of GVHD in OLT recipients, a difference between recipient and donor age of >20 yr, and any human leukocyte antigen class I matches. Taking these two risk factors into consideration while matching prospective donors and recipients may reduce further incidence of GVHD in OLT patients. However, further studies are recommended to validate these findings.

Excellent renal allograft survival in donor-specific antibody positive transplant patients-role of intravenous immunoglobulin and rabbit antithymocyte globulin.

BACKGROUND: Timely transplantation of sensitized kidney recipients remains a challenge. Patients with a complement-dependent cytotoxicity negative and flow cytometry (FC) positive crossmatch carry increased risk of antibody-mediated rejection and thus graft loss. Solid phase assays are available to confirm donor specificity for antibody identified by FC crossmatch. Treatment using induction therapy with rabbit antithymocyte globulin (RATG) and intravenous immunoglobulin (IVIG) may allow successful transplant of these high-risk patients. METHODS: A retrospective study of 264 consecutive patients after exclusions yielded 94 complement-dependent cytotoxicity anti-human globulin crossmatch-negative patients, including group 1: 58 primary transplants with panel-reactive antibody (PRA) less than 20%, group 2: 16 retransplants and PRA more than 20% who were FC crossmatch-negative, and group 3: 20 retransplants and PRA more than 20% who were FC crossmatch-positive. All were treated with RATG induction and maintenance therapy with tacrolimus, mycophenolate mofetil, and corticosteroids. Only group 3 received IVIG at 500 mg/kg daily in three doses. RESULTS: Eighteen of 20 patients in group 3 had donor-specific antibody identified by solid phase assay. Cellular- and antibody-mediated rejections were statistically higher in group 3. Two-year serum creatinine and glomerular filtration rate along with 3-year patient and graft survival were comparable between the groups. CONCLUSIONS: Sensitized patients with positive FC crossmatch and donor-specific antibody identified by solid phase assays can be successfully transplanted using standard RATG induction, IVIG, and maintenance immunosuppression with equal renal function and graft survival to immunologically lower risk recipients. Given these results, this patient group should not be excluded from transplantation based on antibody specificities determined by virtual crossmatch techniques.

Matrix metalloproteinase-9 contributes to brain extravasation and edema in fulminant hepatic failure mice.

BACKGROUND/AIMS: Fulminant hepatic failure (FHF) can be dreadful. When coma sets in, brain edema develops taking FHF into a lethal course. Mechanisms of brain extravasation leading to brain edema remain incompletely understood. Matrix metalloproteinase (MMP)-9 is implicated in various brain injuries. We hypothesized that MMP-9 contributes to brain edema in FHF. METHODS: MMP-9 and its proform were assayed using SDS-PAGE and in situ gelatin zymographies. Brain extravasation was assessed with Evans blue. Brain water was determined by specific gravity and astrocytic endfoot swelling by electron microscopy. FHF in mice was induced by azoxymethane. MMP inhibitor GM6001 and MMP-9 monoclonal antibody were used. RESULTS: Active MMP-9 was significantly increased at the onset of coma and brain extravasation in FHF mice. Blocking MMP-9 with either GM6001 or MMP-9 monoclonal antibody significantly attenuated brain extravasation, astrocytic endfoot swelling, and brain edema. Brains of FHF mice did not show MMP-9 activity. In contrast, livers of these animals showed marked up-regulation of MMP-9 activity. CONCLUSIONS: Our findings suggest that MMP-9 contributes to the pathogenesis of brain extravasation and edema in FHF. The necrotic liver is the source of MMP-9 in FHF. Inhibition of MMP-9 may protect against the development of brain edema in FHF.