Background: Primary sclerosing cholangitis (PSC) is a chronic liver disorder of unknown etiology, characterized by inflammation, fibrosis and stenoses of both extra- and intrahepatic bile ducts. For those who develop end – stage liver disease, orthotopic liver transplantation (OLT) remains the only effective treatment currently available. PSC is accompanied with concomitant ulcerative coilitis (UC) in a significant proportion of patients. Benefits of routine HLA (human leukocyte antigen) typing in donor and recipient prior to OLT were proved in the past. The aim of this study was to assess the impact of HLA-DR mismatch on de novo colitis (after OLT) development and on the course of pre-existing (prior to OLT) UC.
Methods: We retrospectively evaluated records of 57 patients transplanted at Institute for Clinical and Experimental Medicine (Prague, Czech Republic) between July 1994 and November 2011. Only patients with proper records (including regular colonoscopy) ± 5 years from OLT were included. We evaluated likelihood for each variable (course pre-OLT UC, de novo UC development) in patients with either single, or double mismatch in HLA-DR. Input data were analysed with χ2 and Fisher's exact test using MedCalc statistical software. A p-value <0.05 was considered as statistically significant.
Results: Out of 57 patients, 27 (47.4%) had single mismatch and 30 (53.6%) had double mismatch in HLA-DR. No patient had full match. 12/57 (21.1%) had de-novo UC after OLT: 7/27 (25.9%) of single mismatch group and 5/30 (16.7%) of double mismatch group (p=0.60). In 37 (68.5%) patients, UC was diagnosed prior to OLT. 9/16 (56.3%) patients with single mismatch and 6/21 (28.6%) patients with double mismatch had more severe course of UC as compared to course prior to OLT (p=0.17).
Conclusions: Patients with single mismatch in HLA-DR have slight tendency towards worsening of pre-existing UC after OLT as compared to patients with double mismatch. Analysis of combined mismatch in HLA-DR and HLA-DQ could demonstrate more substantial linkages in respective clinical variables. Therefore, these data have to be considered as preliminary as typing for HLA-DQ from frozen blood samples is currently underway.