Abstract
BACKGROUND: Histological abnormalities (chronic hepatitis, fibrosis & steatosis) are increasingly reported in liver biopsies of children after liver transplantation (LT). These changes may be progressive & represent a form of rejection. Liver biochemistry is often initially normal. The LT programme in New Zealand began in 2002, utilising tacrolimus and low-dose steroids for the first year. Patients undergo a protocol biopsy at one year post LT prior to stopping steroids, then at 5 yrs and every 5 yrs thereafter. Target tacrolimus levels are 5–8 g/L and 3–5 g/L after 3 and 12 months respectively. AIMS: The evaluate the incidence and characteristics of histological abnormalities in protocol biopsies at 1 and 5 yrs post paeditric LT in a cohort of patients on predominantly tacrolimus monotherapy METHODS: Between 2002–2009, 51 children underwent LT; 50 (98%) and 49 (96%) patients survived for 1 and 5 yrs respectively. 41 patients (median age at LT 2.3 yrs) underwent a protocol biopsy at 1yr (16 male; median time post LT 12.5 months), and 43 (20 male; median time post LT 5.1 yrs) at 5 yrs. By 5 yrs, 3 had transferred to adult services; 1 was re-transplanted for graft failure & 1 moved overseas. Most patients (30/43) were on tacrolimus monotherapy at 5 yrs. RESULTS: At 1 & 5 yrs 29/41 (71%) & 29/43 (67.5%) biopsies were normal respectively. 2/43 had chronic immune hepatitis at 5 yrs. 1/41 & 3/43 had fibrosis, 3/41 & 3/43 steatosis, and 2/41 and 3/43 acute rejection at 1 & 5 years respectively. Other findings included predominantly biliary changes (6/41 & 2/43 at 1 & 5 yrs respectively). Tacrolimus levels at 5 yrs were slightly higher than anticipated (median trough level 5.1 g/L). CONCLUSIONS: With an immunosuppressive regimen of tacrolimus and low dose steroids for 1 year followed by tacrolimus monotherapy thereafter, the majority of protocol liver biopsies were normal and no progressive changes were observed at 5 yrs. Compared to other LT programmes, we have reduced rates of chronic allograft hepatitis, steatosis and fibrosis at 5 yrs. However, the tacrolimus levels at 5 yrs were higher than planned & this may have played a role. Further evaluation is also required to determine the potential long-term adverse effects of corticosteroid use on linear growth and bone mineral density FUNDING AGENCIES: None