Transient hyperphosphatasemia after pediatric liver transplantation

Background: Transient hyperphosphatasemia (TH), the incidence of which in healthy children is 1.5–2.8%, is associated with a temporary elevation of serum alkaline phosphatase (ALP) without any other liver function test (LFT) abnormalities. Fast α₂ band, detected on agarose gel electrophoresis, is known to be a highly sensitive phenomenon in TH. The aim of this study was to elucidate the characteristics of TH after liver transplantation (LT). Methods: Five TH patients (6.0%) out of 83 who underwent LT between October 1996 and October 2014, were included in this study. Patient background, duration of TH, peak ALP, time course of ALP and its isoenzyme in TH, other LFT, and imaging results were retrospectively investigated. Results: Median patient age at the time of peak ALP during TH was 24 months (range, 16–98 months). Mean duration of TH was 111.0 ± 48.0 days. At 6887 IU/L, median ALP was elevated without any other LFT abnormalities. The first α₂ band was detected in all patients, and the band disappeared at the same phase of ALP normalization. All of the patients improved without any treatment. The prevalence of TH was significantly higher in the patients after LT than in age-matched healthy children (P < 0.05). Conclusions: The detection of fast α₂ band in the early phase allows for effective diagnosis of TH after LT, and 3–4 month follow up without treatment is feasible.