GPT and immune system toxicity: Immunotoxicity was associated with higher peak ALT than other causes of enzyme elevation (N = 17; M = 217, 95% CI 145–324 for immunotoxicity, N = 103; M = 74, 95% CI 59–92 for other causes; ratio of means 0.34, 95% CI 0.19–0.60, p = <0.001) and higher ALT:AST ratio (M = 1.27, 95% CI 0.78–2.06 for immunotoxicity, M = 0.69, 95% CI 0.59–0.80 for other causes, ratio of means 0.54, 95% CI 0.36–0.82, p = 0.004).