Drug and herb induced liver injury: Council for International Organizations of Medical Sciences scale for causality assessment

Table 4 Conditions of unintentional reexposure tests in drug induced liver injury and herb induced liver injury cases

Reexposure test result	Hepatocellular type of liver injury		Cholestatic or mixed type of liver injury
	ALTb	ALTr	ALPb	ALPr
Positive	< 5N	≥ 2ALTb	< 5N	≥ 2ALPb
Negative	< 5N	< 2ALTb	< 5N	< 2ALPb
Negative	≥ 5N	≥ 2ALTb	≥ 5N	≥ 2ALPb
Negative	≥ 5N	< 2ALTb	≥ 5N	< 2ALPb
Negative	≥ 5N	NA	≥ 5N	NA
Uninterpretable	< 5N	NA	< 5N	NA
Uninterpretable	NA	NA	NA	NA

Conditions and criteria for an unintentional reexposure test are described in previous reports[4,21,22,24,26,27]. Accordingly, required data for the hepatocellular type of liver injury are the ALT levels just before reexposure, designed as baseline ALT or ALTb, and the ALT levels during reexposure, designed as ALTr. Response to reexposure is positive, if both criteria are met: first, ALTb is below 5N with N as the upper limit of the normal value, and second ALTr ≥ 2ALTb. Other variations lead to negative or uninterpretable results. For the cholestatic or mixed type of liver injury, corresponding values of ALP are to be used rather than of ALT. ALP: Alkaline phosphatase; ALT: Alanine aminotransferase; NA: Not available.