Table 2.

Diagnosis of definitive and probable Type-1 AIP using international consensus diagnostic criteria.

Diagnosis	Primary basis for diagnosis	Imaging evidence	Collateral evidence
Definitive Type-1 AIP	Histology	Typical/indeterminate	Histologically confirmed LPSP (level 1 H)
	Imaging	Typical	Any non-D level 1/level 2
		Indeterminate	Two or more from level 1 (+level 2 D*)
	Response to steroid	Indeterminate	Level 1 S/OOI + Rt or level 1 D + level 2 S/OOI/H + Rt
Probable Type-1 AIP		Indeterminate	Level 2 S/OOI/H + Rt

^*Level 2 D is counted as level 1 in this setting.