Table 1.
Level 1 and level 2 criteria for Type-1 AIP.
| Criterion | Level 1 | Level 2 |
|---|---|---|
| Parenchymal imaging | Typical: diffuse enlargement with delayed enhancement (sometimes associated with rim-like enhancement) | Indeterminate (including atypical): segmental/focal enlargement with delayed enhancement |
| Ductal imaging (ERP) | Long (>1/3 length of the main pancreatic duct) or multiple strictures without marked upstream dilatation | Segmental/focal narrowing without marked upstream dilatation (duct size, <5 mm) |
| Serology | IgG4, >2x_ upper limit of normal value | IgG4, 1–2x_upper limit of normal value |
| Other organ involvement (OOI) | a or b | a or b |
| a. Histology of extrapancreatic organs | a. Histology of extrapancreatic organs including endoscopic biopsy of bile duct | |
| Any three of the following: | Both of the following: | |
| (1) Marked lymphoplasmacytic infiltration with fibrosis and without granulocytic infiltration | (1) Marked lymphoplasmacytic infiltration with fibrosis without granulocytic infiltration | |
| (2) Storiform fibrosis granulocytic infiltration | (2) Abundant (>10 cells/HPF) IgG4-positive cells | |
| (3) Obliterative phlebitis | ||
| (4) Abundant (>10 cells/HPF) IgG4-positive cells | ||
| b. Typical radiological evidence | b. Physical or radiological evidence | |
| At least one of the following: | At least one of the following: | |
| (1) Segmental/multiple proximal (hilar/intrahepatic) or proximal and distal bile duct stricture | (1) Symmetrically enlarged salivary/lacrimal glands | |
| (2) Retroperitoneal fibrosis | (2) Radiological evidence of renal involvement described in association with AIP | |
| Histology of the pancreas | LPSP (core biopsy/resection) | LPSP (core biopsy) |
| At least 3 of the following: | Any 2 of the following: | |
| (1) Periductal lymphoplasmacytic infiltrate without granulocytic infiltration | (1) Periductal lymphoplasmacytic infiltrate without granulocytic infiltration | |
| (2) Obliterative phlebitis | (2) Obliterative phlebitis | |
| (3) Storiform fibrosis | (3) Storiform fibrosism | |
| (4) Abundant (>10 cells/HPF) IgG4-positive cells | (4) Abundant (>10 cells/HPF) IgG4-positive cells |
Diagnostic steroid trial. Response to steroid (Rt) Rapid (e2 wk) radiologically demonstrable resolution or marked improvement in pancreatic/extrapancreatic manifestations.