Table 1 ICDC criteria for AIP diagnosis.
| TYPE 1 AIP | ||
|---|---|---|
| CRITERION | LEVEL 1 | LEVEL 2 |
| Parenchymal imaging [P] | Typical Diffuse enlargement with delayed enhancement (with or without rim-like enhancement) | Indeterminate (and atypical) Segmental/focal enlargement with delayed enhancement |
| Ductal imaging (ERP) [D] | Long (>1/3 of the total length of MD) or multiple strictures without marked upstream dilation | Segmental/focal narrowing without marked upstream dilation (duct size <5 mm) |
| Serology [S] Other organ involvement [OOI] | IgG4 increased > 2x upper normal value A or B A: histology of extrapancreatic organs (3 or more) 1-marked lymphoplasmacytic infiltration with fibrosis and without granulocytic infiltration 2-storiform fibrosis 3-obliterative phlebitis 4-IgG4-positive cells >10/HPF B: Typical radiological evidence (one of) 1-segmental/multiple proximal or proximal and distal bile duct stricture 2-retroperitoneal fibrosis | IgG4 increased < 2x upper normal value A or B A: histology of extrapancreatic organs+endoscopic biopsies of bile duct (1+2) 1-marked lymphoplasmacytic infiltration without granulocytic infiltration 2- IgG4-positive cells >10/HPF B: physical or radiological evidence (one of) 1-symmetrically enlarged salivary or lachrymal glands 2-radiological evidence of renal involvement |
| Histology of pancreas [H] | LPSP (biopsy/resection) (3 or more) 1-periductal lymphoplasmacytic infiltrate without granulocytic infiltration 2-obliterative phlebitis 3-storiform fibrosis 4-IgG4-positive cells >10/HPF | LPSP (biopsy) (2 of) 1-periductal lymphoplasmacytic infiltrate without granulocytic infiltration 2-obliterative phlebitis 3-storiform fibrosis 4-IgG4-positive cells >10/HPF |
| Response to steroid [Rt] | Diagnostic steroid trial : < 2 weeks treatment with radiological resolution or marked improvement in pancreatic or extrapancreatic manifestations | |
| TYPE 2 AIP | ||
| LEVEL 1 | LEVEL 2 | |
| Parenchymal imaging [P] | Typical Diffuse enlargement with delayed enhancement (with or without rim-like enhancement) | Indeterminate (and atypical) Segmental/focal enlargement with delayed enhancement |
| Ductal imaging (ERP) [D] | Long (>1/3 of the total length of MD) or multiple strictures without marked upstream dilation | Segmental/focal narrowing without marked upstream dilation (duct size <5 mm) |
| Serology [S] Other organ involvement [OOI] | Inflammatory bowel disease | |
| Histology of pancreas [H] | IDCP (resection (biopsy)) (1+2) 1-granulocytic infiltration of duct wall (GEL) with or without granulocytic acinar inflammation 2-IgG4 positive cells 0–10/HPF | IDCP (resection (biopsy)) (1+2) 1-granulocytic and lymphoplasmacytic acinar infiltrate 2-IgG4-positive cells 0–10/HPF |
| Response to steroid [Rt] | Diagnostic steroid trial : < 2 weeks treatment with radiological resolution or marked improvement in pancreatic or extrapancreatic manifestations |
AIP: autoimmune pancreatitis; OOI: Other Organ Involvement; LPSP: lymphoplasmacytic sclerosing pancreatitis; IDCP: idiopathic duct-centric pancreatitis; MD=main pancreatic duct