2020 RCD Criteria (IgG4-Related Disease)
Applies the 2020 revised comprehensive diagnostic criteria for IgG4-related disease.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Characteristic organ swelling, mass or nodule
- Yes
- Serum IgG4, mg/dL
- 300
- Dense lymphoplasmacytic infiltration with fibrosis
- Yes
- IgG4+/IgG+ ratio above 40 percent and over 10 per HPF
- Yes
Result: Definite IgG4-related disease
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What the result means
- Definite
- Items 1 + 2 + 3: characteristic organ involvement, an elevated serum IgG4, and the pathological item.
- Probable
- Items 1 + 3: characteristic organ involvement and the pathological item, without an elevated serum IgG4.
- Possible
- Items 1 + 2: organ involvement and a raised serum IgG4, with NO tissue. The weakest category, not a mild form of the disease.
- Item 1
- One or more organs showing diffuse or localized swelling, a mass or a nodule. Where a single organ is involved, lymph node swelling does not count.
- Item 3
- TWO of three: dense lymphoplasmacytic infiltration with fibrosis; IgG4+/IgG+ ratio above 40 percent with over 10 cells per HPF; storiform fibrosis or obliterative phlebitis.
- What 2020 changed
- The pathological item. Two of three, with storiform fibrosis or obliterative phlebitis as a third route, so a biopsy with poor immunostaining can still carry it.
- Why possible is weak
- Serum IgG4 also rises in malignancy, infection and other autoimmune disease, which is exactly where a mimic would sit.
What you enter
- Characteristic organ swelling, mass or nodule
- Lymph node swelling only, single organ
- Serum IgG4, mg/dL
- Dense lymphoplasmacytic infiltration with fibrosis
- IgG4+/IgG+ ratio above 40 percent and over 10 per HPF
- Storiform fibrosis or obliterative phlebitis
How this is calculated
Umehara H, Okazaki K, Kawa S, et al. The 2020 revised comprehensive diagnostic (RCD) criteria for IgG4-RD. Mod Rheumatol. 2021;31(3):529-533. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.