Proposed criteria for the classification of patients with mixed cryoglobulinaemia
| Criteria | Major | Minor |
|---|---|---|
| HCV+ or HBV+: markers of hepatitis C virus or hepatitis B virus infection (anti-HCV ±HCV RNA; HBV DNA or HBV surface antigen). | ||
| “Definite” mixed cryoglobulinaemia syndrome: | ||
| (a) Serum mixed cryoglobulins (±low C4) + purpura + leucocytoclastic vasculitis. | ||
| (b) Serum mixed cryoglobulins (±low C4) + 2 minor clinical symptoms + 2 minor serological/pathological findings. | ||
| “Incomplete” or “possible” mixed cryoglobulinaemia syndrome: | ||
| (a) Mixed cryoglobulins or low C4 + 1 minor clinical symptom + 1 minor serological ±pathological findings. | ||
| (b) Purpura and/or leucocytoclastic vasculitis + 1 minor clinical symptom + 1 minor serological ±pathological findings. | ||
| (c) Two minor clinical symptoms + 2 minor serological ± pathological findings. | ||
| “Essential” or “secondary” mixed cryoglobulinaemia: | ||
| Absence or presence of well known disorders (infectious, immunological, or neoplastic) at the time of the diagnosis. | ||
| Serological | Mixed cryoglobulins | Rheumatoid factor+ |
| Low C4 | HCV+ | |
| HBV+ | ||
| Pathological | Leucocytoclastic vasculitis | Clonal B cell infiltrates (liver and/or bone marrow) |
| Clinical | Purpura | Chronic hepatitis |
| Membranoproliferative glomerulonephritis | ||
| Peripheral neuropathy | ||
| Skin ulcers | ||