Comparison of clinical and laboratory findings between type I and mixed cryoglobulinemia (type II/III)
| . | Type I . | Mixed cryoglobulinemia (type II/III) . |
|---|---|---|
| Main clinical findings | ||
| Purpura | ∼70% | ∼90% |
| Skin ulcers | ∼30% | ∼15% |
| Glomerulonephritis | ∼30% | ∼30% |
| Peripheral neuropathy | ∼30% | ∼30% |
| Arthralgia | ∼30% | 25%-40% |
| Involvement of lungs, heart, GI tract, and central nervous system | Almost never | Rare (∼5%) |
| Hyperviscosity syndrome | Occasionally; usually in IgM isotype and when M-protein is >4 g/dL | Rarely; never in type III |
| Laboratory findings | ||
| Cryoglobulin composition | Monoclonal Ig’s (usually IgG or IgM) | Type II: monoclonal IgM with RF activity plus polyclonal IgG;Type III: polyclonal IgM with RF activity plus polyclonal IgG |
| Cryocrit | Above 5%; can reach more than 50% | Less than 5% |
| Complement assays | May be decreased | Decreased (mainly C4) |
| RF activity | Occasionally increased | Increased |
| Underlying disease | ||
| Monoclonal gammopathies: MGUS, MM, WM, CLL, non-Hodgkin lymphoma (rarely) | HCV, other infections (eg, HBV, HIV, bacterial endocarditis), connective tissue diseases (mainly systemic lupus erythematosis, rheumatoid arthritis, Sjögren's syndrome), hematologic malignancies (WM, other B-cell non-Hodgkin lymphomas, CLL; type II only), unknown (essential mixed cryoglobulinemia) |
| . | Type I . | Mixed cryoglobulinemia (type II/III) . |
|---|---|---|
| Main clinical findings | ||
| Purpura | ∼70% | ∼90% |
| Skin ulcers | ∼30% | ∼15% |
| Glomerulonephritis | ∼30% | ∼30% |
| Peripheral neuropathy | ∼30% | ∼30% |
| Arthralgia | ∼30% | 25%-40% |
| Involvement of lungs, heart, GI tract, and central nervous system | Almost never | Rare (∼5%) |
| Hyperviscosity syndrome | Occasionally; usually in IgM isotype and when M-protein is >4 g/dL | Rarely; never in type III |
| Laboratory findings | ||
| Cryoglobulin composition | Monoclonal Ig’s (usually IgG or IgM) | Type II: monoclonal IgM with RF activity plus polyclonal IgG;Type III: polyclonal IgM with RF activity plus polyclonal IgG |
| Cryocrit | Above 5%; can reach more than 50% | Less than 5% |
| Complement assays | May be decreased | Decreased (mainly C4) |
| RF activity | Occasionally increased | Increased |
| Underlying disease | ||
| Monoclonal gammopathies: MGUS, MM, WM, CLL, non-Hodgkin lymphoma (rarely) | HCV, other infections (eg, HBV, HIV, bacterial endocarditis), connective tissue diseases (mainly systemic lupus erythematosis, rheumatoid arthritis, Sjögren's syndrome), hematologic malignancies (WM, other B-cell non-Hodgkin lymphomas, CLL; type II only), unknown (essential mixed cryoglobulinemia) |