Classification of cryoglobulins
| Type I cryoglobulinaemia | Type II mixed cryoglobulinaemia | Type III mixed cryoglobulinaemia | |
|---|---|---|---|
| HBV, hepatitis B virus; HCV, hepatitis C virus; Ig, immunoglobulin; m, monoclonal; NHL, non-Hodgkin's lymphoma; RF, rheumatoid factor. | |||
| Composition | Single monoclonal Ig mainly IgG, IgM, or IgA, or monoclonal free light chains | Presence of monoclonal component: usually IgM, IgG, or IgA and polyclonal Ig (mainly IgG) | Polyclonal mixed Ig (all isotypes) |
| Biological characteristics | Self aggregation through Fc fragment of Ig | RF activity of monoclonal component against Fc portion of polyclonal Ig predominant, cross idiotype Wa mRF | RF activity of one polyclonal component (usually IgM) |
| Pathological characteristics | Tissue histological alterations of underlying disorder | Leucocytoclastic vasculitis, B cell expansion, and tissue B cell infiltrates | Leucocytoclastic vasculitis, B cell expansion, and tissue B cell infiltrates |
| Clinical associations | Lymphoproliferative disorders: multiple myeloma, Waldenstrom's macroglobulinaemia, chronic lymphocytic leukaemia, B cell NHL | Viral, bacterial, parasitic infections (mainly HCV, less HBV, others), autoimmune diseases, lymphoproliferative disorders rare in essential form | Viral, bacterial, parasitic infections (mainly HCV, less HBV, others), autoimmune diseases, lymphoproliferative disorders rare in essential form |