Cryoglobulinaemia

Immunoglobulins which undergo reversible precipitation at 4 deg C, dissolve when warmed to 37 deg C. One-third of cases are idiopathic

Three types

• type I (25%): monoclonal
• type II (25%): mixed monoclonal and polyclonal: usually with rheumatoid factor (RF)
• type III (50%): polyclonal: usually with RF

Type I

• monoclonal - IgG or IgM
• associations: multiple myeloma, Waldenstrom macroglobulinaemia

Type II

• mixed monoclonal and polyclonal: usually with RF
• associations: hepatitis C, RA, Sjogren's, lymphoma

Type III

• polyclonal: usually with RF
• associations: rheumatoid arthritis, Sjogren's

Symptoms (if present in high concentrations)

• Raynaud's only seen in type I
• cutaneous: vascular purpura, distal ulceration, ulceration
• arthralgia
• renal involvement (diffuse glomerulonephritis)

Tests

• low complement (esp. C4)
• high ESR

Treatment

• immunosuppression
• plasmapheresis