Investigations for cryoglobulinaemia and cryoglobulinaemic vasculitis
Investigations for cryoglobulinaemia include:
- serum cryoglobulin precipitate
- serum C4 complement protein concentration—reduced
- kidney function tests—serum electrolyte and creatinine concentrations, glomerular filtration rate (GFR), urinalysis; to exclude glomerulonephritis.
If cryoglobulinaemia is detected, investigate the person for a cause. Investigations will depend on the person’s clinical presentation, and the common aetiologies to consider include:
- multiple myeloma—serum electrophoresis
- chronic lymphocytic leukaemia—immunoelectrophoresis
- chronic viral infections
- hepatitis C (HCV)—HCV antibody testing and polymerase chain reaction (PCR) testing
- hepatitis B (HBV)—HBV antibody testing
- human immunodeficiency virus (HIV)—HIV antibody testing
- inflammatory rheumatological disease
- inflammatory markers—raised erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) concentration
- rheumatoid factor (RF) can be falsely elevated secondary to cryoglobulinaemia (especially in hepatitis C) and is nonspecific.