Rapid cryoglobulin screening: an aid to the clinician.

A rapid screening method for serum cryoblobulin is reported. It requires only common laboratory equipment and is based upon the detection of light scattering (500 millimicron) in the early phase of cryoaggregation. All of 28 sera negative for cryoglobulins by the conventional 5-day incubation method were negative by the screening method. Conversely, all sera containing 60 microgram/ml or more of mixed cryoglobulins were positive by the screening method. The initiation phase of cryoprecipitation in mixed cryoglobulins was found to be prompt, as reported previously for monoclonal cryoglobulins. This sensitive method of cryoglobulin detection provides results to the clinician within 2 hours, a helpful insight where consideration of possible immune complex vasculitis exists.