CLASSIFICATION OF THE CRYOGLOBULINEMIC SYNDROME

As cryoprecipitation is a laboratory artifact, it is necessary to iden tify those patients with mixed cryoglobulinemia who actually have the cryoglobulinemic syndrome. In certain cases, although by no means freq uently, mixed cryoglobulins are associated with a vasculitis that prod uces a spectrum of manifestations resembling those of experimental ser um sickness. Therefore, we propose a set of criteria to be used as the starting point for establishing a definitive diagnosis. The next step in the classification of cryoglobulinemic syndromes is to define the primary or secondary nature of the disease process and the mono- or po lyclonal nature of the rheumatoid factor. Finally, the extent of the v asculitis must be assessed by screening for liver and renal involvemen t and peripheral neuropathy. Despite the high prevalence of HCV marker s in both the primary and secondary forms, we believe our classificati on is useful for characterizing groups of patients with different dise ases and different prognoses.