title: Observations on cryoglobulin testing: I. The association of cryoglobulins containing rheumatoid factors with manifestation of cryoglobulinemic vasculitis.
abstract: OBJECTIVE
  To investigate the results of mixed cryoglobulin tests performed on patients with and without hepatitis C virus (HCV) infection, to determine whether type II cryoglobulins containing rheumatoid factor (Type II-RF) were associated with cryoglobulinemic vasculitis.
  
  
  METHODS
  The cryoglobulin test protocol differed from the routine protocol. In addition to determination of both cryoglobulin concentration and immunoglobulin composition, the presence or absence of RF concentrated in the cryoglobulins was determined.
  
  
  RESULTS
  A qualitative and quantitative association of Type II-RF cryoglobulins with cryoglobulinemic vasculitis was present among HCV-infected patients.
  
  
  CONCLUSIONS
  Detection and quantification of Type II-RF may enhance clinical monitoring of cryoglobulinemic vasculitis in HCV-infected patients.
authors.affiliation: Department of Laboratory Medicine, Lahey Clinic, Burlington, MA 01805, USA.
authors.forename: Francesco G
authors.initials: FG
authors.lastname: De Rosa
authors.forename: Vincent
authors.initials: V
authors.lastname: Agnello
mesh_terms: D000328:Adult; D000368:Aged; D003449:Cryoglobulinemia / Q000097:blood* / Q000209:etiology*; D003450:Cryoglobulins / Q000378:metabolism*; D005260:Female; D006403:Hematologic Tests; D006526:Hepatitis C / Q000097:blood* / Q000150:complications*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012217:Rheumatoid Factor / Q000097:blood; D014657:Vasculitis / Q000097:blood* / Q000209:etiology*
chemical_list: D003450:Cryoglobulins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012217:Rheumatoid Factor