Also to be emphasized is that the cryoglobulin concentration is not an index of disease severity; low concentrations of mixed cryoglobulin may be associated with life-threatening presentations, whereas patients with relatively high concentrations can be asymptomatic.
Given that most mixed cryoglobulins are present only in milligram concentrations, quantification by this method is unlikely to yield accurate results.
These cryoprecipitable immune complexes were mainly formed by IgM plus IgG or IgA and kappa light chain, corresponding to type III mixed cryoglobulins.
In conclusion, most HCV cryoglobulinemic patients included in our study presented mixed cryoglobulins and a vigorous polyclonal activation of B-lymphocytes due to chronic HCV infection and persistent immune stimulation.
Mixed cryoglobulins account for approximately 90% of cryoglobulins and are associated with chronic inflammatory diseases and infection.
Although monoclonal immunoglobulin cryoprecipitates (type I) usually appear within 24 h, mixed cryoglobulins may appear only after several days (1, 9).
For mixed cryoglobulins, however, which constitute >90% of the total cryoglobulins and are typically observed in chronic inflammatory conditions (6), further analysis and quantification is important to improve sensitivity and specificity, because visual inspection of mixed cryoglobulins at low concentrations lacks accuracy for detection and quantification.