Mixed cryoglobulins and heterogeneity restriction

: Cryoglobulins from 143 patients were analyzed using an immunoblot technique with a nitrocellulose membrane. Fifty-four p. cent of cases were classified as type III, with polyclonal IgG, IgA, and IgM being the most common components. Type II was found in 24% of cases, with a monoclonal IgM in most instances. Lastly, classification was impossible in 22% of cases, usually because of the presence of oligoclonal IgM bands. Use of this highly sensitive technique to analyse cryoglobulins raises the problem of identification of patterns that are difficult to include in types II and III.