Interaction of plasma fibronectin with selected cryoglobulins.

Plasma fibronectin (PFN) is associated with cryoglobulins of the polyclonal type. Cryoglobulins from two patients with essential mixed cryoglobulinaemia were analysed immunoelectrophoretically to determine a possible association between PFN and immunoglobulin complexes in the formation of cryoprecipitates. In cryoglobulins from each patient, distinctive alterations in electrophoretic migration patterns of both PFN and immunoglobulin were associated with the formation of a cryoprecipitate. The observations indicate that PFN binds to some serum component in the process of cryoglobulin formation. That component may be immunoglobulin.