IgA and temperature dependent IgG complex formation in a patient with Waldenström's hypergammaglobulinaemic purpura.

We describe a patient with hypergammaglobulinaemic purpura and show that the serum contains IgG and IgA immune complexes sedimenting between IgM and IgG on ultracentrifugation. The complexes containing IgG were markedly temperature dependent. A drop in temperature from 37 degrees C to 28 degrees C gave a seventeen-fold increase in the quantity of these complexes. This temperature dependency may be an important factor in localizing the major pathological manifestation of this disease to the skin.