Immune complexes and cryoproteins in ascitic fluid of patients with alcoholic liver disease

27 paired specimens of ascitic fluid and serum obtained from patients with alcoholic liver disease were tested for cryoproteins and immune complexes by the C1q binding assay. 20 sera (74%) and ten ascitic fluid (37%) had significant amounts of cryoproteins. The cryoproteins were of the 'mixed' type of cryoglobulins consisting of IgG, IgM, IgA, C3 and C1q. The C1q binding test was positive in 17 sera (63%) and in 16 ascitic fluid (59%). Intracytoplasmic inclusions of immunoglobulin and complement were found within the ascitic fluid leukocytes by direct immunofluorescence. The presence of immune complexes in the ascitic fluid may be important in the reduction of the complement level of cirrhotic ascitic fluid.