Mixed cryoglobulinemia associated with liver disease is well known, but its mechanism and signification still have to be elucidated. The purpose of this study was to identify and to characterize hepatic disease by their immunochemical features among 60 patients presenting with mixed cryoglobulinemia. Thirteen cases of alcoholic liver disease and 8 of virus B hepatitis out of 40 cases in all of hepatic disease in this group were studied. A higher frequency of type III immunochemical features of cryoglobulinemia in alcoholic disease (83 p. 100), no matter how severe, as well as a higher frequency of type II in virus B hepatitis (62 p. 100) was demonstrated. There was no relationship between virus B hepatitis and cryoglobulinemia in our population. Therefore, the responsibility of virus B hepatitis in essential mixed cryoglobulinemia genesis has to be clarified. The localization of cryoglobulin in the Kupffer cell in two patients with chronic hepatitis confirms the essential role of the reticuloendothelial system in blood clearance of circulating immune complexes.

Thirty human cryoglobulin precipitates obtained from 21 patients were fixed and examined by electron microscopy; following biochemical isolation and identification. This study showed that the fine structure of cryoprecipitates depends on the involved immunoglobulins and on their respective quantities. Monoclonal IgG kappa 1 or 3 cryoglobulins with antibody activity form crystalling precipitates of 22-nm diameter rods and annuli. When polyclonal, they form 6-nm-wide filaments. Mixed IgG and IgM cryoprecipitates appear as cylindric and annular bodies with an internal diameter of 12 nm and a total diameter of 62 nm. When IgM predominates over IgG, globular condensations with a diameter of 30 nm are seen. Mixtures in which the IgG is more abundant than the IgM include fingerprint-like periodic condensations.

Comparative studies of renal biopsy specimens and in vitro cryoprecipitate were carried out in a patient with mixed immunoglobulin G (IgG)-immunoglobulin M (IgM) cryoglobullnemia associated with glomerulonephritis. The IgM isolated from the cryoprecipitate was an antibody with anti-IgG activity. Proliferative endocapillary glomerulonephritis was found in the kidney, with large amorphous deposits in the capillary walls. On immunofluorescent examination, these deposits contained IgG and C3. Ultrastructural studies of both cryoprecipitate and glomerular deposits revealed unusual structures designated as "cylindrical or annular bodies." The morphologic characteristics of these bodies were exactly the same in the kidney and in the cryoprecipitate. These findings suggest an identity between the glomerular deposits and the circulating cryoglobulin, supporting the hypothesis that the glomerulonephritis reported here is an immune-complex disease.

Comparative studies of renal biopsy specimens and in vitro cryoprecipitate were carried out in a patient with mixed immunoglobulin G (IgG)-immunoglobulin M (IgM) cryoglobulinemia associated with glomerulonephritis. The IgM isolated from the cryoprecipitate was an antibody with anti-IgG activity. Proliferative endocapillary glomerulonephritis was found in the kidney, with large amorphous deposits in the capillary walls. On immunofluorescent examination, these deposits contained IgG and C3. Ultrastructural studies of both cryoprecipitate and glomerular deposits revealed unusual structures designated as "cylindrical or annular bodies." The morphologic characteristics of these bodies were exactly the same in the kidney and in the cryoprecipitate. These findings suggest an identity between the glomerular deposits and the circulating cryoglobulin, supporting the hypothesis that the glomerulonephritis reported here is an immune-complex disease.

“Fingerprint bodies” are added to the “atypical” formations described in diseased muscle. These subsarcolemmal inclusions are variable in size and number, not membrane-bound and are formed by fine microtubules. They are not characteristic of a specific muscular disease and occur probably along with a focal anomaly of myofilament synthesis.