title: Renal involvement in essential mixed cryoglobulinemia.
abstract: Essential mixed cryoglobulinemia (EMC) is infrequently recognized in this country. We report studies performed in six patients with EMC evaluated by us over the last 6 years. Purpura was present in three patients and glomerulonephritis in all. Two patients had chronic hepatitis B infection. Positive cryoglobulins and C1q binding, hypocomplementemia (especially low C4), positive rheumatoid factor titer, and negative anti-DNA antibodies were characteristic laboratory findings. The cryoprecipitate had strongly positive rheumatoid factor activity and contained a monoclonal IgM, kappa type in one of the two patients evaluated. The predominant lesion by renal biopsy was mesangiocapillary glomerulonephritis type I; electron microscopy revealed typical fibrillar structures in four cases. The above-mentioned features help distinguish EMC from other forms of glomerulonephritis.
authors.affiliation: Dialysis Unit (111C), Veterans Administration Medical Center, Miami, FL 33125.
authors.forename: G O
authors.initials: GO
authors.lastname: Perez
authors.forename: V
authors.initials: V
authors.lastname: Pardo
authors.forename: M
authors.initials: M
authors.lastname: Fletcher
mesh_terms: D000328:Adult; D000974:Antibodies, Antinuclear / Q000032:analysis; D001706:Biopsy; D003181:Complement C4 / Q000172:deficiency; D003449:Cryoglobulinemia / Q000150:complications*; D005260:Female; D005455:Fluorescent Antibody Technique; D005921:Glomerulonephritis / Q000209:etiology* / Q000276:immunology; D006509:Hepatitis B / Q000209:etiology; D006801:Humans; D007122:Immunoelectrophoresis; D007678:Kidney Glomerulus / Q000473:pathology*; D008297:Male; D008854:Microscopy, Electron; D012217:Rheumatoid Factor / Q000032:analysis
chemical_list: D000974:Antibodies, Antinuclear; D003181:Complement C4; D012217:Rheumatoid Factor