Autoimmune hyperlipidemia in a patient. Atherosclerotic course and chaning immunoglobulin pattern during 21 years of study

Abstract

A 48 year old male patient presented with xanthomatosis, hyperbeta lipoproteinemia and hyper-IgA globulinemia; these two serum components occurred as a "complex." The patient has subsequently been studied for 22 years (1952 to 1974). His serum cholesterol and triglyceride levels have been consistently and excessively high despite efforts to regulate them by means of diet or diet and drugs. Serum immunoglobulin A (IgA) concentration ranged from 1,400 to 3,400 mg/dl compared with a normal value of 156 plus or minus 92 mg/dl. The metabolism of lipoproteins, judged by vitamin A turnover studies was slow. Peripheral atherosclerosis became evident 15 years after beginning the study whereas cinecoronary arteriography concurrently demonstrated only minimum changes. Xanthomas exhibited marked regression only during the last 6 years, after 16 years of diet and the addition of clofibrate for 7 years. Beta lipoprotein and IgA globulin determined by immunofluorescent and immunoelectrophoretic technics were demonstrated in the atherosclerotic material obtained from the patient's arterial wall. They were also found in the plasma cells of the bone marrow. The IgA globulin-beta lipoprotein complex in the serum was broken with difficulty. The patient's isolated IgA globulin, free of lipoprotein, formed a firm complex when mixed with beta lipoprotein prepared from normal human serum. Initially, IgA globulin studies showed presence of both kappa and lambda light chains in normal proportion. But after 18 years, the IgA globulin has become monoclonal, type lambda. The plasma cells of the bone marrow have become progressively more atypical and immature. No clinical indications of multiple myeloma have been found. It is concluded that association of lipoproteins with IgA globulin in the serum of this patient with hyperlipidemia, hyper-IgA globulinemia did not prevent the development of atherosclerotic lesions and the deposition of lipids and lipoproteins in the plaques. It is possible that the lipoprotein-immunoglobulin association may have retarded the process, since it became manifest only after many years of known hyperlipidemia.