[New bioaffine sorbents for selective elimination of autoantibodies against human thyroperoxidase in autoimmune thyroid diseases].

New bioaffine sorbents containing bioselective ligand, synthetic analog of the human thyroperoxidase antigenic determinant--tetrapeptide H-Glu-Gln-betaAla-Lys-OMe, immobilized on two polymeric matrixes--a polyacrylamide gel and CNBr-activated sepharose 4B were synthesized. The offered immunosorbents were shown have high selectivity in relation to autoantibodies against thyroperoxidase and can find an application for medicine and experimental biochemistry for selective elimination of autoantibodies from serum or plasma of the patients suffering from autoimmune thyroid diseases.

Lipoprotein(a) apheresis in severe coronary heart disease: an immunoadsorption method.

Lipoprotein(a) (Lp[a]) is associated with an increased cardiovascular risk. It is similar to low-density lipoprotein with an additional molecule of apo A covalently linked to apo B-100 by one disulfide bridge. Apo A is highly homologous to plasminogen. The kringle 4 motive of plasminogen is repeated between 10 and 40 times in apo (a). Currently, there is no drug therapy available to lower Lp(a). Since October 1993, we have carried out over 160 immunoadsorption treatments on 3 patients with elevated Lp(a) as their only risk factor and a history of myocardial infarction. Lp(a) was removed from plasma by sepharose coupled anti-Lp(a) columns. Lp(a) levels were lowered from above 170 mg/dl to below 30 mg/dl immediately after Lp(a) apheresis. To achieve this, the patient's plasma volume had to be treated 2 to 3 times. Nonspecific protein loss during column changes remained negligible. There were no serious unwanted effects during or after treatment. Minor circulatory problems (tachycardia, flush) occurred in 11% of the treatments but only with plasma flow rates above 55 ml/min. In 1 patient, coronary angiography after 2 years and in another patient after 1 year showed no progression. The third patient has not yet had repeat coronary angiography. Like the others, he reported subjective improvement after 1 year of apheresis. It is concluded that Lp(a) apheresis may retard progression of atherosclerosis in patients with selective Lp(a) elevation. Further studies to support this hypothesis are needed.

[The sorption kinetics in an immunosorbent of circulating immune reactants in the blood of patients with systemic lupus erythematosus]. / Kinetyka sorbtsiï na imunosorbenti tsyrkuliuiuchykh imunnykh reaktantiv z krovi khvorykh na systemnyi chervonyi vovchak.

In a double-blind trial blood content was studied of antibodies to nDNA and dDNA (AB-nDNA and AB-dDNA) using methods of solid-phase and liquid-phase immunoassay, of circulating immune complexes (CIC), beta 2-microglobulin (beta 2-MG), Ig G, M, and A during the time-related run of two sessions of immunosorption (IS) or nonselective hemosorption (NHS) in 22 patients with systemic lupus erythematosus. In eleven patients there was employed for IS DNA-containing active carbon, in other eleven patients carbon was used for NHS. Throughout the whole IS session high- and low-avid AB-nDNA and CIC were getting fixed with the sorbent followed by AB-dDNA, with the concentration gradient for these substances in the column being greater at minute 30 than it was at minute 15. The control carbon fixed AB-nDNA and AB-dDNA as measured by ELISA but at the start of the session it did so also with low-avid AB-at minute 30. At minute 15 of perfusion the blood level of low-avid AB-nDNA and AB-dDNA following the column procedure tended to significantly increase both in NHS and, to a lesser extent, in IS. Neither of the sorbents adsorbed IG. Decline in beta 2-MG concentration in columns with engrafted and matrix carbon at the start of the perfusion and its rise during the second half of the session might be caused by blood cells structural and functional condition as a result of their interaction with the sorbent in question.

An improved affinity support and immunoadsorbent with a synthetic blood group oligosaccharide and polymer coating for hemoperfusion.

An improved affinity support and an immunoadsorbent suitable for extracorporeal perfusion of whole blood (or plasma) are reported. The affinity support consists of calcined diatomite-type silica particles to which a synthetic oligosaccharide hapten, viz. A-trisaccharide representing human blood group A, with a linking spacer-arm is chemically attached. The immunoadsorbent thus obtained is surface-modified with a polymer coating. The modified immunoadsorbent is not hemolytic and shows no loss of biological activity in reducing antibody titers in vitro. An important feature of the improved immunoadsorbent is that the polymer coating provides a better surface resistance and therefore stability to the affinity support to prevent the release of potentially harmful fines. The usefulness of a physically stable support as an affinity adsorbent for the selective removal of specific antibodies or unwanted substances directly from the blood circulation by extracorporeal immunoadsorption has profound medical significance because this would provide an efficient but safe and practical alternative to therapeutic intervention using plasma exchange or plasma perfusion, both of which require plasmapheresis.