Evaluation of adsorption selectivity dextran sulfate bound cellulose beads for the removal of anti-DNA antibodies.

The purpose of this study was to clarify the basic adsorption selectivity characteristics of dextran sulfate (DS) columns (Selesorb, Kaneka Corporation, Osaka, Japan). Recovery rates of blood chemical components, hormones, coagulation factors, and antinuclear antibodies (anti-SS-A, SS-B, Sm, Scl-70, and RNP antibody) in vitro were assessed by mixing normal volunteers' or patients' sera with DS bound cellulose beads. For tested blood chemical components other than triglyceride and total cholesterol, the recovery rate was not changed significantly by incubation. No significant changes in hormone levels resulted from incubation. Among coagulation factors, the activities of antithrombin III, plasminogen, and factors V, VIII, IX, XI, and XII were significantly reduced by incubation. Among antinuclear antibodies tested, anti-SS-A and anti-RNP were absorbed to some extent, but not anti-SS-B, Sm, or Scl-70 antibodies. Taking into account these characteristics, apheresis therapy using a DS column should be performed.

New adsorption column (Lixelle) to eliminate beta2-microglobulin for direct hemoperfusion.

The Lixelle column is an adsorbent column used to eliminate beta2-microglobulin (beta2M) selectively from circulating blood of dialysis related amyloidosis (DRA) patients, which is used in combination with a dialyzer in series. The column has such a high capacity for adsorbing beta2M that the most intensive removal of beta2M has been possible. In clinical trials of the column, the obvious improvement of subjective symptoms such as decreases in the frequency of nocturnal awakening, the joint pain severity index, and the joint mobility index were observed. Hypotension has been the most frequent adverse event observed during treatment since the column was put on the market. It is very important to clarify the causes of both the efficacy and the side effects. A controlled prospective study is now in progress to clarify the efficacy more scientifically. The results will be published soon elsewhere.

Therapeutic selective adsorption of anti-DNA antibody using dextran sulfate cellulose column (Selesorb) for the treatment of systemic lupus erythematosus.

The Selesorb therapeutic dextran sulfate cellulose column (Kaneka Corporation, Osaka, Japan) selectively adsorbs anti-DNA antibody, anti-cardiolipin antibody, and immune complex from the plasma of patients with systemic lupus erythematosus (SLE). The Selesorb system is composed of twin columns attached to an automated regeneration apheresis unit. Anti-DNA antibody in plasma is continuously removed through 1 of the 2 columns alternately. Clinical application of the Selesorb system to SLE patients with high titers of anti-DNA antibody showed improvement of proteinurea, arthralgia, rash, lymphocytopenia, etc., with the concurrent use of steroid and/or immnosuppressant. Angiotensin converting enzyme inhibitor should not be administered to patients treated with the Selesorb system to avoid anaphylactoid reactions based on rapid increases of bradykinin concentrations in the blood.

[Studies on anti-DNA antibodies associated with renal involvement by enzyme-linked immunosorbent assay in patients with systemic lupus erythematosus].

It has been reported that a significantly higher incidence of lupus nephritis was found in patients with high avidity anti-DNA antibodies. Radioimmunoassay (Farr's assay) is a method which enables to detect high avidity anti-DNA antibodies, whereas enzyme-linked immunosorbent assay (ELISA) can detect anti-DNA antibodies from low to high avidity. There are, however some patients who had high levels of anti-DNA antibodies by Farr's assay without renal involvement. In this study, ELISA was developed to detect IgG anti-DNA antibodies highly associated with lupus nephritis by changing salt concentration of reaction buffer solution. Levels of a fraction, we call [0.1 M - 0.3 M] fraction, which was obtained from the antibody levels measured under 0.1 molar of sodium chloride (NaCl) subtracted by antibodies levels under 0.3 molar of NaCl solution were found to be significantly higher in patients with urinary protein (p = 0.0074) and low serum complement (C 3 less than 50 mg/dl; p = 0.0026, C 4 less than 10 mg/dl; p = 0.0280 and CH 50 less than 30 U/mL; p = 0.0662). Among the patients with hypocomplementemia, levels of [0.1 M - 0.3 M] fraction were significantly higher in patients with urinary protein than in patients without renal involvement. This fraction might be consistent with anti-DNA antibodies with intermediate avidity that are related to lupus nephritis. The ELISA procedure established in this study is showed to be a available method to detect anti-DNA antibodies associated with renal disease in patients with systemic lupus erythematosus.

Anti-dsDNA antibody kinetics during in vivo apheresis in systemic lupus erythematosus patients and in an in vitro apheresis model.

Levels of anti-dsDNA measured just after an immunoadsorption procedure in systemic lupus erythematosus (SLE) patients are sometimes paradoxically larger than those measured just before the procedure. A 1:100 in vitro single-compartment immunoadsorption system model was devised to determine which of two models, one- or two-compartment, more closely approximates the kinetics of anti-dsDNA during apheresis procedures. Ten SLE patients were employed in this study. A total of 4,100 ml of plasma was passed through the dextran sulfate cellulose columns during one clinical apheresis session. In eight of ten patients, the log of RIA-measured anti-dsDNA titers decreased linearly as treated plasma volume increased, in both the clinical procedure and the experimental model. The mean adsorption efficacy in the clinical apheresis procedure and in the in vitro model was 0.37 and 0.27, respectively. However, in one patient the RIA-measured level of anti-dsDNA increased during the apheresis procedure; this phenomenon was mirrored in the model (definitely a single pool model). In contrast, the level of anti-dsDNA, as measured by ELISA, decreased in accordance with the increase of treated plasma volume in both the clinical and the in vitro apheresis procedures. Therefore, an increased titer of anti-dsDNA as measured by RIA immediately following clinical apheresis cannot be accounted for exclusively by an inflow of antibodies from a secondary (extravascular) pool into the circulating plasma. In short, a one-compartment model is applicable and an explanation must be sought elsewhere.

Anti-DNA antibody kinetics following selective removal by adsorption using dextran sulphate cellulose columns in patients with systemic lupus erythematosus.

The aim of this study is to determine by mathematical analysis which of two models, the one- or the two-compartment model, more closely approximates the kinetics of anti-dsDNA following immunoadsorption procedures in patients with systemic lupus erythematosus. Titers of anti-dsDNA were measured at specified intervals after apheresis to each model by nonlinear least-squares methods, and Akaike's Information Criterion (AIC) was calculated to determine which model most approximately described the kinetics. The AIC of the two-compartment model was larger than that of the one-compartment model in all 14 SLE patients (P < .001). Therefore, the one-compartment model is thought to be suitable. The generation rate and catabolic rate of anti-dsDNA were obtainable using this model. The anti-dsDNA replenishment curve after an immunoadsorption session was defined by only two parameters: the generation and catabolic rates of anti-dsDNA.

Activities of some enzymes of lignin formation in reaction wood of Thuja orientalis, Metasequoia glyptostroboides and Robinia pseudoacacia.

The activities of the following five enzymes which are involved in the formation of lignin have been compared in reaction wood and in opposite wood: phenylalanine ammonia lyase (EC 4.3.1.5), caffeate 3-O-methyltransferase (EC 2.1.1.-), p-hydroxycinnamate: CoA ligase (EC 6.2.1.12), cinnamyl alcohol dehydrogenase (EC 1.1.1.-) and peroxidase (EC 1.11.1.7). The activities of the four first-named enzymes in the compression wood of Thuja orientalis L. and Metasequoia glyptostroboides Hu et Cheng were 2.8±1.4-fold and 2.6±1.5-fold higher than those in opposite wood, respectively, whereas peroxidase had the same level of activity in either type of wood. On the other hand, no differences were observed in the activities of the five enzymes between tension and opposite woods of Robinia pseudoacacia L. These findings are well in accord with the chemical structure of lignin in the compression and tension woods of the three species studied: high content of lignin rich in condensed units in compression wood, and little difference in lignin between tension and opposite woods.