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.

[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.