Ex vivo removal of IgE in atopic asthma by extracorporeal plasmoimmunoadsorption (EPIA): development of a clinical adsorbent.

We have developed an immunoadsorbent (IA) for ex vivo removal of IgE after in vitro screening of matrix (Sepharose and tresyl-activated Toyopearl) and ligand (monospecific rabbit polyclonal anti-IgE antiserum and monoclonal antibodies (Abs) or their Fab fragments). Specific adsorptive capacity (SAC) for IgE was maximal in Sepharose-based IA with both types of Abs. Fab-containing IA on Sepharose retained 70-90% of the SAC of native Ab-containing IA. Toyopearl-based IA showed comparable SAC under static conditions but worked unsatisfactorily under continuous flow conditions. To assess the complement-activating capacity (CAC) of IA in vitro anaphylatoxin (C3a, C4a, C5a) generation was applied. CAC was directly related with the amount of immobilized Ab ligand, without depending on Ab specific activity. Fab-containing IA showed more CAC than native Ab-containing IA, and polyclonal IA more than monoclonal IA. Therefore, IA for IgE apheresis were prepared from native monoclonal Abs and CNBr-activated Sepharose CL 4B under aseptic conditions and packed into a glass column. This IA was used in 17 clinical IgE apheresis treatments of five atopic asthma patients. No substantial side effects were observed; in vivo IA effectively removed IgE from plasma (83 to 98%).

The delayed respiratory consequences of inhaled radionuclides in population exposed to nuclear catastrophe.

Cytological analysis of bronchoalveolar lavage (BAL) and x-ray energy dispersive spectrometry of intercellular compounds were evaluated in 19 workers ("liquidators") commissioned to clean and contain the nuclear waste after the Chernobyl catastrophe in comparison with ten control subjects. Results showed a significant increase of neutrophils, small monocyte-like alveolar macrophages (AM) and AM with large black cytoplasmic inclusions. In addition, such mineral elements as Zr, Ce, Pr, Sm, Pa, PU and Cs were detected in AM phagosomes in liquidators. These elements were reported as markers of Chernobyl-type nuclear fuel. It is recognized that BAL gives access to particulate matter present in lung parenchyma. Thus, spectrometric analysis of AM inclusions can provide reliable information about the exposure to inhaled radionuclides seven years after the catastrophe.

Hyperactivation of platelets in asthma and introduction of platelet apheresis as treatment procedure.

Functional characteristics of platelets (Pts) were estimated in patients with different asthma forms (atopic and aspirin-sensitive). It was shown that Pts of asthmatics notwithstanding disease form are more sensitive to stimulating action of platelet-activating factor (PAF) in aggregation response and intracellular Ca2+ influx induction than Pts of healthy donors. Intracellular Ca2+ influx was measured using fluorescent zond Fura-2. Antiallergic drugs--ketotifen and sodium chromoglycate--caused 30-40% inhibition of PAF-induced aggregation of asthmatics' Pts. Platelet apheresis (PtA) was applicated attempting to normalize "hyperactivated" state of asthmatics' Pts. PtA treatment was performed using on-line cell separator Fenwal CS-3000 in 27 patients without any considerable side effect. Mean Pt yield was 400-600 X 10(9) cells; blood Pt count restored immediately after treatment. Positive clinical effect (complete reduction of asthmatic attacks for at least 2 months, improvement in respiratory function parameters) was observed in 19 out of 27 patients (70%). The clinical effect correlated well with the normalization of in vitro Pt response to PAF. It may be concluded that platelet apheresis has to be introduced as the treatment method for bronchial asthma, particularly in the patients with PAF-induced "hyperactivation" of Pts in vitro.