acetylcellulose and Hypersensitivity

Metalworking fluids (MWF) are responsible for hypersensitivity pneumonitis (HP). The aim of the present study was to identify the antigen (Ag) responsible for MWF-associated HP, and to optimise serological diagnosis by definition of a threshold allowing discrimination between HP patients and asymptomatic exposed workers. 13 patients, who were workers at a car engine manufacturing plant, were suspected of MWF-associated HP. Microbial analysis of 83 used MWFs was carried out. Sera from 13 MWF-associated HP patients, 12 asymptomatic exposed workers and 18 healthy unexposed controls were tested to determine their immunological responses to three Ags, including Mycobacterium immunogenum. M. immunogenum was identified in 40% of used fluids by culture and confirmed by DNA sequencing. The threshold for differentiating MWF-associated HP patients from asymptomatic exposed workers was five arcs of precipitation (sensitivity 77% and specificity 92%), as determined by electrosyneresis (ES). Using ELISA methods with protein extract from M. immunogenum, a threshold leading to 92% sensitivity and 100% specificity was established. The detection of specific antibodies against M. immunogenum Ag at high levels in case sera suggests that M. immunogenum-contaminated MWF is responsible for MWF-associated HP. To discriminate MWF-associated HP patients from asymptomatic exposed workers, we suggest a five-arc threshold for ES and a 1.6-AU threshold for ELISA methods.

Topics: Adult; Alveolitis, Extrinsic Allergic; Cellulose; Enzyme-Linked Immunosorbent Assay; Humans; Hypersensitivity; Industrial Oils; Male; Metallurgy; Middle Aged; Mycobacterium; Occupational Diseases; Occupational Exposure; Precipitins; Sequence Analysis, DNA

A hypersensitivity reaction occurring in the first minute of the dialysis procedure was observed in seven haemodialysis patients in one day. Hollow-fibre dialysers were used, five made of saponified cellulose ester (SCE) and two of cuprammonium cellulose (CC). All were sterilised with ethylene oxide (ETO) and used for the first time. The severity of the reactions was grade 2. The whole series of dialysers was examined for the presence of ETO concentration. A significantly higher concentration of ETO was found in the polyurethane potting than in the capillaries. The ETO concentrations were 122, 185, 440, 274, 342, and 280 p.p.m. in the following dialysers: Cordis Dow (cellulose acetate CA), Cordis Dow-Plivadial (SCE), Fresenius C-1.3 (CC), Fresenius E-2 (CC), Fresenius E-3 (CC), and Travenol-Medial S 11 flate plate (CC) respectively. According to the clinical signs, ETO concentrations in the dialysers and the lack of reaction when extensive rinsing was used, it can be presumed that these reactions are related to ETO although other mechanisms cannot be excluded.

Topics: Adult; Biocompatible Materials; Cellulose; Ethylene Oxide; Female; Humans; Hypersensitivity; Kidney Failure, Chronic; Kidneys, Artificial; Male; Membranes, Artificial; Middle Aged; Renal Dialysis; Sterilization

Human C3a radioimmunoassay techniques were employed to define both the temporal profile and the amount of complement activation taking place in the extracorporeal circuit during maintenance hemodialysis. Prospective studies demonstrated that C3a formation, like hemodialysis-associated leukopenia, was a transient phenomenon that occurred predominantly during the first 30 min of dialysis. Quantitative comparisons revealed that new Cuprophan hemodialyzers displayed somewhat greater complement-activating potential than cellulose acetate dialyzers. By contrast to new Cuprophan membranes, both reused Cuprophan and polyacrylonitrile dialyzers exhibited only a modest ability to activate human complement. These findings are compatible with the known mechanisms of complement activation and suggest that certain chemical and biochemical methods might be exploited to enhance the biocompatibility of cellulose dialysis membranes.

Topics: Acrylic Resins; Cellulose; Complement Activation; Complement C3; Complement C3a; Humans; Hypersensitivity; Kidneys, Artificial; Leukopenia; Membranes, Artificial; Radioimmunoassay; Renal Dialysis

A sheep model is described that reliably produces acute pulmonary hypertension after blood, previously in contact with a number of different dialysis membranes including Cuprophan, enters the animal's circulation. This hemodynamic manifestation is associated with myocardial ischemia and arrhythmias and coincides in time with neutropenia but precedes maximal hypoxemia. The resulting pulmonary vascular response occurs following both exposure of flowing blood to a dialyzer in an extracorporeal circuit and reinjection of blood previously in static contact with a number of different devices for varying periods of time. Increasing volumes (1-15 ml) previously in static contact (10 min) with regenerated cellulose, saponified cellulose ester, and Cuprophan (hollow fiber and sheet form) caused varying increments in mean pulmonary artery pressure. Contact with either polyacrylonitrile or cellulose acetate resulted in little response. This effect was magnified with all the surfaces, even polyacrylonitrile and cellulose acetate, by prolonging the duration of contact up to 30 min. The hemodynamic events that occurred with this model are similar to those reported in the clinical entity of "dialyzer hypersensitivity." This model may be of value in the quest for elucidation of the mechanisms involved in this syndrome.

Topics: Acrylic Resins; Animals; Cellulose; Disease Models, Animal; Hemodynamics; Hypersensitivity; Hypertension, Pulmonary; Kidneys, Artificial; Leukocyte Count; Membranes, Artificial; Oxygen; Pulmonary Wedge Pressure; Renal Dialysis; Sheep