Ethylene oxide sensitivity in hemodialysis patients.

Sera from 138 patients who had experienced hypersensitivity-type reactions while on hemodialysis (reactors) were examined retrospectively by the radioallergosorbent test (RAST) for specific IgE antibody to ethylene oxide (ETO). Seventy-eight hemodialysis patients without a history of reaction were also evaluated as controls. Elevated serum RAST values (greater than 2.0) were more common in reactors (63%) than in controls (11%, p less than 0.001). In a second study, RAST assays were performed using human serum albumin conjugated to ETO (HSA-ETO) as antigen and also using a concentrate of fluid used to rinse ETO-sterilized dialyzers ("dialyzer extract") as antigen. The RAST ratios obtained with HSA-ETO were similar to those obtained using the dialyzer extract (rank order correlation coefficient = 0.829, p less than 0.001). In a third study, RAST inhibition was demonstrated both by HSA-ETO and dialyzer extract. Our results, extending previously published reports, suggest that hypersensitivity to ETO might play an important role in hemodialysis-associated hypersensitivity-type reactions.

Evaluation of papain/chymopapain cross allergenicity.

Recent clinical evidence suggests that papain and chymopapain may share common allergenicity. Patients that become sensitized to papain may subsequently experience an allergic reaction when they are exposed to chymopapain. This study demonstrates a cross antigenicity between the proteolytic enzyme preparations papain and chymopapain. Serum samples from six patients who demonstrated 4+ skin reactions to papain also revealed positive RAST ratios to both papain and chymopapain. In addition, serum samples from 12 clinically nonreactive patients who had discolysis with chymopapain demonstrated positive RAST results to papain as well as to chymopapain.

Pretreatment serum levels of IgE to chymopapain in reactive patients.

Discolysis (chemonucleolysis) with chymopapain, the proteolytic enzyme, is currently being used in the treatment of herniated lumbar discs. Of the patients receiving treatment, approximately 1% experience an anaphylactic reaction. This reaction is thought to be mediated by IgE antibodies to chymopapain. Because of this, it may be possible to predict potential reactors using in vitro testing. In the current study, five out of seven patients who experienced allergic anaphylaxis during discolysis demonstrated high IgE serum levels to chymopapain before treatment.

Reactivity of IgE and IgG serum levels to chymopapain after chemonucleolysis.

Patients suffering from herniated lumbar intervertebral disks can currently be treated by chemonucleolysis. This procedure involves reducing the nucleus pulposus by injecting chymopapain into the affected intervertebral disk. A small percentage of the patients who undergo this treatment experience an immediate hypersensitivity reaction. In this study the IgE and IgG specific for sensitivity to chymopapain of 21 patients receiving chymopapain (Discase for injection) was monitored over a 6-month period after injection. This study demonstrates that serum levels of IgE and IgG to chymopapain increase after chemonucleolysis.

Detection of endotoxin in the plasma of patients with gram-negative bacterial sepsis by the Limulus amoebocyte lysate assay.

A total of 120 Limulus amoebocyte lysate (LAL) determinations were made on plasma obtained from normal, healthy human blood donors. Results demonstrated a mean endotoxin level in blood of 0.02 to 1.57 pg/ml. The amount of Escherichia coli endotoxin added to human plasma samples can be quantitated by both nephelometry and turbidimetry. Endotoxin-spiked samples were shown to be significantly different from unspiked samples. When plasma samples were collected from 45 patients hospitalized at three centers, a strong association was demonstrated between a positive Limulus amoebocyte lysate assay and a septic condition. Sensitivity, specificity, and false-positive and false-negative rates for the Limulus amoebocyte lysate assay as a diagnostic test for gram-negative bacteremia were estimated.

Characterization of Limulus amoebocyte lysate-reactive material from hollow-fiber dialyzers.

Hollow-fiber hemodialyzers containing cellulose-based membranes have been shown to produce positive results with the Limulus amoebocyte lysate test. This study was undertaken to determine whether endotoxin was causing the reaction. Rinses from 45 parallel-plate and hollow-fiber dialyzers from eight different manufacturers were tested before and after treatment with cellulase, using three lysates and four Limulus amoebocyte lysate methods. In addition, four in vitro cellular methods--human leukocytic pyrogen, lymphocytic activating factor, peritoneal macrophage, and arginase release--were used to evaluate endotoxin activity. The substance causing the reaction was identified by chromatographic methods. Results indicate that the Limulus amoebocyte lysate reactive material is cellulose derived and not pyrogenic.

Comparison of chemical analyses of hollow-fiber dialyzer extracts.

Hollow-fiber hemodialyzers containing cellulose-based membranes have been shown to produce positive results with the Limulus amebocyte lysate (LAL) test. This study was undertaken to determine whether endotoxin was causing the reaction. Rinses from 45 parallel-plate and hollow-fiber dialyzers from eight different manufacturers were tested using three lysates and four LAL methods. In addition, four in vitro cellular methods--human leukocytic pyrogen, lymphocytic activating factor, peritoneal macrophage, and arginase release--were used to evaluate endotoxin activity. The substance causing the reaction was identified using chromatographic methods. Results indicate that the LAL-reactive material is cellulose derived and is not pyrogenic.