Sympathomimetic drug allergy: cross-reactivity study by patch test.

INTRODUCTION: Sympathomimetic (alpha-adrenergic) drugs are mainly used because of their vasoconstrictor properties, for nasal congestion, or as mydriatics. Although sympathomimetic drugs are used often, allergic reactions are rare, especially when the drugs are administered systemically. Cross-reactivity may exist among catecholamine derivatives, although reported data on this are contradictory. In this study, we investigate if there is cross-reactivity in patch tests among these drugs. MATERIAL AND METHODS: Patch tests with 10% phenylephrine and 10% pseudoephedrine in petrolatum, and 10% and 20% ephedrine, 10% phenylpropanolamine, 5% fepradinol, 1% methoxamine, and 10% oxymetazoline, all administered in dimethyl sulfoxide (DMSO), were carried out in 14 patients with a history of allergy to any of these drugs. DMSO was used as the negative control. RESULTS: All patients except one (patient number five) showed positive patch-test reactions to at least two different drugs. Nine patients (64.3%) were cross-sensitized to three or more different drugs, and 57.1% of patients were sensitized to four or more sympathomimetic drugs. Patients who experienced generalized rashes caused by orally administered pseudoephedrine had a stronger response and more cross-reactivity with other sympathomimetic drugs in patch tests than those who experienced local contact dermatitis. CONCLUSIONS: We conclude that there is cross-reactivity among the different sympathomimetic drugs tested, especially if the drug is administered systemically.

Development of a monoclonal antibody capable of detecting prolamine in wheat and oats.

A monoclonal antibody (MAb) capable of detecting the gliadin in wheat flour has been developed. By immunoblot, the monoclonal antibody recognized three bands in the membranes after electrophoresis in an SDS PAGE of the alcohol-soluble proteins of wheat, and only one band in the alcohol extract of the oat flour. ELISA technique can be applied using this monoclonal antibody in the detection of gliadin and avenin in samples from wheat or triticale. The characterization of the antibody shows that it is an IgM class. Sensitivity by ELISA to the gliadin was 80 ng/ml.

Evaluation of six commercial amphetamine and methamphetamine immunoassays for cross-reactivity to phenylpropanolamine and ephedrine in urine.

We evaluated six commercially available amphetamine (A) and methamphetamine (MA) immunoassays for their relative cross-reactivities to isomers of phenylpropanolamine (PPA) and ephedrine (E) in urine: Syva EMIT, Abbott fluorescence polarization (FPIA), Roche, and Diagnostic Products Corporation (DPC) radioimmunoassays for A and MA. Two stereoisomers of PPA and four stereoisomers of E were tested using (1) drug-free urine spiked at 1,000 mg/L or 100 mg/L of each compound and (2) 60 clinical urine specimens not containing A or MA but having varying amounts of PPA and/or E. Specimens responding greater than the 1-mg/L A or MA cutoff were defined as positive. All specimens spiked at 100 mg/L were negative by all immunoassays. All specimens spiked at 1,000 mg/L were positive by EMIT and negative by FPIA, Roche A, and DPC A; 1,000 mg/L/-E and d-pseudoephedrine were also positive by Roche MA and DPC MA. Three of the 60 clinical specimens tested positive by EMIT and one specimen tested positive by DPC A and DPC MA.

Immunocrossreactivity of antisera against grain prolamines of wheat, rye, barley and oats.

Prolamines extracted from wheat (gliadin), rye (secalin), barley (hordein) and oats (avenin) were used to raise antibodies in rabbits. The four prolamines were separated by SDS-PAGE and blotted onto nitrocellulose. The immunocrossreactivity of the separated prolamines with the four antisera was studied. The close botanical relationship between wheat and rye, and to a lesser extent barley, is clearly established. The crossreactivity of gliadin, secalin and hordein with anti-avenin serum was found to be weak. In contrast, avenin shows a strong crossreactivity with anti-gliadin serum.