Development of a progesterone-specific IgE assay for diagnosing patients with suspected progestogen hypersensitivity

Abstract

BackgroundProgesterone hypersensitivity (PH) manifests as a spectrum of allergic symptoms during the luteal phase of the menstrual cycle. Confirming progesterone-specific immunoglobulin E (IgE; sIgE) by skin testing is unreliable because of irritant responses. ObjectiveTo develop a progesterone sIgE assay to assist in diagnosing PH. MethodsA progesterone–bovine serum albumin (BSA) conjugate was characterized and used to analyze sera collected from women in our center with suspected PH in a 1-batch enzyme-linked immunosorbent assay (ELISA) to establish high, low and negative cut-points. Sera collected from healthy nonatopic female subjects and from women with classical PH symptoms were included as negative and positive controls, respectively. Values exceeding the average negative control (OD + 3× the standard deviation) were considered positive. These cut-points were subsequently used to establish positive and negative results for serum from women with suspected PH received from other centers. A subset of high positive sera was used for ELISA-inhibition and in a beta-hexosaminidase mediator release assay to evaluate the specificity and functional relevance of progesterone-specific serum IgE, respectively. The numbers of true negative, false negative, true positive, and false positive samples were determined. ResultsThe direct progesterone sIgE ELISA results ranged from high positive to low positive and negative compared with healthy nonatopic control sera. Enzyme-linked immunosorbent assay inhibition and beta-hexosaminidase mediator release confirmed specificity and functional relevance of progesterone-sIgE, respectively. The sensitivity, specificity positive predictive values and negative predictive values were found to be 82%, 100%, 86%, and 100%, respectively, using the mediator release assay results as the gold standard. ConclusionThis assay has a good specificity and positive predictive value for screening women with suspected PH for progesterone sIgE.