Evaluating the predictive value of the in vitro Platelet Toxicity Assay (iPTA) for the diagnosis of hypersensitivity reactions to sulfonamide drugs: A prospective case‐control study.

Abstract

Drug hypersensitivity reactions (DHRs) are rare but potentially fatal types of adverse drug reactions that develop in susceptible patients following exposure to certain drugs including sulfonamides. Their diagnosis is challenging due to lack of safe and reliable test. The aim of this study was to evaluate the predictive value of the in vitro Platelet Toxicity Assay (iPTA) in diagnosis of DHRs to sulfonamides and to compare its performance to the conventional lymphocyte Toxicity Assay (LTA) test. Blood samples were obtained from 66 individuals (36 DHS‐sulfa patients and 30 controls) and LTA and iPTA were performed. Results were then analyzed to estimate the predictive value, sensitivity and agreement of the two tests. The concentration‐dependent toxicity was significantly greater in the cells from patients versus controls (p<0.05). The two tests had a high degree of agreement (correlation coefficient: R2 = 0.97). The iPTA was significantly more sensitive than the conventional LTA test in detecting the susceptibility of patient cells to in vitro toxicity (p<0.05). The iPTA has considerable potential as a diagnostic tool for DHS as it is cheaper to perform, requires no special reagents and has a greater sensitivity in detecting patients predisposed to DHRs to sulfonamides.