Measurement of Hymenoptera venom specific IgE by the IMMULITE 3gAllergy in subjects with negative or positive results by ImmunoCAP

Abstract

Background: Patients may receive negative results from a specific IgE (sIgE) test such as the ImmunoCAP (CAP) despite a documented history of systemic reaction to a Hymenoptera sting. Thus, further testing may be required using another serological method or venom skin prick tests to confirm allergy diagnosis and correct species.

Objective: To evaluate the sensitivity and the specificity of CAP and IMMULITE 3gAllergy (IMMULITE) for detecting sIgE to Paper wasp (WA) and Yellow Jacket (YJ) venoms using patient clinical history as the comparator.

Methods: Sera from 70 participants with a history of systemic reactions (SR) to WA and/or YJ stings were tested using CAP and IMMULITE. Fifty participants from this group had negative results on CAP. To assess specificity, sera from 71 participants who had never experienced either a WA or YJ sting were tested using CAP and IMMULITE. Fifty participants from this group tested positive using CAP.

Results: In participants with a history of systemic reaction to a Hymenoptera sting, yet who tested negative for WA and/or YJ sIgE according to CAP, the positivity rate according to IMMULITE was 20-42% using 0.10 IU(A)/mL as the limit of detection (LoD), per the manufacturer's specification. When the LoD for CAP (0.35 IU(A)/mL) was applied to the IMMULITE results, positivity according to IMMULITE was 14-26%. Overall, sensitivity, specificity, and agreement with SR were greater for IMMULITE than for CAP. For YJ: sensitivity (IMMULITE:CAP), 42.8%:28.5%; specificity, 53.5%:39.4%; agreement, 48.2%:34%. For WA, sensitivity (IMMULITE:CAP), 58.6%:28.5%; specificity, 49.3%:47.8%; agreement, 43.9%:38.3%.

Conclusion: The IMMULITE performed well for detecting sIgE to Hymenoptera venom.

Keywords: Allergy; IMMULITE; ImmunoCAP; Sensitivity; Specificity; Venom specific IgE.

Fig. 1

Study design. SR, systemic reactions; CAP; ImmunoCAP.

Fig. 2

Quantitative results for Hymenoptera sIgE according to IMMULITE 3gAllergy (IMMULITE) using its 0.1 IU_A/mL cutoff among the 50 participants who had a history of Hymenoptera stings but who tested negative according to ImmunoCAP (CAP) (<0.35 IU_A/mL). Results demonstrate IMMULITE's sensitivity relative to CAP.

Fig. 3

Correlation of quantitative results for participants who were positive for Hymenoptera specific IgE on both immunoassay systems (n = 20). R values were determined by linear regression analysis for results ≥0.35 IU_A/mL (ImmunoCAP) or 0.1 IU_A/mL (IMMULITE 3gAllergy).

Fig. 4

Specificity analysis: Yellow Jacket or wasp specific IgE results on both systems from 50 participants who had no history of Hymenoptera stings.

Fig. 5

Of the 21 participants with negative ImmunoCAP test results (<0.35 IU_A/mL) for specific IgE to both Yellow Jacket and wasp, one generated a low-positive result according to IMMULITE 3gAllergy.