Indeed, we have piloted detection of IgE specific for 5 peanut components (data not shown). The LIPS immunoassay offers a sensitive and efficient method to qualitatively and quantitatively determine an individuals sensitization patterns to major components of allergens, using substantially less serum than is typically used for a single allergen-specific IgE. purification techniques, and ease of optimization.3 Here, we demonstrate the power of synthetic biology coupled with Mouse monoclonal to CD22.K22 reacts with CD22, a 140 kDa B-cell specific molecule, expressed in the cytoplasm of all B lymphocytes and on the cell surface of only mature B cells. CD22 antigen is present in the most B-cell leukemias and lymphomas but not T-cell leukemias. In contrast with CD10, CD19 and CD20 antigen, CD22 antigen is still present on lymphoplasmacytoid cells but is dininished on the fully mature plasma cells. CD22 is an adhesion molecule and plays a role in B cell activation as a signaling molecule the LIPS immunoassay as a TAS4464 novel, rapid method to detect allergen-specific IgE in low-volume samples. Serum samples from healthy volunteers (n = 76), helminth-infected adults (n = 26), and children with peanut allergy (n = 12) were screened for IgE to cat using ImmunoCAP. Cat IgE levels ranged from 0 to more than 100 kU/L. Renilla luciferaseCFel d 1 fusion protein constructs were generated by GenScript Biotech (Piscataway, New Jersey). These constructs were transfected into mammalian 293-F cells that allowed for greater likelihood of proper protein folding and glycosylation. LIPS immunoassays were performed as previously explained.3 Briefly, 5 .001). Receiver operating characteristic analysis gave an area under the curve (AUC) of 0.7887 ( .001). A threshold of 244 LU/ .01. IgE, immunoglobulin E; LIPS, luciferase immunoprecipitation systems. In TAS4464 the subset of samples for which Fel d 1 IgE levels were available, the LIPS signal-to-noise ratio differed significantly among Fel d 1 IgECnegative (n = 40) and Fel d 1 IgECpositive samples(n = 20; Fig 1, bottom panel). Fel d 1 LIPS transmission correlated more closely with Fel d 1 IgE levels ( .001). Receiver operating characteristic analysis gave an AUC of 0.8813 ( .001). TAS4464 A threshold of 395.3 LU/ em /em L distinguished individuals with a positive test result from those with a negative test result, with 85% sensitivity and 75% specificity. These results indicate that LIPS immunoassays can quantify component-specific IgE in small volumes of human serum. Although our sample cohort was relatively small and heterogeneous, the sensitivity of the LIPS assay in identifying individuals with a positive test result for cat IgE was comparable to that reported for aeroallergen skin prick testing; however, specificity was lower. Sensitivity and specificity for distinguishing individuals who were Fel d 1 positive were much like those for skin prick screening.4 We did not have information regarding skin prick sensitivity to cat or clinical symptoms after cat exposure for our cohort; the efficacy of LIPS would likely be increased if our analysis had been able to include these parameters. Future studies will use well-defined clinical cohorts. For Fel d 1, the LU correlated with cat IgE and Fel d 1 IgE levels by ImmunoCAP. This finding is usually TAS4464 consistent with studies that found that Fel d 1 is usually a reliable marker for cat sensitization with high sensitivity and specificity for clinical reactivity to cat.5 For patients with a positive test result for cat IgE with low LIPS signal, it is possible that their IgE response is specific for any different Fel d component; samples with LIPS signal-to-noise ratios in the 25th percentile experienced Fel d 1 IgE levels less than 0.75 and test results were negative for 57%. Most other aeroallergens do not have a component with the same dominance over others that Fel d 1 has in cat2; thus, using a single component to determine sensitivity may not be clinically useful. However, LIPS is usually a high-throughput system for which responses to multiple target antigens can be performed simultaneously,6 and components can be combined in a single assay to determine allergen sensitivity more accurately. Indeed, we have piloted detection of IgE specific for 5 peanut components (data not shown). The LIPS immunoassay offers a sensitive and efficient method to qualitatively.