Reference Values of Total Serum IgE and Their Significance in the Diagnosis of Allergy in Young European Adults

Abstract

Allergic sensitization mediated by immunoglobulin E (IgE) is the basis of allergic diseases, and elevated total IgE, in spite of some well-known limitations, is frequently included as a diagnostic criterion for allergic diseases. The reference value of total IgE (IgE-t) in the literature (1.5–144 kU/l) was established almost 2 decades ago. The aim of this study was to establish IgE-t reference values, establishing an updated cutoff value able to identify atopic subjects, defined as a positive CAP-radioallergosorbent test to at least one of a panel of common allergens, among young European adults. The study included 6,670 subjects from 10 Western European countries within the framework of the European Community Respiratory Health Survey II. IgE-t and specific IgE (IgE-s) were measured for the main inhalant allergens; IgE-s in class 0 for all allergens (66.2%) characterized non-atopy. The reference values were estimated by means of linear regression using a 50% random subsample of non-atopic subjects. Two non-atopic subsamples were examined so that one subsample could be used to establish reference IgE-t values, and these values were compared to those in the second non-atopic subsample to validate the findings. Sensitivity and specificity for atopy were assessed on the other 50% of non-atopic and on all atopic subjects. The 95th percentile of IgE-t reference values in non-smokers was 148 kU/l in women and 169 kU/l in men, while it was 194 and 220 kU/l in female and male smokers, respectively: serum IgE-t above the 95th percentile identifies <32% and above the 99th percentile <20% of atopic adults (low sensitivity), but a serum IgE-t below the 95th percentile identifies >90% and below the 99th percentile identifies >95% of non-atopic adults (good specificity). Due to the adequate specificity, IgE-t values exceeding the normal limits confirm a suspected atopic status; however, because of the low sensitivity, values below the cutoff seem not to exclude an atopic status with sufficient accuracy.

Investigation of Atopy in Primary Cutaneous CD30+ T-Cell Lymphoproliferative Disorders

“…For the prevalence of allergic reactions to penicillin or derivatives, we used the 11.46% (1348/11,761) frequency from Albin's survey [15]. IgE-t levels were compared against several published series of non-atopic controls [2, [16][17][18][19][20][21][22][23].…”

“…Therefore the values for all LyP and pcALCL patients were combined for subsequent comparisons. Several publications have provided IgE-t values for non-atopic adults to establish normal reference ranges (Table 3) [2, [16][17][18][19][20][21][22]. Because these studies likely concerned mostly White adult patients, we excluded nonWhite patients and patients under the age of 17 from our series for comparison with these published reference values.…”

“…For 4407 non-atopic adult subjects studied in the European Community Respiratory Health Survey [21], the IgE-t geometric mean was 23.8 IU/mL and for 3972 patients aged 6 years and older studied in the United States Health and Nutrition Examination 2005-2006 Survey, [23] the IgE-t geometric mean was 21.7 IU/mL. These results are statistically lower (P< 0.001) than the mean IgE values for our patients with CD30CLPD (Table 3).…”

“…In addition, given that IgE-t levels are higher in men than women, [19][20][21]23] we also compared our results with several centers that provided data on men and women (Table 3). For our 51 adult White men with CD30CLPD, the geometric mean was 66 IU/mL and this was significantly higher (all with P< 0.001) than geometric mean values reported for non-atopic men in the southwestern United States (geometric mean 20.3 IU/mL), Canada (geometric mean 12.6 IU/mL), Greece (geometric mean 38.0 IU/mL), northern Italy (geometric mean 28.8 IU/mL), and Iran (geometric mean 19.1 IU/mL).…”

Food allergy: which tests are worth doing and which are not?

“…There is no consensus in the literature as to what constitutes the adult reference range, which appears to vary by region. The adult reference interval has been quoted variously as ,81 kU/L, 15 ,114 kU/L, 16 ,148 kU/L in female and ,169 kU/L in male non-smokers (rising to 194 and 220 kU/L, respectively in smokers) 17 , ,183 kU/L 18 and ,150 kU/L. 19 Approximately a third of atopic adults will have a total serum IgE of ,120 kU/L, i.e.…”