IgE Allergen Component-Based Profiling and Atopic Manifestations in Patients with Netherton Syndrome.

Netherton syndrome (NS; OMIM no. 266500) is an autosomal recessive genodermatosis with atopic dermatitis (AD)–like erythroderma, a bamboo-like hair-shaft defect, and multiple atopic manifestations: asthma, urticaria, angioedema, allergic rhinitis, increased IgE levels, and blood hypereosinophilia.1Hovnanian A. Netherton syndrome: skin inflammation and allergy by loss of protease inhibition.Cell Tissue Res. 2013; 351: 289-300Crossref PubMed Scopus (138) Google Scholar NS is caused by serine protease inhibitor, Kazal type 5 (SPINK5) mutations leading to defective lymphoepithelial Kazal-type related inhibitor (LEKTI), a serine protease inhibitor expressed in the upper epidermal skin layers.1Hovnanian A. Netherton syndrome: skin inflammation and allergy by loss of protease inhibition.Cell Tissue Res. 2013; 351: 289-300Crossref PubMed Scopus (138) Google Scholar Loss of LEKTI inhibition results in a severe skin barrier defect.1Hovnanian A. Netherton syndrome: skin inflammation and allergy by loss of protease inhibition.Cell Tissue Res. 2013; 351: 289-300Crossref PubMed Scopus (138) Google Scholar SPINK5 polymorphisms, especially the 420Lys LEKTI variant, have been associated with atopy and AD.2Fortugno P. Furio L. Teson M. Berretti M. El Hachem M. Zambruno G. et al.The 420K LEKTI variant alters LEKTI proteolytic activation and results in protease deregulation: implications for atopic dermatitis.Hum Mol Genet. 2012; 21: 4187-4200Crossref PubMed Scopus (73) Google Scholar We studied in detail the atopic symptoms in 10 Finnish patients with NS with SPINK5 mutations. Our patients with NS had multiple allergies initiating neonatally and increasing rapidly in early childhood (Table I and see Tables E1 and E2 in this article's Online Repository at www.jacionline.org). Increased serum total IgE levels (up to 17,433 kU/L) were seen in 9 of 10 patients, and 8 of 10 had blood hypereosinophilia (Table I and see Table E2). Urticaria, asthma, and angioedema were common (Table I). We evaluated the IgE antibody profile specifically with the ImmunoCAP ISAC microarray (Thermo Fisher Scientific, Waltham, Mass) in 6 patients with NS 0.4 to 49.5 years of age, enabling the most precise IgE profiling in patients with NS to date (see the Methods section in this article's Online Repository at www.jacionline.org). Repeated ISAC microarray testing within the first 3 years for 2 patients (patients T4 and T6) showed that the initial IgE antibodies increased in intensity and new IgE sensitizations occurred rapidly for both, reaching 17% to 21% at 2 years and 35% by 3.2 years of age (Fig 1 and see Table E1). A similar trend in increasing specific IgE (sIgE) levels to multiple allergens with increasing age was noted for other patients (see Table E2).Table IAtopic features in patients with NSPatient IDAge (y)Atopy heritageAD/U/AO/AS/RIgE (kU/mL)Eos (E9/L)Current symptomatic allergies/eliminated foodsSubsided allergiesH18.5+AD/−/AO/−/−9720.83 (13%)Egg white/ACow's milk/OASWheat/SF, AO, OASRye/AO, OASBarley/AO, OAS, SFBuckwheat/SFFish/SFBirch cross-reactive vegetables and fruits/OASNuts/ElKiwi/ElCelery/ElH27.3+AD/U/AO/AS/R17,4331.47 (21%)Egg white/AO, OAS, GICow's milk/AO, OAS, GI, SFWheat/OASBirch cross-reactive vegetables and fruits/OASBarley/ElRye/ElFish/ElBirch/R, ASTimothy grass/RCat/SFDog/SFHorse/SFBeef/SFPork/SFH314.2−AD/−/−/−/R2,0250.64 (8%)Kiwi/OASNuts/OASBirch/RCow's milk/SFEgg white/SFBarley/SFCitrus fruits/SFSoy/SFT110.5+AD/−/−/−/−4,7401.03 (8%)Banana/OAS, SFEgg white/OAS, SFCat/SF, AOHorse/SF, AOCow's milk/SF, GIWheat/SF, GIT27.5+AD/−/−/−/−4,780NDCarrot/OAS, SFWatermelon/OAS, SFEgg white/OAS, SFCat/PT34.7+AD/−/−/−/−2,0490.59 (4%)Peanuts/OAS, SFWatermelon/OAS, SFCat/PT42.9+AD/−/−/AS/−2401.80 (20%)Wheat/ABarley/SF, GIEgg white/AO, GIT551.4+AD/U/AO/−/−11,4250.36 (4%)Almond/SF, OAS, GICoconut/SF, OAS, GINuts/SF, OAS, GIRaw carrot/SF, OAS, GIKiwi/SF, OAS, GIChickpea/SF, OAS, GIFish/SF, OAS, GICrustacean/SF, OAS, GIBirch/R, SFTimothy grass/R, SFT63.9+AD/U/AO/AS/−7,2292.76 (20%)Cow's milk/AEgg white/GERWheat/GERRye/GERBarley/GERChicken/GERBeef/GERCat/SFT71.3+AD/−/−/−/−190.35 (3%)Cow's milk/GERRye/GERCorn/GERPlum/GERAge indicates age at last evaluation. Atopy heritage indicates AD, asthma, or allergies in 1 or both parents or siblings.A, Anaphylaxis; AD, erythrodermic atopic dermatitis; AO, angioedema; AS, asthma; El, eliminated for caution; Eos, highest blood eosinophilia; GER, gastroesophageal reflux; GI, gastrointestinal symptoms (vomiting and diarrhea); IgE, highest total serum IgE level; ND, no data; OAS, oral allergy symptoms; P, pruritus; R, rhinoconjunctivitis; SF, skin flaring; U, urticaria. Open table in a new tab Age indicates age at last evaluation. Atopy heritage indicates AD, asthma, or allergies in 1 or both parents or siblings. A, Anaphylaxis; AD, erythrodermic atopic dermatitis; AO, angioedema; AS, asthma; El, eliminated for caution; Eos, highest blood eosinophilia; GER, gastroesophageal reflux; GI, gastrointestinal symptoms (vomiting and diarrhea); IgE, highest total serum IgE level; ND, no data; OAS, oral allergy symptoms; P, pruritus; R, rhinoconjunctivitis; SF, skin flaring; U, urticaria. Overall, the sIgE antibodies to allergens triggering clinical symptoms represented common food allergens, such as egg, cow's milk, wheat, and nuts, as well as pollens and animal proteins (see Table E1). All patients reacted against 14% to 37% of the allergen components. In comparison, considering that our study was not a case-control study, a cohort of 140 German pediatric patients with AD studied on an ISAC microarray with 95 allergen components showed mean sensitization to 7.6 ± 7.7 of allergens, ranging from 0% (in 14% of patients) to 34%, and higher numbers of sIgE responses associated with higher total IgE levels (3-26,567 kU/L).3Ott H. Weißmantel S. Kennes L.N. Merk H.F. Baron J.M. Fölster-Holst R. Molecular microarray analysis reveals allergen- and exotoxin-specific IgE repertoires in children with atopic dermatitis.J Eur Acad Dermatol Venereol. 2014; 28: 100-107Crossref PubMed Scopus (12) Google Scholar All our patients with NS had IgE antibodies to multiple potentially anaphylactic stable allergens, such as lipid transfer proteins (LTPs; 83%), storage proteins (17% to 33%), and tropomyosin (33%; see Table E1).4Sastre J. Molecular diagnosis of allergy.Clin Exp Allergy. 2010; 40: 1442-1460Crossref PubMed Scopus (199) Google Scholar Interestingly, patients with NS were sensitized to 1 to 8 different LTPs, especially hazelnut, peach, and mugwort, each in 4 of 6 patients, although LTP allergy is rare in Northern Europe.4Sastre J. Molecular diagnosis of allergy.Clin Exp Allergy. 2010; 40: 1442-1460Crossref PubMed Scopus (199) Google Scholar LTPs are important allergens in the Mediterranean region, but in Finland only 20% of 100 children (2-13 years old) and 12% of 100 adults (40-60 years old) studied for various allergies were sensitized to at least 1 of the 9 LTPs on the microarray (own unpublished data). None of 49 Swedish allergic children aged 3 months to 18 years had LTP IgEs.5Önell A. Hjälle L. Borres M.P. Exploring the temporal development of childhood IgE profiles to allergen components.Clin Transl Allergy. 2012; 2: 24Crossref PubMed Scopus (21) Google Scholar LTPs were not associated with anaphylaxis in our patients with NS. IgE microarrays are beneficial in patients with NS because they simply reveal the full extent of sensitization and sources of clinically relevant allergic reactions that should be avoided. Numerous targeted sIgEs would be needed to obtain equivalent data. However, sIgEs might be more sensitive than microarrays, and sIgEs allow analysis of specific allergen components not included in microarrays. Three patients had anaphylactic reactions induced by egg (patient H1 at age 6 years), wheat (patient T4 at age 0.9 years), and cow's milk (patient T6 at age 6 years), and all had increased IgE levels for the allergens' stable components (see Tables E1 and E2). Otherwise stable allergens have elicited only mild oral allergy symptoms or skin flaring, which can be attributable to sensitization to the labile components of the allergens (Table I and see Table E1). Patients H2, H3, and T5 were sensitized to multiple storage proteins, but no severe allergic reactions have occurred, possibly because of strict elimination from their diets. Oral allergen desensitization was beneficial for 2 patients. Patient H1 had wheat desensitization from 6 years of age, and she currently tolerates small amounts. Patient H2 started milk desensitization at 5.4 years of age for a period of 1.5 years. He currently tolerates small amounts of milk. A decrease in sIgE levels was seen after desensitization for both patients (see Table E2). Successful induction of oral tolerance to wheat and milk has previously been reported in 1 patient with NS.6Pastore S. Gorlato G. Berti I. Barbi E. Ventura A. Successful induction of oral tolerance in Netherton syndrome.Allergol Immunopathol (Madr). 2012; 40: 316-317Crossref PubMed Scopus (4) Google Scholar Severe allergic reactions are common in patients with NS, and thus oral desensitization should be considered. All patients with NS were sensitized to at least 1 panallergen (profilins, pathogenesis-related 10 [PR-10] proteins, and tropomyosins), which are cross-reactive allergens inducing sensitization to multiple allergens.4Sastre J. Molecular diagnosis of allergy.Clin Exp Allergy. 2010; 40: 1442-1460Crossref PubMed Scopus (199) Google Scholar Eighty-three percent had IgE antibodies for PR-10 proteins, 67% for profilins, and 33% for tropomyosins. Patients T5 and T6 had antibodies for all 3 panallergens, and patient H1 had antibodies for PR-10 proteins and profilin. Patient H2 was sensitized to profilins only, and patients H3 and T4 were sensitized to PR-10 proteins (see Table E1). In 3113 allergic Italian patients only 1.2% recognized all 3 panallergens, 13.6% recognized 2 panallergens, and 86.4% recognized only 1 panallergen.7Scala E. Alessandri C. Palazzo P. Pomponi D. Liso M. Bernardi M.L. et al.IgE recognition patterns of profilin, PR-10, and tropomyosin panallergens tested in 3,113 allergic patients by allergen microarray-based technology.PLoS One. 2011; 6: e24912Crossref PubMed Scopus (44) Google Scholar We diagnosed eosinophilic esophagitis (EoE) in patient H2, which is the first reported NS case to our knowledge (see Table E3 in this article's Online Repository at www.jacionline.org). T helper cells and a mixed IgE- and non-IgE–mediated allergic response to allergens play a role in the pathogenesis of EoE. Most pediatric patients with EoE have allergies, asthma, eczema, chronic rhinitis, peripheral eosinophilia, increased IgE levels, nausea, vomiting, diarrhea, and failure to thrive, all features seen in patients with NS.8Sorser S.A. Barawi M. Hagglund K. Almojaned M. Lyons H. Eosinophilic esophagitis in children and adolescents: epidemiology, clinical presentation and seasonal variation.J Gastroenterol. 2013; 48: 81-85Crossref PubMed Scopus (58) Google Scholar Gastroesophageal reflux, irritability, and poor feeding were noted neonatally in patient H2. All symptoms responded rapidly to cisapride started at age 6 months. Concomitant cisapride and omeprazole, occasionally combined with ranitidine, have been used beneficially. Short breaks in the medication have resulted in relapsing symptoms. Gastroesophageal reflux and diarrhea are common in patients with NS and were observed in 7 of 10 patients but concurrently only in patient H2 (See Table E3). Increased fecal calprotectin and antitrypsin levels, reflecting intestinal inflammation and protein loss, respectively, were found in 4 of 7 patients within the first months. The gastrointestinal tract is a major site for food allergen sensitization and an important site of early normal microbial contact. Duodenal biopsy specimens from patients H2 and T1 were normal, and immunostaining excluded deficiency in enteroendocrine cells or major antimicrobial peptides (see Table E3 and the Methods section in this article's Online Repository). Many allergens contain serine or cysteine protease activity, which disrupts the epithelial barrier, and some induce inflammatory responses, causing greater sensitization. Whether LEKTI inhibits the activity of environmental proteases is not known. Loss of LEKTI inhibition of allergen proteases combined with increased allergen penetration caused by severe barrier defect could contribute to the rapid and vast allergic sensitization observed in patients with NS. Reduced LEKTI expression in sinonasal epithelium is associated with chronic rhinosinusitis and allergies, but LEKTI is not expressed in the gut epithelium.9Fruth K. Goebel G. Koutsimpelas D. Gosepath J. Schmidtmann I. Mann W.J. et al.Low SPINK5 expression in chronic rhinosinusitis.Laryngoscope. 2012; 122: 1198-1204Crossref PubMed Scopus (14) Google Scholar Disruption of the airway epithelial barrier might also predispose patients with NS to increased sensitization by inhaled allergens. Further studies will be needed to elucidate whether the early and promiscuous sensitization to especially LTP allergens, which are more ingestion than inhalation induced, could be explained by a functional barrier defect in the mucous membranes of the intestine in patients with NS and whether the intestinal microbiome might contribute to this effect. We thank the patients and families for participating in this study. We also thank Mrs Kaija Järvinen and Mrs Alli Tallqvist for their skilful technical assistance. Download .docx (.01 MB) Help with docx files Materials and Methods Download .docx (.07 MB) Help with docx files Tables E1-E3