A Very Rare Case of Allergy to Beluga Caviar

Allergology International 68 (2019) 375e376

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Allergology International

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Letter to the Editor A very rare case of allergy to beluga caviar

Dear Editor, proteins. Despite the negative SPT to salmon and herring roe, she was asked to avoid all fish roe. A 48 year old buyer of luxury foods developed tingling and itch- Beluga caviar is obtained from the Caspian sea sturgeon, Huso ing of her ears with a burning sensation of her face, nausea and huso and our patient's reaction was due to an IgE mediated allergy faintness within 2e3 min of eating of two types of Beluga caviar, to one or more sturgeon egg proteins or other compounds in the foie gras, quail eggs, wheat blinis and champagne at a friend's din- caviar preparation. Allergy to sturgeon caviar is exceptionally rare ner party. There was also swelling of the face and a mild constrict- and to our knowledge there have been only 2 previously reported ing sensation of her throat. Her voice was noted to be altered and cases.1,2 However, neither have involved allergy to both ingested she had loose motions one hour later and a single vomit 2 h subse- and airborne caviar proteins. Allergy to salmon caviar appears to e quently. An oral antihistamine led to gradual improvement over 2 h be a more frequent problem3 8 and there are also rare cases of al- although her nausea continued for several days. The reaction was lergy to king fish caviar.9 The precise allergen responsible for the not accompanied by respiratory symptoms, itching of the torso Beluga caviar allergy was considered to be vitellogenin by Perez and limbs or skin rash. None of the other diners suffered ill health Gordo et al.1 In salmon roe allergy, IgE mediated reactivity was and exercise, stress, non-steroidal anti-inflammatory drugs, and detected towards fragments of vitellogenin and to lipovitellin while proton pump inhibitors could not be implicated as cofactors. The that in king fish caviar the allergy was to a 33 kDa alpha S1 casein patient's medical history included hay fever but without indication like protein.9 Thus, there is similarity in the fish roe proteins that of an oral allergy syndrome. She had mild asthma and her eczema induce reactivity in those with allergy to different types of caviar. had been absent for many years. She was not on regular medication. However, given that the skin testing was negative to salmon and For the one year prior to this reaction the patient had under- herring roe in our patient, it is likely that the specific IgE antibodies taken monthly visits to a caviar manufacturing company without here are restricted to species specific epitopes in the sturgeon egg allergic reactivity. On reflection, she wondered whether the con- vitellogenin or else other proteins entirely. Regardless, the rarity sumption of caviar 9 and 12 months previously may have pro- of Beluga caviar allergy may be related to the infrequent consump- duced a mild burning sensation of the ears and nausea. She tion of this tasty but expensive delicacy. The infrequent consump- denied problems eating fish, crustaceans, bread, poultry and tion of fish roe more generally may explain the relative rarity of hen egg both prior to and since the reaction. There was no clinical allergy to fish eggs compared to fish meat allergy. suggestion of allergy to fungi. Skin prick to prick testing showed a very significant 11 mm wheal to the Oscietra caviar with a 5e6 mm wheal to the Imperial caviar (Fig. 1). The results were negative to boiled quail egg and fois gra. Later testing was also negative to salmon and herring roe. The patient's routine blood tests were normal as was her complement C4 at 0.28 g/L and mast cell tryptase at 3.1. Her specific IgE was less than 0.35kUA/ L to house dust mite, dog dander, sesame seed, soya bean, mixed moulds, cod and the omega 5 gliadin protein. Skin prick testing with the Oscietra and Imperial caviar was completely negative in 5 healthy volunteers. Recently our patient developed itching and tingling of her lips within 2 h of undertaking one of her regular visits to the caviar fac- tory. She then suffered dyspnea with bronchospasm and cough fol- lowed by facial redness and then urticaria on her arms. The reaction was controlled by an oral antihistamine. She now carries a salbuta- mol inhaler in addition to her anti-histamines and adrenaline auto- injector. This was deemed especially important if she anticipated exposure to high levels of airborne caviar and other fish roe

Peer review under responsibility of Japanese Society of Allergology. Fig. 1. Results of the skin prick testing to the 2 types of caviar consumed. https://doi.org/10.1016/j.alit.2018.12.009 1323-8930/Copyright © 2019, Japanese Society of Allergology. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/). 376 Letter to the Editor / Allergology International 68 (2019) 375e376

Acknowledgements 2. Untersmayr E, Focke M, Kinaciyan T, Poulsen LK, Boltz-Nitulescu G, Scheiner O, et al. Anaphylaxis to Russian Beluga caviar. J Allergy Clin Immunol 2002;109: 1034e5. The patient described in this report has provided full signed 3. Flais MJ, Kim SS, Harris KE, Greenberger PA. Salmon caviar-induced anaphylactic consent allowing the publication of her clinical details and her an- shock. Allergy Asthma Proc 2004;25:233e6. onymity has been preserved. 4. Gonzalez-De-Olano D, Rodríguez-Marco A, Gonzalez-Mancebo E, Gandolfo- Cano M, Melendez-Baltan as A, Bartolome B. Allergy to red caviar. J Investig Aller- gol Clin Immunol 2011;21:493e4. Conflict of interest 5. Kondo Y, Tanaka K, Inuo C, Tsuge I, Urisu A. A patient with salmon roe allergy The authors have no conflict of interest to declare. showing taxonomy-unrelated cross-reactivity with sea urchin roe. Ann Allergy Asthma Immunol 2011;107:283e4. 6. Takeuchi M, Oda Y, Suzuki I. Intussusception secondary to anaphylactic reaction a b,* to salmon roe (ikura). Pediatr Int 2013;55:649e51. Ciara Jade Bansal , Amolak Singh Bansal 7. Minhas J, Saryan JA, Balekian DS. Salmon roe (ikura)-induced anaphylaxis in a child. Ann Allergy Asthma Immunol 2017;118:365e6. a School of Medicine, Barts and London Medical School, London, UK 8. Shimizu Y, Nakamura A, Kishimura H, Hara A, Watanabe K, Saeki H. Major b St Anthony's Hospital, North Cheam, Surrey, UK allergen and its IgE cross-reactivity among salmonid fish roe allergy. J Agric Food Chem 2009;57:2314e9. * Corresponding author. St Anthony's Hospital, North Cheam, Surrey, SM3 9DW, UK. 9. Chen YH, Wu HJ, Tsai JJ, Lee MF. Anaphylactic shock caused by a 33-kDa alpha E-mail address: [email protected] (A.S. Bansal). S1-casein-like allergen in kingfish caviar. J Investig Allergol Clin Immunol 2009;19:245e6. References Received 1 November 2018 1. Perez-Gordo M, Sanchez-Garcia S, Cases B, Pastor C, Vivanco F, Cuesta-Herranz J. Received in revised form 28 November 2018 Identification of vitellogenin as an allergen in Beluga caviar allergy. Allergy Accepted 18 December 2018 2008;63:479e80. Available online 30 January 2019 139 Practitioner's Corner

7. Bagnasco D, Ferrando M, Varricchi G, Passalacqua G, Canonica GW. A Critical Evaluation of Anti-IL-13 and Anti- Salmon Roe as an Emerging Allergen in Western IL-4 Strategies in Severe Asthma. Int Arch Allergy Immunol. Countries 2016;170:122-31. 8. Sastre J, Dávila I. Dupilumab: A New Paradigm for the Cosme J1, Spínola-Santos A1, Bartolomé B2, Pastor-Vargas C3, Treatment of Allergic Diseases. J Invest Allergol Clin Immunol. Branco-Ferreira M1,4, Pereira-Santos MC4,5, Pereira-Barbosa M1,4 2018;28:139-50. 1Serviço de Imunoalergologia, Hospital de Santa Maria, Centro 9. Kim H, Ellis AK, Fischer D, Noseworthy M, Olivenstein R, Hospitalar Lisboa Norte, Lisboa, Portugal Chapman KR, et al. Asthma biomarkers in the age of biologics. 2R&D Department, Roxall, Bilbao, Spain Allergy Asthma Clin Immunol. 2017;17:13-48. 3Department of Immunology, Instituto de Investigación Sanitaria 10. Phillips-Angles E, Barranco P, Lluch-Bernal M, Dominguez- Hospital, Universitario Fundación Jiménez Díaz. (IIS-FJD, Ortega J, López-Carrasco V, Quirce S. Aspirin tolerance UAM), Madrid, Spain. RETIC ARADyAL, Instituto de Salud in patients with nonsteroidal anti-inflammatory drug- Carlos III, Spain exacerbated respiratory disease following treatment with 4Clínica Universitária de Imunoalergologia, Faculdade de omalizumab. J Allergy Clin Immunol Pract. 2017;5:842-84. Medicina, Universidade de Lisboa, Lisboa, Portugal 5Laboratório de Imunologia Clínica, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal

J Investig Allergol Clin Immunol 2019; Vol. 29(2): 139-141 Manuscript received August 30, 2018; accepted for publication doi: 10.18176/jiaci.0347 October 21, 2019.

Marta Sánchez-Jareño Key words: Anaphylaxis. Food allergy. Immunoblotting. Lipovitellin. Allergy Department, Hospital Universitario La Paz Salmon roe. E-mail: [email protected] Palabras clave: Anafilaxia. Alergia alimentaria. Immunoblotting. Lipovitellin. Huevas de salmón.

Salmon roe, which is also known as salmon caviar, red caviar, or ikura and is frequently consumed in countries such as Japan or Russia, is a delicacy commonly served in sushi- based meals [1,2]. Allergic reactions to salmon roe have been reported in Japan [3,4], and a few cases were recently described in western countries (3 cases in France [5], 2 cases in the USA [2,6]). Nevertheless, studies on the allergenicity of salmon roe are rare [7]. We report the first case of salmon roe anaphylaxis in a young adult in Portugal. A 26-year-old man with a history of mild controlled persistent asthma and persistent, moderate- severe allergic rhinitis who was sensitized to house dust mites was admitted to our emergency department complaining of dyspnea, rhinorrhea, ocular pruritus, epigastric pain, and nausea. The symptoms began a few minutes after the ingestion of a sushi meal comprising rice, salmon, salmon roe, wasabi, soy, and ginger and were treated with intramuscular epinephrine, intravenous corticosteroids, and antihistamines. Uvular edema persisted in the emergency department. The patient denied having eaten other foods, taken any drugs (including nonsteroidal anti-inflammatory drugs), being infected, or having recently exercised. Skin prick tests with commercial food extracts were negative for salmon and other fish, shellfish, soy, rice, total egg, egg white, egg yolk, ovalbumin, and ovomucoid. Skin prick-prick tests were positive for chum salmon (Oncorhynchus keta) roe (17×10 mm) and negative for egg (white and yolk), ginger, salmon, flying fish roe (tobiko), sturgeon roe (caviar), and black scabbard fish roe. Specific IgE (sIgE) was 0.28 kUA/L

for salmon roe extract (ImmunoCAP, Phadia) and negative for the reaction and the fact that we were able to rule out all other extracts of salmon and other fish (<0.10 kUA/L). SDS-PAGE possible triggers. Furthermore, SDS-PAGE immunoblotting immunoblotting (Roxall) with chum salmon roe extract and the had additional value in our etiological investigation, confirming patient’s serum revealed a 20-kDa IgE-binding band (Figure). the presence of sIgE to salmon roe in the patient’s serum. Roe This band was manually excised from the gel, digested with from fish or other aquatic species is enclosed in the ovarian trypsin, and assessed using mass spectrometry following membrane, and salmon roe contains 3 major components that the methods of Pastor et al [8]. Proteins were identified by are equivalent to hen’s egg yolk proteins, namely, lipovitellin, searching a nonredundant protein sequence database (National phosvitin, and β’-component [3]. Nevertheless, there does not Center for Biotechnology Information) using the Mascot seem to be cross-reactivity between salmon roe proteins and program (http://www.matrixscience.com). The resulting hen’s egg [1,3]. These proteins are degradation fragments of peptides identified by mass spectrometry corresponded to vitellogenin, a protein synthesized in fish liver that is carried the region of vitellogenin that forms lipovitellin. After the to the oocytes through the bloodstream [9]. β’-component allergic reaction, the patient tolerated salmon and other fish is a dimer composed of 2 proteins (16 kDa and 18 kDa, roes (tobiko, caviar, and black scabbard fish). The patient eats respectively) derived from the same polypeptide chain and is fish and shellfish regularly with no complaints. We report a associated with cross-reactivity between fish roes. The 20-kDa case of salmon roe allergy confirmed by positive in vivo and in IgE-reactive protein detected in our study was identified as the vitro tests. In this case, no oral food challenge was performed. lipovitellin from salmon roe, a protein that has been reported to Yanagida et al [1] reported that a value of 34.6 kUA/L of the be an allergen both in salmon roe [3,9] and in beluga caviar [10]. sIgE to salmon roe has a 95% positive predictive value for a To our knowledge, this is the first reported case of salmon positive oral challenge result. Despite the low level of sIgE roe allergy without concomitant salmon allergy in a Portuguese to salmon roe detected in the present case, we decided not to patient. Allergic reaction to fish roe is rare in western countries; perform an oral food challenge test because of the severity of however, given the increase in consumption of fish roe in these countries, salmon roe allergy should be considered when P C M kDa evaluating patients with anaphylaxis after ingestion of sushi.

Acknowledgments

97.0 The authors are grateful to Phadia and Roxall for their help with the investigation. 66.0 Funding The authors declare that no funding was received for the 45.0 present study.

Conflicts of Interest The authors declare that they have no conflicts of interest.

Previous Presentations 30.0 With the exception of protein identification, data from this case report were presented as a poster at the EAACI 2018 annual congress.

20.1 References 1. Yanagida N, Minoura Y, Takahashi K, Sato S, Ebisawa M. Salmon roe-specific serum IgE predicts oral salmon roe food challenge test results. Pediatric Allergy and Immunology. 2016;27:320-32. 14.4 2. Minhas J, Saryan JA, Balekian DS. Salmon roe (ikura) induced anaphylaxis in a child. Ann Allergy Asthma Immunol. 2017;118:365-83. 3. Shimizu Y, Nakamura A, Kishimura H, Hara A, Watanabe K, Saeki H. Major allergen and its IgE cross-reactivity among salmonid fish roe allergy. J Agric food Chem. 2009;57:2314-9. 4. Takeuchi M, Oda Y, Suzuki I. Intussusception secondary to Figure. SDS-PAGE with salmon roe extract. Samples with 2-mercaptoethanol. Lane P, Patient’s serum; Lane C, control serum anaphylactic reaction to salmon roe (ikura). Pediatr Int. (pool of sera from nonatopic individuals); Lane M, molecular mass marker. 2013;55:649-51.

5. Pages A, Leduc V, De Lacoste de Laval A, Nelson JR, Pere B. Allergy to salmon eggs without concomitant fish allergies, Rapid Desensitization to Adalimumab Is Associated three pediatric cases. Rev French Allergol. 2015;44:301-4. With Decreased Basophil Sensitivity 6. Flais MJ, Kim SS, Harris KE, Greenberger PA. Salmon caviar-induced anaphylactic shock. Allergy Asthma Proc. Thévenot J1,2, Ferrier le Bouëdec MC3, Buisson A4, Bommelaer G4, 2004;24:233-6. D’Incan M3,5, Rouzaire P1,5,6 7. Prados-Castaño M, Piñero-Saavedra M, Leguisamo-Milla 1CHU de Clermont-Ferrand, Service d’Immunologie Biologique, S, Pastor C, Cuesta J, Bartolomé B. Anaphylaxis Due to Oat Pôle de Biologie et d’anatomopathologie, Clermont-Ferrand, Ingestion. J Investig Allergol Clin Immunol. 2016;26:48-72. France 8. Pastor C, Cuesta-Herranz J, Cases B, Pérez-Gordo M, Figueredo 2INRA/Agrocampus Ouest, UMR 1253, Science et Technologie E, de las Heras M, et al. Identification of major allergens in du Lait et de l'Oeuf, Rennes, France watermelon. Int Arch Allergy Immunol. 2009;149:289-90. 3CHU de Clermont-Ferrand, Service de Dermatologie, CHU 9. Kondo Y, Kakami M, Koyama H, Yasuda T, Nakajima Y, Estaing, Clermont-Ferrand, France Kawamura M, et al. IgE cross-reactivity between fish roe 4CHU de Clermont-Ferrand, Service de Gastroentérologie, CHU (salmon, herring and pollock) and chicken egg in patients Estaing, Clermont-Ferrand, France anaphylactic to salmon roe. Allergol Int. 2005:54:317-23. 5UMR 1240 INSERM/IMoST UCA 10. Perez-Gordo M, Sanchez-Garcia S, Cases B, Pastor C, Vivanco 6CHU de Clermont-Ferrand, Service d’Histocompatibilité, Pôle F, Cuesta-Herranz J. Identification of vitellogenin as an de Biologie et d’anatomopathologie, Clermont-Ferrand, France allergen in Beluga caviar allergy. Allergy. 2008;63:479-80. J Investig Allergol Clin Immunol 2019; Vol. 29(2): 141-143 doi: 10.18176/jiaci.0350

Key words: Adalimumab. Rapid desensitization. Basophil activation test. CDsens. Manuscript received May 24, 2018; accepted for publication November 5, 2018. Palabras clave: Adalimumab. Desensibilización rápida. Test de activación de basófilos. CDsens. Joana Cosme Serviço de Imunoalergologia Hospital de Santa Maria E-mail: [email protected] Adalimumab is a fully human recombinant monoclonal antibody against TNF-α that is used mainly in inflammatory diseases such as Crohn disease and ulcerative colitis. Immediate hypersensitivity reactions to this molecule have been reported and may be local or systemic, ranging from pruritus to anaphylaxis [1]. Rapid subcutaneous desensitization to adalimumab has been undertaken by several teams and appears to be an effective management approach, especially in patients with no obvious alternative therapeutic options [2-5]. Rapid drug desensitization protocols for patients who experience hypersensitivity reactions consist of incremental, step-by-step administration of the full therapeutic doses of the eliciting drug [6]. Despite the absence of consensus on the appropriate protocol, particularly for subcutaneous drugs, the few cases reported in literature validate the concept. Here, we report that successful desensitization to adalimumab in 2 patients is associated with a decrease in basophil sensitivity, which we monitored using the basophil activation test (BAT). Patient #1 was a 30-year-old woman with severe Crohn disease diagnosed 12 years ago. She experienced severe urticarial lesions at the injection site within 1 hour of the first injection of adalimumab (40 mg). This was a new course after a 6-year interruption of treatment (colectomy surgery, pregnancy). Patient #2 was a 38-year-old woman with severe ulcerative colitis diagnosed 10 years ago. She reported urticarial lesions at the injection site within 1 hour of the fifth injection of adalimumab (40 mg). For both patients, the results of prick testing with adalimumab were negative (100 mg/mL), although intradermal testing at 1:1000 (injection of 0.02 mL of

Anaphylaxis to Beluga caviar

Lefèvre Sébastien,1 Moumane Laurianne,2 Jacquenet Sandrine,3 Beaudouin Etienne1

Abstract

Fish roe is an extremely rare cause of anaphylaxis and although its consumption has increased in recent years. We described the case of a 59-year-old man, who experienced an anaphylactic reaction after consuming caviar. Skin prick-test were performed with Beluga caviar, salmon caviar, cod, salmon, hen egg yolk and egg white, ovalbumin, ovomucoid, shrimp and mold. Only SPT to Beluga caviar was positive. The absence of sensitization to fish and hen egg was confirmed by undetectable specific IgEs to cod, parvalbumin (Gad c 1 and Cyp c 1), egg yolk and egg white, ovalbumin and ovomucoid. An immunoblot was also performed and showed an IgE-reactive band indicated that the patient was sensitized to a 26 kDa protein in Beluga caviar. In the present case, immunoblotting of the patient’s serum revealed a single IgE-reactive band at 26 kDa band, which does not appear to correspond to the previous cases.

Key words: Anaphylaxis; caviar; food allergy; immunoblot; vitellogenin

From: Corresponding author: 1 Allergy department, Metz Regional Hospital, 1 allée du Château, 57530 Sébastien Lefèvre Ars-Laquenexy, France Allergy department, Metz Regional Hospital, 2 Allergy department, Besançon University Hospital, 3 boulevard 1 allée du Châteaux, 57530 Ars-Laquenexy, France Flemming, 25030 Besançon, France E-mail: [email protected] 3 GENCLIS SA, 15 rue du Bois de la Champelle, 54500 Vandoeuvre-les-Nancy, France

Introduction Scientific, Wattham, USA) and immunoblotting. SPTs were Fish roe is an extremely rare cause of anaphylaxis and al- performed with Beluga caviar (from sturgeon Petrossian, Paris, though its consumption has increased in recent years, little has France), salmon caviar (Petrossian, Paris, France), cod, salmon, been published on allergic reactions to these caviar products.1-5 hen egg yolk and egg white. Beluga caviar is a luxury delicacy that is eaten as a garnish or spread. Only two cases of Beluga caviar–induced anaphylaxis 1 Results have been reported in the literature. We report herein a new Only SPT to Beluga caviar was positive (wheal 15 mm). In anaphylaxis case to Beluga caviar without allergies to other roes. order to rule out irritation causing these results, the same tests were performed in 3 healthy volunteers. Positive controls were Methods 10% histamine chlorhydrate (7 mm) and 9% codeine sulfate (5 A 59-year-old man, with no atopic history, experienced an mm). Negative control was physiological serum (no reaction). anaphylactic reaction after consuming caviar. Until now, he was The absence of sensitization to fish and hen egg was con- accustomed to consuming caviar without reaction, once a year firmed by undetectable specific IgEs to cod, parvalbumin (Gad for Christmas. Ten minutes after the consumption of approx- c 1 and Cyp c 1), egg yolk and egg white, ovalbumin and ovomu- imately one teaspoon of Beluga caviar without any other food coid (ImmunoCAP® Thermo Fisher Scientific, Wattham, USA). or alcohol, he presented a severe anaphylactic reaction with Since ImmunoCap® to Beluga caviar was not commercially hypotension (60/40 mmHg) and dyspnea, requiring intramus- available, specific IgEs were detected by immunoblot. Briefly, a cular epinephrine (0.3 mg) in prehospital care enabling clinical protein extract from Beluga caviar was prepared and proteins improvement. Tryptase was sampled during the first hour after separated by Sodium Dodecyl Sulfate (SDS)-PAGE, showing the onset of the anaphylactic reaction and showed an increase numerous proteins mainly around 25 kDa as well as greater than at 16.8 µg/L. The basal tryptase rate was measured 24h later at 70 kDa. Separated proteins were then transferred onto a Poly- 5.6 µg/L. vinylidene difluoride (PVDF) membrane and the immobilized IgE sensitization was investigated by skin prick tests (SPTs), proteins were incubated overnight at +4°C with the patient’s specific IgE measurements (ImmunoCAP® Thermo Fisher serum. After washing and incubation with an enzyme-labeled Asian Pac J Allergy Immunol DOI 10.12932/AP-010918-0399 anti-human IgE antibody, the addition of enzyme substrate Conclusion allowed detecting bands in the presence of specific IgEs in the To the best of our knowledge, this is the first case of Beluga patient’s serum. The resulting IgE-reactive band indicated that caviar anaphylaxis described in France. Our patient presented the patient was sensitized to a 26 kDa protein in Beluga caviar. a selective food allergy to Beluga caviar. Both skin prick testing A control immunoblot performed in the absence of the patient’s and immunoblotting pointed to an IgE-mediated reaction. The serum did not show any nonspecific IgE reactive bands (Figure resulting sensitization appeared to be due to a 26 kDa protein, 1). which has not been described previously.

Conflicts of interest S Lefèvre, L Moumane and E Beaudouin: none S Jacquenet is employed by Genclis SA, a biotechnology company specialized in allergy

References 1. Untersmayr E, Focke M, Kinaciyan T, Poulsen LK, Boltz-Nitulescu G, Scheiner O, et al. Anaphylaxis to Russian Beluga caviar. J Allergy Clin Immunol.2002;109(6):1034‑5. 2. Flais MJ, Kim SS, Harris KE, Greenberger PA. Salmon caviar-induced anaphylactic shock. Allergy Asthma Proc.2004;25(4):233‑6. 3. Perez-Gordo M, Sanchez-Garcia S, Cases B, Pastor C, Vivanco F, Cuesta -Herranz J. Identification of vitellogenin as an allergen in Beluga caviar allergy. Allergy.2008;63(4):479‑80. 4. Chen YH, Wu HJ, Tsai JJ, Lee MF. Anaphylactic shock caused by a 33-kDa alpha S1-casein-like allergen in kingfish caviar. J Investig Allergol Clin Immunol. 2009;19(3):245‑6. 5. González-De-Olano D, Rodríguez-Marco A, González-Mancebo E, Gandolfo-Cano M, Meléndez-Baltanás A, Bartolomé B. Allergy to red caviar. J Investig Allergol Clin Immunol. 2011;21(6):493‑4. Figure 1. Coomassie blue-stained-SDS-PAGE with Beluga 6. Bergink EW, Wallace RA. Precursor-product relationship between caviar (A) and corresponding IgE immunoblots with (B) or amphibian vitellogenin and the yolk proteins, lipovitellin and phosvitin. without (C) patient’s serum. Lane 1: Beluga caviar. M: molec- J Biol Chem. 1974;249(9):2897‑903. 7. Hiramatsu N, Hiramatsu K, Hirano K, Hara A. Vitellogenin-derived ular weight markers in kDa. yolk proteins in a hybrid sturgeon, bester (Huso huso x Acipencer ruthenus): identification, characterization and course of proteolysis during embryogenesis. Comp Biochem Physiol, Part A Mol Integr Physiol. Discussion 2002;131(2):429‑41. The main component in fish roe is yolk, the latter of which is comprised of 3 major proteins: lipovitellin (21 kDa), phosvitin (35 kDa) and ß’-component (ß’-c, 18 kDa)). These three proteins derived from the same precursor, vitellogenin, with an apparent molecular mass of 580 kDa, appear as two major bands corresponding to 180 kDa and 120 kDa after SDS-PAGE.6,7 Gonzalez-de-Olano et al. have identified several proteins in salmon roe (18 and 21 kDa), trout roe (18 kDa) and slated hake roe (18 and 30 kDa).5 In their description of the first case of Russian Beluga caviar anaphylaxis, Untersmayr et al. performed an immunoblot with the patient’s serum which revealed four unidentified IgE-reactive bands of 30, 84, 100 and 118 kDa, the latter two being more reactive.1 In the reported case of Iranian Beluga caviar anaphylaxis, immunoblotting showed a broad spectrum of IgE-reactive bands ranging from 23 to 120 kDa, identified as fragments of vitellogenin by mass spectrometry.3 In the present case, immunoblotting of the patient’s serum revealed a single IgE-reactive band at 26 kDa band, which does not appear to correspond to the previous cases (Figure 1). Moreover, we can speculate that this protein is not a fragment of vitellogenin since another reactive band would likely have been found in this instance.