日本新生児成育医学会雑誌　第28巻　第2号　72～77頁（2016年）

日本新生児成育医学会雑誌 28(2)：296-301；2016　

受付日：平成27．12．21

受理日：平成28．04．13

IgEの関与が疑われるミルクアレルギーを呈した極低出生体重児の一絨毛膜二羊膜双胎

Monochorionic Diamniotic Twins with Very Low Birth Weight Exhibiting IgE-mediated Milk Allergies

奈良県総合医療センター　新生児集中治療室

Department of Neonatal Intensive Care Unit, Nara Prefecture General Medical Center

梶本昂宏・恵美須礼子・小林遼平・新居育世・安原　肇・扇谷綾子・箕輪秀樹

Takahiro KAJIMOTO，Reiko EBISU，Ryohei KOBAYASHI，Ikuyo ARAI，Hajime YASUHARA，Ayako OHGITANI，Hideki MINOWA

Key Words：milk allergy，very low birth weight infants，monochorionic diamniotic twins

　IgEの関与が疑われるミルクアレルギーを発症した極低出生体重児の双胎例を経験した。在胎週数は28週5日で出生体重は症例1が986g，症例2が1,145gであった。症例1 は人工乳投与により無呼吸発作が増悪した。日齢27に完全人工乳栄養となったところ無呼吸発作の増悪および全身色不良を認め禁乳とした。Radioallergosorbent test（RAST）で牛乳蛋白に陽性を示した。Allergen-specific lymphocyte stimulation test（ALST）は陰性であった。症例2も同様に人工乳投与により無呼吸発作の増悪と腹部膨満を認めた。RASTで牛乳蛋白に陽性，ALSTでラクトフェリンに陽性を示した。両症例とも母乳およびアレルギー用ミルク投与で症状は改善した。本症例ではIgEが発症に関与している可能性があると考えられた。新生児のミルクアレルギーは消化管症状に乏しいこともあり注意が必要である。

　Here, we report two cases of very low birth weight infants who developed IgE-dependent milk allergies. The female infants were monochorionic diamniotic twins at a gestational age of 28 weeks and 5 days. The birth weights for each infant were 986g and 1,145g, respectively. Patient 1 was provided enteral feeding from Day 2. The patient’s apnea worsened with administration of milk formula and the patient was treated with aminophylline, after which the clinical course was observed. On Day 27, the patient was able to tolerate full bottle-feeding, which aggravated the ongoing apnea and resulted in the patient’s skin color turning pale. We concluded that the patient was in a state of shock and full parenteral feeding was started. As the radioallergosorbent test（ RAST） was positive for milk proteins, patient 1 was diagnosed with milk allergies. However, the allergen-specific lymphocyte stimulation test（ ALST） was negative. Patient 2 was provided enteral feeding from Day 3 with breast milk. After Day 8 when formula was added to breast feeding, the patient’s apnea and abdominal distension progressed. On Day 27, feeding formula was stopped due to observed vomiting. This patient was also diagnosed with milk allergies based on positive results on both RAST for milk protein and ALST for lactoferrin. Both of the infants were healthy after being fed their mother’s milk and allergy-specific formula. The oral provocation test at 1 year of age for patient 1 showed signs of allergy to cow’s milk. In these patients, allergy symptoms are caused, at least in part, by IgE. Therefore, caution with regard to milk allergies, especially in newborn infants, should be exercised because there are no specific symptoms.