title: A case of neonatal alloimmune thrombocytopenia in the presence of both anti-HPA-4b and anti-HPA-5b antibody: clinical and serological analysis of the subsequent pregnancy.
abstract: Neonatal alloimmune thrombocytopenia (NAIT) is induced by maternal alloantibodies raised against fetal platelet antigens inherited from the paternal parent. In contrast to Caucasians, in Asians, predominantly in Japanese, most frequently detected antibodies in NAIT are anti-HPA-4b and anti-HPA-5b. In some NAIT cases multiple alloantibodies are detected. In such cases it is very difficult to determine which antibody is the dominant antibody in NAIT. In this case report, we describe a NAIT case (first sibling) with severe thrombocytopenia and cephalhematoma in the presence of both anti-HPA-4b and anti-HPA-5b antibodies in the maternal serum. We carefully examined titers of anti-HPA antibodies during the subsequent pregnancy with HPA-4b-positive and HPA-5b-negative fetus determined by amniocentesis at gestational week 16. We administered IVIG (1 g/kg/w) to the mother from gestational week 32 to 35. The mother subsequently delivered a second sibling with normal platelet count by cesarean section. Although we could not completely rule out the involvement of anti-HPA-4b, our findings suggested that anti-HPA-5b was implicated in the NAIT in the first sibling.
authors: Department of Blood Transfusion, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors: Tomoko
authors: T
authors: Kiyokawa
authors: Yangsook
authors: Y
authors: Koh
authors: Kazuya
authors: K
authors: Mimura
authors: Kotarosumitomo
authors: K
authors: Nakayama
authors: Mika
authors: M
authors: Hosokawa
authors: Mikiko
authors: M
authors: Sakuragi
authors: Tamayo
authors: T
authors: Morikawa
authors: Mayumi
authors: M
authors: Nakao
authors: Hiroshi
authors: H
authors: Aochi
authors: Yasuo
authors: Y
authors: Fukumori
authors: Takeshi
authors: T
authors: Kanagawa
authors: Keisuke
authors: K
authors: Nagamine
authors: Tadashi
authors: T
authors: Kimura
authors: Yoshiaki
authors: Y
authors: Tomiyama
mesh_terms: D016824:Antigens, Human Platelet / Q000276:immunology*; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000008:administration & dosage*; D007155:Immunologic Factors / Q000008:administration & dosage*; D007518:Isoantibodies / Q000276:immunology*; D011247:Pregnancy; D054098:Thrombocytopenia, Neonatal Alloimmune / Q000097:blood / Q000276:immunology / Q000517:prevention & control
chemical_list: C510800:4b alloantigen, human; C055973:5b alloantigen, human; D016824:Antigens, Human Platelet; D016756:Immunoglobulins, Intravenous; D007155:Immunologic Factors; D007518:Isoantibodies