{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T12:17:44Z","timestamp":1788178664306,"version":"build-2803163510"},"reference-count":25,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T00:00:00Z","timestamp":1788134400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T00:00:00Z","timestamp":1788134400000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Transfusion"],"abstract":"Abstract<\/jats:title>\n \n Background<\/jats:title>\n \n The cluster of differentiation 44 glycoprotein carries the Indian blood group system, including the antithetical antigens In\n a<\/jats:sup>\n and In\n b<\/jats:sup>\n . The In\n b<\/jats:sup>\n antigen is highly prevalent, with more than 99.9% of Caucasians being In\n b<\/jats:sup>\n \u2010positive, whereas In\n b<\/jats:sup>\n \u2010negative individuals are found almost exclusively in South Asian populations (~0.02%). Anti\u2010In\n b<\/jats:sup>\n can cause hemolytic transfusion reactions, but little data are available on hemolytic disease of the fetus and newborn (HDFN), suggesting minimal placental transfer, with only one reported case of a positive neonatal direct antiglobulin test (DAT).\n <\/jats:p>\n <\/jats:sec>\n \n Case Report<\/jats:title>\n \n A woman of Indian origin developed an anti\u2010In\n b<\/jats:sup>\n alloantibody with a titer of 64 during her first pregnancy. This was detected only at delivery, with no evidence of transplacental transfer of antibodies or HDFN. The anti\u2010In\n b<\/jats:sup>\n titer increased after delivery, reaching a peak of 1024, and remained stable throughout the second pregnancy. At birth, the second neonate showed a strongly positive DAT, with anti\u2010In\n b<\/jats:sup>\n detectable in both the plasma and eluate, confirming transplacental transfer and red blood cell binding. Testing of maternal plasma showed immunoglobulin G1 predominance over immunoglobulin G3 and moderate\u2010to\u2010high hemolytic potential in the monocyte monolayer assay and antibody\u2010dependent cellular cytotoxicity (ADCC) test, with a monocyte index of 7.7\u201310% and ADCC of ~40%. Despite these findings, the neonate exhibited no signs of hemolysis.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n \n This case demonstrates that high\u2010titer, functionally active maternal anti\u2010In\n b<\/jats:sup>\n antibodies can coexist with neonatal anti\u2010In\n b<\/jats:sup>\n reactivity without causing hemolysis. The marked discrepancy between serological, functional, and clinical findings underscores the limited predictive value of current assays in rare blood group incompatibilities.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.1111\/trf.70384","type":"journal-article","created":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T11:46:39Z","timestamp":1788176799000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Positive neonatal direct antiglobulin test and free circulating panagglutinin due to high\u2010titer immunoglobulin G1\n \n anti\u2010In\n b<\/sup>\n <\/scp>\n without in vivo hemolysis"],"prefix":"10.1111","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6149-2614","authenticated-orcid":false,"given":"Salim","family":"Oulghazi","sequence":"first","affiliation":[{"name":"Department of Immunohematology German Red Cross Blood Donor Service Baden\u2010W\u00fcrttemberg\u2010Hesse Frankfurt Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Siebo","family":"Albers","sequence":"additional","affiliation":[{"name":"Department of Immunohematology German Red Cross Blood Donor Service Baden\u2010W\u00fcrttemberg\u2010Hesse Frankfurt Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-9609-3209","authenticated-orcid":false,"given":"Sofia Lejon","family":"Crottet","sequence":"additional","affiliation":[{"name":"Department of Immunohematology Interregional Blood Transfusion SRC Ltd. Bern Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0088-2675","authenticated-orcid":false,"given":"Halvard","family":"Bonig","sequence":"additional","affiliation":[{"name":"Department of Immunohematology German Red Cross Blood Donor Service Baden\u2010W\u00fcrttemberg\u2010Hesse Frankfurt Germany"},{"name":"Faculty of Medicine Institute for Transfusion Medicine and Immunohematology, Goethe University Frankfurt Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0038-385X","authenticated-orcid":false,"given":"Susanne","family":"Braeuninger","sequence":"additional","affiliation":[{"name":"Department of Immunohematology German Red Cross Blood Donor Service Baden\u2010W\u00fcrttemberg\u2010Hesse Frankfurt Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,8,31]]},"reference":[{"issue":"4","key":"e_1_2_7_2_1","doi-asserted-by":"crossref","first-page":"136","DOI":"10.2478\/immunohematology-2025-020","article-title":"The Indian (IN 023) blood group system: an update","volume":"41","author":"Joshi SR","year":"2025","journal-title":"Immunohematology"},{"issue":"16","key":"e_1_2_7_3_1","doi-asserted-by":"crossref","first-page":"4311","DOI":"10.1182\/bloodadvances.2023012241","article-title":"Maternal red blood cell alloimmunization prevalence in the United States","volume":"8","author":"Sugrue RP","year":"2024","journal-title":"Blood Adv"},{"issue":"2","key":"e_1_2_7_4_1","doi-asserted-by":"crossref","first-page":"e57","DOI":"10.1097\/AOG.0000000000002232","article-title":"Prevention of Rh D Alloimmunization","volume":"130","author":"Practice Bulletin No. 181","year":"2017","journal-title":"Obstet Gynecol"},{"issue":"9","key":"e_1_2_7_5_1","doi-asserted-by":"crossref","first-page":"715","DOI":"10.1038\/nri2155","article-title":"FcRn: the neonatal fc receptor comes of age","volume":"7","author":"Roopenian DC","year":"2007","journal-title":"Nat Rev Immunol"},{"key":"e_1_2_7_6_1","doi-asserted-by":"crossref","DOI":"10.1155\/2012\/985646","article-title":"IgG placental transfer in healthy and pathological pregnancies","volume":"2012","author":"Palmeira P","year":"2012","journal-title":"Clin Dev Immunol"},{"issue":"2","key":"e_1_2_7_7_1","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1016\/j.transci.2014.02.008","article-title":"Noninvasive fetal RhD genotyping","volume":"50","author":"Clausen FB","year":"2014","journal-title":"Transfus Apher Sci"},{"issue":"1","key":"e_1_2_7_8_1","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1097\/AOG.0b013e31817d453c","article-title":"Management of rhesus alloimmunization in pregnancy","volume":"112","author":"Moise KJ","year":"2008","journal-title":"Obstet Gynecol"},{"issue":"2","key":"e_1_2_7_9_1","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1111\/vox.12265","article-title":"Haemolytic disease of the fetus and newborn","volume":"109","author":"Haas M","year":"2015","journal-title":"Vox Sang"},{"issue":"2","key":"e_1_2_7_10_1","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1111\/trf.15631","article-title":"Diagnostic value of laboratory monitoring to predict severe hemolytic disease of the fetus and newborn in non\u2010D and non\u2010K\u2010alloimmunized pregnancies","volume":"60","author":"Koelewijn JM","year":"2020","journal-title":"Transfusion"},{"issue":"5","key":"e_1_2_7_11_1","doi-asserted-by":"crossref","first-page":"941","DOI":"10.1111\/j.1537-2995.2007.01625.x","article-title":"Effect of screening for red cell antibodies, other than anti\u2010D, to detect hemolytic disease of the fetus and newborn: a population study in the Netherlands","volume":"48","author":"Koelewijn JM","year":"2008","journal-title":"Transfusion"},{"issue":"1","key":"e_1_2_7_12_1","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1056\/NEJM200001063420102","article-title":"Noninvasive diagnosis by Doppler ultrasonography of fetal anemia due to maternal red\u2010cell alloimmunization. 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