[Acquired B antigen in a pregnant woman belonging to the A1 blood group: case report].
BACKGROUND
This article presents a case of acquired B antigen in a 24 year old pregnant woman, with A1 Rh D positive blood group verified by expression ABO tube test, secretor status, and investigation of group specific substance in saliva, by agglutinating inhibition test and examination of blood groups in patient's family (both parents and sister).


METHODS
Since the patient was a clinically healthy woman, without anamnestic data and clinical signs of any kind of disease (such as diseases of the gastrointestinal system, especially colonic disorders), and with regular course of pregnancy, this acquired irregular agglutination of red blood cells, suggested a possible infection with Gram-negative bacteria. That is why she underwent additional investigations of blood and urine.


CONCLUSIONS
Hemocultures were negative, but urine tests revealed a urinary infection with uropathogenic strains of Escherichia coli O86. Eight months later the patient was retested, and findings of acquired B antigen and latent urinary infection with E. coli still persisted, proving the cause of irregular agglutination.
Vojvodić
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Zavod za transfuziju krvi Novi Sad, 21000 Novi Sad, Hajduk Veljkova 9.
D000017:ABO Blood-Group System; D000328:Adult; D004927:Escherichia coli Infections / Q000097:blood*; D005260:Female; D006386:Hemagglutination Tests; D006801:Humans; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000097:blood*; D012204:Rh-Hr Blood-Group System
D000017:ABO Blood-Group System; D012204:Rh-Hr Blood-Group System