ABO blood group latest 2023 already graded A

ABO blood group latest 2023 already graded A Precursor D-galactose N-acetylglucosamine D- galactose H substance L-fucose B gene - antigen Precursor + H substance + D-galactose A gene - antigen Precursor + H substance + N-acetylgalactosamine O gene Precursor + H substance Old terminology agglutinogen (antigen) agglutinin (antibody) blood banking is overseen by FDA and AABB What is found in serum antibodies what is found on cell membrane antigens IF antigens are present on cell and antibodies are present you will see agglutination A antigens on cells anti B antibodies B antigens on cells anti A antibodies A and B antigens on cells NO antibodies O - no A or B antigens anti A anti B ABO antibodies are expected A frequency 40% B frequency 10% AB frequency 5% O frequency 45% Universal donor O, all can accept no antigens present Universal acceptor AB ABO identical exact type as patients ABO compatible Can use either acceptable type EX: type A or O to A person Chromosome #9 A and B are co dominant genotype genes inherited phenotype genes expressed blood type H system is on chromosome # 19 H gene controls L fucosyltransferase adds L fucose A or B antigens cannot build without H who has the most H on surface? least? most- O type least - AB type forward type and reverse must match Bombay O Have anti H, anti A and anti B RARE <0.1% can only receive packed cells from other bombay O because they will have a transfusion reaction crossmatch for bombay O no agglutination How to confirm bombay O add anti-H (ulex europas) 2 forms of anti H 1. cold not a problem in body 2. warm bombay O cold autoantibodies shortened survival of RBC in transfusion reaction warm autoantibodies HDN IgG 37C and cross placenta IgM Cold temps, do not cross placenta Exception to IgM cold ABO Secretor Presence of A/B, and H in secretions secretor controlled by a pair of allelic genes on chromosome # 19 How many Se (versus se) need to be present to be expressed One Se codes for L fusosyltransferase which adds L fucose into water soluble precursor substance % of secretors 78 % of non secretors 22 secretors produce two types of ABO antigens alcohol soluble - RBC water soluble - body fluids non secretors produce one type of ABO antigens alcohol soluble ABO testing sample EDTA tube spun down to separate plasma and cells Reagents for ABO forward: Anti A, Anti B reverse: A cells, B cells ABO reactions must be greater than _____ or retest 2+ Most important tube tap piece? consistent tube tapping technique 4+ solid button with clear background 3+ 2-3 larger clumps with a clear background 2+ medium sized clumps with a slightly cloudy background 1+ numerous clumps with a cloudy reddish background 0 /= no visible agglutination background very cloudy forward type looks for Unknown antigens on cell use known antibody (antisera) determines ABO type reverse type looks for unknown antibody in plasma uses known antigen confirms the forward type Bombay O test findings forward: = anti A, = anti B, = anti H reverse: 4+ A cells, 3+ B cells O type test findings = anti A, = anti B, + anti H Blood should never be transfused if it carries the antigen that the recipient lacks #1 reason we stop transfusion fever ABO antibodies are naturally naturally occurring Titer concentration of antibody and reaction strength Lower titer levels may be seen in immunocomprimised patients like elderly, cancer may be enhanced by cold incubation due to IgM loving cold ABO antibodies are ______________________ in newborns undetected * forward type only IgM are effective complement activators Newborn samples from cord have whartons jelly can cause false + so wash cells really well