bb unit 3 sum

Kell major ag

antithetical, developed at birth HDFN, K (KEL1, v immunogenic stimulating ab production) less than 9%, k (KEL2/cellano) more than 90%

other Kell ag

analogous to Rh C/c and E/e, Kpa low frequency, kpb high frequency, Jsa 20% african amer, Jsb hugh frequency ag 80-100%

biochem of Kell ags

on single glycoprotein integral to the red cell membrane, disulfide bonded regions, sensitive to sulfhydryl reagents

sulfhydryl reagents

2-mercaptoethanol 2-ME, dithiothreitol DTT, 2-aminoethylisothiouronium bromude AET

K0 or Knull

lacks all Kell ags, expresses Kx ag, make anti-Ku KEL5 in transfusion (high frequ on all cells except K0), rare donors found by ARDP

all Kell alleles

on chromosome 7, K KEL1 and k KEL2, Kpa KEL3 and Kpb KEL4, Jsa KEL6 and Jsb KEL 7, KEL11 and KEL17 Wka

high vs low incidence alleles

k, Kpb, Jsb, KEL11 vs K, Kpa, Jsa, KEL17

Kell ab

IgG, rbc or bacterial infection stimulation, best agglu in IAT, no complement, hemolytic transfusion reactions HTR and HDFN, not treated with enzymes

Kx

1 ag, XK gene on chromosome X (MALES), biologically important, lacking the ag causes rbc abnormalities

mcleod syndrome

rbc abnormalities, muscular and neurologic defects, increased creatine kinase, chronic granulomatous disease (impaired phagocytosis- engulf but not kill)

duffy system

well developed ag at birth, destroyed by enzymes, Fya and Fyb, codominant

duffy in races

caucasians- Fy (a+b+, a-b+, a+b-)

asians- Fya is high incidence

african amer- Fy (a-b-)

duffy ab

anti-Fya and anti Fyb, IgG, no complement, stim by rbc transfus or preg, no reaction to enzyme-treated rbcs

duffy and malaria

Fya or b is receptor for parasite to rbcs, Plasmodium knowlesi and plasmodium vivax will not invade Fy (a- and b-) cells, people from west and central africa are typically Fy(a-b-)= selective evelution

Kidd system

3 ag- Jka Jkb, Jk3, blacks Jk(a+b-), cauc Jk(a+b+), Jk3 present when a and b absent, fully developed at birth and on fetal rbc

Kidd null

far east or pacific islands, Jk(a-b-) can have anti-Jk3 and rbcs resistant to 2M urea, suboptimal urine concentrating ability

Kidd ab

anti-Jka and anti-Jkb, IgG, clinically sig, dosage (a+b- reacts, a+b+ nonreactive), complement, HTRs, HDFN, appear with other abs, enzymes LISS and PEG enhance detection

Lutheran system

28 ags, high incidence, weakly expressed on cord blood, not affected by enzymes, Lua (low incid) and Lub (high inci 99%) antithetical, null= recessive rare

anti-Lua

stimulated by rbc, IgM and G, room temp, mixed field, not clinically sig

anti-Lub

rare bc high incid ag, IgG, AHG test, mixed field, transfusion reaction clinically sig

Lewis system

6 ag (Lea and Leb) in secretions (glycoproteins) and plasma (glycolipids absorbed onto rbc membranes), not at birth newborns are a-b-, preg women may be a-b- as well

lewis ag

Le= Lea,

Le, H, Se= Lea becomes Leb

sese= no b

ewis ab

produced by Le(a-b-), IgM, not sig, agglu at IS 37C and AGH, confirm presense with neutralization

I system

I and i ag not antithetical, form on A, B, H chain rbc precursor, newborns i (linear), adults I (branched, by 2 years of age),

I abs

cold IgM, complement, not sig, autoantibody, alloanti-I rare, compound (anti-IH, stronger aggly with rnc with many H sites), prewarm to avoid reaction

autoanti-I

mycoplasma pneumoniae, cold hemagglutinin dieseas

anti-i

infectious mononucleosis, lymphoproliferative disease, cold hemagglutinin disease

P1PK system

P1 (in plasma and hydatid cyst fluid), Pk, NOR ags, structurally related to ABH ags

GLOB system

P and PX2 ags, structurally related to ABH ags

P1

rbc expresses P, P1, and Pk ags, not at birth, most common phenotype, no abs

autoanti-P

cold paroxysmal hemoglobinuria, IgG (donath landsteiner ab)- biphasic hemolysin binding P1 or 2 cells at low temp before comp activation, in children after viral infection

P2

lacks P1 ag but expresses P and Pk ags, 2nd most common phenotype, anti-P1 (alloab IgM, rt, not sug)

Anti-P1

in P2 individuals, IgM enhanced by enzymes, non rbc stim, neutralized by P1 substance

P1k

rbc expresses P1 and Pk, rare phenotype, anti-P (alloab clinically sig, spontaneous abortion)

P2k

rbc expressing only Pk, rare pheno, anti-P and anti-p1 (alloab)

p

null and rare pheno, neg for P P1 Pk ag, anti-PP1Pk (Tja, alloab- hemolytic, sig, 3 specificities)

anti-PP1Pk

in null, hemolysis in vitro, sig

MNS M and N

coded by glycophorin A GPA (sialoglycophorin A membrane, 131 AAs), positions 1 and 5 on GPA, dosage (homo enhances M+N- or M-N+)

MNS S s and U

coded by glycophorin B GPB (sialoglycophorin B membrane, 72 AAs), S and s at position 29, S methionine, s threonine, U near membrane, present with S or s, no GPB neg S s U

MNS abs

Anti-M= IgM and G, rarely sig, HDFN, reactions vary depending on pH,

anti-N= IgM, rarely sig, N-likein dialysis from formaldehyde sterilized instruments

Anti-S,s,U= IgG, clin sig, U is rare found in S-s- african amer

HLAs

on leukocytes and tissue cells, abs produced due to transfusion or preg and are associated with platelet refractoriness, match for organ or HPC transplant

HLA inheritance

1 haplotype, genes are part of MHC (class I= platelets leukocytes nuc cells, ABC, II= macrophages DC B, III= complement- C4 fac B C2 and cytokines TNF-a LTbeta LT)

HLA testing

lymphocytotoxicity test method for serological ID using complement and dye to detect if ag-ab reaction (pos stain dark)

Platelet ags

elicit immune responses, abs cause destruction of platelets as neonatal alloimmune thrombocytopenia NAIT due to mom ab, posttransfusion purpura PTP, most common ab is against HPA-1a or P1A1

ab screen detects and used for

detects atypical or unexpected abs, pre-transfusions, preg women, post transfusion reactions, blood and plasma donors

ab screen in plasma

expected anti-a or anti-b, unexpected ab- due to transfusion or HDFN, if IgM not sig IgG sig

clin sig ab

IgG, 37C incubate, AHG IAT, hem transfusuion reaction HTRs and HDFN

screening cells

single or pooled, group O, donor cells (single-donor vials increased sesitivity), 2-3 vials (donor) phenotyped for each ag, 18 ags

antigram

2 or 3 screening cells, ags present in each vial, reaction to one of more cells indicates atypical ab presence

autocontrol AC and DAT determine

if plasma ab are directed against the patients cells or transfused cells (allo or auto)

autocontrol AC

patients serum of plasma with their own rbs, incubated simultaneously during same phases as ab screen or ab panel

DAT

performed if auto control with initial screen or panel is positive, patient cells plus AHG reagent to detect in vivo ig coating

ab id- patient transfusion history

mixed rbc pop from prev transfusion can remain up to 3 months, they may have come from another hospital

ab id- patient history other

ab associated diseases, ab at higher frequency due to race

initial ab panel

10-20 cells, group O cells, each cell is ag typed and antigram lists phenotype and records/interprets results, uses potentiators

saline- potentiator

enhances only if incubated for a long time

potentiator

LISS low ionic strength solution (common), Bovine serum solution BSA, Polyethylene glycol PEG, proteolytic enzymes (destroy some enzymes)

LISS

sensitive, economical, shorter incubation BUT enhances cold agglu, miss weak anti-K ab, equal pans of plasma/serum, if altered ionic strength sensitivity decreases

BSA

affects 2nd stage of agglu, reduces the repulsion between rbc, does not enhance warm autoab, BUT longer incub time, not sensitive for most ab besides Rh system

PEG

increases sensitivity, detects presence of ab not found with BSA or LISS, use anti-IgG AHG BUT enhances warm autoab, IgM ab react poorly, no 37C, require wash

enzymes- ficin, papain

eliminates Fya, Fyb, M, N, S s variable affect = loss of reactivity in panel ab, enhances Rh, JK, LE, P1 ab, BUT enhances cold autoab, can help investigate complex ab problems but not alone

Gel tech

avoids cold reactive ab, increases sensitivity, automated, BUT enhances warm autoab, misses weak anti-K and anti-E due to LISS suspended rbc

solid phase SPRCA

avoids cold reactive ab, increases sensitivity, automated, BUT enhances warm autoab, misses weak anti-K due to LISS potentiator, hard to read if manual

interpretation autocontrols

positive- auto or allo ab to recently transfused cells is present

neg- indicated alloab

positive BUT NEG DAT- false pos

IgM reactivity

rt or below, during IS crossmatching, anti-Lea, anti-Leb, anti-M, anti-N, anti-I, anti-P1 ab

IgG reactivity

37 C or with AHG

IgM and IgG reactivity

reactions at diff phases on same panel

reaction strength

affected by doage, if varies- multiple ab

ruling out abs

use homo panel cells all neg in all phases, cross out ags present

patterns

if single ab present reaction matches one of the ag columns, varying if multiple ab

rule of 3

ensures valid results, 3 ag pos cells must react, 3 ag neg cells must not react with patient plasma, fix by using selected cells

phenotyping the patient

confirm patients abs by detecting their rbc ag (no alloab for what they have, if recently transfused use rbc separation tech)

multiple abs

more difficult, varying reactions, use selected cells, proteolytic enzymes, other chemicals (dithiothreitol denatures Kell ags)

proteolytic enzymes

Duffy (Fya Fyb) and MNS ags are destroyed, Rh, Kidd, and Lewis ag are enhanced, 1 stage test (enzymes rbcs and serum incubate), 2 stage test (pretreat panel cells with enzymes, wash, use as usual)

ab to high frequency ags

98% or higher, suspect alloab if most panel cells are pos with neg autocontrol, confirm ab presence with enzymes- enhance/destroy ags or dithiothreitol destroy Kell ags

high frequency ab at rt

I, H, P, P1, PP1Pk

high frequency ab affected negative with ficin treated cells

Ch, Rh, JMH

high titer low avidity ab

ab to high frequency ag reacting weakly in AHG phase, not implicated in transfusion or HDFN, inconsistent reaction, not sig, with other ab, nonreactive with autologous cells, fix with titration and inhibition

ab to low frequency ags

suspect when screen is neg and crossmatch is pos, only 1 reactive cell, anti-Cw, anti-Wra, anti-V, anti-Cob, anti-Bga, anti-Kpa, and anti-Lua ab

enhance weak IgG ab by

repeat with diff enhancment like enzymes or PEG, chakc ag dosage on weak or missing reactions, select diff cells from a new panel, incub longer within limits of reagent, phenotype if not recently transfused, increase serum to cell ratio within limit of reagent

cold alloab

IgM ab reacting at IS during crossmatch and sometimes 37 C, not sig, variable= anti-P1 anti-M anti-N abs, incub below rt to enhance, neutralization to detect sig abs (must perform parallel control to ensure neg reaction not due to dilution)

autoab

react with ALL reagents, autocontrol and DAT pos, id underlying alloab when autoab found, adsorption tech to remove

cold autoab

react during IS crossmatching, pos autocontrol and DAT (C3), patient history of mild anemia, mycoplasma pneumoniae infection, infectious mononucleosis, id anti-I anti-H anti-IH with “cold panels“

avoiding cold autoab reactions

monospecific IgG AHG reagent, skip IS crossmatching and 37 C testing, use 22% BSA not LISS, prewarm to 37C to avoid reactivity, lastly use adsorption tech

prewarming

prewarm saline to 37 C, label one tube per reagent or donor sample, add 1 drop of 2-5% saline suspended rbc to each tube, incubate rbc tubes, patient serum tube, and pipette at 37 C for 5-10 min, add 2 drops serum to rbc tubes and mix while still in incub, incub for 30-60min, fill each tube with the saline in incub, centrifuge, wash 3-4x with saline, add anti-IgG according to manufacturer directions, centrifuge, grade results, confirm neg by adding IgG coated rbcs

adsorption- rabbit erythrocyte stroma RESt

remove cold IgM ab, anti-I specificities BUT adsorbs anti-B and other IgM abs

cold autoadsorbtion

patient rbcs remove cold autoab determining if alloab are present BUT cannot use if recent transfusion

warm autoadsorption

patient rbcs remove warm autoab determining if alloab are present BUT cannot use if recent transfusion

differential (allogeneic) adsorption

uses known phenotyped rbcs to separate warm autoab from alloab and alloab with several specificities, BUT may adsorb alloab to high frequency ag

auto specificity

warm autoabs are directed to the