ERYTHROCYTE ANTIGENS AND ANTIBODIES

Crizelda Dayrit Liwanag, MS, RMT

• Discovered in 1900• On RBC’s, platelets &

endothelial cells• Considered also in solid

organ & BM transfusion• A, B & H Ag’s• A, B, AB, O phenotypes• Autosomal dominant –

A, B, AB• Autosomomal recessive

- O

ABO

MNSs

P

• 700 erythrocyte antigens

• 29 blood group systems by ISBT

• Usually high frequency and expressed by most donors (>90-99%)

• Some are private Ag’s• See Table 34-6 (JBH)

Intro1.Ag’s & Ab’s2.Ig class3.Serologic Phase of Det’n4.CS5.Stat

• ISBT 001• Ab’s against missing

antithetical Antigen• Null & weak phenotypes:–A2 (A1 are agglutinated by

Dolichos biflorus)–A2 may have anti-A1–Acquired B – bacteria or

Ca w/c deacetylates A Ag–Cis AB - single autosomal

allele for both A & B

ABO

MNSs

P

–Cis B(A) – trace A due to B-gene enzyme synthesis–Bombay & para-

bombay

ABO

MNSs

P

• Biochemistry:–CHO Ag’s, post

translation modification of glycoproteins & glycolipids–Type 2 oligosaccharide

precursor (repeating galactosaminyl motifs) & sphingolipids (type 1, 2, 3, 4)–FUT 1 (bld) & FUT 2

(sec) – alpha 1-2 H Ag

ABO

MNSs

P

• Biochemistry:–B Ag – alpha 1-3 Gal–A Ag – alpha 1-3 N-

acetylGal–Decreased Ag’s in

malignancy– Increased incidence of

diseases (autoimmune, neoplastic & infectious diseases)

ABO

MNSs

P

• Antibodies:–Naturally occuring

(IgM)–Absent 3-6 mts–Stable 5-10 yrs–Decreases with age–Anti-A,B is in grp O–RT saline 4 deg C– IgA & IgG – infrequent– IgG at 37, after stim–Can fix C’, HDN, HtR

ABO

MNSs

P

• Antibodies:–Rej’n of organs & BM

(due to delayed engraftment)–Anti-A1 in A2, A2B,

Ax, A3–Anti-H in A1 & A1B

non secretors, autoantibody usually, alloanti-H in Bombay & para

ABO

MNSs

P

• ISBT 002• 43 Ags• M/N & S/s – common• Only on RBC’s• Null phenotypes:–U – most common in

blacks–MkMk – lacks all–En (a-) – M-N- pheno

due to loss of glycophorin A

ABO

MNSs

P

• Null phenotypes:–Henshaw (rec

glycophorin B)–S-s-Uvar

ABO

MNSs

P

• Antigens–Glycophorin A• 31 kDa• 131 aa• Type I glycoprotein• 72 a.a extracellular

domain• Transmembrane

domain• Major sialomucin on

RBC (zeta potential)• M & N reside here

ABO

MNSs

P

• Antigens–Glycophorin B• 20 kDa• 72 aa• extracellular N-

terminal domain• S/s & U reside here

ABO

MNSs

P

• Antibodies–Naturally occurring–RT saline– IgM–Anti M & N – show dosage–Destroyed by pre-

treatment of RBC’s with enzymes or neuraminidase

– Enhanced by pH 6.5 albumin, preincubation of RBC in a glucose sol’n

ABO

MNSs

P

• Antibodies–Anti M – common–Anti N – uncommon–Auto anti-N – dialysis

(due to formaldehyde neoantigen)

–Anti-S,s, U – always significant• IgG, 37, immune• May show dosage• U – unaffected by

enzymes• P. falciparum resistance

in glycophorin deficient En(a-)

ABO

MNSs

P

• ISBT 003 & 028• Pk, P, P1 – high

frequency, major Ag’s• Glycosphingolipids like

Lewis• RBC’s are rich in P Ag• Pk & P – also on WBC,

plasma, kidney, lungs, heart, placenta, uroepith, fibroblasts & synovium

• P1 on RBCs only

ABO

MNSs

P

QUIZ

1. ISBT No. of ABO2. ISBT No. of MNSs3. ISBT No. of P4. ISBT No. of Rh5. Autosomal recessive ABO

blood type6. High frequency P antigen7. Most common MNSs Ab8. Naturally/Immune: ABO9. Naturally/Immune: MNSs10.Naturally/Immune: Rh

Happy New Year!!!

QUIZ

11. ABO/MNSs/P: bombay12. ABO/MNSs/P:

formaldehyde neoantigen13. ABO/MNSs/P: glycophorins

A & B14. ABO/MNSs/P: weakened by

37 degrees incubation15. ABO/MNSs/P: Henshaw16. IgM/G/A/D/E: 80% of total

Ig in serum17. IgG1/G2/G3/G4: most

predominant18. IgG1/G2/G3/G4: most

efficient in complement fixation

Happy New Year!!!

ANSWERS

1. ISBT 001 ABO2. ISBT 002 MNSs3. ISBT 003 P4. ISBT 004 Rh5. Autosomal recessive ABO

blood type – TYPE O6. High frequency P antigen -

Pk/P/P17. Most common – anti-M 8. Naturally: ABO9. Naturally: MNSs10.Immune: Rh

Happy New Year!!!

ANSWERS

11. ABO: bombay12. MNSs: formaldehyde

neoantigen 13. MNSs: glycophorins A & B14. ABO: weakened by 37

degrees incubation15. MNSs: Henshaw16. IgG: 80% of total Ig in

serum17. IgG1: most predominant18. IgG3: most efficient in

complement fixation

Happy New Year!!!

• ISBT 004• Landsteiner & Wiener

immunized guinea pigs & rabbits with Rhesus monkey RBCs

• Antibody produced agglutinated 85% of human RBCs

• Similar to Levine & Stetson’s earlier studies

• Later proven to be Lw

Rh

Lutheran

Kell

Lewis

Duffy

• Most complex• 50 antigens• Wiener nomenclature (8

possible combinations of three-factor complexes

• Fisher-Race (genetic evidence of the antithetical or allelic nature of C/c or E/e Ags)

• Rosenfeld (numerical)• ISBT

Rh

Lutheran

Kell

Lewis

Duffy

• (3) integral membrane proteins – RHD, RHCE, RHAG

• Weak D Antigen–Former Du–1%–Causes: • Trans, two weak alleles • Partial D (RHD proteins

w/ missing D epitopes)

Rh

Lutheran

Kell

Lewis

Duffy

• Weak & Deletion C/c and E/e phenotypes

• Rh Null–Lack Fy5 and Lw–Markedly decreased

expression of S/s and U–Amorph & regulator

type–Stomatocytes &

spherocytes• Rh Mod

Rh

Lutheran

Kell

Lewis

Duffy

• Immune antibodies• IgG1 and IgG3 mostly• IgA and IgM also

known• Enhanced by enzyme

treatment, temp…• Immunogenecity of

Abs: D > c > E > C > e

• Anti-Cw and E can be naturally occurring

Rh

Lutheran

Kell

Lewis

Duffy

• Hypothesized to have a role in membrane transport

• Poikilocytosis*

Rh

Lutheran

Kell

Lewis

Duffy

• Ubiquitously found on human tissues

• 18 antigens• ISBT 005• Antibodies are not CS• Mixed field: Anti-Lua

• Enzyme pre treatment• Null/weak phenotypes:–Autosomal recessive–Autosomal dominant–X-linked

Rh

Lutheran

Kell

Lewis

Duffy

• High affinity receptor for laminin

• Overexpression is hypothesized to play a role in metastasis of cancer (esp ovarian)

• Migration of erythrocytes

Rh

Lutheran

Kell

Lewis

Duffy

• Kell and Kx• ISBT 006 and 019• Racial differences• RBCs, erythroid and

megakaryocyte progenitors, skeletal muscle and testis

• KoKo – autosomal recessive, true null phenotype

Rh

Lutheran

Kell

Lewis

Duffy

• McLeod – antigens are depressed/absent

• X-linked recessive phenotype – XK protein is absent in RBCs, acanthocytes & neuromuscular disorders

• Transient depression of Kell antigens in septic & AIHA due to anti-Kell ab’s

Rh

Lutheran

Kell

Lewis

Duffy

• Clinically significant• HDN –

reticulocytopenia & little or no bilirubinemia

• Possible role in erythroid development

Rh

Lutheran

Kell

Lewis

Duffy

• Not of erythroid origin• Produced by GI and

passively absorbed by RBC

• Le(a_b_)• Naturally occurring• Important in disease

(H. pylori, Candidial vaginitis, heart disease)

Rh

Lutheran

Kell

Lewis

Duffy

• ISBT 008• Fya, Fyb – autosomal

codominant• Fy3, Fy5, Fy6 – high

incidence on all RBCs except Duffy null

• Fy4 – found to be unrelated

• Fyx – low expression of Fyb

Rh

Lutheran

Kell

Lewis

Duffy

• RBCs, purkinje’s cells, postcapillary venule & endothelial cells

• Clinically significant• IgG• Receptor for P. vivax

Rh

Lutheran

Kell

Lewis

Duffy

• ISBT 009• Jka and Jkb• Jk(a-b-) or null is rare

except in Polynesians and Finns

• In RBCs, descending vasa recta endothelial cells of renal medulla, heart, skeletal muscle, colon, SI, thymus, brain, pancreas, spleen, prostate, bladder, liver

Kidd

Diego

Cartwright

Xg

• Facilitates transport of urea

• Delayed HTR• IgG1 and IgG3 and

capable of activating complement

• Transient and disappear after stimulation

Kidd

Diego

Cartwright

Xg

• ISBT 010• RBCs and along the

collecting ducts• No racial differences

in expression• Immune, stimulated

or naturally occurring• Plays role in acid-

base equilibrium and gas transport

Kidd

Diego

Cartwright

Xg

• ISBT 011• On neural synapses

and neuromuscular junctions

• Clinically benign antibodies

• Associated with shortened red cell survival

Kidd

Diego

Cartwright

Xg

• ISBT 012• Single antigen Xga

• Two phenotypes• Mostly in men• HTR and HDN• Stimulated or

naturally occurring• IgG, can sometimes

fix complement

Kidd

Diego

Cartwright

Xg

• ISBT 013• Specific for RBCs and

erythropoietic tissues• ERMAP (in adhesion

and signaling) • Antibodies are rare

and usually benign• Usually IgG

Scianna

Dombrock

Colton

LW

• ISBT 014• RBCs, fetal liver,

spleen• Integrin-associated

adhesion & circulating NAD+

Scianna

Dombrock

Colton

LW

• ISBT 015• Coa and Cob

• Coa – high incidence antigen present on 99.7% of donors

• Rare Co (a-b-) null phenotype

Scianna

Dombrock

Colton

LW

• RBC’s, PCT, descending LOH, renal vasa recta endothelium, chroid plexus, ciliary body, microvessels, gall bladder, placenta, some epithelial cells

Scianna

Dombrock

Colton

LW

• Antibodies are clinically significant

• Associated with shortened RBC survival, HTR and HDN

• Usually IgG isotype• Immune antibodies• Enhanced by AHG,

protease treatment, can sometimes bind C’

Scianna

Dombrock

Colton

LW

• Null phenotypes can make anti-Co3 or Anti-Coa+b

• Antigens reside on aquaporins, therefore, null cells have residual water permeability

Scianna

Dombrock

Colton

LW

• Null phenotypes can make anti-Co3 or Anti-Coa+b

• Antigens reside on aquaporins, therefore, null cells have residual water permeability

Scianna

Dombrock

Colton

LW

• ISBT 016• Landsteiner-Wiener• LWa & LWb

• Antigen exp is dependent on Rh exp

• Role in adhesion during erythroid early dev’t

• Clinically benign Ab’s• Plasma origin,

absorbed on RBC’s

Scianna

Dombrock

Colton

LW

• ISBT 017• 10 antigens• Ch/Rg• Plasma origin, passively

absorbed onto RBCs• Do not cause HDN nor

HTR, however, anaphylaxis w/ plasma & plts.

• IgG isotype• Bacterial meningitis

susceptibility in C4 deficiency

Ch/RdGerbichCromerIndianOKRAPHJMHGIL

• ISBT 020• Glycoproteins are on

fetal RBCs, platelets, kidney & fetal liver

• Usu clinically significant

• Null/weak phenotypes–Yus (Ge -2,3,4)–Gerbich (Ge-2,-3,4)–Leach (Ge-2,-3,-4)

Ch/RdGerbichCromerIndianOKRAPHJMHGIL

• Biological role: cytoskeleton formation

• Delayed HTR• Severe HDN• Low RBC viability• IgM or IgG• Both immune &

naturally occurring• Resistant to enzymes

Ch/RdGerbichCromerIndianOKRAPHJMHGIL

• ISBT 021• Present on Decay

accelerating factor present on tissues & secretions–All hematopoietic

stem cells, vascular endothelium, GI & GU epithelium, brain & body fluids–Cord RBCs

Ch/RdGerbichCromerKnopsIndianOKRAPHJMHGIL

• May cause HTR & low RBC viability

• IgG isotype• Null phenotypes: rare

autosomal recessive–Suffer from GI

disorders

Ch/RdGerbichCromerKnopsIndianOKRAPHJMHGIL

• ISBT 022• Adult & cord RBCs,

neutrophils, B lymphocytes & dendritic cells

• Vary in strength between individuals: Knb, Mcb, Sla

• Antibodies are clinically insignificant

• HTLA (high titer, low avidity)

• Plays role in phagocytosis of Leishmenia, Legionella & Mycobacteria, P. falciparum

Ch/RdGerbichCromerKnopsIndianOKRAPHJMHGIL

• ISBT 023• Inb common in whites• Ina & AnWj only among

Indians & Arab populations

• Carried by CD44 on hematopoietic cells, epithelial cells & neural tissue (thus, adhesion of WBC)

• AnWj transiently depressed during pregnancy & AIHA

• In(Lu) is an ex of weak phenotype

Ch/RdGerbichCromerKnopsIndianOKRAPHJMHGIL

• ISBT 024• Single high frequency

antigen, Oka

• RBCs, WBCs, hematopoietic progenitors

• Anti-Oka is described only in Japan

• IgG immune isotype

Ch/RdGerbichCromerKnopsIndianOKRAPHJMHGIL

• ISBT 025• Single antigen RAPH

or MER2• Decreases in

expression with erythroid maturation

• IgG immune isotype• Does not cause HTR

or HDN

Ch/RdGerbichCromerKnopsIndianOKRAPHJMHGIL

• ISBT 026• John Milton Hagen• Single high incidence

antigen JMH• RBCs, lymphocytes,

activated macrophages, thymus, brain, respiratory epithelium, placenta, testes & spleen

Ch/RdGerbichCromerKnopsIndianOKRAPHJMHGIL

• Carried on CD108, a semaphorin (cell signaling) family glycoprotein

Ch/RdGerbichCromerKnopsIndianOKRAPHJMHGIL

• ISBT 029• GIL (100% in donors)• Associated with HTR• Not HDN• Causes +DAT• Resistant to

proteases, sialidases & DTT

• Transportation of urea & glycerol

Ch/RdGerbichCromerKnopsIndianOKRAPHJMHGIL

• ISBT 027• I and i • i (cord cells, precursor

of I)• 18 months of age, I

increases• Both are ubiquitously

found on glycoproteins & glycolipids of all cell types

I

• The iadult is a rare, autosomal recessive phenotype associated with congenital cataracts

• Elevated i Ag is also observed on cord RBCs, reticulocytes, PNH and HEMPAS

• IgM, low titered cold agglutinins, may cross react

I

• High titered anti-I is observed in cold autoimmune hemolytic anemia–Setting of malignancy

& infection, particularly M. pneumoniae

I