OTHER BLOOD GROUP SYSTEMS PART 2 (I TO KIDD) Flashcards
are structurally related to the ABO antigens
I blood group antigens
are found on RBC membranes as well as in plasma, milk, and amniotic fluid
I blood group antigens
are found on all RBCs.
Both I and i antigens
are poorly developed at birth
I antigens
As the I antigenic strength [?], i antigen strength [?].
increases
decreases
have strong I antigen expression and weak i antigen expression.
Most adults
are naturally occurring, cold-reacting IgM anti-bodies
Anti-l antibodies
They fail to react with cord RBCs.
Anti-l antibodies
react in a broader temperature range and can cause cold-agglutinin disease (CAD).
Some anti-l antibodies
may be Idlopathic or may be associated with diseases, such as Mycoplasma pneumoniae Infections.
CAD
are not associated with HDN
Anti-l antibodies
are rare
Anti-i antibodies
Like anti-l, they are cold-reacting antibodles
Anti-l antibodies
They may be seen In cases of Infectious mononucleosis
Anti-i antibodies
may cause an associated hemolytic anemia that disappears as the infection resolves
Anti-l antibodies
Testing for anti-l or anti-i antibodies is done at [?] using [?]
4°C
group O RBCs or cord RBCs
are associated with cold agglutinin syndrome and Mycoplasma pneumoniae infections.
Anti-l antibodies
are linked to infectious mononucleosis.
• Anti-i antibodies
are associated with Hodgkin’s lymphoma.
• Anti-IT antibodies
have also been reported in influenza infections.
• Cold autoantibodies
Conditions associated with increased i antigen expression on red blood cells (RBCs) include:
• Shortened marrow maturation time dyserythropolesis
• Shortened marrow maturation time dyserythropolesis, seen in:
• Acute leukemia.
• Hypoplastic anemia.
• Megaloblastic anemia.
• Sideroblastic anemia.
• Thalassemia.
• Sickle cell disease.
• Paroxysmal nocturnal hemoglobinuria (PNH).
• Chronic hemolytic anemia.
Reactive lymphocytes in infectious mononucleosis have
increased i antigen
while those in chronic lymphocytic leukemia have
decreased i antigen
is associated with Increased i activity on RBCs
• Chronic dyserythropoietic anemia type ll or hereditary erythroblastic multinuclearity with a positive acidified serum test
(HEMPAS)
are susceptible to lysis by both anti-i and anti-l antibodies.
HEMPAS RBCs
may be involved in binding immune complexes formed by certain drugs and drug antibodies, leading to complement activation and hemolysis.
• I antigen
• In Asians, the [?] has been associated with congenital cataracts, with mutations at the [?] identified In some cases, suggesting a genetic mechanism for this condition.
adult i phenotype
I locus
The MNS antigens are determined by the
MN and Ss loci
is associated with glycophorin A
MN
is associated with glycophorin B
Ss
There are five principal antigens in the MNS system:
M, N, S, s, and U.
RBCs with the S or s antigen also have the
U antigen.
are important markers in paternity studies.
MNS antigens
are relatively common
Anti-M antibodies
They are usually naturally occurring and may be both IgM and IgG
Anti-M antibodies
do not bind complement
Anti-M antibodies
react optimally at room temperature or below
Anti-M antibodies
They are only rarely associated with HDN or HTR
Anti-M antibodies
are rare
Anti-i
Anti-N antibodies
Anti-S, anti-s, and anti-U antibodies
They are weak, naturally occurring IgM antibodies that react best at room temperature or below
Anti-N antibodies
They are not usually associated with HDN or HTR
Anti-N antibodies
These IgG antibodies usually develop following RBC stimulation
Anti-S, anti-s, and anti-U antibodies
have been associated with severe HDN and HTR
Anti-S, anti-s, and anti-U antibodies
Although usually reactive in the antiglobulin phase of testing, some saline reactive antibodies have been reported.
Anti-S, anti-s, and anti-U antibodies
In addition to human, rabbit, and monoclonal serum-typing reagents, lectin reagents are also used to test for
M and N antigens
Examples include Vicia graminia and several Bauhinia species for [?], and several Iberis species for [?].
anti-N
anti-M
demonstrate a dosage effect
Many M, N, and S antibodies
they react more strongly with homozygous than heterozygous cells.
M, N, and S antibodies
are destroyed by enzyme treatment
M and N antigens
are not as easily destroyed or have no effect
S, s, and U
The Kell (K) system is comprised of 21 high- and low-incidence antigens, the most significant of which are [?].
K and k
lack all Kell antigens
K, or Knull phenotype
An antigen associated with the Kell system, [?], Is located on the X chromosome.
Kx
RBCs that lack the [?] also have greatly weakened expression of the other Kell system antigens.
Kx antigen
These RBCs are morphologically acanthocytes, have decreased survival, and are less permeable to water.
Kx antigen
This syndrome, known as [?], is also characterized by splenomegaly, reticulocytosis, and occasional association with chronic granulomatous disease (CGD).
MacLeod syndrome
are destroyed or inactivated by sulfhydryl reagents.
Kell antigens
The two most important antibodies of the Kell system are
anti-K and anti-k (Cellano)
is second only to the D antigen in Immunogenicity, and the resulting antibody is relatively common in transfusion practice.
K antigen
Finding donor units is rarely a problem, however, because more than 90% of the population is
K-negative
are usually IgG antibodies that react best at 37C
Anti-K antibodies
may occasionally bind complement
Anti-K antibodies
They can cause both HDN and HTR
Anti-K antibodies
are rare but can cause both HDN and HTR
Anti-k antibodies
Antibodies to Ko (Knull) antigens are called [?]
anti-Ku or anti-KEL5 antibodies
are considered clinically significant
Anti-Ku
Anti-KEL5
Ko patients should be transfused with
K° cells.
In testing, K, cells can be made by treating normal RBCs with
2- aminoethylisothiouronium (AET) bromide or dithiothreitol (DTT) plus cysteine- activated papain (ZZAP)
is a rare condition occurring exclusively in males, inherited through an X-linked pattern from carrier mothers.
Mcleod phenotype
• Individuals with the Mcleod phenotype lack the [?] and have reduced expression of other Kell antigens.
Kx and Km antigens
• RBCs from individuals with the [?] often exhibit acanthocytosis, reduced deformability, and decreased survival, leading to chronic hemolytic anemia.
McLeod phenotype
includes neurological and muscular disorders such as progressive muscular dystrophy, cardiomyopathy, areflexia, choreiform movements, and elevated serum enzyme levels
McLeod syndrome
has been associated with X-linked chronic granulomatous disease (CGD), characterized by severe infections due to phagocytes’ inability to produce NADH-oxidase
McLeod phenotype
explains the variable expression of Kx in carrier females, resulting in RBC populations with normal Kx expression and others exhibiting the McLeod phenotype characteristics.
Lyon hypothesis
Duffy system (FY) has four alleles that are responsible for the major antigens and resulting phenotypes:
Fya, Fyb Fy, and Fyx
are produced by codominant alleles.
Fya and Fyb antigens
is a weakened form of Fyb
Fyx
allele produces no gene product.
Fy
There are four phenotypes:
a. Fy (a+b-)
b. b. Fy (a-b+)
c. c. Fy (a+b+)
d. d. Fy (a-b-)
There is a high incidence of this phenotype among blacks.
Fy (a-b-)
The RBCs of individuals with this phenotype are resistant to infection by Plasmodium vivax.
Fy (a-b-)
The most common FY antibodies are [?], which are both commonly encountered in blood banks.
Fya and Fyb
are very rare
Other Duffy antibodies
are usually IgG
Anti-Fya and anti-Fyb antibodies
often bind complement
Anti-Fya and anti-Fyb antibodies
generally react only at the antiglobulin phase of testing
Anti-Fya and anti-Fyb antibodies
Both are destroyed by proteolytic enzyme treatment and heating to 56°C
Anti-Fya and anti-Fyb antibodies
[?] are seen more frequently than [?], and both occur more commonly in combination with other RBC antibodies than alone.
Anti-Fya antibodies
Fyb antibodies
Although both can cause delayed HTR, only [?] has occasionally been implicated in HDN.
Fya
There is a long-standing correlation between Duffy blood group antigens and [?].
malaria Infection
Africans and black Americans, who typically lack the Duffy antigens Fy a and Fyb, have been found to be resistant to infection by [?], a malaria parasite.
Plasmodium vivax
Studies conducted by Miller et al in 1955 demonstrated that [?] only invade red blood cells (RBCs) carrying normal Fya or Fyb antigens. Blocking these antigen sites with antibodies or denaturing enzymes rendered RBCs resistant to invasion,
malaria merozoites
Based on in-vivo epidemiologic data and parallel resistance factors for [?] (a simian malaria parasite) and P. vivax in West African populations, it was suggested that Fya and Fyb might serve as the invasion receptors for P. vivax.
P. knowlesi
The invasion process involves two receptor sites:
one for initial attachment and another for invasion.
While [?] occurs irrespective of Duffy type, the subsequent junction and [?] are Duffy antigen-dependent.
initial attachment
invasion
Studies indicate that [?], a component of the Duffy glycoprotein, is important for invasion by P. vivax.
Fy6
Monoclonal antibodies targeting [?] have been shown to block invasion of RBCs by P. vivax,
Fy6
There are two major antigens in the Kidd (JK) system, Jka and Jkb, which allows for four phenotypes:
(1) Jk (a+b-)
(2) Jk (a+b+)
(3) Jk (a-b+)
(4) Jk (a-b-)
A third antigen, [?], is present on both Jka- and Jkb-positive RBCs.
Jk3
may exhibit dosage effect
Jka and Jkb
reactivity may be enhanced by enzyme treatment
Jka and Jkb
poorly immunogenic
Jka and Jkb antigens
resulting antibodies can cause severe HTR
Jka and Jkb antigens
are especially noted for causing delayed reactions
Jka and Jkb antigens
can occasionally cause mild HDN
Jka and Jkb antigens
are IgG1 or IgG3
Jka and Jkb antibodies
bind complement very efficiently
Jka and Jkb antibodies
Both react best at 37•C in the antiglobulin phase of testing, but saline-reactive antibodies may be seen
Jka and Jkb antibodies
can be difficult to detect
Jka and Jkb antibodies
enhancement techniques, such as enzymes, low ionic strength saline (LISS), or polyethylene glycol (PEG), can help identify them.
Jka and Jkb antibodies
: These organisms have been associated with Jkb-like specificity
Enterococcus faecium and Micrococcus
They are capable of converting Jk(b) cells to Jk(b), indicating a potential interaction with the Jkb antigen.
Enterococcus faecium and Micrococcus
: This organism may have triggered the production of an autoanti-Jkb, suggesting a possible autoimmune response induced by exposure to
Proteus mirabilis
