Immunohematology - Common Blood Groups (Kell, Duffy, Kidd, Lutheran)

Flashcards covering the vocabulary and key concepts of the Kell, Duffy, Kidd, and Lutheran blood group systems based on immunohematology lecture notes.

Kell Blood Group System

Designated as ISBT system $006$, these antigens are located on $\text{Chromosome 7}$ and are sensitive to sulfhydryl reagents but resistant to ficin and papain.

K (Kell) antigen

A low-incidence antigen found in less than $9\%$ of the population; it is considered the most immunogenic antigen after the D antigen.

k (cellano) antigen

A high-prevalence Kell system antigen found in more than $90\%$ (specifically $99.8\%$) of the population.

Sulfhydryl reagents

Chemicals such as $2\text{-mercaptoethanol (2-ME)}$, $\text{Dithiothreitol (DTT)}$, and $\text{ZZAP}$ that break disulfide bonds and migrate or destroy Kell antigens.

Anti-Ku (KEL5)

An antibody produced by individuals with the $K_0$ (Kellnull) phenotype that recognizes a universal Kell antigen present on all red cells except those of the Kellnull phenotype.

McLeod Syndrome

An X-linked condition characterized by the absence of $Kx$ and $Km$ antigens, resulting in the presence of acanthocytes and compensated hemolytic anemia.

Chronic Granulomatous Disease (CGD)

A condition sometimes associated with McLeod syndrome where phagocytes cannot produce $\text{NADPH oxidase}$, leading to an inability to kill engulfed organisms.

Duffy Blood Group System

Designated as ISBT system $008$, its antigens ($Fy^a$ and $Fy^b$) are located on $\text{Chromosome 1}$ and serve as receptors for chemokines and malarial parasites.

ACKR1 (DARC)

The $\text{Atypical Chemokine Receptor 1}$, formerly known as Duffy Antigen Receptor for Chemokines, which acts as a portal for $Plasmodium\text{ }vivax$.

Fy(a-b-) phenotype

A phenotype common in individuals of African descent ($68\%$ prevalence) that provides resistance to malaria caused by $Plasmodium\text{ }vivax$ and $Plasmodium\text{ }knowlesi$.

$$Fy^x$$

An inherited weak form of the $Fy^b$ antigen that does not produce a distinct antibody but may type as $Fy(b-)$.

Kidd Blood Group System

Designated as ISBT system $009$, these antigens ($Jk^a$ and $,Jk^b$) are located on $\text{Chromosome 18}$ and are well-developed at birth.

Delayed Hemolytic Transfusion Reaction (HTR)

A clinical event notoriously associated with Kidd antibodies ($Anti-Jk^a$ and $Anti-Jk^b$) because their titers decline rapidly and may become undetectable shortly after sensitization.

Dosage (Kidd)

The phenomenon where Kidd antibodies react more strongly with homozygous cells, such as those with the $Jk(a+b-)$ phenotype, than with heterozygous cells.

Anti-Jk3

An inseparable $\text{IgG}$ antibody found in some individuals with the $Jk(a-b-)$ null phenotype that reacts with all red cells except the patient's own (autocontrol).

Lutheran Blood Group System

Designated as ISBT system $005$, these antigens are located on $\text{Chromosome 19}$ and are poorly developed at birth, reaching full expression at age $15$.

Anti-Lu^a

A usually naturally occurring $\text{IgM}$ antibody that reacts at room temperature and is generally not clinically significant.

Anti-Lu^b

A warm-reacting $\text{IgG}$ alloantibody associated with transfusion reactions and, rarely, hemolytic disease of the newborn.

In(Lu) Gene

A dominant regulator gene that suppresses the expression of normal Lutheran antigens, resulting in a dominant type $Lu(a-b-)$ phenotype.

Recessive type Lu(a-b-)

A phenotype resulting from the inheritance of two silent $Lu$ alleles; individuals with this type lack all Lutheran antigens and can produce $Anti-Lu3$.