Untitled - D Ank Unlimited

Kidd blood group system 432 kinetochore autoantibodies
Ki-67⎯carcinoma of the breast.
not clinically useful. The Ki protein contains an antigenic
determinant that is homologous to the Sv40 large T antigen
nuclear localization signal.
Kidd Blood Group System
Reactions with
Anti- Phenotype Frequency
Phenotype Jk a Jk b Caucasian African American
Jk (a+b–) + 0 28 57
Kj (a+b+) 0 + 49 34
Jk (a–b+) + + 23 9
Jk (a–b–) 0 0 Very rare Very rare
Kidd blood group system
The anti-Jk a antibodies originally detected in the serum of a
woman giving birth to a baby with hemolytic disease of the
newborn (HDN). The anti-Jk b antibodies were discovered
in the serum of a patient following a transfusion reaction.
Although Kidd system antibodies sometimes lead to HDN,
the disease is not usually severe; however, the antibodies
are problematic and cause severe hemolytic transfusion
reactions, especially of the delayed type. These occur
when antibodies developing quickly in a booster response
to antigens on transfused erythrocytes destroy red cells in
the circulation. As shown in the table, four phenotypes are
revealed by the reactions of anti-Jk a and anti-Jk b antibodies.
A dominant inhibitor gene (In[Jk]) may encode a null
phenotype. Jk3 is believed to be present on both Jk(a + ) and
Jk(b + ) red cells. Anti-Jk3 is frequently induced by red blood
cell stimulation.
killed vaccine
An immunizing preparation composed of viral or bacterial
microorganisms that are dead but retain their antigenicity,
making them capable of inducing a protective
immune response with the formation of antibodies and/
or stimulation of cell-mediated immunity. Inactivation is
by irradiation, chemical treatment, or heat. Killed vaccines
do not induce even mild cases of the disease that are
sometimes observed with attenuated (greatly weakened
but still living) vaccines. Although the first killed vaccines
contained intact dead microorganisms, some modern
preparations contain subunits or parts of microorganisms
to be used for immunization. Killed microorganisms
may be combined with toxoids, as in the case of the DPT
(diphtheria–pertussis–tetanus) preparations administered to
children.
killed virus vaccines
Immunogen preparation containing virons deliberately
killed by heat, chemicals, or radiation.
killer activatory receptors (KARs)
Natural killer (NK) cell or cytotoxic T cell surface receptors
that can activate killing by these cell types.
killer cell (K cell)
A large granular lymphocyte bearing Fc receptors on
its surface for immunoglobulin G (IgG), which makes it
capable of mediating antibody-dependent, cell-mediated
cytotoxicity. Complement is not involved in the reaction.
Antibody may attach through its Fab regions to target cell
epitopes and link to the killer cell through attachment of its
Fc region to the Fc receptor of the K cell, thereby facilitating
cytolysis of the target by the killer cell, or an IgG
antibody may first link via its Fc region to the Fc receptor
on the killer cell surface and direct the K cell to its target.
Cytolysis is induced by insertion of perforin polymer in
the target cell membrane in a manner that resembles the
insertion of C9 polymers in a cell membrane in complement-mediated
lysis. Perforin is showered on the target cell
membrane following release from the K cell.
killer cell immunoglobulin-like receptors (ICIRs)
Molecular configurations on NK cells that interact with
MHC class I molecules and transmit either activating or
inhibitory signals to natural killer (NK) cells. NK cell
receptors that bind to MHC class I molecules and transmit
either activating or inhibitory signals to the T cell.
killer inhibitory receptors (KIRs)
Natural killer (NK) cell receptors that recognize self major
histocompatibility complex (MHC) class I molecules and
transmit inhibitory signals that block activation of NK cell
cytolytic processes. These receptors prevent NK cells from
killing normal host cells expressing MHC class I molecules
but allow lysis of virus-infected cells for which MHC class
I expression has been suppressed. The inhibitory receptors
fall into several classes that include immunoglobulin
superfamily members, heterodimers of CD94 and selectin,
and Ly49. These receptors possess cytoplasmic tails bearing
immunoreceptor tyrosine inhibition motifs (ITIMs) that
participate in initiating inhibitory signal pathways.
killer T cell
A T lymphocyte that mediates a lethal effect on a target cell
expressing a foreign antigen bound to major histocompatibility
complex (MHC) molecules on target cell surfaces. A
synonym for a cytotoxic T cell.
kilobase (kb)
One thousand DNA or RNA base pairs.
kinetochore autoantibodies
Autoantibodies specific for the mitotic spindle apparatus;
also known as centromere autoantibodies. They have
been found in the cutaneous form of systemic sclerosis,