Clinical Biochemistry of Domestic Animals (Sixth Edition) - UMK ...

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Chapter | 7 The Erythrocyte: Physiology, Metabolism, and Biochemical Disorders
absence of band 3 results in hereditary spherocytosis in
Japanese black cattle ( Ban et al. , 1995 ; Inaba et al. , 1996 ).
Hereditary spherocytosis has been reported in golden
retriever dogs with reductions in RBC membrane spectrin
( Slappendel, 1998 ). RBCs from these dogs exhibited
increased osmotic fragility, but spherocytes were not recognized
in stained blood films ( Slappendel et al. , 2005 ).
Hereditary elliptocytosis occurs with certain defects in
α-spectrin, β -spectrin, band 3, and protein 4.1 deficiency
in humans ( Bruce, 2006 ; Delaunay, 2007 ). Hereditary
elliptocytosis has been reported in a dog with protein 4.1
deficiency ( Smith et al. , 1983a ) and in a dog with mutant
β -spectrin ( Di Terlizzi et al. , 2007 ).
C . Blood Group Isoantigens
Large numbers of protein and complex carbohydrate antigens
occur on the external surface of RBCs. Some antigens
are present on RBCs from all members of a species,
and others (including blood group isoantigens) segregate
genetically, appearing in some but not all members of a
species. Blood group isoantigens are detected serologically
on the surface of RBCs using agglutination or hemolysis
tests. With detailed genetic studies, these isoantigens can be
placed into blood groups (RBC isoantigen systems). Blood
groups have individual chromosomal loci, and each locus
has from two to many allelic genes. Most blood groups
(such as the ABO system in humans) derive their antigenicity
from the carbohydrate composition of membraneassociated
glycolipids and glycoproteins. The amino acid
sequence of membrane proteins accounts for the antigenic
determinants in other blood groups, such as the complex Rh
system in humans ( Agre and Cartron, 1991 ). Most isoantigens
are produced by erythroid cells, but some, such as the
J group in cattle, the DEA-7 (Tr) group in dogs, the R group
in sheep, and the A and O groups in pigs, are produced by
other tissues and adsorbed from plasma ( Andrews, 2000 ;
Penedo, 2000 ).
Blood groups in domestic animals have been reviewed
( Andrews, 2000 ; Bowling, 2000 ; Penedo, 2000 ). They have
been most extensively characterized in horses and cattle, in
which blood typing was routinely used for animal identification
and parentage testing. Blood typing for these purposes
is being phased out in favor of assays based on DNA
sequence.
1 . Blood Group Isoantigens of Clinical
Signifi cance
Isoantigens vary in their potential to cause transfusion
reactions when mismatched blood is given. Many isoantigens
are weak (do not induce antibodies of high titer)
or induce antibodies that do not act at normal body temperature.
Fortunately only a few isoantigens appear to be
important in producing hemolytic disease in animals. More
than 13 canine blood groups have been described. DEA 1.1
antibody-antigen interactions result in most of the acute
hemolytic transfusion reactions in dogs ( Andrews, 2000 ),
but transfusion reactions have been reported against DEA
1.2 ( Hale, 1995 ), DEA 4 ( Melzer et al. , 2003 ), and an
unclassified common antigen ( Callan et al. , 1995 ) on dog
RBCs. A new blood type termed Dal has been reported in
a low percentage of Dalmatian dogs ( Blais et al. , 2007 ).
Dalmatians lacking the Dal antigen develop alloantibodies
after being transfused with Dal -positive RBCs. Sensitized
animals are likely at risk for delayed or acute hemolytic
reactions when transfused again with Dal -positive RBCs.
Incompatibilities in the AB blood group of cats have
been recognized to cause transfusion reactions and neonatal
isoerythrolysis ( Auer and Bell, 1983 ; Giger and Akol, 1990 ;
Giger and Bücheler, 1991 ; Hubler et al. , 1987 ). The A and
B isoantigens (blood types) result from the action of two
different alleles at the same gene locus, with A being dominant
over B ( Andrews, 2000 ). Type A cat RBCs have glycolipids
with terminal N-glycolyneuraminic acid (NeuGc)
on their surface, whereas type B cat RBCs have glycolipids
with terminal N-acetylneuraminic acid (NeuAc) on their
surface ( Andrews et al. , 1992 ). Because the enzyme CMP-
N-acetylneuraminic hydroxylase converts NeuAc to NeuGc,
it has been proposed that type B cats lack this enzyme. Cats
rarely express both type A and type B antigens (type AB)
on RBCs. The frequency of blood types varies with location
and breed of cat. From 0.3% (northeast) to 4.7% (west
coast) of domestic short- and long-hair cats in the United
States are type B, but up to 50% of purebred cats in certain
breeds in the United States are type B ( Andrews, 2000 ). In
contrast to the low prevalence of type B in mixed-breed cats
in the United States, about one-third of the mixed-breed cats
in Australia are type B ( Malik et al. , 2005 ). A new blood
group antigen, termed Mik , has been reported in domestic
shorthair cats that is capable of inducing a hemolytic transfusion
reaction when Mik -positive RBCs are transfused into
a Mik -negative recipient cat that has naturally occurring anti-
Mik alloantibodies in its plasma ( Weinstein et al. , 2007 ).
Horse RBC isoantigens are recognized to occur at
seven blood group loci. The frequency of expression of
RBC isoantigens varies by breed of horse ( Bowling, 2000 ).
Historically, Aa and Qa have been the most common antigens
associated with neonatal isoerythrolysis in foals.
Mares negative for one of these antigens develop antibodies
against them and transfer these antibodies to their foals
through colostrum. Hemolysis occurs when the foal inherits
the respective antigen from the sire ( Bowling, 2000 ). Other
isoantigens associated with neonatal isoerythrolysis in foals
include Db, Dg, Pa, Qb, Qc, and a combination of Qa, Qb,
and Qc ( Boyle et al. , 2005 ; MacLeay, 2001 ). Neonatal isoerythrolysis
has been reported in mule foals because of an
RBC antigen not found in horses but present in some donkeys
and mules ( Boyle et al. , 2005 ; McClure et al. , 1994 ).