Biomedical Engineering Reference
In-Depth Information
that necessitate blood transfusion in nonhuman primates
include acute traumatic hemorrhage, acute or chronic blood
loss from gastric ulceration as seen in Helicobacter pylori
infection, and chronic blood loss resulting from severe
intestinal parasitic infestation or retained placenta. Addi-
tional indications for transfusion in nonhuman primates
include severe hemolytic anemia resulting from Plasmo-
dium spp. infection and vitamin E-responsive hemolytic
crises as seen in Aotus spp. If the aforementioned condi-
tions occur in conjunction with clinical signs of impaired
oxygen delivery such as tachycardia, tachypnea, and
altered mentation, transfusion may be warranted (
Brainard,
2009
).
Blood components that are used in veterinary medicine
include whole blood, packed red blood cells (pRBCs),
fresh frozen plasma (FFP), stored plasma, cryoprecipitate,
platelet rich plasma (PRP), platelet concentrate, and more
recently, concentrated albumin products (
Brainard, 2009
).
The indications for FFP, stored plasma, cryoprecipitate,
PRP, platelet concentrate, and concentrated albumin
products are limited to conditions that are rarely seen in
the clinical care of nonhuman primates including roden-
ticide toxicity, von Willebrand Disease (vWD), and
thrombocytopathia. The cost and effort involved in the
procurement and storage of these products as well as the
probability that they will be utilized prior to their expi-
ration date are considerations when developing a blood or
blood component storage program. The transfusion of
whole blood, pRBCs, and/or FFP may be utilized more
frequently than other blood components in nonhuman
primates.
Whole blood contains plasma proteins, platelets, red
blood cells, and white blood cells and is considered fresh
until 6 hours after collection. After this period of time, the
platelets are no longer functional, but the blood may be
stored and used for up to 25 days. Although the lifespan of
blood cells in nonhuman primates (baboons, chimpanzees)
is about half that seen in humans in vivo, refrigerated (4
C)
and frozen whole blood from nonhuman primates has
a comparable storage life to human blood products with
a similar biochemical degradation profile for adenosine
triphosphate (ATP), 2,3 diphosphoglycerate (DPG), Na
þ
,
and K
þ
(
Rowe, 1994
). Whole blood may be used to treat
anemia, coagulopathy, thrombocytopenia, and hypo-
proteinemia and can contribute to an animal's volume
resuscitation. As a general rule, every 3 ml/kg administered
will increase the recipient's PCV by 1% (
Brainard, 2009
).
pRBCs are procured through centrifugation and stored in
anticoagulants. While their use is limited to the treatment of
severe anemia, they are more efficient than whole blood in
that only 1 ml/kg of pRBCs is needed to increase the
recipient's PCV by 1% (
Brainard, 2009
). FFP is indicated
in cases of severe coagulopathy, disseminated intravascular
coagulation (DIC), and severe inflammation. It is procured
through centrifugation, must be frozen within 8 hours, and
is good for 1 year. FFP may be given at 10 ml/kg as
frequently as three times daily (
Brainard, 2009
).
The practicality and feasibility of identifying animals
in advance of need to be used as a donor population may
depend on the number of cases requiring transfusion at
a particular institution. Many nonhuman primate trans-
fusions that occur in a clinical setting employ an “open
system,” in which animals that are in need of blood
receive fresh whole blood that is immediately procured
from a suitable donor (
Oakley, 2009
). However, it is
critical that any animal identified as a potential donor be
pre-screened for pathogens and that all test results be
readily accessible. This is especially true if the recipient
animal is immunocompromised, as subclinical infections
in donor animals have been shown to cause acute clinical
disease in immunocompromised recipients in a nonhuman
primate research setting (
Bronsdon et al., 1999
). Addi-
tionally, designated donors should be blood typed using
one or more methods whenever possible (
Rowe, 1994;
Chen et al., 2009
).
Like human and companion animal patients, adverse
immunological reactions in the face of repeated blood
transfusions underscore the need to ascertain donor and
recipient blood types and cross-match prior to transfusion,
when possible (
Rowe, 1994
). Nonhuman primates possess
the same ABO blood system that is found in humans, but
little if any blood group antigens are bound to the RBCs, in
contrast to humans. A and B blood group antigens are
found only on epithelium, exocrine secretions, and vascular
endothelium in rhesus and cynomolgus macaques, but there
are many other nonhuman primate specific antigens that are
expressed on the surface of RBCs (
Socha et al., 1987; Chen
et al., 2009
). This reality has implications for blood typing
of nonhuman primates, making the process more complex
in nonhuman primates than in human patients. A
commercially available reverse gel assay is available that
can reliably determine the blood type of a nonhuman
primate patient (
Chen et al., 2009
). Other methods avail-
able for blood typing nonhuman primates include immu-
nohistochemical staining of biopsied tissues and salivary
hemagglutinin inhibition assay. These assays are more
complicated to run and require more laboratory expertise
than the reverse gel assay. While blood typing for human
AB antigens may not be helpful for some species of
nonhuman primates, cross-matching of donors and recipi-
ents prior to transfusion will help to determine incompati-
bilities related to nonhuman primate specific blood group
antigens. Depending on the availability of laboratory
resources, it may not be feasible to perform blood typing in
an emergency situation in a timely fashion. In acute
emergency situations where the life of the animal is
immediately at risk and no resources are available for
cross-matching or blood typing, a transfusion can be
