JE , Brooks TP . Immunoturbidimetric quantification of serum immunoglobulinG concentration in foals . Am J Vet Res 1990 ; 51 : 1211 – 1214 .
19. McCue PM . Evaluation of a turbidimetric immunoassay for measurement of plasma IgG
Shi J Zhou Y , et al. Detection of red blood cell-bound immunoglobulinG by flow cytometry and its application in the diagnosis of autoimmune hemolytic anemia . Int J Hematol 2001 ; 73 : 188 – 193 . 10.1007/BF02981936
16. Mangan KF Besa
A bsorption of maternal antibodies in neonatal calves is commonly evaluated by measuring immunoglobulinG (IgG) as it is the primary immunoglobulin in bovine colostrum. 1 Radial immunodiffusion assays (RID) are the reference test for measuring
Objective—To evaluate precolostral hypogammaglobulinemia
in neonatal llamas and alpacas, to determine
when postcolostral peak serum IgG concentrations
develop, to determine whether differences in
postcolostral serum IgG concentrations between llamas
and alpacas exist, and to determine postcolostral
half-life of serum IgG in llamas and alpacas.
Design—Prospective observational study.
Animals—29 llama and 10 alpaca crias.
Procedure—Blood samples were collected prior to
suckling and on days 1, 2, and 3 after parturition and
analyzed for serum IgG concentration by use of a
commercial radial immunodiffusion assay. Additional
samples were collected on days 8, 13, and 18 from 8
crias to determine mean half-life of IgG.
Results—Llamas and alpacas are born severely
hypogammaglobulinemic. Mean serum IgG concentrations
for day-1, -2, and -3 samples for llamas were
1,578 mg/dl, 1,579 mg/dl, and 1,401 mg/dl, respectively,
and for alpacas were 2,024 mg/dl, 1,806 mg/dl,
and 1,669 mg/dl, respectively. Peak serum
immunoglobulin concentration developed between
days 1 and 2. Mean half-life of IgG for all crias was
Conclusions and Clinical Relevance—Although
increased mortality has been linked to failure of passive
transfer, it is clearly possible to raise crias that
have low serum immunoglobulin concentrations.
Llamas and alpacas do not differ significantly with
respect to immunoglobulin absorption or IgG concentration
in neonates. The optimal sampling time for
passive transfer status is between 1 and 2 days.
(Am J Vet Res 2000;61:738–741)
Objective—To determine the effects of dexamethasone
on development of IgG subclass responses following
vaccination of healthy horses.
Animals—11 mature Thoroughbreds.
Procedure—Horses received 2 IM injections at 2-
week intervals of a vaccine containing inactivated
infectious bovine rhinotracheitis, bovine viral diarrhea,
and parainfluenza-3 viral antigens and were then randomly
assigned to 2 groups. Six horses received dexamethasone
(0.2 mg/kg of body weight, IM) twice
weekly for 8 weeks starting the day of the first vaccination.
Five control horses received an equivalent volume
of saline (0.9% NaCl) solution. Antigen-specific
serum IgG subclass titers were determined weekly
after vaccination by use of an ELISA.
Results—Vaccination resulted in similar antigen-specific
serum IgG(T) titers in dexamethasone-treated
and control horses. In contrast, although control horses
developed IgGa and IgGb responses after vaccination,
corticosteroid administration completely inhibited
these responses in treated horses.
Conclusions and Clinical Relevance—Cortico
steroids can have profound effects on primary
immune responses in horses and can significantly
affect IgG responses to inactivated vaccines.
Corticosteroid treatment regimens commonly used
to treat diseases in horses may result induction of a
nonprotective IgG subclass response, leaving treated
horses susceptible to disease. Additionally, mechanisms
regulating IgGa and IgGb responses appear to
differ from those regulating IgG(T) responses. Further
defining these mechanisms is a critical step in designing
effective vaccines, and corticosteroid-induced
immunomodulation may be a valuable tool for studying
immune responses in horses. (Am J Vet Res
Objective—To determine whether serum IgG concentrations
in neonatal calves are adversely affected
by short-term frozen storage of colostrum.
Sample Population—Experiment 1 consisted of 10
pairs of Holstein calves (n = 20) fed matched aliquots
of either fresh (n = 10) or frozen and thawed (10)
colostrum. In experiment 2, 26 Holstein calves were
fed either fresh (n = 13) or frozen and thawed (n = 13)
Procedure—Experiment 1 consisted of calves resulting
from observed parturitions; calves were randomly
assigned to treatment groups (fresh or frozen and
thawed colostrum) in pairs. Calves were fed 4 L
aliquots of colostrum via oroesophageal intubation at
3 hours of age. Serum IgG concentrations at 2 days of
age were compared between the 2 groups by use of
a paired t-test. Experiment 2 consisted of calves
resulting from observed parturitions; calves were randomly
assigned to treatment groups (fresh or frozen
and thawed colostrum). Calves were fed 4 L aliquots
of colostrum via oroesophageal intubation at 3 hours
of age. Regression analysis was used to determine
whether calf serum IgG concentration was a function
of colostral IgG concentration and colostrum storage
Results—Significant differences were not observed
between the 2 groups in experiment 1. No significant
relationship was observed between colostrum storage
group and serum IgG concentration in experiment
2. The model that best predicted serum IgG concentrations
accounted for 20% of the variability in
serum IgG concentration.
Conclusion and Clinical Relevance—Frozen
colostrum is an adequate source of IgG for calves. (J
Am Vet Med Assoc 2001;219:357–359)
Objective—To determine the effects of intensive serial plasmapheresis on total plasma protein and total IgG concentrations in donor horses involved in a plasmapheresis program.
Animals—18 horses (13 mares and 5 geldings; 13 Belgians, 3 Percherons, 1 Standardbred, and 1 warmblood) ranging from 7 to 14 years of age (mean ± SD, 10 ± 3 years) and weighing 822 ± 128 kg.
Procedures—Horses from which 22 mL of plasma/kg of donor body weight was harvested at 14-day intervals for a minimum of 8 consecutive plasmapheresis donations were retrospectively selected for use in the evaluation. Automated plasmapheresis procedures were performed by use of 2 modified plasmapheresis instruments/donor horse. Plasma samples were obtained at each donation and used for determination of total protein and total IgG concentrations. Total plasma protein concentrations were determined via refractometry. A commercially available ELISA was used to determine total equine IgG concentrations.
Results—The 18 donor horses were used in 8 to 19 serial donations (mean ± SD, 13 ± 3 donations) during the study. Donor horses had significant decreases in both plasma protein and IgG concentrations over the study period.
Conclusions and Clinical Relevance—Serial plasmapheresis procedures caused significant decreases in both plasma protein and IgG concentrations in donor horses; however, decreases were not physiologically relevant. Performing plasmapheresis in horses in accordance with the evaluated automated plasmapheresis procedures did not result in a critical decrease in total plasma protein or total IgG concentrations.