Article

An automated biochemical assay for haptoglobin: Prevention of interference from albumin

Comparative Haematology International 04/1999; 9(3):117-124. DOI:10.1007/BF02600369 pp.117-124

ABSTRACT Measurement of the acute phase serum protein, haptoglobin (Hp), is performed by biochemical methods based on haemoglobin binding,
in many veterinary diagnostic laboratories. During attempts to develop a robust biochemical assay for serum Hp it was discovered
that serum albumin interfered with the assay system increasing results by as much as 0.28 mg/ml, which could affect interpretation
of results especially in species with low normal Hp concentrations. A reagent cocktail (SB-7) was devised which inhibited
the interfering effect of albumin. An automated assay for Hp utilising SB-7 was developed for production as a biochemical
assay kit and was evaluated for use in veterinary diagnosis. The intra-assay coefficients of variation were of 0.9%, 0.9%
and 1.3% for Hp concentrations of 2.0, 1.0 and 0.23 mg/ml, respectively and interassay coefficients of variation of 1.7% and
4.5% for Hp of 2.08 mg/ml and 0.24 mg/ml, respectively. The lower limit of detection of was 0.02 mg/ml, linearity extended
to 8 mg/ml and recovery was 101±7% (mean ±SD). The assay had correlation coefficients (R2) of 0.96 and 0.90 when compared with immunodiffusion assays of canine Hp and bovine Hp, respectively. Lipaemia and bilirubinaemia
caused no interference. Haemolysis did not affect measurement of low levels of Hp, but at serum Hp concentrations of 0.4 and
1.8 mg/ml the apparent Hp concentration was decreased. Elevated concentrations of Hp were measured in cattle with mastitis,
dogs with polyarthritis and rats experimentally infected withBordetella pertussis. The automated assay is precise and has negligible interference from albumin.

0 0
 · 
0 Bookmarks
 · 
14 Views
  • Source
    Article: Maternal undernutrition and the ovine acute phase response to vaccination.
    Peter D Eckersall, Fraser P Lawson, Carol E Kyle, Mary Waterston, Laura Bence, Michael J Stear, Stewart M Rhind
    [show abstract] [hide abstract]
    ABSTRACT: The acute phase response is the immediate host response to infection, inflammation and trauma and can be monitored by measuring the acute phase proteins (APP) such as haptoglobin (Hp) or serum amyloid A (SAA). The plane of nutrition during pregnancy is known to affect many mechanisms including the neuroendocrine and neuroimmune systems in neonatal animals but effects on the APP are unknown. To investigate this phenomenon the serum concentration of Hp and SAA was initially determined in non-stimulated lambs from 3 groups (n = 10/group). The dams of the lambs of the respective groups were fed 100% of requirements throughout gestation (High/High; HH); 100% of requirements for the first 65 d of gestation followed by 70% of requirements until 125 d from when they were fed 100% of requirements (High/Low; HL); 65% of liveweight maintenance requirements for the first 65 d gestation followed by 100% of requirements for the remainder of pregnancy (Low/High; LH). The dynamic APP response in the lambs was estimated by measuring the concentration of Hp and SAA following routine vaccination with a multivalent clostridial vaccine with a Pasteurella component, Heptavac Ptrade mark following primary and secondary vaccination. The Hp and SAA concentrations were significantly lower at the time of vaccination (day 8-14) than on the day of birth. Vaccination stimulated the acute phase response in lambs with increases found in both Hp and SAA. Maternal undernutrition led to the SAA response to vaccination being significantly lower in the HL group than in the HH group. The LH group did not differ significantly from either the HH or HL groups. No significant effects of maternal undernutrition were found on the Hp concentrations. A significant reduction was found in all groups in the response of SAA following the second vaccination compared to the response after the primary vaccination but no change occurred in the Hp response. Decreased SAA concentrations, post-vaccination, in lambs born to ewes on the HL diet shows that maternal undernutrition prior to parturition affects the innate immune system of the offspring. The differences in response of Hp and SAA to primary and secondary vaccinations indicate that the cytokine driven APP response mechanisms vary with individual APP.
    BMC Veterinary Research 02/2008; 4:1. · 2.00 Impact Factor
  • Source
    Article: Traits associated with innate and adaptive immunity in pigs: heritability and associations with performance under different health status conditions.
    Mary Clapperton, Abigail B Diack, Oswald Matika, Elizabeth J Glass, Christy D Gladney, Martha A Mellencamp, Annabelle Hoste, Stephen C Bishop
    [show abstract] [hide abstract]
    ABSTRACT: There is a need for genetic markers or biomarkers that can predict resistance towards a wide range of infectious diseases, especially within a health environment typical of commercial farms. Such markers also need to be heritable under these conditions and ideally correlate with commercial performance traits. In this study, we estimated the heritabilities of a wide range of immune traits, as potential biomarkers, and measured their relationship with performance within both specific pathogen-free (SPF) and non-SPF environments. Immune traits were measured in 674 SPF pigs and 606 non-SPF pigs, which were subsets of the populations for which we had performance measurements (average daily gain), viz. 1549 SPF pigs and 1093 non-SPF pigs. Immune traits measured included total and differential white blood cell counts, peripheral blood mononuclear leucocyte (PBML) subsets (CD4+ cells, total CD8alpha+ cells, classical CD8alphabeta+ cells, CD11R1+ cells (CD8alpha+ and CD8alpha-), B cells, monocytes and CD16+ cells) and acute phase proteins (alpha-1 acid glycoprotein (AGP), haptoglobin, C-reactive protein (CRP) and transthyretin). Nearly all traits tested were heritable regardless of health status, although the heritability estimate for average daily gain was lower under non-SPF conditions. There were also negative genetic correlations between performance and the following immune traits: CD11R1+ cells, monocytes and the acute phase protein AGP. The strength of the association between performance and AGP was not affected by health status. However, negative genetic correlations were only apparent between performance and monocytes under SPF conditions and between performance and CD11R1+ cells under non-SPF conditions. Although we cannot infer causality in these relationships, these results suggest a role for using some immune traits, particularly CD11R1+ cells or AGP concentrations, as predictors of pig performance under the lower health status conditions associated with commercial farms.
    Genetics Selection Evolution 01/2009; 41:54. · 2.88 Impact Factor
  • Source
    Article: Characterisation of physiological and immunological responses in beef cows to abrupt weaning and subsequent housing.
    Eilish M Lynch, Bernadette Earley, Mark McGee, Sean Doyle
    [show abstract] [hide abstract]
    ABSTRACT: Weaning involves the permanent separation of the calf from the dam and has been shown to be stressful for both. The objectives of this study were to characterise the effect of i) abrupt weaning and ii) subsequent housing on the extended physiological and immunological responses of beef cows. At weaning (day (d) 0, mean age of calf (s.d.) 212 (24.5) d), cows were abruptly separated from their calves and returned to the grazing area. After 35 d at pasture, cows were housed in a slatted floor shed and offered grass silage ad libitum plus a mineral-vitamin supplement daily. Rectal body temperature was recorded and blood samples were obtained on i) d 0 (weaning), 2, 7, 14, 21, 28, 35 and subsequently on ii) d 0 (housing), 2, 7, 14 and 21 for physiological, haematological and immunological measurements. Post-weaning, concentration of cortisol and dehydroepiandrosterone were unchanged (P > 0.05). Rectal body temperature, neutrophil number and neutrophil: lymphocyte ratio increased (P < 0.01) on d 2 compared with pre-weaning baseline. Lymphocyte and neutrophil number decreased (P < 0.05) on d 2 to 7 and d 7 to 21, respectively, compared with pre-weaning baseline. Interferon-gamma production decreased (P < 0.05) on d 2 compared with pre-weaning baseline. An increase (P < 0.05) in acute phase proteins, fibrinogen and haptoglobin was evident on d 2 to 35 compared with pre-weaning baseline. Concentration of glucose increased on d 2 to 28, whereas non-esterified fatty acid decreased on d 2 to 35 compared with pre-weaning baseline. Post-housing, concentrations of cortisol, rectal body temperature, total leukocyte number, and glucose were unchanged (P > 0.05). On d 2 post-housing, neutrophil number and neutrophil: lymphocyte ratio increased (P < 0.05), whereas lymphocyte number and concentrations of dehydroepiandrosterone, fibrinogen and non-esterified fatty acid decreased (P < 0.05) compared with pre-housing baseline. Concentration of haptoglobin increased (P < 0.05) on d 14 to 21 post-housing. A transitory increase in neutrophil number and decrease in lymphocyte number, increased neutrophil:lymphocyte ratio coupled with decreased interferon-gamma production, and increased concentration of acute phase proteins indicate a stress response in cows post-weaning, whereas post-housing, changes were less marked.
    BMC Veterinary Research 01/2010; 6:37. · 2.00 Impact Factor

Show more

Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

acute phase serum protein
 
apparent Hp concentration
 
assay system
 
automated assay
 
bovine Hp
 
canine Hp
 
Elevated concentrations
 
haemoglobin binding
 
Hp concentrations
 
Hp utilising SB-7
 
interassay coefficients
 
interfering effect
 
low normal Hp concentrations
 
lower limit
 
robust biochemical assay
 
serum albumin interfered
 
serum Hp
 
serum Hp concentrations
 
veterinary diagnostic laboratories
 
withBordetella pertussis
 

P D Eckersall