Marilyn Rodriguez

Differences in protein fractions of avian plasma among three commercial electrophoresis systems

Abstract Previous studies have defined the presence of 6 protein fractions in plasma from many psittaciform species. Additionally, extensive reference intervals have been published for many of these species with the Beckman Paragon electrophoresis system, which had been commonly used in clinical laboratories to analyze the protein fractions of avian plasma. In mid-2009, Beckman discontinued the Paragon product line, leaving 2 primary alternative systems: Helena and Sebia. To compare electrophoresis results from the 3 commercial protein electrophoresis systems, specimens from 40 African grey parrots (Psittacus erithacus) were analyzed with the electrophoresis systems from Beckman, Helena, and Sebia. Marked differences in fraction migration were found between the Beckman/Helena and Sebia systems, which manifested as a large decrease in prealbumin and an increase in α1 globulins in the latter system. Both proportional and constant errors were observed among the fraction quantitation data of both the Helena and Sebia systems compared with the Beckman system. Based on Bland-Altman plot data and imprecision studies, the Helena system appears more similar with the Beckman system, although neither the Helena nor the Sebia systems are identical to the Beckman system. Because of the differences in electrophoresis methods, clinicians should be careful to consistently use particular clinical laboratories. For best application, reference intervals should be established based on both species and electrophoresis system.

Use of refractometry for determination of psittacine plasma protein concentration

BACKGROUND Previous studies have demonstrated both poor and good correlation of total protein concentrations in various avian species using refractometry and biuret methodologies. OBJECTIVES The purpose of the current study was to compare these 2 techniques of total protein determination using plasma samples from several psittacine species and to determine the effect of cholesterol and other solutes on refractometry results. METHODS Total protein concentration in heparinized plasma samples without visible lipemia was analyzed by refractometry and an automated biuret method on a dry reagent analyzer (Ortho 250). Cholesterol, glucose, and uric acid concentrations were measured using the same analyzer. Results were compared using Deming regression analysis, Bland-Altman bias plots, and Spearmans rank correlation. RESULTS Correlation coefficients (r) for total protein results by refractometry and biuret methods were 0.49 in African grey parrots (n=28), 0.77 in Amazon parrots (20), 0.57 in cockatiels (20), 0.73 in cockatoos (36), 0.86 in conures (20), and 0.93 in macaws (38) (P< or =.01). Cholesterol concentration, but not glucose or uric acid concentrations, was significantly correlated with total protein concentration obtained by refractometry in Amazon parrots, conures, and macaws (n=25 each, P<.05), and trended towards significance in African grey parrots and cockatoos (P=.06). CONCLUSIONS Refractometry can be used to accurately measure total protein concentration in nonlipemic plasma samples from some psittacine species. Method and species-specific reference intervals should be used in the interpretation of total protein values.

Protein and cholesterol electrophoresis of plasma samples from captive cownose ray (Rhinoptera bonasus)

Our study was undertaken to assess the application of semiautomated methods available at the reference laboratory level for the evaluation of plasma protein and cholesterol via electrophoresis in samples from cownose rays (Rhinoptera bonasus). Three groups of animals were assessed: clinically normal, clinically abnormal, and parasitized with leeches. As reported previously, the albumin band was negligible; the protein electrophoretograms were dominated by a large beta-globulin fraction. While the group of samples from the leech-parasitized rays did not show any large differences, the abnormal group exhibited significantly elevated total solids and cholesterol levels. The latter was related to a significant increase in very low density lipoprotein levels. The results demonstrate the potential application of these laboratory methods in quantitation of plasma proteins and cholesterol fractions in subclass Elasmobranchii.

ASSESSMENT OF HEMOGLOBIN BINDING PROTEIN IN LOGGERHEAD SEA TURTLES (CARETTA CARETTA) UNDERGOING REHABILITATION

Abstract:  The acute phase response is an important component of the early reaction of the immune system to insults including infection, inflammation, trauma, neoplasia, and stress. Acute phase proteins are valuable prognostic indicators in many mammalian species but have been poorly studied in reptiles thus far. This study examined 18 paired samples from loggerhead sea turtles (Caretta caretta) for changes observed during the rehabilitation period. Analyses performed included packed cell volume (PCV), hemoglobin binding protein, and plasma protein electrophoresis. Significant differences were observed in all of the protein electrophoresis values. Notably, the concentration of hemoglobin binding protein (as determined by a haptoglobin assay) increased in conjunction with rising total protein (by refractometry) and PCV. The results indicate that this assay may have the potential to be a useful tool in assessing the health of sea turtles.

APPLICATION OF 3-HYDROXYBUTYRATE MEASUREMENT AND PLASMA PROTEIN ELECTROPHORESIS IN THE DIAGNOSIS OF ASPERGILLOSIS IN AFRICAN PENGUINS (SPHENISCUS DEMERSUS)

Abstract New alternative laboratory means are needed to improve the options for antemortem diagnosis of avian aspergillosis. In this study, 3-hydroxybutyrate was measured in plasma samples collected from a cohort of African penguins (Spheniscus demersus) maintained under human care. Results were interpreted in combination with those of protein electrophoresis and compared with anti-Aspergillus antibody and galactomannan antigen detection. Overall, 3-hydroxybutyrate levels were found significantly increased in Aspergillus-diseased cases versus the control penguin group (P = 0.002). Mean absolute concentration of β-globulins was increased >20% in samples from infected birds, and α2-globublins were also found to be significantly increased versus clinically normal controls (P < 0.001 and P = 0.001 respectively). Of note, the α2-globulins were also significantly increased versus penguins with inflammatory (non-aspergillosis) diseases (P = 0.001). The specificity of 3-hydroxybutyrate, β-globulins, and α2-globulins for aspergillosis was 78.6%, 79.6%, and 92.2%, respectively. Using these measures in tandem resulted in high specificity (>90%) and negative predictive value (≥80%). In contrast, anti-Aspergillus antibody and galactomannan antigen did not distinguish between infected cases and controls (P > 0.05). This study demonstrates that basic testing in tandem with the new biomarker 3-hydroxybutyrate may provide reliable evidence for the diagnosis of aspergillosis in penguins.