Plasma protein electrophoresis as a prognostic indicator in Aspergillus species‐infected Gentoo penguins (Pygoscelis papua papua)

• Published in: Veterinary clinical pathology Vol. 46; no. 4; pp. 605 - 614
• Main Authors: Naylor, Adam D., Girling, Simon J., Brown, Donna, Crompton, Claire G., Pizzi, Romain
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.12.2017
• Subjects: Albumin; Aspergillosis; Birds; blood protein electrophoresis; clinical decision‐making; Death; Decision making; Electrophoresis; G ratio; Gel electrophoresis; Globulins; Medical prognosis; Medical treatment; prognosis; Proteins; Pygoscelis papua papua; spheniscidae; Statistical analysis; Survival; Veterinary medicine; clinical decision-making; blood protein electrophoresis; prognosis; spheniscidae; Aspergillosis
• ISSN: 0275-6382; 1939-165X
• DOI: 10.1111/vcp.12527

Background Avian aspergillosis presents a significant threat to captive penguin populations. Currently, a lack of objective prognostic factors limits disease staging, objective reassessment throughout treatment, comparative evaluation of treatment regimes, and appropriate timing of euthanasia. Objective The study objective was to investigate absolute and relative plasma protein fractions by agarose gel electrophoresis (EPH) as predictors of survival in Gentoo penguins (Pygoscelis papua papua) under treatment for aspergillosis. Methods One hundred and eighty‐three EPH profiles from individual clinical cases were examined retrospectively. Animal survival to 90 days post sampling was established from clinical records; birds either survived (n = 146) or died within 90 days (n = 37), and time to death was recorded. Results Fourteen variables showed statistically significant differences (P < .05) between surviving and dying birds. Receiver operating characteristic curve analysis identified total albumin concentration (albumin + prealbumin) and albumin‐to‐globulin (A:G) ratio as having strongest discriminatory values (95% CI) at 0.788 (0.710–0.866) and 0.784 (0.696–0.871), respectively. Albumin (concentration and percentage of total protein) displayed moderate discriminatory value but additionally a weak positive correlation with time to death (95% CI); r = .353 (0.033–0.608) and .424 (0.116–0.658), respectively. Conclusions Optimized test cutoffs for total albumins, albumin (concentration and percentage of total protein), and A:G ratio achieved moderate sensitivity and specificity, strong negative predictive values, but weak positive predictive values due to a low prevalence of death. Selection of appropriate test cutoff values may provide valuable adjunctive prognostic tools for clinical decision‐making when the prognosis is difficult to assess clinically.