Comparison of three immunoglobulin G assays for the diagnosis of failure of passive transfer of immunity in neonatal alpacas

Pinn, Toby L.; Gagliardo, Lucille F.; Purdy, S. R.; Appleton, Judith A.; Stokol, Tracy

doi:10.1177/1040638712472182

Cited by 11 publications

(14 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The use of total protein concentration does not accurately reflect the serum immunoglobulin concentration in neonatal NWC . A diagnosis of FTPI can be made at 48 hours of age if serum immunoglobulin concentration is less than 9 mg/mL; however, a large variation was observed in a study comparing protein electrophoresis, radial immunodiffusion, and immunoturbidimetric assays for measuring serum immunoglobulin in neonatal NWC . It appears that the immunoglobulin measurement in NWC is largely dependent on the assay used and that there is, thus, no widely accepted definition of FTPI in NWC.…”

Section: Discussionmentioning

confidence: 99%

Clinical Findings and Survival in 56 Sick Neonatal New World Camelids

Bertin

Squires

Kritchevsky

et al. 2014

Veterinary Internal Medicne

View full text Add to dashboard Cite

BackgroundInformation pertaining to clinical presentation and outcome of neonatal New World camelids (NWC) is limited when compared to calves and foals.HypothesisValues of variables at admission and subsequent treatment would predict survival in sick neonatal NWC.AnimalsFifty‐six client‐owned sick neonatal NWC presented over a 10‐year period to the Purdue University Veterinary Teaching Hospital.MethodsA retrospective study was performed. Inclusion criteria were NWC less than 30 days of age with complete medical records that presented between 2000 and 2010.ResultsThe median age at presentation was 1 day (range 1–20). The most common diagnoses were systemic inflammatory response syndrome (50%), congenital defects (41%), ophthalmic lesions (21%), sepsis (16%), and gastrointestinal diseases (16%). Sixty‐six percent of NWC survived to discharge. Clinicopathologic findings on admission were variable and not specific for disorders. Factors associated with survival were absence of choanal atresia (P = .001, OR: 55.9 [2.5–1,232]), administration of llama plasma (P = .013, OR: 4.9 [1.4–17.7]), and antimicrobial treatment with trimethoprim‐sulfamethoxazole (TMS) (P = .016, OR: 6.5 [1.3–32.2]).Conclusions and Clinical ImportanceThe use of antibiotics, particularly TMS, and llama plasma are recommended in sick neonatal NWC. Results from this study could contribute toward defining a NWC‐specific sepsis scoring system.

show abstract

Section: Discussionmentioning

confidence: 99%

Clinical Findings and Survival in 56 Sick Neonatal New World Camelids

Bertin

Squires

Kritchevsky

et al. 2014

Veterinary Internal Medicne

View full text Add to dashboard Cite

show abstract

“…The most common clinical reason for measuring camelid immunoglobulins is suspicion of FTPI, therefore early and accurate diagnosis is required to provide timely medical intervention . Testing methods available for use in camelids include total serum protein and globulin concentration measurements, zinc sulfate turbidity, glutaraldehyde coagulation, sodium sulfate precipitation, immunoturbidimetric assay (IT), and radial immunodiffusion (RID) . Of these, RID provides quantitative data and is currently considered the reference method test for IgG quantification in various species .…”

mentioning

confidence: 99%

Use of Fourier‐Transform Infrared Spectroscopy to Quantify Immunoglobulin G Concentrations in Alpaca Serum

Burns

Hou

Riley

et al. 2014

Veterinary Internal Medicne

View full text Add to dashboard Cite

BackgroundRapid, economical, and quantitative assays for measurement of camelid serum immunoglobulin G (IgG) are limited. In camelids, failure of transfer of maternal immunoglobulins has a reported prevalence of up to 20.5%. An accurate method for quantifying serum IgG concentrations is required.ObjectiveTo develop an infrared spectroscopy‐based assay for measurement of alpaca serum IgG and compare its performance to the reference standard radial immunodiffusion (RID) assay.AnimalsOne hundred and seventy‐five privately owned, healthy alpacas.MethodsEighty‐two serum samples were collected as convenience samples during routine herd visits whereas 93 samples were recruited from a separate study. Serum IgG concentrations were determined by RID assays and midinfrared spectra were collected for each sample. Fifty samples were set aside as the test set and the remaining 125 training samples were employed to build a calibration model using partial least squares (PLS) regression with Monte Carlo cross validation to determine the optimum number of PLS factors. The predictive performance of the calibration model was evaluated by the test set.ResultsCorrelation coefficients for the IR‐based assay were 0.93 and 0.87, respectively, for the entire data set and test set. Sensitivity in the diagnosis of failure of transfer of passive immunity (FTPI) ([IgG] <1,000 mg/dL) was 71.4% and specificity was 100% for the IR‐based method (test set) as gauged relative to the RID reference method assay.Conclusions and Clinical ImportanceThis study indicated that infrared spectroscopy, in combination with chemometrics, is an effective method for measurement of IgG in alpaca serum.

show abstract

“…When compared with reported Se and Sp of other methods available to assess FTPI in neonatal camelids, these results are equivalent to or better than most [8, 10, 26, 42]. Both ATR-IR spectroscopic assays correctly classified the majority of FTPI cases as such, and the misclassified samples had RID IgG concentrations very close to the diagnostic cut-off of 1000 mg/dL.…”

Section: Discussionmentioning

confidence: 63%

“…The correlation with RID-IgG concentrations was lower than that reported for comparison of RID-IgG to immunoturbidimetric methods [10], but higher than that reported for comparisons of serum total protein refractometry versus RID-IgG [8]. The Bland-Altman plots (Fig 5) revealed a non-significant bias for the portable ATR-IR-based assay as compared to the lab system counterpart.…”

Section: Discussionmentioning

confidence: 67%

“…Several diagnostic tests are available for measuring serum IgG concentration and assessing FTPI in llamas and alpacas including: radial immunodiffusion (RID) assay, immunoturbidimetric assay, gamma-glutamyl transferase, zinc sulfate turbidity, glutaraldehyde coagulation, sodium sulfate precipitation, and refractometry [8, 10, 11]. Although RID is the historical direct and quantitative reference method for measuring IgG concentrations, it has significant drawbacks including high cost, time required to obtain results (18–24 h), requirements for a high level of technical skills to perform, utilization of labile reagents, and poor adaptation to field settings [12, 13].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Application of laboratory and portable attenuated total reflectance infrared spectroscopic approaches for rapid quantification of alpaca serum immunoglobulin G

et al. 2017

View full text Add to dashboard Cite

The objective of this study was to develop and compare the performance of laboratory grade and portable attenuated total reflectance infrared (ATR-IR) spectroscopic approaches in combination with partial least squares regression (PLSR) for the rapid quantification of alpaca serum IgG concentration, and the identification of low IgG (<1000 mg/dL), which is consistent with the diagnosis of failure of transfer of passive immunity (FTPI) in neonates. Serum samples (n = 175) collected from privately owned, healthy alpacas were tested by the reference method of radial immunodiffusion (RID) assay, and laboratory grade and portable ATR-IR spectrometers. Various pre-processing strategies were applied to the ATR-IR spectra that were linked to corresponding RID-IgG concentrations, and then randomly split into two sets: calibration (training) and test sets. PLSR was applied to the calibration set and calibration models were developed, and the test set was used to assess the accuracy of the analytical method. For the test set, the Pearson correlation coefficients between the IgG measured by RID and predicted by both laboratory grade and portable ATR-IR spectrometers was 0.91. The average differences between reference serum IgG concentrations and the two IR-based methods were 120.5 mg/dL and 71 mg/dL for the laboratory and portable ATR-IR-based assays, respectively. Adopting an IgG concentration <1000 mg/dL as the cut-point for FTPI cases, the sensitivity, specificity, and accuracy for identifying serum samples below this cut point by laboratory ATR-IR assay were 86, 100 and 98%, respectively (within the entire data set). Corresponding values for the portable ATR-IR assay were 95, 99 and 99%, respectively. These results suggest that the two different ATR-IR assays performed similarly for rapid qualitative evaluation of alpaca serum IgG and for diagnosis of IgG <1000 mg/dL, the portable ATR-IR spectrometer performed slightly better, and provides more flexibility for potential application in the field.

show abstract

Comparison of three immunoglobulin G assays for the diagnosis of failure of passive transfer of immunity in neonatal alpacas

Cited by 11 publications

References 17 publications

Clinical Findings and Survival in 56 Sick Neonatal New World Camelids

Clinical Findings and Survival in 56 Sick Neonatal New World Camelids

Use of Fourier‐Transform Infrared Spectroscopy to Quantify Immunoglobulin G Concentrations in Alpaca Serum

Application of laboratory and portable attenuated total reflectance infrared spectroscopic approaches for rapid quantification of alpaca serum immunoglobulin G

Contact Info

Product

Resources

About