Systematic Review and Meta-Analysis of Diagnostic Accuracy of Serum Refractometry and Brix Refractometry for the Diagnosis of Inadequate Transfer of Passive Immunity in Calves

S. Buczinski, E. Gicquel, G. Fecteau, Y. Takwoingi, Munashe Chigerwe, J. M. Vandeweerd

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Background: Transfer of passive immunity in calves can be assessed by direct measurement of immunoglobulin G (IgG) by methods such as radial immunodiffusion (RID) or turbidimetric immunoassay (TIA). IgG can also be measured indirectly by methods such as serum refractometry (REF) or Brix refractometry (BRIX). Objectives: To determine the accuracy of REF and BRIX for assessment of inadequate transfer of passive immunity (ITPI) in calves. Design: Systematic review and meta-analysis of diagnostic accuracy studies. Methods: Databases (PubMed and CAB Abstract, Searchable Proceedings of Animal Science) and Google Scholar were searched for relevant studies. Studies were eligible if the accuracy (sensitivity and specificity) of REF or BRIX was determined using direct measurement of IgG by RID or turbidimetry as the reference standard. The study population included calves <14 days old that were fed with natural colostrum (colostrum replacement products were excluded). Quality assessment was performed by the QUADAS-2 tool. Hierarchical models were used for meta-analysis. Results: From 1,291 references identified, 13 studies of 3,788 calves were included. Of these, 11 studies evaluated REF and 5 studies evaluated BRIX. The median (range) prevalence of ITPI (defined as calves with IgG <10 g/L by RID or TIA) was 21% (1.3-56%). Risk of bias and applicability concerns were generally low or unclear. For REF, summary estimates were obtained for 2 different cutoffs: 5.2 g/dL (6 studies) and 5.5 g/dL (5 studies). For the 5.2 g/dL cutoff, the summary sensitivity (95% CI) and specificity (95% CI) were 76.1% (63.8-85.2%) and 89.3% (82.3-93.7%), and 88.2% (80.2-93.3%) and 77.9% (74.5-81.0%) for the 5.5 g/dL cutoff. Due to the low number of studies using the same cutoffs, summary estimates could not be obtained for BRIX. Conclusions and Clinical Importance: Despite their widespread use on dairy farms, evidence about the optimal strategy for using refractometry, including the optimal cutoff, are sparse (especially for BRIX). When using REF to rule out ITPI in herds, the 5.5 g/dL cutoff may be used whereas for ruling in ITPI, the 5.2 g/dL cutoff may be used.

Original languageEnglish (US)
JournalJournal of Veterinary Internal Medicine
DOIs
StateAccepted/In press - Jan 1 2017

Fingerprint

passive immunity
Refractometry
Passive Immunization
systematic review
brix
meta-analysis
immunoglobulin G
Meta-Analysis
calves
Serum
Immunodiffusion
colostrum
immunoassays
Immunoglobulin G
Colostrum
Immunoassay
reference standards
animal science
dairy farming
Nephelometry and Turbidimetry

Keywords

  • Accuracy
  • IgG
  • Refractometry
  • Sensitivity
  • Specificity

ASJC Scopus subject areas

  • veterinary(all)

Cite this

@article{1f65ed6c8d9e4138854f83c6847f40ea,
title = "Systematic Review and Meta-Analysis of Diagnostic Accuracy of Serum Refractometry and Brix Refractometry for the Diagnosis of Inadequate Transfer of Passive Immunity in Calves",
abstract = "Background: Transfer of passive immunity in calves can be assessed by direct measurement of immunoglobulin G (IgG) by methods such as radial immunodiffusion (RID) or turbidimetric immunoassay (TIA). IgG can also be measured indirectly by methods such as serum refractometry (REF) or Brix refractometry (BRIX). Objectives: To determine the accuracy of REF and BRIX for assessment of inadequate transfer of passive immunity (ITPI) in calves. Design: Systematic review and meta-analysis of diagnostic accuracy studies. Methods: Databases (PubMed and CAB Abstract, Searchable Proceedings of Animal Science) and Google Scholar were searched for relevant studies. Studies were eligible if the accuracy (sensitivity and specificity) of REF or BRIX was determined using direct measurement of IgG by RID or turbidimetry as the reference standard. The study population included calves <14 days old that were fed with natural colostrum (colostrum replacement products were excluded). Quality assessment was performed by the QUADAS-2 tool. Hierarchical models were used for meta-analysis. Results: From 1,291 references identified, 13 studies of 3,788 calves were included. Of these, 11 studies evaluated REF and 5 studies evaluated BRIX. The median (range) prevalence of ITPI (defined as calves with IgG <10 g/L by RID or TIA) was 21{\%} (1.3-56{\%}). Risk of bias and applicability concerns were generally low or unclear. For REF, summary estimates were obtained for 2 different cutoffs: 5.2 g/dL (6 studies) and 5.5 g/dL (5 studies). For the 5.2 g/dL cutoff, the summary sensitivity (95{\%} CI) and specificity (95{\%} CI) were 76.1{\%} (63.8-85.2{\%}) and 89.3{\%} (82.3-93.7{\%}), and 88.2{\%} (80.2-93.3{\%}) and 77.9{\%} (74.5-81.0{\%}) for the 5.5 g/dL cutoff. Due to the low number of studies using the same cutoffs, summary estimates could not be obtained for BRIX. Conclusions and Clinical Importance: Despite their widespread use on dairy farms, evidence about the optimal strategy for using refractometry, including the optimal cutoff, are sparse (especially for BRIX). When using REF to rule out ITPI in herds, the 5.5 g/dL cutoff may be used whereas for ruling in ITPI, the 5.2 g/dL cutoff may be used.",
keywords = "Accuracy, IgG, Refractometry, Sensitivity, Specificity",
author = "S. Buczinski and E. Gicquel and G. Fecteau and Y. Takwoingi and Munashe Chigerwe and Vandeweerd, {J. M.}",
year = "2017",
month = "1",
day = "1",
doi = "10.1111/jvim.14893",
language = "English (US)",
journal = "Journal of Veterinary Internal Medicine",
issn = "0891-6640",
publisher = "Wiley-Blackwell",

}

TY - JOUR

T1 - Systematic Review and Meta-Analysis of Diagnostic Accuracy of Serum Refractometry and Brix Refractometry for the Diagnosis of Inadequate Transfer of Passive Immunity in Calves

AU - Buczinski, S.

AU - Gicquel, E.

AU - Fecteau, G.

AU - Takwoingi, Y.

AU - Chigerwe, Munashe

AU - Vandeweerd, J. M.

PY - 2017/1/1

Y1 - 2017/1/1

N2 - Background: Transfer of passive immunity in calves can be assessed by direct measurement of immunoglobulin G (IgG) by methods such as radial immunodiffusion (RID) or turbidimetric immunoassay (TIA). IgG can also be measured indirectly by methods such as serum refractometry (REF) or Brix refractometry (BRIX). Objectives: To determine the accuracy of REF and BRIX for assessment of inadequate transfer of passive immunity (ITPI) in calves. Design: Systematic review and meta-analysis of diagnostic accuracy studies. Methods: Databases (PubMed and CAB Abstract, Searchable Proceedings of Animal Science) and Google Scholar were searched for relevant studies. Studies were eligible if the accuracy (sensitivity and specificity) of REF or BRIX was determined using direct measurement of IgG by RID or turbidimetry as the reference standard. The study population included calves <14 days old that were fed with natural colostrum (colostrum replacement products were excluded). Quality assessment was performed by the QUADAS-2 tool. Hierarchical models were used for meta-analysis. Results: From 1,291 references identified, 13 studies of 3,788 calves were included. Of these, 11 studies evaluated REF and 5 studies evaluated BRIX. The median (range) prevalence of ITPI (defined as calves with IgG <10 g/L by RID or TIA) was 21% (1.3-56%). Risk of bias and applicability concerns were generally low or unclear. For REF, summary estimates were obtained for 2 different cutoffs: 5.2 g/dL (6 studies) and 5.5 g/dL (5 studies). For the 5.2 g/dL cutoff, the summary sensitivity (95% CI) and specificity (95% CI) were 76.1% (63.8-85.2%) and 89.3% (82.3-93.7%), and 88.2% (80.2-93.3%) and 77.9% (74.5-81.0%) for the 5.5 g/dL cutoff. Due to the low number of studies using the same cutoffs, summary estimates could not be obtained for BRIX. Conclusions and Clinical Importance: Despite their widespread use on dairy farms, evidence about the optimal strategy for using refractometry, including the optimal cutoff, are sparse (especially for BRIX). When using REF to rule out ITPI in herds, the 5.5 g/dL cutoff may be used whereas for ruling in ITPI, the 5.2 g/dL cutoff may be used.

AB - Background: Transfer of passive immunity in calves can be assessed by direct measurement of immunoglobulin G (IgG) by methods such as radial immunodiffusion (RID) or turbidimetric immunoassay (TIA). IgG can also be measured indirectly by methods such as serum refractometry (REF) or Brix refractometry (BRIX). Objectives: To determine the accuracy of REF and BRIX for assessment of inadequate transfer of passive immunity (ITPI) in calves. Design: Systematic review and meta-analysis of diagnostic accuracy studies. Methods: Databases (PubMed and CAB Abstract, Searchable Proceedings of Animal Science) and Google Scholar were searched for relevant studies. Studies were eligible if the accuracy (sensitivity and specificity) of REF or BRIX was determined using direct measurement of IgG by RID or turbidimetry as the reference standard. The study population included calves <14 days old that were fed with natural colostrum (colostrum replacement products were excluded). Quality assessment was performed by the QUADAS-2 tool. Hierarchical models were used for meta-analysis. Results: From 1,291 references identified, 13 studies of 3,788 calves were included. Of these, 11 studies evaluated REF and 5 studies evaluated BRIX. The median (range) prevalence of ITPI (defined as calves with IgG <10 g/L by RID or TIA) was 21% (1.3-56%). Risk of bias and applicability concerns were generally low or unclear. For REF, summary estimates were obtained for 2 different cutoffs: 5.2 g/dL (6 studies) and 5.5 g/dL (5 studies). For the 5.2 g/dL cutoff, the summary sensitivity (95% CI) and specificity (95% CI) were 76.1% (63.8-85.2%) and 89.3% (82.3-93.7%), and 88.2% (80.2-93.3%) and 77.9% (74.5-81.0%) for the 5.5 g/dL cutoff. Due to the low number of studies using the same cutoffs, summary estimates could not be obtained for BRIX. Conclusions and Clinical Importance: Despite their widespread use on dairy farms, evidence about the optimal strategy for using refractometry, including the optimal cutoff, are sparse (especially for BRIX). When using REF to rule out ITPI in herds, the 5.5 g/dL cutoff may be used whereas for ruling in ITPI, the 5.2 g/dL cutoff may be used.

KW - Accuracy

KW - IgG

KW - Refractometry

KW - Sensitivity

KW - Specificity

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DO - 10.1111/jvim.14893

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JO - Journal of Veterinary Internal Medicine

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SN - 0891-6640

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