Validation of IgG cut-off values and their association with survival in neonatal foals.

The research investigates existing methods of assessing immunoglobulin levels in neonatal foals and their relationship with survival rates. It explores how unverified thresholds of IgG, used to determine immunity failure, relate to the probability of survival in different groups of foals.

Objective and Methodology

• The focus of the study was to evaluate the existing IgG cut-off values for assessing the failure of transfer of passive immunity (FTPI) in foals, its connection with survival outcomes, and whether FTPI can be predicted through serum total protein, albumin, and globulin levels in hospitalized foals. This analysis was necessary since the original cut-off values were established around 30 years ago based largely on empirical data.
• The cross-sectional study examined clinicopathological variables in 597 foals aged 7 days or less from 3 equine hospitals. These variables included serum IgG, fibrinogen, TP, and albumin concentrations. Based on their health status, foals were categorized into healthy, sick nonseptic, and septic groups.
• To compute odds ratios for survival, a variety of regression techniques (univariate, multivariate, and multinomial logistic regression) were used.

Results

• The findings from the research upheld the established IgG cut-off value of > 8 g/l as being representative of adequate transfer of passive immunity (ATPI).
• The research also found an increasing risk of nonsurvival corresponding with lower IgG concentrations in foals.
• Interestingly, higher TP concentrations were associated with a lower likelihood of FTPI, whereas higher albumin concentrations entailed a greater likelihood of FTPI.
• The research also developed a regression equation for predicting IgG levels in foals based on serum proteins.

Conclusion

• The study verified that serum IgG values of <8 g/l in hospitalized foals showed a proportional association with mortality.
• The research recommends immediate assessment of IgG concentrations in hospitalized foals, and those found with FTPI should promptly receive immunotherapy.