Parallel testing of plasma iron and fibrinogen concentrations to detect systemic inflammation in hospitalized horses

Abstract

Plasma iron concentration alone is an accurate marker of SI in hospitalized horses. Alteration of both plasma iron and fibrinogen concentrations improves the specificity and positive predictive value for diagnosis of SI. Alteration of either one of both increases sensitivity and negative predictive value. Surviving horses normalized plasma iron concentrations during follow-up period. The combination of plasma iron and fibrinogen concentrations may help in the detection of SI. Follow-up of plasma iron concentrations may provide useful prognostic information.

Plasma iron concentrations and systemic inflammatory response syndrome in neonatal foals

“…Neonatal foals in the stud control group (n = 135), only had a 24 hours range of age dispersion between all individuals, and their mean plasma iron concentration was 181.84 μg/dL, which is similar to the estimated average concentrations in neonatal foals of 1 day of age 14 ; but presented a wider distribution (58.8‐305 μg/dL) compared to previously published plasma iron concentration in adults (105‐277 μg/dL) 2,12 . In healthy foals at birth, plasma iron and ferritin concentrations are lower than in adult horses, followed by a rapid increase in the first 24 hours as a result of absorption of colostrum iron 14 .…”

“…In the studied population of neonatal foals, there was no significant difference in mean plasma iron concentrations between healthy foals and sick foals ( P = .99). In equine medicine, previous reports suggest that plasma iron concentrations in adult horses are an acute and sensitive indicator of systemic inflammation 2,12 . In adult horses plasma iron concentration is considered decreased when values fall below the reference interval (105‐277 μg/dL) 2 .…”

“…In adult horses, plasma iron concentration acutely decreases in cases with systemic inflammation 2 . Low iron and high fibrinogen plasma concentrations are both sensitive indicators of systemic inflammation in horses, with sensitivity of 90 and 82%, respectively 12 . Rapid development of hypoferremia is particularly valuable during the earliest phases of infection, before other components of innate and adaptive immunity are mobilized 2 …”

Overview of Clinical Pathology and the Horse

“…Serum amyloid A is another indicator of the acute phase reaction in horses. 19,20,33 Following a decrease in neutrophil levels with acute inflammation, the neutrophil counts will increase as the marrow responds (4-5 days); but this increase also depends on a reduction in neutrophil loss to tissues and the ability of the marrow production to exceed demand. 31,32 The increase in neutrophils may be accompanied by a monocytosis; the persistence of a monocytosis indicates that the inflammatory process has become chronic.…”

“…[13][14][15][16][17][18] HEMATOLOGY The basic assessment of hematology parameters includes a CBC with manual differential and fibrinogen levels and may also include a spun packed cell volume (PCV) and plasma protein (PP) level (total solids). 19,20 The parameters, PP (total solids) plus PCV and evaluation of a stained smear can provide the basic information needed to determine if there is an inflammatory condition present and an anemia or protein decrease and can also be used to monitor the animal and determine if there is progression of the disease.…”