Serum Amyloid A and Haptoglobin Concentrations are Increased in Plasma of Mares with Ascending Placentitis in the Absence of Changes in Peripheral Leukocyte Counts or Fibrinogen Concentration

Abstract

Mares with placentitis aborted within 5-25 days after inoculation. Concentrations of SAA and Hp rapidly increased subsequent to experimental induction of placentitis and remained increased until abortion. Neither Fb nor WBC appeared to be useful markers for placentitis. Parturition did not trigger increase in either SAA or Hp in normal foaling mares.

Use of a Qualitative Horse-Side Test to Measure Serum Amyloid A in Mares With Experimentally Induced Ascending Placentitis

“…Mares with experimentally induced placentitis had elevated SAA concentration starting 2 days after inoculation, and SAA remained elevated until abortion [11]. In addition, foaling did not induce an elevation on SAA levels [11].…”

“…In a recent study in our laboratory, we investigated whether SAA could be used as diagnostic tool for mares with experimentally induced bacterial placentitis [11]. Mares with experimentally induced placentitis had elevated SAA concentration starting 2 days after inoculation, and SAA remained elevated until abortion [11]. In addition, foaling did not induce an elevation on SAA levels [11].…”

“…Thus, our group has been focused on identifying new diagnostic tests for equine placentitis. To date, several markers (e.g., acute-phase proteins, fetoplacental steroids, alpha-fetoprotein) have been investigated in experimental cases, and some appear to be useful tools to detect experimentally induced placentitis [7][8][9][10][11]. Among these markers, acute-phase proteins, particularly serum amyloid A (SAA), appear to be a sensitive but nonspecific marker for placentitis [7][8][9][10][11].…”

“…Two of eight mares with experimentally induced ascending placentitis that received treatment (i.e., antibiotics, altrenogest, and pentoxifylline) had an elevation in SAA [15]; however, all five mares with experimentally induced placentitis that were untreated had an elevation in SAA and aborted thereafter [15]. In a recent study in our laboratory, we investigated whether SAA could be used as diagnostic tool for mares with experimentally induced bacterial placentitis [11]. Mares with experimentally induced placentitis had elevated SAA concentration starting 2 days after inoculation, and SAA remained elevated until abortion [11].…”

“…Different commercial kits have been marketed over the last 2 years; however, research comparing horse qualitative tests against well-established quantitative tests has not been performed. The Eiken assay has been the most widely studied method to quantify SAA in the horse [11,14,16]. Therefore, the objectives of this study were to assess (1) changes in SAA detected by a lateral flow device (LFD) in mares with experimentally induced placentitis and (2) to examine the correlation of this assay with a quantitative immunoassay.…”