Inflammation: A Focus on Serum Amyloid A

The last few years it seems almost every research paper on diseases which involve inflammation, the majority of diseases, discusses the possible use of serum amyloid A (SSA) in the diagnosis and perhaps more importantly, monitoring of progress of the disease. This test is becoming one of the most useful field techniques for diagnosing early infectious disease, differencing non-infectious from inflammatory disease from infections, and monitoring the progress of treatment. Excerpted from Wikipedia:

Acute-phase serum amyloid A proteins (A-SAAs) are secreted during the acute phase of inflammation. These proteins have several roles, including the transport of cholesterol to the liver for secretion into the bile, the recruitment of immune cells to inflammatory sites, and the induction of enzymes that degrade extracellular matrix. …. Serum amyloid A (SAA) is also an acute phase marker that responds rapidly. Similar to C-reactive protein, levels of acute-phase SAA increase within hours after inflammatory stimulus, and the magnitude of increase may be greater than that of CRP. Relatively trivial inflammatory stimuli can lead to SAA responses. It has been suggested that SAA levels correlate better with disease activity in early inflammatory joint disease than do erythrocyte sedimentation rate and CRP.

The key to this usefulness is how sensitive SAA levels are to inflammation, how much more reactive SAA levels are to inflammation caused by infection, and how rapidly it changes in response to change in the severity of the disease. Making this test more useful is a field SAA test available.
DrO

Vet Clin North Am Equine Pract. 2020 Jan 29.
Equine Inflammatory Markers in the Twenty-First Century: A Focus on Serum Amyloid A.
Long A1, Nolen-Walston R2.

Author information:
1. Department of Clinical Studies, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA.
2. Department of Clinical Studies, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA. Electronic address: rnolenw@upenn.edu.
Abstract

Serum amyloid A (SAA) is a marker of inflammation and infection in the horse that can be assessed in the field, with rapid and marked changes seen following initiation of an inflammatory stimulus. This quality of SAA also makes its clinical use challenging, because even small inflammatory conditions can cause large changes in SAA levels. Review of the current literature provides guidelines for responses of SAA to various conditions, which can be applied to specific clinical cases. The practitioner is encouraged to use SAA in conjunction with physical examination and other diagnostic modalities to guide treatment and monitor case progression.