Sorted By Test Name - Mayo Medical Laboratories

NEFA
8280
FRTIX
80315
In the presence of compatible symptoms, a Francisella tularensis antibody titer of 1:160 or greater in an
acute specimen supports a presumptive diagnosis of tularemia. However, a titer > or =1:160 may also
reflect past infection. An equivocal titer may be due to crossreactive antibodies (Brucella, Yersinia, or
Proteus OX19), past infection, or very recent infection. A four-fold rise in titer between acute and
convalescent sera is required for definitive serologic diagnosis of tularemia.
Test Performed By: Focus Diagnostics, Inc.
5785 Corporate Avenue
Cypress, CA 90630-4750
Free Fatty Acids, Total, Serum
Clinical Information: All but 2% to 5% of serum fatty acids are esterified. The "nonesterified" or
"free" fatty acids are protein-bound. The amount of free fatty acids in the serum rises after a fatty meal,
but tends to fall after ordinary meals. Levels are elevated in obesity. Lipoactive hormones such as
epinephrine, norepinephrine, glucagon, thyrotropin, and adrenocorticotropin release free fatty acids.
Tumors producing such hormones cause release of excessive quantities of free fatty acids. Serum free
fatty acids are also increased in patients with uncontrolled type 2 diabetes mellitus and are an indicator of
insulin resistance. Free fatty acids are associated with increased reactive oxygen species (ROS), probably
mediated by free fatty acid activation of NADPH oxidase. The link between increased ROS and decreased
nitric oxide production is a contributor to endothelial dysfunction.
Useful For: Evaluation of metabolic status of persons with endocrinopathies Detection of
pheochromocytoma and of glucagon-, thyrotropin-, and adrenocorticotropin-secreting tumors Monitoring
of control of diabetes mellitus (serum-free glycerol is a very useful companion test in assessing diabetes
and may be ordered by special request from Mayo Medical Laboratories). The correlation with insulin
resistance and downstream cardiovascular risk may be a useful treatment aid in some patients.
Interpretation: Abnormally high levels of free fatty acids are associated with uncontrolled diabetes
mellitus and with conditions that involve excessive release of a lipoactive hormone such as epinephrine,
norepinephrine, glucagon, thyrotropin, and adrenocorticotropin.
Reference Values:
> or =16 years: 0.00-0.72 mmol/L
Reference values have not been established for patients that are