Lactoferrin (Lf) ADDE Test

Lactoferrin (Lf) ADDE Test


Lactoferrin is a key biomarker primarily associated with dry eye disease (DED). It is a protein contained in tears that protects the ocular surface with its antimicrobial and anti-inflammatory properties. Lactoferrin is one of the eye’s main immunological defense mechanisms and plays an important role in the maintenance of ocular health.


What is Dry Eye Disease

The new TFOS and DEWS II definition of dry eye disease refers to the following “Dry eye is a multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities play etiological roles.”

Dry eye disease is one of the most prevalent ocular surface diseases diagnosed in over 20 million U.S. patients. and is one of the leading causes of patient visits to eye care professionals. An unstable tear film leads to increased inflammation and damage to eye structures and nerves. Moderate to severe dry eye can significantly and negatively impact daily life. Symptoms of DED include eye pain or discomfort, tearing, fluctuating vision, limitations in performing daily activities (e.g. reading, driving, use of digital devices), and ocular fatigue.

Two forms of DED exist, aqueous deficient resulting from reduced tear secretion, and evaporative resulting from excessive tear evaporation. The core mechanism of dry eye disease is evaporation-induced tear hyperosmolarity (higher salt concentration than normal), which triggers a cascade of events leading to ocular surface damage and chronic inflammation.

Testing and Results

The measurement of ocular lactoferrin, as a biomarker, has long been established and accepted as the “medical standard” in assessing the secretory function of the lacrimal gland.

Low lactoferrin levels directly correlate to aqueous deficiency or hyposecretion of tears.  Normal lactoferrin levels indicate normal lacrimal gland function. In contrast, meibomian gland dysfunction leads to increased tear evaporation.

Identification of reduced levels tear lactoferrin allows for the clinical differentiation between aqueous deficient and evaporative DED, leading to more targeted and effective treatment coupled with the ability to evaluate response to therapy.

More Information

Test time: 10 mins               
Sample (size and type): 0.5 microliter in tears
Test results:   High Lf: > 1.0 mg/ml Low Lf: < 0.8 mg/ml
Sensitivity: 83%
Specificity: 98%
Shelf life: 12 months
Medicare and Private Insurance Reimbursable CPT code: 83520


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