What is Interferon-gamma (INF-g, IFN-g)

IFN-gamma (IFN-γ or type II interferon) is an immune protein. It is essential for the body’s immune response against fungal, bacterial, and viral infections. It controls genes that are responsible for immune and inflammatory responses. It is also the main activator of macrophages, natural killer cells, and neutrophils [R].

IFN-gamma levels generally increase during infections or immune disorders. This cytokine is a part of the Th1 immune response [R].

Normal Range of interferon-gamma

The normal range may vary by test.

• <2.0 pg/mL
• 5 pg/mL or less
• ≤3.0 pg/mL

High interferon-gamma

IFN-gamma levels normally increase as you age [R].

Lipopolysaccharides (LPS) is one of the most significant simulators of interferon gamma [R].

LPS can be elevated by a leaky gut, infections, or a host of other conditions.

Nitric oxide also increases interferon gamma.

Causes of High interferon-gamma

High IFN-gamma levels can be caused by:

• Canker sores (recurrent aphthous stomatitis) (n=21) [R]
• Patchy hair loss (alopecia areata) (n=60) [R]
• Alcoholism (n=47) [R]
• Alcoholic liver scarring (cirrhosis) (n=26) [R]
• Measles (acute phase, <7 days of illness) (n=54) [R]
• Hepatitis B (n=60) [R]
• Tuberculosis (active pulmonary tuberculosis (n=10) and latent tuberculosis infection (n=430)) [R, R]
• Multiple sclerosis (n=29, n=21) [R, R]
• Systemic sclerosis (n=49) [R]
• Isoniazid treatment for tuberculosis (n=26) [R]
• Melioidosis, an infectious bacterial disease (n=62) [R]

Elevated IFN-gamma levels are associated with:

• Increased severity of airway inflammation in asthma patients (n=17) [R]
• Psoriasis severity (n=21, n=30) [R, R]
• Kidney damage in type 2 diabetic patients (n=100) [R]
• Increased severity of heart disease (n=104) [R]
• Amyotrophic lateral sclerosis (ALS) disease progression (n=52) [R]
• Lupus (n=64) [R]
• Mixed connective tissue disease (n=15) [R]
• Tumor stage, tumor size, and recurrence in liver cancer patients (n=63) [R]

Recommendations for High interferon-gamma:

We recommend the following lifestyle changes:

Get medical attention for any underlying health conditions.

Exercise more. Endurance training (but not moderate exercise) can help decrease IFN-gamma levels [R].

Refrain from drinking alcohol [R].

Eat a diet high in omega-3 fatty acids. Some foods with high omega-3 levels include fatty fish, shellfish, and fortified dairy products [R, R].

Supplements that have shown some kind of ability to lower interferon-gamma in animal or cellular models:

• Fish oil (R)
• Curcumin (R)
• Olive leaf  extract (R, R2)
• Andrographis  (R1, R2, R3, R4)
• Boswellia (R)
• Lithium (R)
• Theanine (R, R2)
• Glucosamine (R)
• Ginkgo (R)
• American Ginseng  (R, R2)
• Theaflavins (R, R2)
• Nettle leaf  (R)
• EGCG (R)
• Hops (xanthohumol) (R)
• Feverfew/Parthenolide (R)
• Aloe (R)
• Resveratrol [R]

This IFNG gene page has more substances that can reduce interferon gamma.

Low interferon-gamma

Low IFN-gamma levels can be caused by:

• Endurance exercising training (n=30) [R]
• Second-hand smoke exposure (n=40) [R]
• Candida albicans oral infection (n=26) [R]
• Trauma (n=38) [R]
• Heart surgery (n=20) [R]
• Epstein Barr virus infection [R, R]
• Hepatitis C (n = 63) [R]
• Corticosteroid treatment (n=131) [R]

Low interferon-gamma Recommendations

Moderate exercise can enhance IFN-gamma production [R].

Sun exposure on your body (UVA), which increases nitric oxide, can in turn increase interferon gamma.

Supplements that can help increase interferon gamma:

• Glutamine [R]
• Probiotics (Lactobacillus rhamnosus GG) [R]
• Vitamin E [R]
• Glycine [R]

This IFNG gene page has more substances that can increase interferon gamma.

Interferon Gamma Genes and SNPs

Interferon-gamma levels are also determined by variations in the IFNG gene:

• rs1861494
• rs2069705
• rs1861493
• rs2069727
• rs2069707

If you have a genetics file, you can upload it to SelfDecode to get your results.

Abnormal interferon-gamma?

We created Lab Test Analyzer, a tool that easily lets you know which lab results you need to be concerned about, includinng interferon-gmma, and how to bring these within the optimal range.