TNF receptor associated periodic syndrome (also known as "TRAPS", "Tumor necrosis factor receptor associated periodic syndrome" or "familial Hibernian fever") is a periodic fever syndrome

Periodic fever syndrome

The periodic fever syndromes are a set of disorders, many of which are genetic disorders in which the mechanisms which initiate and control inflammation are disturbed, leading to uncontrolled inflammation throughout the body...

 associated with mutations in a receptor

Receptor (biochemistry)

In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...

 for the molecule tumor necrosis factor

Tumor necrosis factors

Tumor necrosis factors refers to a group of cytokines family that can cause cell death . The first two members of the family to be identified were:...

 (TNF) that is inheritable in an autosomal dominant manner. Individuals with TRAPS have episodic symptoms such as recurrent high fevers

Fevers

Fevers are a five-piece band formed in 2010 in Ottawa, Ontario. The band consists of Colin MacDougall , Jim Hopkins , Martin Charbonneau , Sarah Bradley and Mike Stauffer . Theirs is a fresh take on a classic genre, combining indie rock and electronic music...

, rash

Rash

A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...

, abdominal pain

Abdominal pain

Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem...

, joint/muscle aches and puffy eyes. TRAPS was first described in 1982 in a boy of Scottish-Irish origin. At that time, it was named familial Hibernian fever.

The main source of TNF (tumor necrosis factor) is cells in the immune system

Immune system

An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...

 called macrophage

Macrophage

Macrophages are cells produced by the differentiation of monocytes in tissues. Human macrophages are about in diameter. Monocytes and macrophages are phagocytes. Macrophages function in both non-specific defense as well as help initiate specific defense mechanisms of vertebrate animals...

s which produce it in response to infection and other stimuli. TNF helps activate other immune cells and plays a major role in initiation of inflammation

Inflammation

Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

. Individuals with TRAPS have a mutation in the tumor necrosis factor receptor-1

CD120

CD120 , also known as the tumor necrosis factor receptor . This protein is a member of the tumor necrosis factor receptor superfamily.- Receptor subtypes :...

 (TNFR1) gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

. The mechanisms by which mutations in TNFR1 lead to the TRAPS phenotype

Phenotype

A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...

 are still under investigation. Impaired shedding of the TNF receptor is one of the possible defects. Most mutations affect the extracellular domain of the receptor, some also the cleavage site.

Several medications have been studied for the treatment of TRAPS including etanercept

Etanercept

Etanercept is a drug that treats autoimmune diseases by interfering with the tumor necrosis factor by acting as a TNF inhibitor. Pfizer describes in a SEC filing that the drug is used to treat rheumatoid, juvenile rheumatoid and psoriatic arthritis, plaque psoriasis and ankylosing spondylitis...

, infliximab

Infliximab

Infliximab is a monoclonal antibody against tumour necrosis factor alpha . It is used to treat autoimmune diseases. Remicade is marketed by Janssen Biotech, Inc...

, tacrolimus

Tacrolimus

Tacrolimus is an immunosuppressive drug that is mainly used after allogeneic organ transplant to reduce the activity of the patient's immune system and so lower the risk of organ rejection...

 and Il-1Ra (anakinra

Anakinra

Anakinra is a drug used to treat rheumatoid arthritis.-Mechanism:Anakinra is an interleukin-1 receptor antagonist...

). Studies on treatment efficacy in a larger group of patients affected with TRAPS are however lacking to date.