Definition
Tumour necrosis factor receptor 1-associated periodic syndrome (TRAPS) is the acronym for the name of the disease:
Tumor necrosis factor (TNF)
Receptor
Associated
Periodic
Syndrome
Periodic syndrome associated with tumour necrosis factor receptor 1.
It is a rare genetic auto-inflammatory disease.
Epidemiology
It is a cosmopolitan disease, meaning that it affects people from all over the world.
It is estimated that there are
around a hundred patients in France with TRAPS syndrome.
200 to 300 worldwide.
The disease affects both men and women.
The age of onset is between 4 and 20 years.
Genetic
TRAPS is associated with mutations in the TNFRSF1A gene, which encodes the type 1 TNF receptor on the surface of innate immune cells (white blood cells).
Clinical
Outbreaks of the disease are long, generally lasting between 7 and 21 days, or even 28 days. They are marked by high fever and abdominal pain.
Erythematous, oedematous, hot rashes on the upper and lower limbs and chest may also accompany the fever.
Migratory muscle pains (myalgias) are also specific, heralding the onset of attacks.
Chest pain, scrotal pain, joint pain and oedema around the eyes are less common.
When blood is taken during an attack, patients always have a very high level of inflammation, with very high levels of C Reactive Protein (CRP) and white blood cells (neutrophil-type leukocytes).
Diagnostic
Because of its later onset, diagnosis is more likely to be made in adolescence or young adulthood.
It is based on the detection of mutations in the TNFRSF1A gene by a simple blood test.
Evolution
AA amyloidosis is the main and most feared complication of TRAPS in cases where there has been untreated inflammation for many years. CRP should therefore be checked twice a year, and renal function and proteinuria at least once a year.
Treatment
The aims of the treatment are to:
- Relieve symptoms (fever and pain)
- Normalise C-reactive protein during and outside attacks.
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=> Corticosteroids may be used in the event of an attack, if there are few of them and if there is no inflammation between attacks.
=> If this is not the case (≥ 3 attacks per year and/or high CRP between attacks), anti-interleukin 1 biotherapies are effective and should be offered to patients with numerous attacks and chronic inflammation.
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Canakinumab is the drug approved for use in TRAPS syndrome in France.