[Hereditary systemic autoinflammatory diseases. Part II: cryopyrin-associated periodic syndromes, pediatric systemic granulomatosis and PAPA syndrome]

Imaging findings of sterile pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome: differential diagnosis and review of the literature

Pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome is a rare autosomal-dominant autoinflammatory disease of incomplete penetrance and variable expression. PAPA syndrome is the result of a mutation in the proline serine threonine phosphatase-interacting protein 1 (PSTPIP1/CD2BP1) gene located on chromosome 15, which results in an abnormal overproduction of the pro-inflammatory cytokine interleukin-1β (IL-1). This syndrome clinically manifests as early onset of recurrent episodes of acute aseptic inflammation of the joints, generally occurring in the first two decades of life, followed by manifestation of characteristic skin lesions in the third decade, after an obvious decline in the joint symptoms. Although uncommon, the potential clinical implications of PAPA syndrome warrant an appropriate diagnosis in a timely fashion.

[Syndrome CINCA/NOMID]

CINCA/NOMID syndrome was first reported in 1981, identified as a new disease in 1987 and the main cause discovered in 2001, when mutations in the CIAS1 gene modifying the structure of the protein cryopirin were found in those patients (although other factors seem to play a role). Together with the major symptoms that characterized the syndrome, neurological, cutaneous and articular manifestations, others have been added which seem to be quite constant among CINCA/NOMID diagnosed patients: pre and perinatal symptoms, morfological changes, outbreaks of fever and biological abnormalities which reveal a persistent inflammatory background. The radiological studies have been able to identify the physis as the origin of the osteoarticular malformations seen in this syndrome. Diferential diagnosis includes diseases with similar onset at the neonatal period or infancy: systemic onset juvenile idiopathic athritis, periodic fever associated with mevalonate kinase deficiency, deficiency of IL-1 receptor antagonist (DIRA) and Muckle-Wells syndrome.

[CAPS treatment]

Non-steroidal anti-inflammatories, corticoids and antihistamines, as well as a great many other molecules, have classically been used to control the symptoms of cryopyrin-associated periodic syndromes (CAPS), with very few encouraging results. Knowledge of its genetic character, and its aetiopathogenesis associated with inflammasome and the production of interleukin-1 (IL-1) has led to the development of new therapeutic weapons that have not just obtained improvements of the symptoms and quality of life of the patients, but also managed to control the underlying inflammation. Results show that anakinra, an IL-1 receptor antagonist molecule, improved the clinical symptoms and the inflammatory markers of patients with CAPS has motivated research with other molecules directed against IL-1: rilonacept and canakinumab. It is likely that the use of these molecules could prevent the development of the late complications associated with chronic inflammation.

[Young woman with relapsing arthritis]

A 28-years old lady complains of self-limited episodes of relapsing knee arthritis of 48-72h of duration every 2 weeks. Immunological profile was all negative. At the same time, radiological images did not reveal any abnormality. She underwent to knee arthroscopy, however, a definite diagnosis was not reached. We discuss the differential diagnosis of relapsing arthritis.

Current concepts in immunology

The annual Congress of the Spanish Immunology Society is the forum at which clinical immunologists and scientists communicate novel findings in the field. This year's meeting was held in Palma de Mallorca, Spain, from 21 to 24 May 2008. It was opened and organized by Nuria Matamoros, head of the Immunology Department of Hospital Son Dureta, Mallorca, Spain. The meeting comprised an opening lecture, four highly successful plenary sessions, 11 oral and poster sessions where recent results of different groups were shown, four workshops in which interlaboratory studies of quality control on different immune tests were discussed and a closing lecture. Some of the most interesting plenary presentations given at this meeting are summarized.