Investigation of the genetic overlap between rheumatoid arthritis and psoriatic arthritis in a Greek population.

OBJECTIVES: Several rheumatoid arthritis (RA) susceptibility loci have also been found to be associated with psoriatic arthritis (PsA), demonstrating that there is a degree of genetic overlap between various autoimmune diseases. We sought to investigate whether single nucleotide polymorphisms (SNPs) mapping to previously reported RA and/or PsA susceptibility loci, including PLCL2, CCL21, REL, STAT4, CD226, PTPN22, and TYK2, are associated with risk for the two diseases in a genetically homogeneous Greek population. METHOD: This study included 392 RA patients, 126 PsA patients, and 521 healthy age- and sex-matched controls from Greece. Genotyping of the SNPs was performed with Taqman primer/probe sets. Bioinformatic analysis was performed using BlastP, PyMOL, and Maestro and Desmond. RESULTS: A significant association was detected between the GC genotype of rs34536443 (TYK2) in both the PsA and RA cohorts. The C allele of this SNP was associated with PsA only. Evidence for association with PsA was also found for the GG genotype and G allele of the rs10181656 SNP of STAT4. The TC genotype of the rs763361 SNP of CD226 was associated with PsA only. CONCLUSIONS: Genetic overlap between PsA and RA was detected for the rs34536443 SNP of the TYK2 gene within a Greek population. An association of STAT4 (rs10181656) with PsA was confirmed whereas CD226 (rs763361) was associated with PsA but not with RA, in contrast to previous reports. The different findings of this study compared to previous ones highlights the importance of comparative studies that include various ethnic or racial populations.

Outcome of refractory to conventional and/or biologic treatment adult Still's disease following canakinumab treatment: Countrywide data in 50 patients.

OBJECTIVE: To assess the efficacy and safety of the IL-1b inhibitor canakinumab in all adults with refractory Still's disease identified from the National Organization For Medicines for off-label drug use. METHODS: In a retrospective longitudinal multicenter cohort of 50 patients (median age 39 years) with active Still's disease despite treatment with corticosteroids (n = 11), conventional and synthetic (n = 34) and/or biologic disease modifying anti-rheumatic drugs (n = 30), we assessed the efficacy of canakinumab 150-300 mg administered every 4 (n = 47) or 8 weeks (n = 3) as combination therapy or monotherapy (n = 7) during a median follow-up of 27 (3-84) months. RESULTS: Α complete response was initially observed in 78% of patients within 3 months (median), irrespective of age at disease onset. A partial response was evident in 20%. One patient had resistant disease. Treatment de-escalation was attempted in 15 of 39 complete responders and a complete drug discontinuation in 21 patients for 8 months (median). Eleven patients (22%) relapsed during treatment, one during de-escalation process, and 11 after treatment discontinuation. Overall, 9 of 11 relapses were successfully treated with canakinumab treatment intensification or re-introduction. At last visit, 18% of patients were off treatment due to remission and 26% due to disease activity. Canakinumab had a significant corticosteroid sparing effect allowing weaning in 21 of 41 cases. Infections (20%, severe 4%) and leucopenia (6%) led to treatment cessation in one patient. CONCLUSION: High rates of sustained remission were observed in this, largest so far, real-life cohort of adult patients with refractory Still's disease treated with canakinumab.