Drug Survival and Predictors of Drug Survival for Methotrexate Treatment in a Retrospective Cohort of Adult Patients with Localized Scleroderma

Data regarding the efficacy and safety of methotrexate (MTX) in adults with localized scleroderma (LoS) is scarce. This study gathered data from a retrospective cohort of adult patients with LoS (n?=?107), treated with MTX (1993-2015). MTX drug survival and predictors thereof were analysed. After 1 and 2 years, 26% and 63% of patients stopped MTX due to disease remission, respectively. Patients with younger age at MTX initiation (hazard ratio (HR) 1.159 (95% confidence interval (CI) 1.052-1.277)) and those with no other autoimmune diseases (HR 3.268 (95% CI 1.334-8.009)) more often stopped MTX due to disease remission. In addition, 24% of patients stopped MTX due to treatment failure within one year. Patients with circumscribed superficial LoS (HR 0.221 (95% CI 0.081-0.601)) experienced treatment failure less often than those with other LoS subtypes. Finally, adding folic acid (HR 0.184 (95% CI 0.079-0.425)) and reducing treatment delay (HR 1.056 (95% CI 1.004-1.112)) could be the most important factors in minimizing MTX treatment failure in LoS in clinical practice.

Expression and activity of citrullinating peptidylarginine deiminase enzymes in monocytes and macrophages

BACKGROUND

Antibodies directed to proteins containing the non-standard amino acid citrulline, are extremely specific for rheumatoid arthritis (RA). Peptidylcitrulline can be generated by post-translational conversion of arginine residues. This process, citrullination, is catalysed by a group of calcium dependent peptidylarginine deiminase (PAD) enzymes.

OBJECTIVE

To investigate the expression and activity of four isotypes of PAD in peripheral blood and synovial fluid cells of patients with RA.

RESULTS

The data presented here show that citrullination of proteins by PAD enzymes is a process regulated at three levels: transcription-in peripheral blood PAD2 and PAD4 mRNAs are expressed predominantly in monocytes; PAD4 mRNA is not detectable in macrophages, translation-translation of PAD2 mRNA is subject to differentiation stage-specific regulation by its 3' UTR, and activation-the PAD proteins are only activated when sufficient Ca(2+) is available. Such high Ca(2+) concentrations are normally not present in living cells. In macrophages, which are abundant in the inflamed RA synovium, vimentin is specifically citrullinated after Ca(2+) influx.

CONCLUSION

PAD2 and PAD4 are the most likely candidate PAD isotypes for the citrullination of synovial proteins in RA. Our results indicate that citrullinated vimentin is a candidate autoantigen in RA.