Priority 2 from the Psoriatic Arthritis PSP

UNCERTAINTY: What factors affect how psoriatic arthritis will progress, the likely severity of the disease in an individual and whether it will go into remission?  (JLA PSP Priority 2)
Overall ranking 2
JLA question ID 0108/2
Explanatory note This question aims to generate evidence to fill the evidence gaps in relation to which factors predict the likely progression of psoriatic arthritis for an individual. For example, smoking, obesity or genetic variables. Whether for some people psoriatic arthritis go into remission without any treatment and if specific factors make psoriatic arthritis more difficult to treat for some people. 
Evidence

This question has been partially addressed in the evidence base from the following systematic reviews and guideline:
Singh, 2018. Obesity is an under-reported predictor of inferior response to anti-TNF agents in patients with select immune-mediated inflammatory diseases. A thorough evaluation of obesity as an effect modifier in clinical trials is warranted, and intentional weight loss may serve as adjunctive treatment in patients with obesity failing anti-TNF therapy https://pubmed.ncbi.nlm.nih.gov/30499259/
Shan, 2019. A systematic review on inflammatory diseases, not just PsA. Obesity hampered the effect of anti-TNF agents, but not those of abatacept and tocilizumab, suggesting that a personalized treatment strategy should be considered for obese patients with inflammatory diseases https://pubmed.ncbi.nlm.nih.gov/29635017/
Gupta, 2021. A systematic review with eleven studies consistently showed higher prevalence of comorbidities in PsA than controls. Five studies showed that comorbid patients had more severe disease, poorer quality of life, and increased discontinuation of treatment. Comorbidities, particularly cardiometabolic disorders, were highly prevalent in PsA and more common than in healthy controls. Comorbidities were associated with adverse disease features. More research is needed https://pubmed.ncbi.nlm.nih.gov/33423070/
Gratacos, 2019. To update the study of the association between obesity and treatment response in psoriatic arthritis. Concludes, there seems to be a greater risk of withdrawal of treatment due to inefficacy and difficulty in achieving remission in patients with psoriatic arthritis if they are obese https://pubmed.ncbi.nlm.nih.gov/31708450/
Health Research Classification System category Inflammatory and immune system
Extra information provided by this PSP
Original uncertainty examples What is the likely progression of psoriatic arthritis? 
Submitted by 39 uncertainties submitted 
PSP information
PSP unique ID 0108
PSP name Psoriatic Arthritis
Total number of uncertainties identified by this PSP. 46  (To see a full list of all uncertainties identified, please see the detailed spreadsheet held on the JLA website)
Date of priority setting workshop 12 July 2021