Priority 3 from the Psoriatic Arthritis PSP

UNCERTAINTY: Can tests be developed to predict whether a person has or will develop psoriatic arthritis?  (JLA PSP Priority 3)
Overall ranking 3
JLA question ID 0108/3
Explanatory note Diagnosing psoriatic arthritis, especially early, can be difficult due to the wide variety of potential symptoms when people present to healthcare professionals. This question aims to develop evidence for improving diagnosis, for example, by creating a specific test for psoriatic arthritis, particularly for early diagnosis. This would allow healthcare professionals who are not rheumatology specialists to  confirm the diagnosis of psoriatic arthritis or predict whether someone will develop psoriatic arthritis in the future. This would reduce the time to diagnosis and enable early treatment if necessary. Examples would include a blood test, identifying biomarkers, creating new diagnostic algorithms, or even an early warning kit available for undiagnosed psoriatic arthritis. 
Evidence

This question has been partially addressed in the evidence base from the following systematic reviews and guideline:

Wang, 2019. Evidence that serum lipocalin-2 concentrations are higher in psoriasis/PsA patients than controls. However, more large-scale studies are warranted to explore the association between serum lipocalin-2 and the pathogenetic mechanisms of psoriasis/PsA https://pubmed.ncbi.nlm.nih.gov/31467617/
Iragorro, 2019. Evidence that questionnaire-based tools have moderate accuracy to identify PsA among psoriasis patients. Further research needed https://pubmed.ncbi.nlm.nih.gov/30380111/
Landini Enriquez, 2020. This systematic review demonstrates despite the existence of eleven validated PsA screening PROMs, none were supported by very high-quality evidence of their content validity, which brings the opportunity for the creation of a new proposal PROM for the screening of PsA. Future research needed https://pubmed.ncbi.nlm.nih.gov/32153017/
Elmamoun, 2019. Limited Data on assessment of systemic inflammation using acute-phase reactants (CRP and ESR) Weak evidence to support normalisation of these biomarkers in predicting good clinical outcomes/remission criteria. The predictive value for cardiovascular outcomes was generally good. Further studies are needed https://pubmed.ncbi.nlm.nih.gov/30385708/
Mahil, 2019. Limited evidence indicates that weight loss can improve pre-existing psoriasis and PsA, and prevent the onset of psoriasis in obese individuals. Together with the National Institute for Health and Care Excellence obesity guidance, this informed a local obesity screening and management pathway, providing multidisciplinary weight loss interventions https://pubmed.ncbi.nlm.nih.gov/30729517/
NICE, 2018. Adults with suspected axial or peripheral spondyloarthritis are referred to a rheumatologist https://www.nice.org.uk/guidance/qs170
Health Research Classification System category Inflammatory and immune system
Extra information provided by this PSP
Original uncertainty examples What progress is being made on developing a definitive test for psoriatic arthritis diagnosis?  
Submitted by 108 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