Dr Paras Karmacharya discusses the findings of the PsA Research Consortium (PARC) cohort study that underscores the need for personalized treatment approaches in psoriatic arthritis, accounting for unique disease features.

Paras Karmacharya, MD, is a rheumatologist at Vanderbilt University Medical Center in Nashville, Tennessee.

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Transcript

Hi everyone, I'm Paras Karmacharya.

I'm a physician scientist and assistant professor of medicine at Vanderbilt University Medical Center. Our research here that we are presenting is about identifying psoriatic arthritis phenotypes from our cohort called the PARC cohort.

This is a longitudinal multi-center cohort study that includes ve centers around the U.S. including Vanderbilt University, UPenn, Utah, NYU, and Cleveland Clinic. And so we identified, we recruited about 627 patients from this cohort, which also included about 2,900 visits of those patients. This was from 2017 to 2022.

Our objective was basically to identify clinical phenotypes of these patients. The reason being that we know that the different domains or the clinical features that patients with psoriatic arthritis have, but we don't know exactly how they cluster together or what subgroups of psoriatic arthritis actually exist clinically in a real-world setting. And so that was the objective of this study.

We used something called factor analysis initially because there was a lot of collinearity in the different clinical features that we chose. We chose clinical features based on clinical relevance. And these included both categorical as well as continuous variables. And first we performed factor analysis to reduce the collinearity and the dimensionality of this data. And following that, we performed something called hierarchical clustering to find different types of clusters, clinical clusters in psoriatic arthritis.

What we found was 3 different clusters, and these were consistent across different visits. Cluster one represented patients with mild psoriatic arthritis, so they had less in tenor joints, less swollen joint counts. And then the patient reported outcomes were also significantly better in cluster 1 compared to cluster 2 and cluster 3. Similarly, the CRP value was also lower in cluster one. As one would expect, the BMI was also lower in this, numerically lower in this cluster.

Beyond that, patients in cluster three actually had higher prevalence of patients with psoriasis. So we termed this as patients with severe psoriatic arthritis and severe psoriasis.

So we had 3 different clusters, mild psoriatic arthritis, the cluster two represented severe psoriatic arthritis, and cluster three represented severe psoriatic arthritis and severe psoriasis.

Now, these distinct clusters were stable throughout the different visits that we had in the cohort. And we also looked at a subset of patients where these were just patients starting or changing therapy and these were pretty stable in that subset of patients as well.

So in conclusion, this was a large multicenter study which showed distinct psoriatic arthritis phenotypes and highlighted the importance of these for personalized medicine in psoriatic arthritis and personalized approaches and towards these patients in these three different phenotypes. Thank you very much.

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