ANTI-INFLAMMATORY EFFECT OF BIOLOGIC THERAPY IN PATIENTS WITH PSORIATIC DISEASE COMPARED WITH TREATMENT WITH NON-BIOLOGIC DMARDS: A PROSPECTIVE COHORT FDG-PET STUDY

Psoriatic arthritis (PsA) and cutaneous psoriasis (PsO) are linked with an increased risk of adverse cardiovascular events. We hypothesized that central vascular inflammation on F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) in the ascending aorta would improve in these patients following therapy with biologic agents compared to PsO patients receiving non-biologic therapy and non-inflammatory control patients. We also postulated that in patients responding to biologics, there would an improvement in coronary microvascular dysfunction as measured by myocardial blood flow reserve (MFR) determined by rubidium-82 (82Rb) PET.

We studied 3 patient cohorts (patients with PsA and/or PsO started on biologic agents, patients with PsO managed on non-biologic therapy, and control patients with non-inflammatory arthritis). The primary outcome of our study was the change in vascular inflammation, estimated as the target-to-background ratio (TBR) by FDG PET in the most diseased segment of the ascending aorta at baseline compared to 6-month follow-up (TBRmax). We also performed 82Rb PET studies at baseline and 6-month follow-up to determine any changes on left ventricular MFR. A total of 34 participants were enrolled in the study (11 PsA and/or PsO patients on biologic agents, 13 patients in PsO group managed on non-biologic therapy, and 10 in the non-inflammatory control group). The majority (64.7%) of participants were men and the median age was 62 years (IQR: 48, 69). A significant drop in the thoracic aorta uptake was observed in the biologic-treated group (thoracic aorta change in TBRmax: -0.46±0.55) when compared to the change in the thoracic aorta FDG uptake of the PsO group treated with non-biologic therapy (thoracic aorta change in TBRmax: 0.23±0.67). Furthermore, the group with imaging evidence of a response to biologic agents (i.e. TBRmax drop > median value of 7%) maintained MFR (3.40±1.23 MFR to 3.5±1.2 MFR over 6 months) when compared to the group with a below median response on TBRmax which had a drop in MFR (2.9±0.8 MFR to 2.2±0.6 over 6 months) (P=0.03).

In a cohort of psoriasis patients treated with biologics, the FDG uptake in the thoracic aorta decreased over the study period compared to psoriasis patients treated with non-systemic therapies as well as controls. Additionally, psoriasis patients treated with biologics who demonstrated a significant anti-inflammatory response on FDG PET imaging, maintained their MFR compared to non-responders. This study supports the notion that there is a positive impact of immune therapies on vascular inflammation and microvascular disease in patients with chronic inflammation.