A recent study has identified several potential biomarkers that could predict treatment response in patients with psoriatic arthritis (PsA). The research, led by Rachel Offenheim from the Psoriatic Arthritis Research Program, analyzed data from a biobank of PsA patients treated with TNF inhibitors (TNFi), Interleukin-17 inhibitors (IL-17i), and methotrexate (MTX), comparing them with untreated PsA patients and psoriasis patients. The findings suggest that serum levels of CXCL10, MMP3, S100A8, ACP5, and CCL2 are affected by these treatments and may serve as predictive markers. These findings could help clinicians tailor treatments more effectively, improving patient outcomes in PsA management.
Biomarkers and Treatment Response
The study involved analyzing serum samples from PsA patients at baseline and after 3-6 months of treatment. Protein levels were quantified using a Luminex multiplex assay, and logistic regression models were developed to assess the predictive potential of the biomarkers. Treatment response was defined as achieving low disease activity or remission according to Disease Activity in PSoriatic Arthritis (DAPSA) scores, a 75% reduction in Psoriasis Area and Severity Index (PASI) scores, and a 50% reduction in actively inflamed joint count.
The researchers found that TNFi treatment reduced serum levels of CXCL10 (P <.001), MMP3 (P <.001), S100A8 (P <.001), ACP5 (P <.001), and CCL2 (P <.05) in PsA patients. Conversely, IL-17i increased ACP5 (P <.01) and CCL2 (P <.05), while MTX reduced MMP3 (P <.05). Significant differences in MMP3 (P <.01) and S100A8 (P <.05) levels were observed between untreated PsA patients and those treated with biologics. No significant differences were found in patients with psoriatic conditions (PsC).
Predictive Potential of Biomarkers
High baseline levels of ACP5 (area under the curve [AUC] = 0.80) in patients treated with biologics and low baseline levels of MMP3 (AUC = 0.80) in untreated patients were predictive of DAPSA response. Additionally, high baseline levels of CXCL10 (AUC = 0.87) and S100A8 (AUC = 0.88) in patients treated with biologics, along with high baseline levels of MMP3 (AUC = 0.93) and ACP5 (AUC = 0.93) and low baseline levels of S100A8 (AUC = 0.86) in untreated patients, were predictive of a PASI response. High baseline levels of MMP3 (AUC = 0.82) and S100A8 (AUC = 0.84), and low baseline levels of ACP5 (AUC = 0.90) were predictive of a response in actively inflamed joint count in patients treated with biologics.
Clinical Implications
According to Offenheim and colleagues, these results highlight the potential of MMP3, S100A8, ACP5, and CXCL10 as serum biomarkers to predict treatment response in PsA patients. The ability to predict treatment response could significantly improve patient management by allowing for more personalized and effective treatment strategies. Further research is needed to validate these findings and explore their clinical utility in diverse patient populations.
