Serum PCSK9 is positively correlated with disease activity and Th17 cells, while its short-term decline during treatment reflects desirable outcomes in ankylosing spondylitis patients

Longitudinal variation of serum PCSK9 in ulcerative colitis: association with disease activity, T helper 1/2/17 cells, and clinical response of tumor necrosis factor inhibitor

AIMS

Proprotein convertase subtilisin/kexin type 9 (PCSK9) modulates CD4+ T cell differentiation and inflammatory response, the latter ones mediate ulcerative colitis (UC) initiation. This study intended to explore the correlation of serum PCSK9 with disease activity, T helper (h)1/Th2/Th17 cells, and clinical response of tumor necrosis factor inhibitor (TNFi) in UC patients.

METHODS

In 65 UC patients underwent TNFi treatment, serum PCSK9 was evaluated at baseline (W0), week (W)2, W6, and W12 by enzyme-linked immunosorbent assays; meanwhile, Th1/Th2/Th17 cells were determined at W0 by flow cytometry. Besides, serum PCSK9 was detected in 65 healthy controls (HCs).

RESULTS

Serum PCSK9 was increased in UC patients compared to HCs (P<0.001), which also positively correlated with C-reactive protein (P=0.009), total Mayo score (P=0.018), Mayo-defined disease activity (P=0.020), Th1 (P=0.033), and Th17 (P=0.003) cells, but not Th2 cells (P=0.086) in UC patients. Interestingly, serum PCSK9 was steadily declined from W0 to W12 (P<0.001). W2-W0, W6-W0, and W12-W0 serum PCSK9 change (PCSK9 at W2, W6, or W12 minus PCSK9 at W0, respectively) was gradually becoming greater during TNFi treatment (P<0.001). Furthermore, forty-five (69.2%) patients achieved clinical response at W12, whose serum PCSK9 at W6 (P=0.041) and W12 (P=0.001) was lower, and W6-W0 (P=0.043), W12-W0 (P=0.019) serum PCSK9 change was more obvious compared to patients without clinical response at W12.

CONCLUSIONS

Serum PCSK9 is positively related to disease activity, Th1, and Th17 cells in UC patients; further, its decline correlates with TNFi response achievement in these patients.

Targeting proprotein convertase subtilisin/kexin type 9 (PCSK9): from bench to bedside

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has evolved as a pivotal enzyme in lipid metabolism and a revolutionary therapeutic target for hypercholesterolemia and its related cardiovascular diseases (CVD). This comprehensive review delineates the intricate roles and wide-ranging implications of PCSK9, extending beyond CVD to emphasize its significance in diverse physiological and pathological states, including liver diseases, infectious diseases, autoimmune disorders, and notably, cancer. Our exploration offers insights into the interaction between PCSK9 and low-density lipoprotein receptors (LDLRs), elucidating its substantial impact on cholesterol homeostasis and cardiovascular health. It also details the evolution of PCSK9-targeted therapies, translating foundational bench discoveries into bedside applications for optimized patient care. The advent and clinical approval of innovative PCSK9 inhibitory therapies (PCSK9-iTs), including three monoclonal antibodies (Evolocumab, Alirocumab, and Tafolecimab) and one small interfering RNA (siRNA, Inclisiran), have marked a significant breakthrough in cardiovascular medicine. These therapies have demonstrated unparalleled efficacy in mitigating hypercholesterolemia, reducing cardiovascular risks, and have showcased profound value in clinical applications, offering novel therapeutic avenues and a promising future in personalized medicine for cardiovascular disorders. Furthermore, emerging research, inclusive of our findings, unveils PCSK9's potential role as a pivotal indicator for cancer prognosis and its prospective application as a transformative target for cancer treatment. This review also highlights PCSK9's aberrant expression in various cancer forms, its association with cancer prognosis, and its crucial roles in carcinogenesis and cancer immunity. In conclusion, this synthesized review integrates existing knowledge and novel insights on PCSK9, providing a holistic perspective on its transformative impact in reshaping therapeutic paradigms across various disorders. It emphasizes the clinical value and effect of PCSK9-iT, underscoring its potential in advancing the landscape of biomedical research and its capabilities in heralding new eras in personalized medicine.