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.

Reflection and transmission of coupled elastic waves by a semiconduction interlayer with consideration of photothermal effects.

The wave propagation problem through an inhomogeneous semiconduction slab sandwiched between two thermoelastic half-spaces is studied in this paper. Due to the photothermal effects and photoacoustic effects, the multiple physical fields coupled waves are generated in the semiconduction interlayer. For the inhomogenous semiconduction slab of finite thickness, the multiple physical fields coupled waves cannot be expressed explicitly. Instead, the state vector is defined, and the state transfer equation is derived to obtain the transfer matrix of the inhomogeneous slab. The reflection and transmission coefficients as well as the dissipation energy are estimated. The influences of the photothermal effects and photoacoustic effects are discussed based on the numerical results. It is found that the photothermal effects and photoacoustic effects result in some different vibration modes and associated propagation modes. The gradient profiles of the inhomogeneous interlayer have complicated influences on the reflection and transmission behaviors and can be well-designed to adjust the propagation behavior.