From the Guidelines
Blood markers for plaque psoriasis include C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), tumor necrosis factor-alpha (TNF-α), interleukin-17 (IL-17), interleukin-23 (IL-23), and interleukin-6 (IL-6), which are essential for diagnosing and monitoring disease activity. According to the most recent guidelines, psoriasis is a chronic inflammatory skin disease characterized by well-demarcated, red plaques with silvery scale, commonly involving the scalp, elbows, knees, and presacral region 1. The severity of psoriasis is defined in part by the total body surface area (BSA) involved, with less than 3% BSA considered mild, 3% to 10% BSA considered moderate, and greater than 10% considered severe disease.
Some key points to consider when evaluating blood markers for plaque psoriasis include:
- The Psoriasis Area Severity Index (PASI) is a more specific means of quantifying the extent and severity of psoriasis, taking into account not only BSA but also the intensity of redness, scaling, and plaque thickness 1.
- Psoriasis is an inflammatory, immune-mediated condition involving cutaneous T-cells, dendritic cells, and keratinocytes with subsequent release of a variety of cytokines and other soluble mediators 1.
- Blood markers such as CRP and ESR are elevated during active inflammation, while specific markers like TNF-α, IL-17, IL-23, and IL-6 play key roles in the pathogenesis of psoriasis.
- Complete blood count may reveal thrombocytosis (elevated platelets) and leukocytosis (increased white blood cells) in severe cases.
- Regular monitoring of these markers can help guide treatment decisions and assess disease progression over time.
It's essential to note that no single blood test can definitively diagnose psoriasis, and these markers should be interpreted alongside clinical presentation and skin findings 1. The most recent guidelines recommend using a combination of clinical evaluation and blood markers to diagnose and monitor plaque psoriasis, with a focus on assessing systemic inflammation and response to biologic therapies targeting specific inflammatory pathways 1.
From the Research
Blood Markers for Plaque Psoriasis
- Inflammatory markers such as high-sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), and fibrinogen can be used to assess disease severity and response to treatment in patients with plaque psoriasis 2.
- A study found that hs-CRP and ESR levels decreased after treatment with adalimumab, and the decrease in hs-CRP and ESR levels was associated with a higher likelihood of achieving a 75% reduction in Psoriasis Area and Severity Index (PASI) score 3.
- Another study found that biologics such as etanercept, adalimumab, and ustekinumab can reduce inflammatory markers such as CRP and ESR, and improve disease severity in patients with moderate-to-severe plaque psoriasis 4, 5.
- A network meta-analysis found that biologics such as infliximab, bimekizumab, ixekizumab, and risankizumab were the most effective treatments for achieving a 90% reduction in PASI score, and that these treatments were associated with a higher proportion of patients reaching PASI 90 compared to non-biological systemic agents and other biologics 6.
Inflammatory Markers
- hs-CRP is a sensitive marker of inflammation and can be used to monitor disease activity and response to treatment in patients with plaque psoriasis 2, 3.
- ESR is another inflammatory marker that can be used to assess disease severity and response to treatment in patients with plaque psoriasis 2, 3.
- Fibrinogen is an acute-phase protein that can be used as a marker of inflammation in patients with plaque psoriasis 2.
Treatment Response
- A reduction in hs-CRP and ESR levels is associated with a higher likelihood of achieving a 75% reduction in PASI score, indicating a good response to treatment 3.
- Biologics such as etanercept, adalimumab, and ustekinumab can reduce inflammatory markers and improve disease severity in patients with moderate-to-severe plaque psoriasis 4, 5.
- A network meta-analysis found that biologics such as infliximab, bimekizumab, ixekizumab, and risankizumab were the most effective treatments for achieving a 90% reduction in PASI score 6.