Background: Chinese medicine (CM) classifies psoriasis vulgaris into three syndromes: blood-heat syndrome (BHS), blood-stasis syndrome (BSS), and blood-dryness syndrome (BDS). The levels of several immunological serum markers in BHS have been established. We aimed to investigate the immune status of patients with psoriasis vulgaris of BSS and BDS.
Methods: Seven databases were searched, covering nearly 40 years. Fifteen studies including 957 individuals (386 patients with psoriasis vulgaris of BSS, 233 patients with BDS, and 338 healthy controls) were identified. Differences in interleukin (IL) levels between subjects and controls were pooled as mean differences (MDs) with 95% confidence intervals (CI) using a random-effects model.
Results: For BSS, interferon (IFN)-γ (MD 3.85, 95% CI: 1.27 to 6.44), tumor necrosis factor (TNF)-α (MD 1.71, 95% CI: 0.70 to 2.72), IL-4 (MD 7.66, 95% CI: 4.67 to 10.65), IL-17 (MD 5.06, 95% CI: 0.28 to 9.85), IL-6 (MD 99.34, 95% CI: 45.84 to 152.84), and IL-22 (43.88, 95% CI: 28.17 to 59.59) levels were significantly higher in patients than in controls, while pooled IL-10 levels were lower in patients (MD -10.33, 95% CI: -12.03 to -8.63). The MD in IL-8 levels between cases and controls was not significant. Subjects with BDS showed higher levels of IFN-γ (MD 2.33, 95% CI: 0.22 to 4.45), TNF-α (MD 2.33, 95% CI: 1.26 to 3.40), and IL-23 (MD 46.18, 95% CI: -7.60 to 99.97) and lower levels of IL-4 levels (MD -2.47, 95% CI: -4.78 to -0.15) than did controls. The MDs in IL-17, IL-6, and IL-8 levels were not statistically significant.
Conclusions: Our pooled analysis suggests that the levels of several ILs are specifically altered in BSS and BDS. Larger, well designed, controlled studies are needed to confirm these results and fully clarify these effects.
Keywords: Chinese medicine (CM); Psoriasis vulgaris; blood-dryness syndrome (BDS); blood-stasis syndrome (BSS); immune status.