Objective To investigate the relationship between serum platelet-activating factor (PAF) level, T cell immune function and disease activity in vitiligo patients. Methods A total of 102 patients with vitiligo treated in our hospital from July 18th, 2022 to July 26th, 2023 were enrolled as study subjects. According to VIDA score, the patients were divided into an advanced-stage group (n=54) and a stable stage group (n=49). PAF and T lymphocyte levels were compared between the two groups. Logistic regression analysis was performed to examine the relationship between PAF levels and disease activity, as well as their correlation with T cell subsets. Unconditional logistic regression modeling was employed to analyze the interaction between PAF levels and T cell subsets in disease activity. Results No significant difference was observed in CD3⁺ levels between advanced and stable stage vitiligo patients. PAF and CD8⁺ levels in advanced group were significantly higher than those in stable group, while CD4⁺ levles and CD4⁺/CD8⁺ ratios were significantly lower than those in stable group. When PAF level was 18.24 ng/L, the maximum Youden index reached 0.670, with corresponding sensitivity of 84.22% and specificity of 82.77%. The area under ROC curve AUC was 0.858. The intensity of association between PAF level and disease activity was nonlinear dose-response relationship. Among patients with VIDA score ≥1, significant differences were observed in both CD4⁺ and CD8⁺ levels across different PAF levels, and the CD4⁺/CD8⁺ ratios in vitiligo patients with different VIDA scores was significantly different. Interaction analysis revealed that after adjusting for confounding factors, the effect of PAF levels and T cell subsets on disease activity in vitiligo patients showed significant interaction in both additive model (RERI=4.674, 95%CI: 1.032~11.942; AP=0.763, 95%CI: 0.336~1.201; S=6.854, 95%CI: 1.904~16.520) and multiplicative model (OR=3.461, 95%CI: 1.365~8.713). Conclusion Serum PAF, CD4⁺, CD8⁺ and CD4⁺/CD8⁺ of vitiligo patients are closely related to disease activity, and PAF level interacts with T cell subsets (CD4⁺, CD8⁺, CD4⁺/CD8⁺) in the disease activity of vitiligo patients. PAF and T cell immune function may contribute to the occurrence and development of vitiligo, which could serve as clinical indicators of disease activity to guide timely management.
Humans ; Vitiligo/blood* ; Platelet Activating Factor/immunology* ; Male ; Female ; Adult ; Middle Aged ; Young Adult ; T-Lymphocytes/immunology* ; Adolescent ; T-Lymphocyte Subsets/immunology*

Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugular venipuncture, while ruminal samples were collected using rumenocentesis. Lactic acid from plasma and ruminal samples was measured by HPLC. PAF-induced ROS production and L-selectin shedding were measured in vitro in bovine neutrophils by a luminol chemiluminescence assay and flow cytometry, respectively. A significant increase in ruminal and plasma lactic acid was recorded in these animals. Specifically, a decrease in PAF-induced ROS production was observed 8 h after oligofructose overload, and this was sustained until 48 h post oligofructose overload. A reduction in PAF-induced L-selectin shedding was observed at 16 h and 32 h post oligofructose overload. Overall, the results indicated that neutrophil PAF responses were altered in heifers with ruminal acidosis, suggesting a potential dysfunction of the innate immune response.
Acidosis/chemically induced/immunology/*veterinary ; Animals ; Blood ; Cattle ; Cattle Diseases/chemically induced/*immunology ; Female ; Flow Cytometry/veterinary ; *Immunity, Innate ; L-Selectin/metabolism ; Neutrophils/*drug effects ; Oligosaccharides/*pharmacology/toxicity ; Platelet Activating Factor/*pharmacology ; Reactive Oxygen Species/metabolism ; Rumen

OBJECTIVEGastrointestinal dysfunction is closely correlated with the destruction of intestinal barrier function induced by serious infection. Platelet activating factor (PAF) may induce intestinal injuries. This study aimed to investigate the effect of PAF on the injury of intestinal mucosal immuno-barrier function in young rats.

METHODSEighteen-day-old Wistar rats were randomized to lipopolysaccharide (LPS) (5 mg/kg), LPS plus PAF receptor antagonist and normal saline injection (Control). PAF receptor antagonist BN52021 5 mg/kg was administered before or 30 minutes after LPS injection (pretreatment or treatment). The ileum specimens (n=8) were harvested at 1.5, 3, 6, 24, 48 and 72 hrs after LPS injection. Double antibody-PEG radioimmunoassay was used to determine the secretory IgA (sIgA) content in intestinal mucosa. Hematoxylin and erosin staining was used for histological evaluation. The ratio of wet and dry weight (W/D) of ileum tissues was calculated.

RESULTSIntestinal villi edema, capillary congestion, extension of the subepithelial lympho channel, and polymorphonuclear infiltration in enteric cavity were noted in the LPS group at 1.5, 3, 6 and 24 hrs after LPS injection. In the PAF receptor antagonist group only villi edema was found. The W/D ratio in the LPS group was significantly higher than that in the Control group at all time points, but it was slightly reduced by the PAF receptor antagonist pretreatment or treatment. The sIgA content was obviously decreased after 1.5, 3, 6, 24 and 48 hrs of LPS challenge compared with that in the Control group (P < 0.01). It reached to a nadir at 6 hrs (0.15 +/- 0.04 microg/mL). The level of sIgA in the PAF receptor antagonist group was higher than that in the LPS group at each time point. There was no statistical difference in the sIgA level between the PAF receptor pretreatment and treatment groups.

CONCLUSIONSPAF plays roles in the injury of intestinal immuno-barrier function. Preventive and remedial use of PAF receptor antagonist BN52021 may relieve intestinal injury.

Animals ; Diterpenes ; pharmacology ; Ginkgolides ; Immunoglobulin A, Secretory ; analysis ; Intestines ; immunology ; pathology ; Lactones ; pharmacology ; Lipopolysaccharides ; toxicity ; Platelet Activating Factor ; physiology ; Rats ; Rats, Wistar