Role of selectins on IgE-mediated skin reaction

The Diagnostic Value of Fe3+ and Inflammation Indicators in the Death of Sepsis Patients: A Retrospective Study of 428 Patients

Background

Studies have shown that a variety of blood inflammatory markers can be used to assess the criticality of patients with sepsis. In this study, the blood inflammatory factors related to the sepsis survival group and the death group were compared and analyzed, which can be used by clinicians to adjust sepsis patient treatment.

Methods

This study used retrospective methods to analyze the medical records of 428 patients with sepsis. The test of blood samples includes the patient's age, gender, hospital stays, the concentration of procalcitonin (PCT), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), neutrophil-to-lymphocyte ratio (NLR), D-dimer (DD), Fe³⁺, and hemoglobin (Hb) in the venous blood of patients with sepsis. The detection of PCT methods adopts the sandwich immunofluorescence (IF). ROC curve was used for the diagnosis and analysis of various factors of sepsis.

Results

Among all the patients with sepsis, 133 patients died, with a mortality rate of 31.07%. Analysis of related inflammatory indicators and the patient's baseline parameters showed the patients age, the values of PCT, ANC, NLR, and DD in death group were statistically higher than those in survival group (all p values were <0.05). However, the concentration of Fe³⁺ and ALC show an opposite trend between the two groups. Regression analysis results showed the patient's gender, Fe³⁺, PCT, ANC, and DD are all independent prognostic factors for patients with sepsis. The results of the ROC curve of related diagnostic indicators show that DD has the best area under curve (AUC=0.700), the most sensitive index is ANC (74.44), and the most specific index is PCT (89.80). The results of the two-by-two combined diagnosis of the four indicators showed that the PCT+DD group had better AUC (0.748) and specificity (78.23), and the Fe³⁺+DD group had the best sensitivity (75.89).

Conclusion

In this study, the patient's gender and the inflammation-related markers of Fe³⁺, PCT, ANC, and DD can be used as independent risk factors affecting the prognosis of patients with sepsis. The combination of PCT+DD and Fe³⁺+DD has high diagnostic value for patients with sepsis.

CD44, but not l-selectin, is critically involved in leucocyte migration into the skin in a murine model of allergic dermatitis

CD44 and l-selectin (CD62L) are major adhesion receptors that mediate leucocyte recruitment at inflammatory sites and lymph nodes, by supporting cell rolling under blood flow. Both CD44 and CD62L have been implicated in inflammatory skin disorders, but their specific involvement in an immediate-type allergic reaction remains uncertain. We used mice deficient in CD44 or CED62L or both in order to determine whether one or both of these molecules were required for leucocyte extravasation in an atopic dermatitis-like allergic response. Wild-type (WT) mice and mice deficient in CD44, CD62L or both were immunized with ovalbumin (OVA). Inflammatory reaction in the ear was elicited once by means of intradermal injection of OVA. Effective sensitization of CD62L knockout (KO) mice required intraperitoneal antigen injection; however, OVA-specific T helper 2 (Th2)-type immune responses and IgE production in mice lacking CD44, CD62L or both were comparable to those in WT mice following intraperitoneal immunization. We employed intravital videomicroscopy to monitor the recruitment of fluorescence-labelled leucocytes to the ear tissue following challenge with OVA. The number of adherent leucocytes was significantly reduced in CD44 KO and CD44/CD62L double KO mice, indicating that CD44 was involved in firm adhesion, the committed step of leucocyte extravasation. Histology of the OVA-challenged ears showed a diminished leucocyte infiltration in the ears of CD44 KO and double KO mice. The results of our study demonstrate that CD44, but not CD62L, is required for leucocyte extravasation during a Th2-type inflammatory response.

Therapeutic potential of a novel synthetic selectin blocker, OJ-R9188, in allergic dermatitis

1. We investigated the ability of a newly synthesized sugar derivative, OJ-R9188, [N-(2-tetradecylhexadecanoyl)-O-(L-alpha-fucofuranosyl)-D-seryl]-L-glutamic acid 1-methylamide 5-L-arginine salt, to block binding of selectins to their ligands in vitro and inhibit the infiltration of leukocytes in vivo. 2. OJ-R9188 prevented the binding of human E-, P- and L-selectin-IgG fusion proteins to immobilized sialyl Lewis(x) (sLe(x))-pentasaccharide glycolipid, with IC(50) values of 4.3, 1.3, and 1.2 microM, respectively. 3. In a mouse model of thioglycollate-induced peritonitis, OJ-R9188 at 10 mg kg(-1), i.v. inhibited neutrophil accumulation in the peritoneal cavity. In the IgE-mediated skin reaction, OJ-R9188 at 3 and 10 mg kg(-1), i.v. significantly inhibited extravasation of neutrophils and eosinophils into the inflammatory sites and at 10 mg kg(-1), i.v. also inhibited infiltration caused by picryl chloride-induced delayed-type hypersensitivity in mice. These results suggest that OJ-R9188 may be a useful selectin blocker, with activity against human and mouse E-, P- and L-selectins in vitro and in vivo, and that blocking selectin-sLe(x) binding is a promising strategy for the treatment of allergic skin diseases.