Thymopentin ameliorates experimental colitis via inhibiting neutrophil extracellular traps.

BACKGROUND: The long-term prognosis of Crohn's disease (CD) remains unsatisfactory. Therefore, we assessed the therapeutic effect of thymopentin (TP5) in a mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis, which mimics CD, and analyzed its impact on neutrophil extracellular traps (NETs). METHODS: NET markers, including myeloperoxidase (MPO), neutrophil elastase (NE), citrullinated histone H3 (CitH3), peptidyl arginine deiminase IV (PAD4), and double-stranded DNA (dsDNA) were assessed by immunostaining and enzyme-linked immunosorbent assay. NET formation was evaluated in vitro. Neoseptin 3, a specific NET agonist, was used to reverse the effect of TP5 on TNBS-induced colitis. The action mechanism of TP5 was investigated using RNA-seq. RESULTS: TP5 ameliorated weight loss (P < 0.001), disease activity index (DAI) (P = 0.05), colon shrinkage (P = 0.04), and elevated levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, IL-6, and neutrophils in the TNBS group. The TNBS group exhibited increased MPO, NE, CitH3, PAD4, dsDNA and MPO-DNA levels (all P < 0.001), which decreased after TP5 administration (P = 0.01, P < 0.001, P < 0.001, P < 0.001, P = 0.02, and P = 0.02 respectively). Tissue CitH3 levels were positively correlated with DAI and TNF-α levels (P < 0.05). Furthermore, phorbol 12-myristate 13-acetate-stimulated NET formation increased by 1.8-, 2.8-, and 2.3-fold in vitro in the control, TNBS + saline, and TNBS + TP5 groups, respectively. Neoseptin 3 significantly reversed the effect of TP5. RNA-seq revealed potential pathways underlying the effect of TP5. CONCLUSION: TP5 effectively ameliorated colitis by suppressing NETs in the experimental CD model.

Association of Neutrophil Extracellular Traps with Fistula Healing in Patients with Complex Perianal Fistulizing Crohn's Disease.

BACKGROUND AND AIMS: Perianal fistulizing Crohn's disease [pfCD] is a disabling phenotype of Crohn's disease [CD] with suboptimal outcomes. We assessed neutrophil extracellular traps [NETs] in perianal fistulas and implicated their roles in pfCD healing. METHODS: Patients with complex pfCD who developed preplaced seton drainage were recruited during the verified maintenance of remission in CD. Fistula tracts were sampled during definitive surgery plus seton removal. Patient demographics, CD classification, medication strategy and healing of pfCD were recorded. RNA sequencing was applied for transcriptomic profile analysis. NET components, including myeloperoxidase [MPO], neutrophil elastase [NE] and citrullinated histone H3 [CitH3], were identified using immunofluorescence. Serum infliximab [IFX], anti-IFX antibodies, and tissue levels of IFX, adalimumab [ADA], MPO and CitH3 were determined using enzyme-linked immunosorbent assays. Peptidyl arginine deiminase IV [PAD4], tumour necrosis factor [TNF]-α, and NE were detected using immunohistochemistry. Gene expression levels of PAD family members were assessed with quantitative PCR. RESULTS: Twenty-one patients were included, 15 of whom adopted IFX as maintenance treatment. RNA-sequencing revealed differences in neutrophil associated pathways between unhealed and healed fistulas. NET components [MPO/NE/CitH3] were detectable in the fistulas and were parallel with the levels of PAD4. Eleven of 21 [52%] patients experienced complete healing of the pfCD 108 weeks post-operatively. Fistula NETs were significantly increased in patients with unhealed pfCD. Increased NETs were associated with abundant TNF-α production and the absence of IFX in fistulas. CONCLUSIONS: NETs exist in pfCD fistulas, which are associated with unhealed post-operative fistulas in pfCD, suggesting their prognostic roles in pfCD.

[Diagnostic Value of G and GM Tests in Acute Leukemia Patients with Invasive Fungal Disease].

OBJECTIVE: To analyze the diagnostic value of (1, 3) -ß-D-glucan and galactomannan (GM) tests in the patients with acute leukemia complicated by invasive fungal disease, and explore the application of serological detection (G/GM) and lung CT for early diagnosis of invasive fungal disease (IFD). METHODS: A total of 493 patients with acute leukemia complicated by high risk invasive fungal infection, also receival G and GM tests, in Department of hematology of our hospital from June 2016 to December 2016 were selected and were divided into IFD-confirmed group (62 cases) including confirmed and clinical diagnesed IFD, and IFD-unconfirmed group (431 cases) including suspected IFD and non-IFD according to the diagnostic criteria of IFD. The results of G and GM tests in patients of 2 groups were analyzed, then the diagnostic efficacy of G and GM done and combination evaluated. In addition, 26 patients whose lung CT negative at hospitalization, moreover, presentation of changes in lung by CT during hospitalization and serological G and GM test positive were selected, and the difference of time between serological that postive and presentation of changes in lung by CT were compared for the estimation of early diagnotic value. RESULTS: The positive rate of (1, 3) -ß-D-glucan in IFD-confirmed group and IFD-unconfirmed group was 56.5% and 10.4%, respectively. Meanwhile, that of galactomannan test was 41.9% and 9.0%, respectively. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of (1, 3) -ß-D-glucan was 56%, 90%, 44% and 92%, and that of galactomannan was 42%、91%、40% and 93%, respectively. Moreover, the combination of (1, 3) -ß-D-glucan and galactomannan could raise the sensitivity to 69% and specificity to 98%. The positive results of serological detection (G/GM) come earlier about five days than CT changes. CONCLUSION: Both (1, 3) -ß-D-glucan and galactomannan test have high sensitivity and specificity, and the combination of them can improve the diagnostic efficacy, and make the clinical antifungal therapy more precisely. In the early clinical diagnosis of IFD, the positive results of serological detection coming earlier than lung CT.