Identification of serum interleukin-13 and interleukin-13 receptor subunit expressions: Rheumatoid arthritis-associated interstitial lung disease.

AIM OF THE WORK: To identify the role of serum IL-13, and its receptor subunit expressions as a serologic marker of rheumatoid arthritis (RA)-associated ILD (RA-ILD). PATIENTS AND METHODS: Fifty RA patients with ILD and 50 RA patients without ILD were examined, in addition to 50 controls. Disease Activity Score in 28 joints (DAS-28), the Health Assessment Questionnaire (HAQ), and medication history were evaluated. ESR, CRP, RF, Anti-CCP, Serum Krebs von den Lungen-6 (KL-6), surfactant protein D (SP-D) levels, Interleukin 13 and its receptors (IL-13 Rα1 and L-13 Rα2), and mRNA relative expression levels in peripheral blood mononuclear cells (PBMCs) were measured. High-resolution computed tomography (HRCT) scores were used with all RA patients with interstitial lung disease. RESULTS: Mean age, percent of male affection, duration of the disease, DAS28 and MHAQ were significantly higher in the RA-ILD group than in the RA-no ILD group. ESR, CRP, RF, anti-CCP, serum KL-6, SP-D, IL-13 levels, IL-13 Rα1and IL-13 Rα2 mRNA expressions were significantly increased in RA patients compared to controls; in addition, their levels were significantly higher in the RA-ILD group than in the RA-no ILD group. Serum IL-13 levels and IL-13 Rα1and IL-13 Rα2 were positively correlated with RF, Anti-CCP, KL-6, SP-D, and the HRCT score (P < .001). CONCLUSIONS: Serum IL-13 and its receptor subunit expressions are useful biomarkers which can be used in detecting severity of the interstitial lung disease in RA patients.

Group 2 Innate Lymphoid Cells Participate in Renal Fibrosis in Diabetic Kidney Disease Partly via TGF-ß1 Signal Pathway.

AIM: To explore the role of group 2 innate lymphoid cells (ILC2s) in the pathogenesis of renal fibrosis in diabetic kidney disease (DKD). METHODS: The proportion of ILC2s and the levels of Th2 cytokines (IL-4, IL-5, and IL-13) in the peripheral blood of normal control subjects (NC) or patients with type 2 diabetes mellitus (DM), early diabetic kidney disease (DKD1), or late diabetic kidney disease (DKD2) were analyzed by flow cytometry and ELISA. The expression of transforming growth factor-ß1 (TGF-ß1), fibronectin (FN), collagen1, IL-4Rα, and IL-13Rα1 in renal tubular epithelial cells (HK-2) induced by IL-4, IL-13, or high glucose was analyzed by ELISA or qPCR. RESULTS: The proportion of ILC2s and the levels of IL-4, IL-5, and IL-13 were significantly increased in DKD patients and were positively correlated with the severity of DKD (P < 0.05). The expression of TGF-ß1, FN, and collagen1 was significantly upregulated in HK-2 cells induced by IL-4 or IL-13 (P < 0.05). Moreover, the IL-4Rα and IL-13Rα1 mRNA in HK2 cells were increased followed by high glucose alone or combined with IL-4 or IL-13, but the differences were not statistically significant (P > 0.05). However, compared with high-glucose stimulation alone, the expression of TGF-ß1, FN, and collagen1 was significantly increased in HK-2 cells induced by high glucose combined with IL-4 or IL-13 (P < 0.05). CONCLUSIONS: ILC2s may participate in renal fibrosis in DKD partly via TGF-ß1 signal pathway.