Idiopathic interstitial pneumonia (IIP) is characterized by varying degrees of interstitial fibrosis. IL-13 and IL-4 are strong inducers of tissue fibrosis, whereas IFN-gamma has antifibrotic potential. However, the roles of these substances in IIP remain unknown. IL-13, IL-4, and IFN-gamma were measured in the BAL fluid of 16 idiopathic pulmonary fibrosis (IPF) patients, 10 nonspecific interstitial pneumonia (NSIP) patients, and 8 normal controls. The expression of IL-13 and IL-13Ralpha1/alpha2 in lung tissues was analyzed using ELISA and immunohistochemistry. IL-13 levels were significantly higher in IPF patients than the others (P<0.05). IL-4 levels were higher in both IPF and NSIP patients than in normal controls (P<0.05), and IFN-gamma levels were lower in NSIP patients than in normal controls (P=0.047). IL-13 levels correlated inversely with FVC% (r=-0.47, P=0.043) and DLCO% (r=-0.58, P=0.014) in IPF and NSIP patients. IL-13 was strongly expressed in the smooth muscle, bronchial epithelium, alveolar macrophages and endothelium of IPF patients. IL-13Ralpha1, rather than IL-13Ralpha2, was strongly expressed in the smooth muscle, bronchial epithelium, and endothelium of IPF patients. IL-13 and its receptors may contribute to the pathogenesis of fibrosis in IIP and appear to be related to the severity of the disease.
Adult ; Female ; Humans ; Idiopathic Interstitial Pneumonias/diagnosis/*metabolism ; Idiopathic Pulmonary Fibrosis/diagnosis/*metabolism ; Interferon-gamma/analysis ; Interleukin-13/*analysis ; Interleukin-13 Receptor alpha1 Subunit/*metabolism ; Interleukin-13 Receptor alpha2 Subunit/*metabolism ; Interleukin-4/analysis ; Lung/physiopathology ; Male ; Middle Aged

OBJECTIVETo study the roles of serum and urinary interleukins (IL)-13Ralpha2, IL-4, IL-6, IL-8 and tumor necrosis factor-alpha(TNF-alpha) in pediatric Henoch-Schonlein purpura (HSP).

METHODSSerum and urinary levels of IL-13Ralpha2, IL-4, IL-6, IL-8 and TNF-alpha were examined using ELISA in 52 children with HSP and 45 healthy children. The results were compared between the two groups.

RESULTSSerum levels of IL-13Ralpha2, IL-4, IL-6, IL-8 and TNF-alpha in HSP patients with or without renal lesions were higher than those in the control group (p<0.01 or 0.05). Urinary levels of IL-6 and TNF-alpha in HSP patients without renal lesions were higher than those in the control group (p<0.05). Except for urinary levels of IL-6 and TNF-alpha, urinary IL-13Ralpha2 levels in HSP patients with renal lesions (HSPN) were higher than those in the control group (p<0.05).

CONCLUSIONSCytokines IL-13Ralpha2, IL-4, IL-6, IL-8 and TNF-alpha may play roles in the pathogenesis of pediatric HSP/HSPN.

Adolescent ; Child ; Child, Preschool ; Cytokines ; physiology ; Female ; Humans ; Interleukin-13 Receptor alpha2 Subunit ; blood ; physiology ; Interleukin-6 ; physiology ; Male ; Purpura, Schoenlein-Henoch ; etiology ; immunology ; Tumor Necrosis Factor-alpha ; physiology

BACKGROUNDType 2 cytokine interleukin (IL)-13 and its decoy receptor, IL-13 receptor (R) alpha2 appear to play a major role in tissue fibrosis of schistosomiasis and asthma. IL-13 is a key regulator of the extracellular matrix (ECM). It is known to signal to cells by binding to the IL-13Ralpha1, which then heterodimerizes with IL-4Ralpha. In contrast, IL-13Ralpha2 binds IL-13 with high affinity but does not signal. IL-13Ralpha2 is known to down-regulate granulomatous inflammation and prolong host survival in Schistosoma mansoni (S. mansoni) infection, but little is known about the location and expression level of IL-13Ralpha2 in the context of S. japonicum infection.

METHODSWe established S. japonicum-infected mouse models. Kinetic serum levels of IL-13Ralpha2 were examined with ELISA. IL-13Ralpha2 mRNA and protein of liver tissues were determined by PCR and immunoblotting analysis, respectively. Detection of IL-13Ralpha2 expression and location in macrophages was performed by TaqMan PCR and fluorescent immunocytochemistry technique, respectively.

RESULTSA marked elevation of mRNA and protein expression of IL-13Ralpha2 was observed in mice during S. japonicum infection. An enhanced expression of IL-13Ralpha2 was further demonstrated in primary macrophages of murine schistosomiasis.

CONCLUSIONSIL-13Ralpha2 in macrophages may be a critical contributor to pathogenesis of schistosomiasis. The data highlight the potential importance of cell signaling and antifibrotic gene therapeutics in T helper 2 cell (Th2)-mediated diseases.

Animals ; Blotting, Western ; Cells, Cultured ; Enzyme-Linked Immunosorbent Assay ; Female ; Interleukin-13 Receptor alpha2 Subunit ; metabolism ; Macrophages ; immunology ; Male ; Mice ; Mice, Inbred BALB C ; Random Allocation ; Reverse Transcriptase Polymerase Chain Reaction ; Schistosoma japonicum ; pathogenicity ; Schistosomiasis japonica ; immunology ; microbiology