leukotriene-e4 and Scleroderma--Systemic

The leukotrienes are a family of arachidonic acid-derived lipid mediators with proinflammatory and profibrotic properties. The aim of this study was to analyze the role of leukotriene B(4) (LTB(4)) and LTE(4) in the pathogenesis of scleroderma lung disease (SLD).. Nineteen systemic sclerosis (SSc) patients with SLD, 11 SSc patients without SLD, and 10 healthy controls were studied. Bronchoalveolar lavage (BAL) fluid was obtained during routine bronchoscopy of the right middle lobe in all study subjects. Levels of LTB(4) and LTE(4) were measured using enzyme immunoassay kits.. Levels of LTB(4) and LTE(4) were significantly higher in SSc patients with SLD (251 +/- 170 pg/ml and 479 +/- 301 pg/ml, respectively), than those in patients without SLD (114 +/- 86 and 159 +/- 149 pg/ml) and those in normal controls (86 +/- 49 and 110 +/- 67 pg/ml). In the total group of patients with SSc, levels of both leukotrienes correlated positively with the total number of cells in the BAL fluid and correlated negatively with the forced vital capacity. After intravenous pulse therapy with cyclophosphamide in 6 patients, there was a significant reduction in the concentration of LTB(4) (from 380 +/- 196 pg/ml to 155 +/- 123 pg/ml) but no significant difference in the levels of LTE(4) (from 697 +/- 325 pg/ml to 418 +/- 140 pg/ml).. Our findings show that LTB(4) and LTE(4) levels are elevated in SSc patients with SLD and correlate with parameters of inflammation in the lungs. These results indicate that leukotrienes may contribute to the pathogenesis of SLD and may represent a new therapeutic target.

Topics: Adult; Bronchoalveolar Lavage Fluid; Cyclophosphamide; Female; Humans; Immunosuppressive Agents; Injections, Intravenous; Leukotriene B4; Leukotriene E4; Male; Middle Aged; Pulmonary Fibrosis; Pulse Therapy, Drug; Scleroderma, Systemic; Treatment Outcome

Leukotrienes are a family of arachidonic acid derivatives with potent proinflammatory and profibrotic properties, and 5-lipoxygenase (5-LOX) catalyzes two key steps in the leukotriene biosynthetic pathway. Since inflammatory cell infiltrates and excessive fibrosis are hallmarks of systemic sclerosis (SSc) skin lesions, we undertook the present study to investigate the expression of 5-LOX in skin biopsy specimens from patients with SSc.. Expression of 5-LOX in skin sections from 10 SSc patients and 8 healthy controls was examined by in situ hybridization with specific riboprobes and by immunohistochemistry analysis with 5-LOX monoclonal antibodies. Synthesis of 5-LOX by cultured dermal fibroblasts from 7 patients with SSc and 4 controls was measured by fluorescence-activated cell sorter analysis. In addition, concentrations of leukotriene B4 (LTB4) and LTE4 in fibroblast supernatants after stimulation were determined using enzyme immunoassays.. Expression of 5-LOX was found in all skin sections from SSc patients as well as from controls. However, the number and percentage of 5-LOX-positive cells were significantly higher in SSc skin sections compared with control sections. Expression of 5-LOX was seen in cells within perivascular inflammatory infiltrates as well as in fibroblasts throughout the skin. The experiments with cultured skin fibroblasts revealed that 5-LOX was constitutively expressed in these cells, which resulted in the production of leukotrienes after cell stimulation. Whereas no difference was found for LTE4, SSc fibroblasts produced significantly higher amounts of LTB4 after stimulation, compared with healthy control fibroblasts.. The results of this study suggest that the 5-LOX pathway may be of significance in the pathogenesis of SSc and may represent a target for new treatment strategies.

Topics: Arachidonate 5-Lipoxygenase; Cells, Cultured; Female; Fibroblasts; Humans; Immunohistochemistry; In Situ Hybridization; Leukotriene B4; Leukotriene E4; Male; Middle Aged; RNA, Messenger; Scleroderma, Systemic; Skin; Transcriptional Activation

The peptidoleukotrienes, leukotriene (LT) C4 and its metabolites LTD4 and LTE4, cause diverse physiologic effects and have been implicated in several disease processes. A potential role for enhanced peptidoleukotriene synthesis in the pathogenesis of autoimmune disease in general and systemic lupus erythematosus (SLE) in particular has been suggested by animal studies. Therefore, we measured the urinary levels of LTE4 in patients with active and inactive SLE as well as in patients with rheumatoid arthritis (RA), scleroderma (Scl), and in healthy controls. Comparisons were made to other standard clinical tests in assessing individual patient disease activity. A marked increase in urinary LTE4 levels in patients with active SLE was noted (319 +/- 49 pg/mg creatinine, n = 20) relative to patients with inactive SLE (80 +/- 8 pg/mg creatinine, n = 7 [p less than 0.02]), patients with RA (86 +/- 8 pg/mg creatinine [p less than 0.01]), and healthy controls (68 +/- 4.3 pg/mg creatinine, n = 6 [p less than 0.01]). Patients with Scl also had elevated urinary LTE4 levels (188 +/- 33 pg/mg creatinine, n = 7) relative to controls (p less than 0.02), while values from patients with RA were not significantly different from controls. Using the Systemic Lupus Activity Measurement as a gauge of clinical activity, a rise in urinary LTE4 levels was noted during stages of active disease with a subsequent decline following the resolution of these symptoms. Our data indicate that increased synthesis of leukotrienes is associated with active SLE and Scl and suggest that these leukotrienes may mediate certain symptoms associated with these diseases.

Topics: Adult; Arthritis, Rheumatoid; Creatine; Female; Humans; Leukotriene E4; Lupus Erythematosus, Systemic; Male; Middle Aged; Scleroderma, Systemic; SRS-A