[Regression of retroperitoneal fibrosis by combination therapy with tamoxifen and steroids]

Retroperitoneal fibrosis secondary to different etiologies (hemilaminectomy and hypothyroidism): reports of two cases

Retroperitoneal fibrosis (RF) is a clinical entity characterized by the progressive proliferation of connective tissue that rarely forms a mass involving the periaortic area of the abdomen, which may be idiopathic as well as a result of an inflammatory process after aneurysmal dilatation of the aorta. This fibrotic tissue may cover both aorta and iliac arteries, reach the retroperitoneum and surrounding ureters, and cause serious obstructions and renal insufficiency in three-quarters of patients. Most of the patients are known to have atherosclerosis and local inflammation against the antigens of the plaques. A systemic autoimmune disease presenting with retroperitoneal fibrosis seems to be pronounced more frequently nowadays because of the elevated acute-phase reactant levels, positive autoantibodies, and concurrent autoimmune diseases affecting other organs in majority of the diagnosed patients. Ultrasonography, computed tomography, magnetic resonance imaging, positron emission tomography, and retroperitoneal biopsy are useful in diagnosing and assessing the full extent of the disease. Surgical interventions such as ureterolysis and aneurysm repair are frequently performed, but medical therapy including steroids and immunosuppressants is often needed because of the inflammatory and chronic-relapsing nature of the disease. In this paper, we described two cases diagnosed with RF secondary to hemilaminectomy and hypothyroidism, and we summarized the literature related to RF.

Gender-based differences in bleomycin-induced pulmonary fibrosis

The role of gender and sex hormones is unclear in host response to lung injury, inflammation, and fibrosis. To examine gender influence on pulmonary fibrosis, male and female rats were given endotracheal injections of either saline or bleomycin. Female rats showed higher mortality rates and more severe fibrosis than did male rats, as indicated by higher levels of lung collagen deposition and fibrogenic cytokine expression. To clarify the potential role of female sex hormones in lung fibrosis, female rats were ovariectomized and treated with either estradiol or vehicle plus endotracheal injections of either saline or bleomycin. The results showed diminished fibrosis in the ovariectomized, bleomycin-treated rats without hormone replacement. Estradiol replacement restored the fibrotic response to that of the intact female mice in terms of lung collagen deposition and cytokine expression, which was accompanied by higher plasma estradiol levels. Furthermore, fibroblasts from bleomycin-treated rats exhibited increased responsiveness to estradiol treatment, causing dose-dependent increases in procollagen 1 and transforming growth factor-beta1 mRNA expression relative to untreated controls. Taken together these findings suggest that female mice may have an exaggerated response to lung injury relative to male mice because of female sex hormones, which have direct fibrogenic activity on lung fibroblasts. This may provide a mechanism for a hormonally mediated intensification of pulmonary fibrosis.