Autopsy versus clinical findings in patients with systemic sclerosis in a case series from patients of the EUSTAR database.

OBJECTIVES: Subclinical organ pathology occurs regularly in systemic sclerosis (SSc) and affects correct prognosis as well as treatment choices. We aimed to evaluate autopsy data for organ involvement with subsequent correlation to clinical data in order to assess discrepancies in pathological and clinical findings in SSc. METHODS: A standardised autopsy questionnaire from diseased patients registered in the European Scleroderma Trials and Research group (EUSTAR) cohort was analysed on cause of death and various manifestations in different organ systems. Clinical data obtained from the EUSTAR database of the corresponding patients including cause of death and disease manifestations of lung, heart, kidney, gastrointestinal, skin or musculoskeletal organ involvement were retrospectively analysed and compared to autopsy data. RESULTS: 11 patients (6 women, 5 male) aged between 23 and 84 were included. Cause of death defined by pathologist and clinician were identical in 9/11 cases. In 8 individuals, cause of death was related to heart and lung pathologies. Heart and lung involvement (both 10/11) were the most frequently detected organ involvement at autopsy. Here, myocardial fibrosis occurred in 66% and lung fibrosis in 50% of the patients. Clinically, diastolic function abnormalities (6/11), conduction block (4/11), reduced DCLO (6/11) and dyspnea (8/11) were the most prevalent cardiopulmonary findings. For heart and renal involvement we found higher prevalence in autopsy than by clinical diagnosis. Especially myocardial fibrosis and renal arteriosclerosis were only obtained by autopsy in several individuals. CONCLUSIONS: Clinical diagnostic procedures are limited in detection of end-organ damage, especially for cardiac involvement. All the more post mortem examinations are needed for quality verification of clinical diagnosis and might help as to better understand the disease processes as well as to improve patient care.

Activation of pregnane X receptor inhibits experimental dermal fibrosis.

OBJECTIVE: To assess the antifibrotic effects of pregnane X receptors (PXRs) in experimental dermal fibrosis. METHODS: The antifibrotic effects of PXR activation by 5-pregnen-3ß-ol-20-one-16α-carbonitrile (PCN) were studied in the bleomycin model for prevention of dermal fibrosis and the modified bleomycin model for the treatment of established bleomycin-induced dermal fibrosis. Activation of canonical transforming growth factor (TGF)ß signalling was analysed by immunofluorescence staining for phosphorylated smads. The antifibrotic effects of PXR activation were further studied in murine fibroblasts and murine T cells under Th2 conditions. In the T cell experiments, synthesis of the profibrotic cytokines, interleukin (IL)-4 and IL-13, was assessed by quantitative PCR, and IL-13 levels in the murine skin were determined by multiplex bead array technology. RESULTS: Activation of PXR effectively inhibited the development of bleomycin-induced dermal fibrosis and induced the regression of established dermal fibrosis as assessed by skin thickening, hydroxyproline content and myofibroblasts. Reduced levels of phosphorylated smad2 and smad3 suggested that the antifibrotic effects of PXRs were mediated by inhibition of canonical TGFß signalling. While PXR activation appeared to have no direct effects on fibroblasts, it potently inhibited the release of the profibrotic cytokine, IL-13, from Th2 cells. Consistent with these findings, IL-13 levels were reduced in bleomycin-challenged murine skin upon PXR activation. CONCLUSIONS: Our findings demonstrate a novel antifibrotic role for PXRs in inflammatory dermal fibrosis. The antifibrotic effects of PXRs appear to be indirect: PXR activation reduces the release of the Th2 cytokine, IL-13, from T cells resulting in decreased canonical TGFß signalling.

Blockade of canonical Wnt signalling ameliorates experimental dermal fibrosis.

BACKGROUND AND OBJECTIVES: Fibrosis is a major socioeconomic burden, but effective antifibrotic therapies are not available in the clinical routine. There is growing evidence for a central role of Wnt signalling in fibrotic diseases such as systemic sclerosis, and we therefore evaluated the translational potential of pharmacological Wnt inhibition in experimental dermal fibrosis. METHODS: We examined the antifibrotic effects of PKF118-310 and ICG-001, two novel inhibitors of downstream canonical Wnt signalling, in the models of prevention and treatment of bleomycin-induced dermal fibrosis as well as in experimental dermal fibrosis induced by adenoviral overexpression of a constitutively active transforming growth factor (TGF)-ß receptor I. RESULTS: PKF118-310 and ICG-001 were well tolerated throughout all experiments. Both therapeutic approaches showed antifibrotic effects in preventing and reversing bleomycin-induced dermal fibrosis as measured by skin thickness, hydroxyproline content and myofibroblast counts. PKF118-310 and ICG-001 were effective in inhibiting TGF-ß receptor I-driven fibrosis as assessed by the same outcome measures. CONCLUSIONS: Blockade of canonical Wnt signalling by PKF118-310 and ICG-001 showed antifibrotic effects in different models of skin fibrosis. Both therapies were well tolerated. Although further experimental evidence for efficacy and tolerability is necessary, inhibition of canonical Wnt signalling is a promising treatment approach for fibrosis.