Lymphocyte modulation of fibroblast function in systemic sclerosis

Therapeutic efficacy of combined glucocorticoid, intravenous cyclophosphamide, and double-filtration plasmapheresis for skin sclerosis in diffuse systemic sclerosis

We treated skin sclerosis with triple therapy consisting of a glucocorticoid, intravenous cyclophosphamide, and double-filtration plasmapheresis. The objective of this study was to analyze its effectiveness in a case series of patients who received triple therapy.We enrolled 8 patients with diffuse cutaneous systemic sclerosis (dcSSc) who received triple therapy at our hospital from 2008 to 2016. We analyzed the mean change in the modified Rodnan skin score (mRSS), percentage of the predicted forced vital capacity (%FVC), percentage of the predicted carbon monoxide diffusing capacity (%DLCO), and serum KL-6 levels from baseline to follow-up.All patients were treated with an intermediate dose of oral prednisolone (30.6 ± 2.1 mg/day) initially. The mean cumulative dose of intravenous cyclophosphamide was 1.4 ± 0.2 g. The mean mRSS decreased significantly at follow-up compared with that at baseline (27.0 ± 3.3 vs 15.8 ± 3.5; P = .03). At the end of the treatment, the mean %FVC and %DLCO were improved moderately, although the differences were not significant. The serum KL-6 levels decreased from 578.9 ± 146.5 to 205.3 ± 43.1 U/ml (P = .02). No significant correlation was found between the change in mRSS or disease duration and the initial skin score severity.Triple therapy may improve skin sclerosis, with effectiveness equal or superior to other reported treatments. This preliminary case series demonstrates the potential of triple therapy for treating dcSSc. However, prospective studies with long-term follow-up should be performed to assess its role.

Serum Soluble CD163 and its association with various disease parameters in patients with systemic sclerosis

OBJECTIVE

Cluster of differentiation 163 (CD163) is a receptor that binds haptoglobin-hemoglobin complexes and is mainly expressed on macrophages and monocytes. As a result of shedding, the extracellular portion of CD163 circulates in the blood as a soluble CD163 (sCD163). This study aimed to measure serum sCD163 levels in patients with systemic sclerosis (SSc) and to assess its association with the clinical, laboratory, and radiological features of the disease.

MATERIAL AND METHODS

We measured serum sCD163 levels in 24 patients with SSc and in 30 healthy controls. Complete history of the patients was recorded and thorough clinical, rheumatological, and dermatological examinations were performed. For SSc, the skin thickness score was scored according to the modified Rodnan skin score method and pulmonary involvement was assessed in all patients using high-resolution computed tomography and by performing pulmonary function tests.

RESULTS

The mean serum sCD163 levels in patients with diffuse and limited SSc (61.64±19.57 and 60.8±21.43 ng/mL, respectively) demonstrated a highly statistically significant increase compared with the mean serum levels in healthy controls (36.97±16.37 ng/mL) (p<0.001). Patients with SSc having elevated serum sCD163 levels had significantly higher pulmonary artery systolic pressure (PASP) than those with normal serum sCD163 levels (p<0.05). Furthermore, the serum sCD163 levels were significantly correlated with PASP (r=0.53, p<0.05) in patients with SSc. The mean serum sCD163 level in patients with SSc having digital ulceration (DU) (70.82±18.3 ng/mL) demonstrated a statistically significant increase (p<0.05) compared with that in SSC patients without DU (53.23±18.09 ng/mL).

CONCLUSION

The elevated serum sCD163 levels in patients with SSc and its association with pulmonary hypertension suggest a possible role of macrophages in the pathogenesis and vascular involvement of SSc.

The pathogenesis of cutaneous fibrosis

Cutaneous fibrosis is an integral component of a variety of human disorders including keloids, hypertrophic scar, and most notably, scleroderma. Each has its own etiology and unique clinical characteristics, but all involve the dysregulation of connective tissue metabolism, in particular, the activation of dermal fibroblasts. In this review, we examine various molecular events in scleroderma that may lead to fibroblast activation, and propose a new model to explain the persistence of such activation by scleroderma fibroblasts in the apparent absence of exogenous stimuli.

Scleroderma fibroblasts show increased responsiveness to endothelial cell-derived IL-1 and bFGF

Fibroblasts cultured from lesional skin in scleroderma (systemic sclerosis) demonstrate an activated phenotype that may be important in pathogenesis. Endothelial cell-derived cytokines can modulate fibroblast properties, and endothelial cell changes occur early in scleroderma. Thus, endothelial cell and fibroblast dysfunction may be linked through the paracrine activity of soluble endothelial cell products. We have explored endothelial cell-fibroblast interactions in vitro by investigating the modulation of scleroderma and control fibroblast properties by endothelial cell-conditioned medium (EC-CM). EC-CM caused a concentration-dependent stimulation of fibroblast DNA and protein synthesis and upregulation of cell surface ICAM-1 expression. Scleroderma fibroblasts showed consistently greater responses than control cells. Medium conditioned by mechanically wounded endothelial cells had a greater effect than that from resting endothelial cells. Pre-incubation of EC-CM with anti-bFGF significantly reduced the promotion of fibroblast thymidine incorporation but did not affect endothelial cell-induced leucine incorporation. Conversely, anti-IL-1 antibodies abrogated EC-CM-induced leucine incorporation and ICAM-1 expression but did not diminish thymidine incorporation. Recombinant bFGF or IL-1 modulated fibroblast properties similarly. These data demonstrate that endothelial cell-derived IL-1 and bFGF modulate fibroblast properties independently and that lesional scleroderma strains are more responsive than control fibroblasts to endothelial cell-induced modulation, which supports the hypothesis that altered endothelial cell-fibroblast communication may be involved in the pathogenesis of scleroderma.