[An up date on pulmonary hypertension related to systemic sclerosis]

Systemic sclerosis (scleroderma) is a chronic, progressive connective tissue disease characterized by typical skin changes and internal organ involvement. Arterial pulmonary hypertension is found in approximately 10-15% of patients with systemic sclerosis, and is considered as one of the most fatal complications of the disease. When pulmonary hypertension secondary to scleroderma related interstitial lung disease, left-sided cardiac insufficiency and thrombo-embolic disease is also taken into account, the frequency of pulmonary hypertension in systemic sclerosis may be as high as.50%. Recent investigations brought new information considering the pathogenesis of pulmoanry hypertension and allowed new therapeutic approches to be introduced. Early diagnosis of pulmonary hypertension is a key issue in clinical practice, but it is a challange in patients with systemic disease such as systemic sclerosis. Current review presents up to date information on the pathogenesis, early diagnosis and treatment of pulmonary hypertension related to systemic sclerosis.

[Interstitial lung disease related to systemic connective tissue diseases]

Interstitial lung disease (ILD) is one of the most frequent and most serious complications of connective tissue diseases such as systemic sclerosis, systemic lupus erythematosus, dermato- and polymyositis, Sjogren's syndrome, or mixed connective tissue disease. Diagnosis of ILD is often delayed in patients with connective tissue diseases because of the systemic character of the primary condition, restricted physical activity of the patient and insufficient awareness of the physycian. The aim of the current review is to present the up-to-date information on ethiopathology, classification, diagnosis and treatment of ILD in patients with connective tissue diseases.

Endothelin receptor antagonism--new perspectives in the treatment of systemic sclerosis

Endothelin-1 is a naturally occurring polypeptide which possesses a broad range of activities including vasospastic, proinflammatory and profibrotic properties. Systemic sclerosis is a multisystem connective tissue disease characterized by vascular damage, inflammatory infiltrates and progressive fibrosis of the skin and internal organs. The results of the recent studies indicate that endothelin-1 may be a key element of the pathogenesis of systemic sclerosis. Accordingly, new class of drugs, endothelin receptor antagonists have been introduced for treatment of patients with systemic sclerosis. This article reviews the role of endothelin-1 in the pathogenesis of systemic sclerosis and the implications of endothelin receptor antagonism in the treatment of systemic sclerosis.

The occurrence of pulmonary hypertension in patients with systemic sclerosis hospitalized in the Department of Rheumatology and Internal Diseases Medical University of Białystok in years 2003-2004

Pulmonary hypertension (PH) is one the most fatal complications of systemic sclerosis (SSc). The aim of the present study was to investigate the occurrence of PH in SSc patients hospitalized in Department of Rheumatology and Internal Diseases University Hospital of Bialystok in years 2003-2004. PH was defined as pulmonary artery systolic pressure (PASP) higher than 35 mmHg as evaluated by ECHO-Doppler. We found PH in 23 out of 53 (43%) SSc patients included in the study. In the majority of patients 20/23 (87%) PH coexisted with the presence of scleroderma lung disease as evaluated by high resolution computed tomography of the lungs. In the remaining 3/23 (13%) patients isolated (arterial) PH was detected. Patients with isolated PH tend to have higher values of PASP (82 +/- 39.0 mmHg) than those with PH and interstitial lung disease (42.5 +/- 6.4 mmHg). The results of our study indicate that PH is a frequent complication of SSc.

Elevated levels of leukotriene B4 and leukotriene E4 in bronchoalveolar lavage fluid from patients with scleroderma lung disease

OBJECTIVE

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).

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Chemokines and chemokine receptors in the pathogenesis of systemic sclerosis

Abstract  Activation of the immune system and increased synthesis of extracellular matrix proteins by fibroblasts are hallmarks in the pathogenesis of systemic sclerosis (SSc). The mechanisms that initiate the accumulation of inflammatory cells are still unknown. Chemokines are a family of small molecules that are divided into subfamilies according to the position of NH2-terminal cysteine motif. A new nomenclature for chemokines recently has been introduced in an attempt to overcome the confusion resulting from a number of different names for the same chemokines. Recent data indicate that chemokines, and in particular MCP-1 (CCL2), might be involved in the pathogenesis of SSc at different levels. MCP-1 is highly upregulated in skin specimens from SSc patients compared with those from healthy controls. Dermal fibroblasts release MCP-1, which is able to induce and perpetuate the migration of inflammatory cells into the skin. Interestingly, data from animal models, as well as from in vitro studies, indicate that MCP-1 might also be involved in the increased synthesis of extracellular matrix proteins, by either direct or indirect mechanisms. In conclusion, chemokines represent interesting candidates for target-directed therapies for SSc. This concept has to be confirmed by further studies using animal models for SSc and other fibrotic diseases.

gamma delta-Lymphocytes in the peripheral blood of patients with rheumatoid arthritis--correlation with clinical and laboratory parameters of the disease and with the treatment used

Rheumatoid arthritis (RA) is a chronic, autoimmune disease in the pathogenesis of which T-lymphocytes are believed to play a crucial role. The aim of this work was to investigate a subpopulation of gamma delta-lymphocytes in the peripheral blood of patients with RA in the context of chosen parameters of the disease. Moreover, we studied the influence of disease modifying antirheumatic drugs (DMARDs) on the number of gamma delta-lymphocytes in the peripheral blood of patients with RA. The gamma delta-lymphocytes were studied using monoclonal anti-delta 1 antibodies labelled with fluorescein (Becton Dickinson) then counted under a fluorescence microscope (Olympus). We found a significant increase in the number of gamma delta-lymphocytes in the peripheral blood of patients with RA as compared with normal controls. The highest numbers were observed in patients with RA and extraarticular manifestation of the disease. Treatment with DMARDs led to a gradual normalisation of the elevated values of gamma delta-lymphocytes.

Overexpression of monocyte chemoattractant protein 1 in systemic sclerosis: role of platelet-derived growth factor and effects on monocyte chemotaxis and collagen synthesis

OBJECTIVE

In addition to its chemotactic properties, recent evidence suggests that monocyte chemoattractant protein 1 (MCP-1) might participate in the fibrotic process by inducing the secretion of extracellular matrix (ECM) components. Since the factors that initiate the accumulation of inflammatory infiltrates and ECM deposits in systemic sclerosis (SSc) skin lesions are still unknown, this study was undertaken to examine the role of MCP-1 in SSc.

METHODS

In situ hybridization and immunohistochemistry studies for MCP-1 were performed on skin biopsy specimens from patients with SSc and healthy controls. To identify possible stimulators of MCP-1 overexpression in SSc lesions, cultured dermal fibroblasts were incubated with recombinant platelet-derived growth factor (PDGF) and analyzed by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay. The chemotactic effects of SSc fibroblasts were examined using a modified Boyden chamber assay. To analyze the fibrotic potential of MCP-1, cultured dermal fibroblasts were incubated with recombinant MCP-1, and type I procollagen was measured by radioimmunoassay and real-time PCR.

RESULTS

MCP-1 was expressed by fibroblasts, keratinocytes, and perivascular infiltrates throughout the skin, in involved as well as uninvolved skin areas, from 10 of 11 SSc patients, whereas no expression of MCP-1 was found in healthy controls. Stimulation with PDGF resulted in a significant increase in MCP-1 messenger RNA and protein, with differences between healthy control fibroblasts and fibroblasts from SSc patients. The chemotactic activity for peripheral blood mononuclear cells of SSc fibroblast supernatants increased in a time-dependent manner. Antibodies blocking MCP-1 decreased the chemotactic activity of SSc fibroblasts by a mean +/- SD of 37 +/- 12%. Despite an increase in type I collagen levels over time, no effect of recombinant MCP-1 on the synthesis of type I collagen was observed.

CONCLUSION

These data indicate that MCP-1 might contribute to the initiation of inflammatory infiltrates in SSc. Possible stimuli of MCP-1 in dermal SSc lesions include PDGF, which is known to be expressed in SSc. In contrast to previous findings in fibrotic lung diseases, no effect of MCP-1 on collagen synthesis was observed in SSc dermal fibroblasts in vitro.

Evidence of 5-lipoxygenase overexpression in the skin of patients with systemic sclerosis: a newly identified pathway to skin inflammation in systemic sclerosis

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Lymphatic microangiopathy of the skin in systemic sclerosis

METHODS

The cutaneous capillary lymphatic system in patients with systemic sclerosis was investigated using fluorescence microlymphography. The distal upper limbs of 16 healthy controls (mean age 62.3+/-13.1 yr) and 16 patients with systemic sclerosis (mean age 58.9+/-13.6 yr) were examined and the following parameters were evaluated: (a) single lymphatic capillaries; (b) lymphatic capillary network and cutaneous backflow; (c) extension of the stained lymphatics; (d) diameter of single lymphatic capillaries.

RESULTS

At the finger level, lymphatic capillaries were lacking in five patients, while they were present in all controls (P < 0.05). Extension of the stained lymphatics was increased in 11 patients (8.1+/-6.0 mm) compared to the 16 healthy controls (2.0+/-1.2 mm) (P < 0.0001). Cutaneous backflow was observed in three patients (P < 0.05). At the hand level, lymphatic network extension was significantly different between patients (3.8+/-2.4 mm) and controls (1.2+/-0.8 mm) (P < 0.01); however, no significant differences were found at the forearm level.

CONCLUSION

Lesional skin in patients with systemic sclerosis exhibits evidence of lymphatic microangiopathy.