The clinical relevance of serum antinuclear antibodies in Japanese patients with systemic sclerosis

Background

Systemic sclerosis (SSc) is a connective tissue disorder with excessive fibrosis of the skin and various internal organs. Although SSc is a heterogeneous disease, it has been reported that the particular antinuclear antibodies (ANA) are often indicative of clinical features, disease course and overall severity.

Objective

To clarify the association of clinical and prognostic features with serum ANA in Japanese patients with SSc.

Methods

We studied 203 Japanese patients diagnosed with SSc, who visited our hospital during the period 1983–2005. Six SSc-related ANA were identified using indirect immunofluorescence, double immunodiffusion and immunoprecipitation assays.

Results

Patients with SSc were classified into six ANA-based subgroups and a group without ANA. As expected, antitopoisomerase I antibody (Ab, n = 64), anti-RNA polymerases (RNAP) Ab (n = 12) and anti-U3 RNP Ab (n = 5) were associated with diffuse cutaneous SSc, whereas anticentromere Ab (ACA, n = 75), anti-Th/To Ab (n = 7) and anti-U1 RNP Ab (n = 10) were frequently detected in patients with limited cutaneous SSc. Clinical features of the ANA-negative group (n = 10) were heterogeneous. Consistent with previous findings in Caucasian and/or black African patients, antitopoisomerase I Ab was associated with the involvement of vascular and pulmonary fibrosis, leading to decreased survival rate. However, no patients with anti-RNAP Ab developed renal crisis and the frequency of isolated pulmonary hypertension in patients with ACA, anti-Th/To Ab or anti-U3 RNP Ab was similar to that in other ANA-based subgroups.

Conclusion

These results indicate that the clinical relevance of SSc-related ANA in Japanese patients differs in some aspects from that in Caucasian and/or black African patients.

Phototriggering system for an ultrahigh-speed video microscopy

A phototrigger system is developed as a part of a video microscope mounting an ultrahigh-speed video camera capable of image capturing at frame rates as high as 1x10(6) framess. The extremely high frame rate is achieved by implementing in situ image storage. A distinguished feature of the camera is the on-chip overwriting mechanism that allows to keep in storage the latest image sequence of 103 frames; the old signals are continuously drained out of the storage. The trigger system is designed to synchronize recording operations with an occurrence of a target event within the limited image capturing duration. The target event is detected through a sudden change in the output of a sensor mounted to an optical port of the microscope. To reduce noise contribution, a two-sensor architecture is implemented. One sensor detects the target event while the one produces a reference signal used for noise reduction. Both sensors are connected to the same optical port by using a specially designed beam splitting unit. To provide high sensitivity, avalanche photodiodes are used as photoelements. System evaluation shows that its sensitivity is high and response time is less than 3 mus. This is sufficiently fast for high-speed video-microscopy observations at 1x10(6) frames/s when using a video camera with a storage of 103 frames. As an example, the system was used in a microscopic observation of a soap film collapse.

Blockade of CD40/CD40 ligand interactions attenuates skin fibrosis and autoimmunity in the tight-skin mouse

OBJECTIVE

To assess the association of CD40/CD40 ligand (CD40L) interactions with the development of skin fibrosis and autoimmunity in tight-skin (TSK/+) mouse, which is a mouse model for human systemic sclerosis.

METHODS

Newly born TSK/+ mice were treated with murine anti-CD40L monoclonal antibody (100 microg intraperitoneally weekly). Hypodermal thickness of 8-week-old female mice (defined as the thickness of a subcutaneous loose connective tissue layer beneath the panniculus carnosus) was measured under a light microscope. All skin sections were taken from the para-midline, upper back region. Serum anti-topoisomerase I autoantibody levels, serum immunoglobulin levels and plasma soluble CD40L levels were determined by enzyme-linked immunosorbent assay. For analysis of lymphocyte surface molecules, single cell suspensions of lymphocytes were stained by monoclonal antibodies. Proliferation of TSK/+ B cells and fibroblasts to anti-CD40 antibodies was assessed by the uptake of [3H]-labelled thymidine and bromodeoxyuridine, respectively.

RESULTS

The blockade of CD40/CD40L interactions by anti-CD40L monoclonal antibody significantly reduced cutaneous fibrosis (65%) and anti-topoisomerase I autoantibody in TSK/+ mice. Anti-CD40L monoclonal antibody also normalised B lymphocyte abnormal activation in TSK/+ mice, demonstrated by hyper-gamma-globulinaemia. Furthermore, augmented CD40/CD40L interactions in TSK/+ mice were suggested by upregulated expression of CD40L on CD4(+) T cells, elevated plasma soluble CD40L levels. The hyperresponsiveness to CD40 stimulation was also observed in TSK/+ B cells and fibroblasts.

CONCLUSIONS

Cutaneous fibrosis and autoimmunity in TSK/+ mice are closely correlated with CD40/CD40L interactions.

Aberrant human tissue kallikrein levels in the stratum corneum and serum of patients with psoriasis: dependence on phenotype, severity and therapy

BACKGROUND

Human tissue kallikreins (KLKs) are a family of 15 trypsin-like or chymotrypsin-like secreted serine proteases (KLK1-KLK15). Multiple KLKs have been quantitatively identified in normal stratum corneum (SC) and sweat as candidate desquamation-related proteases.

OBJECTIVES

To quantify KLK5, KLK6, KLK7, KLK8, KLK10, KLK11, KLK13 and KLK14 in the SC and serum of patients with psoriasis, and their variation between lesional and nonlesional areas and with phenotype, therapy and severity. The overall SC serine protease activities were also measured.

METHODS

Enzyme-linked immunosorbent assays and enzymatic assays were used.

RESULTS

The lesional SC of psoriasis generally contained significantly higher levels of all KLKs. KLK6, KLK10 and KLK13 levels were significantly elevated even in the nonlesional SC. The overall trypsin-like, plasmin-like and furin-like activities were significantly elevated in the lesional SC. Plasmin-like activity was significantly elevated also in the nonlesional SC. The SC chymotrypsin-like activity was only slightly elevated in psoriasis. KLK7 serum levels did not differ between normal volunteers and patients with psoriasis. Serum KLK6, KLK8, KLK10 and KLK13 levels in patients with untreated psoriasis significantly correlated with Psoriasis Area and Severity Index score. Serum KLK5 and KLK11 levels decreased in patients with psoriasis after therapy, especially with etretinate. Patients with erythrodermic psoriasis exhibited significantly higher serum KLK levels than normal subjects or patients with psoriasis vulgaris or arthropathic psoriasis.

CONCLUSIONS

We found aberrant KLK levels in the SC and serum of patients with psoriasis and suggest that KLKs might be involved in the pathogenesis of this disease.

Association of CD22 gene polymorphism with susceptibility to limited cutaneous systemic sclerosis

Activating and inhibitory signal transducers, CD19 and CD22, have been substantially implicated both in human systemic sclerosis (SSc) and tight-skin mouse, a model for SSc. We previously showed that a single nucleotide polymorphism (SNP) in CD19 promoter region was significantly associated with increased CD19 expression level and with susceptibility to SSc. In the present study, we examined whether CD22 polymorphisms were associated with susceptibility to SSc. CD22 variations were genotyped in 126 Japanese patients with SSc [47 diffuse cutaneous SSc and 79 limited cutaneous SSc (lcSSc)] and 93 unrelated healthy controls. At the c.2304C > A SNP coding for a synonymous substitution in exon 13, A/A genotype was observed in six patients with SSc (4.8 %) but none in the controls (P=0.040). All six patients with A/A genotype belonged to the lcSSc subgroup (7.6%, P=0.008 vs controls). Surface expression level of CD22 tended to be lower in B cells from the patients with A/A genotype (n=5) as compared with C/A (n=7) or C/C (n=14) genotype (17% decrease, P=0.0032). Taken together with our previous observation on CD19 polymorphism, intrinsic difference in the expression level of CD19 and CD22 was suggested to play a causative role in a proportion of patients with lcSSc.

A retrospective review of adenosquamous carcinoma of the uterine cervix

16049

Background: Adenosquamous carcinoma (ASC) of the uterine cervix is a rare mixture of malignant squamous and glandular epithelial elements. Clinical analyses of this disease were hardly performed independently from those of adenocarcinoma (AC) of the uterine cervix since both of the patients with these diseases show poorer outcome, compared with those with squamous cell carcinoma, which is present in the majority of cervical cancer. In this study, we investigated clinical features including diagnosis and treatment of this disease. Methods: During 1980–2006, total of 270 patients, who were diagnosed as carcinoma of the uterine cervix, were included in our analysis. A retrospective review of patients with ASC were preformed in their age, stage, lymph node metastasis, tumor markers (SCC, CEA, CA125 and CA19–9), treatment, relapse rate and its location, and survival. Results: There were total of 17 and 34 patients, who were histologically confirmed as having ASC (6.3%) and AC (12.6%) of the uterine cervix, respectively. All the ASC patients underwent surgery. The average age of the patients was 45.0 (26–78). The distribution of illness stages among the patients were IA, 4; IB, 8; IIA, 2; IIB, 2; IIIB, 1. Lymph node metastasis was seen in two patients (11.8%). There were no significant difference in these indexes between ASC and AC. Elevation of serum CA125 was observed in two ASC patients but no AC patients. The recurrence rates were 17.6% and 14.7% in ASC and AC, respectively. Five-year survival were 77.8% in ASC and 78.0% in AC, whereas 92.2% in SCC. Conclusions: These analyses indicate that clinical behavior and its outcome of ASC is similar to those of AC. The treatment based on these clinical features may be a useful to improve the prognosis of this disease.

No significant financial relationships to disclose.

The significance of radiotherapy for adenocarcinoma of uterine cervix

5590

Background: We conducted the present study to determine the significance of radiotherapy for cervical adenocarcinoma. Methods: A total of 1,133 patients with cervical cancer, who underwent radiotherapy in 7 institutes between 1996 and 2005, were enrolled in this study. There were 966 squamous cell carcinoma (SCC) and 167 adenocarcinoma (AC). The mean age of patients with AC was 53.6 (range: 28–81) and 55.9 (range: 22–92) for SCC. Patients were distributed as follows: 370 in stage 1b, 116 in stage IIa, 344 in stage IIb, 16 in stage IIIa, 240 in stage IIIb, and 47 in stage IVa. All patients were identified with the medical records. Of 1,133 patients, 544 received radiotherapy as primary treatment, and 589 underwent adjuvant radiotherapy. Results: Regarding primary treatment, the 5-year survival rate for AC was 41.8% and that for SCC was 62.5% (p=0.0172). The rate of refractory or recurrence for patients with AC was significantly higher than that for SCC (53.3% vs. 33.3%, p=0.0068). Patients with AC more commonly showed recurrence inside irradiated field compared with SCC (83.3% vs. 58.2%, p=0.0240). The outcome for patients with AC was significantly worse compared with SCC in adjuvant treatment (5-year survival rate: 27.5% vs. 45.4%, p=0.0434). Recurrence for AC were significantly higher observed than that for SCC (40.0% vs. 24.7%, p=0.0008). The incidence of recurrence inside irradiated field and lymph node involvement did not differ between AC and SCC (30.1% vs. 43.8%, 46.7% vs. 44.0%). Conclusions: Cervical adenocarcinoma had poorer prognosis because of its low radiosensitivity compared with SCC. New strategy for cervical adenocarcinoma should be necessary.

No significant financial relationships to disclose.

An improved procedure for rapid determination of viral RNA sequences of avian RNA viruses

A system for rapid determination of viral RNA sequences, RDV, was improved for detection of avian RNA virus in allantoic fluids. We detected avian paramyxovirus nucleotide sequences using RDV method ver 2.0.

Role of intercellular adhesion molecule-1 in a murine model of toluene diisocyanate-induced asthma

BACKGROUND

Adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) are thought to contribute to the airway inflammation and airway hyper-responsiveness (AHR) of allergic asthma. Some differences from allergic asthma have been noted, including airway neutrophilia, and the involvement of ICAM-1 in toluene diisocyanate (TDI) asthma is currently unclear.

OBJECTIVE

We utilized mice lacking ICAM-1 expression (ICAM-1(-/-)) to investigate the role of ICAM-1 in airway inflammation and AHR in TDI-induced asthma.

METHODS

Male C57BL/6J mice (ICAM-1(+/+)) and ICAM-1(-/-) mice were intranasally sensitized to TDI solution or solvent alone. Airway inflammation, AHR and cytokine secretion were assessed 24 h after challenge by TDI or solvent. The production of antigen-specific IgG and IgE by TDI sensitized and non-sensitized mice was determined.

RESULTS

TDI challenge to ICAM-1(+/+) mice induced an increase in airway inflammatory cell numbers, AHR and cytokine secretion of TNF-alpha, macrophage inflammatory protein-2 (MIP-2), IL-4, IL-5 and IFN-gamma into the bronchoalveolar lavage fluid. All these pathophysiological changes were reduced in ICAM-1(-/-) mice. Serum levels of TDI-specific IgG and IgE of ICAM-1(-/-) and ICAM-1(+/+) mice were comparable.

CONCLUSION

These results suggest that ICAM-1 plays an essential role in airway inflammation and AHR in TDI-induced asthma.

A clue for telangiectasis in systemic sclerosis: elevated serum soluble endoglin levels in patients with the limited cutaneous form of the disease

BACKGROUND

The transforming growth factor-beta (TGF-beta) system plays a critical role both in systemic sclerosis (SSc) and hereditary hemorrhagic telangiectasia (HHT). Endoglin, known as a gene responsible for HHT, is a TGF-beta receptor preferentially expressed on endothelial cells. The role of endoglin in SSc is potentially intriguing since limited cutaneous SSc (lcSSc) and HHT share several symptoms, including telangiectasia.

OBJECTIVE

To determine serum levels of soluble endoglin (sEndoglin) and clinical associations in patients with SSc.

METHODS

Serum sEndoglin levels were examined by ELISA in 70 patients with SSc, 20 patients with systemic lupus erythematosus and 20 healthy individuals.

RESULTS

Serum sEndoglin levels were significantly elevated in patients with lcSSc compared with diffuse cutaneous SSc and systemic lupus erythematosus patients as well as normal controls. Patients with elevated sEndoglin levels had telangiectasia more frequently than those with normal sEndoglin levels. Furthermore, pulmonary artery pressure was positively correlated with sEndoglin levels in patients with lcSSc.

CONCLUSION

Abnormal expression/function of endoglin may be linked to lcSSc-specific manifestations.

Identification of a novel autoantibody reactive with 155 and 140 kDa nuclear proteins in patients with dermatomyositis: an association with malignancy

OBJECTIVE

Myositis-specific autoantibodies (MSAs) are a useful tool in diagnosis, defining clinical subsets and predicting prognosis of dermatomyositis (DM) and polymyositis (PM). In this study, we identified a novel MSA reactive with 155 and 140 kDa nuclear proteins [anti-155/140 antibody (Ab)] and determined the clinical feature of DM patients positive for this autoantibody (autoAb).

METHODS

Sera from 52 Japanese patients with DM, 9 with PM, 48 with systemic lupus erythematosus (SLE), 126 with systemic sclerosis and 18 with idiopathic interstitial pneumonia were examined by immunoprecipitation assays. Positive sera were further characterized by immunodepletion and immunofluorescence staining.

RESULTS

Seven of the 52 (13%) Japanese patients with DM immunoprecipitated 155 and 140 kDa proteins from 35S-labelled K562 leukaemia cell extract. No patients with SLE, systemic sclerosis or idiopathic interstitial pneumonia as well as healthy controls were positive for this autoAb. Patients with anti-155/140 Ab developed heliotrope rash, Gottron's papules or sign and flagellate erythema significantly more frequently than those negative. Notably, internal malignancy was found at significantly higher frequency in those positive than those negative (71 vs 11%; P < 0.005). In contrast, none of these patients positive for this autoAb had interstitial lung disease.

CONCLUSIONS

This novel MSA is associated with cancer-associated DM and may serve as a diagnostic serological marker for this specific subset.

Regulation of local and metastatic host-mediated anti-tumour mechanisms by L-selectin and intercellular adhesion molecule-1

Malignant melanoma is often accompanied by a host response of inflammatory cell infiltration that is highly regulated by multiple adhesion molecules. To assess the role of adhesion molecules, including L-selectin and intercellular adhesion molecule-1 (ICAM-1), in this process, subcutaneous primary growth and metastasis to the lung of B16 melanoma cells not expressing L-selectin, ICAM-1 or their ligands were examined in mice lacking L-selectin, ICAM-1 or both. Primary subcutaneous growth of B16 melanoma was augmented by loss of L-selectin, ICAM-1 or both, while pulmonary metastasis was enhanced by the loss of L-selectin or combined loss of L-selectin and ICAM-1. In both situations, the combined loss of L-selectin and ICAM-1 exhibited the greatest effect. This enhancement was associated generally with a reduced accumulation of natural killer (NK) cells, CD4+ T cells and CD8+ T cells and also with a diminished release of interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha but not interleukin (IL)-6. Cytotoxicity against melanoma was not defective by the absence of ICAM-1, L-selectin or both, suggesting that the enhancement of tumour growth and metastasis caused by the loss of adhesion molecules results from an impaired migration of effector cells into the tissue rather than from a suppression of the cytotoxic response. The results indicate that L-selectin and ICAM-1 contribute co-operatively to the anti-tumour reaction by regulating lymphocyte infiltration to the tumour.

Serum levels of 8-isoprostane, a marker of oxidative stress, are elevated in patients with systemic sclerosis

OBJECTIVE

To determine serum levels and clinical correlation of 8-isoprostane, which is produced in vivo through free radical-catalysed peroxidation of arachidonic acid and reflects oxidative stress, in patients with systemic sclerosis (SSc).

METHODS

Serum 8-isoprostane levels from 32 patients with diffuse cutaneous SSc (dSSc) and 25 patients with limited cutaneous SSc (lSSc) were examined by enzyme-linked immunosorbent assay.

RESULTS

Serum 8-isoprostane levels were elevated in dSSc and lSSc patients by 75-fold compared with normal controls (n=32). Serum 8-isoprostane levels correlated negatively with pulmonary function, such as percentage vital capacity and diffusion capacity for carbon monoxide, and correlated positively with renal vascular damage determined by colour flow Doppler ultrasonography. Serum 8-isoprostane levels also correlated positively with serum levels of IgG and anti-agalactosyl IgG autoantibody.

CONCLUSION

Increased 8-isoprostane levels correlated with the severity of pulmonary fibrosis, the extent of renal vascular damage and immunological abnormalities in SSc, suggesting that enhanced oxidative stress is related to the development of SSc.

Serum levels of monocyte chemotactic protein-3/CCL7 are raised in patients with systemic sclerosis: association with extent of skin sclerosis and severity of pulmonary fibrosis

OBJECTIVE

To determine serum levels of monocyte chemotactic protein-3 (MCP-3) and its clinical associations in patients with systemic sclerosis (SSc).

METHODS

Serum MCP-3 levels from 69 patients with SSc were examined by ELISA.

RESULTS

Serum MCP-3 levels were raised in patients with SSc (n = 69) compared with healthy controls (n = 28). Patients with diffuse cutaneous SSc (n = 36) had higher levels of serum MCP-3 than those with limited cutaneous SSc (n = 33). Patients with raised MCP-3 levels had pulmonary fibrosis and decreased vital capacity (VC) more often than those with normal MCP-3 levels. MCP-3 levels correlated positively with the extent of skin fibrosis, and inversely with %VC and carbon monoxide transfer factor (Tlco) in patients with SSc.

CONCLUSION

MCP-3 levels were increased in patients with SSc, and correlated with the extent of skin sclerosis and the severity of pulmonary fibrosis. These results suggest that MCP-3 may have a role in the development of fibrosis in SSc.

Anti-phosphatidylserine-prothrombin complex antibodies in patients with localized scleroderma

OBJECTIVE

Although some antiphospholipid antibodies (Abs) are found in patients with localized scleroderma (LSc), Ab against phosphatidylserine-prothrombin complex (PS/PT) has not been examined. We investigated anti-PS/PT Ab levels in patients with LSc.

METHODS

IgG anti-PS/PT Ab levels in serum samples taken from patients with LSc (n = 42) were measured using ELISA.

RESULTS

IgG anti-PS/PT Ab was detected in 17% of the LSc patients, while it was not detected in any normal controls (n = 32) or psoriasis vulgaris (n = 25), and this frequency was similar to that of systemic sclerosis (17%, n = 41). Among 3 LSc subgroups, generalized morphea, the severest form of LSc, had a frequency (27%) comparable with that of systemic lupus erythematosus (32%, n = 25). Among 7 LSc patients with anti-PS/PT Ab, 2 developed symptomatic thromboembolism (A 70-year-old man developed deep vein thrombosis and pulmonary infarction, although he was negative for other antiphospholipid Abs. A 6-year-old boy positive for lupus anticoagulant had cerebral infarction). By contrast, symptomatic thromboembolism was not detected in 35 LSc patients without anti-PS/PT Ab.

CONCLUSION

Patients with LSc, especially generalized morphea, exhibit anti-PS/PT Ab at a frequency comparable with collagen diseases such as systemic sclerosis and systemic lupus erythematosis. Examination of this Ab may be useful to recognize the risk of thromboembolism in patients with LSc.

A role for Id in the regulation of TGF-beta-induced epithelial-mesenchymal transdifferentiation

Epithelial-mesenchymal transdifferentiation (EMT) is a critical morphogenic event that occurs during embryonic development and during the progression of various epithelial tumors. EMT can be induced by transforming growth factor (TGF)-beta in mouse NMuMG mammary epithelial cells. Here, we demonstrate a central role of helix-loop-helix factors, E2A and inhibitor of differentiation (Id) proteins, in TGF-beta-induced EMT. Epithelial cells ectopically expressing E2A adopt a fibroblastic phenotype and acquire migratory/invasive properties, concomitant with the suppression of E-cadherin expression. Id proteins interacted with E2A proteins and antagonized E2A-dependent suppression of the E-cadherin promoter. Levels of Id proteins were dramatically decreased by TGF-beta. Moreover, NMuMG cells overexpressed Id2 showed partial resistance to TGF-beta-induced EMT. Id proteins thus inhibit the action of E2A proteins on the expression of E-cadherin, but after TGF-beta stimulation, E2A proteins are present in molar excess of the Id proteins, thus over-riding their inhibitory function and leading to EMT.

Multiple tissue kallikrein mRNA and protein expression in normal skin and skin diseases

BACKGROUND

Human tissue kallikreins are a gene family (KLK1-KLK15) encoding for 15 secretory serine proteases (hK1-hK15). Two tissue kallikrein proteins, hK5 and hK7, were previously found in the stratum corneum (SC), stratum granulosum (SG) and appendages. hK8 was also shown to be secreted via lamellar granules and numerous KLK mRNAs were previously identified. KLKs are believed to be responsible for desquamation of corneocytes and sebum, sweat and hair maturation.

OBJECTIVES

To demonstrate immunohistochemically the expression of hK6, hK8 and hK13 in normal skin tissue and to show an increased cell number expressing kallikrein mRNAs and proteins in psoriasis vulgaris (PV) and atopic dermatitis (AD).

METHODS

Samples of normal, PV and AD skin were obtained. hK6-, hK8- and hK13-specific antibodies were produced and used for immunohistochemical analysis. Multiple KLK mRNAs were synthesized and used for in situ hybridization study.

RESULTS

Three other hKs, namely hK6, hK8 and hK13, were immunohistochemically identified as new skin serine proteases in the whole SC, SG, sebaceous glands, eccrine sweat glands, hair follicles and nerves. We also demonstrated an increased number of cells expressing KLK mRNAs and hKs in PV and AD. In PV, KLK mRNAs/hKs were predominantly expressed in the upper epidermis. In AD, hK distribution was rather diffuse and expanded into the lower epidermis.

CONCLUSIONS

The colocalization of various hKs seems to be essential for the regulation of serine protease activity in skin and for steady desquamation and skin barrier function. Moreover, the increased number of cells expressing multiple KLK mRNA and hK in PV and AD could be a clue to elucidate their pathogenesis.

Increased cutaneous T-cell-attracting chemokine levels in sera from patients with systemic sclerosis

OBJECTIVE

We sought to assess serum cutaneous T-cell-attracting chemokine (CTACK) levels and CTACK expression levels in skin from patients with systemic sclerosis (SSc), and determine whether serum CTACK levels correlate with clinical features in SSc patients.

METHODS

Serum samples were obtained from 73 SSc patients, 32 patients with systemic lupus erythematosus and 26 patients with dermatomyositis. Serum CTACK levels were determined by enzyme-linked immunoabsorbent assay. CTACK mRNA expression in sclerotic skin was assessed by real-time reverse transcription-polymerase chain reaction.

RESULTS

Serum CTACK levels were significantly increased in patients with diffuse cutaneous SSc (dSSc; n=32) and those with limited cutaneous SSc (lSSc; n=41) compared with normal controls (n=31; P<0.05 and P<0.0005, respectively). The presence of calcinosis and muscle involvement was more frequently detected in SSc patients with elevated CTACK levels (P<0.05 and P<0.05, respectively). Elevated C-reactive protein levels were also observed more frequently in SSc patients with increased CTACK levels (P<0.05). CTACK mRNA expression levels in the sclerotic skin of SSc patients were augmented. In a longitudinal study, serum CTACK levels were generally decreased during the follow-up.

CONCLUSIONS

The increased serum CTACK levels and enhanced skin CTACK expression in SSc patients suggest that CTACK is related to the inflammation associated with SSc.

Autoantibodies to a collagen-specific molecular chaperone, heat-shock protein 47, in systemic sclerosis

Heat-shock proteins are highly conserved and immunogenic proteins, which may be involved in the initiation and perpetuation of autoimmune diseases. Heat-shock protein 47 (HSP47) is expressed by collagen-secreting cells such as fibroblasts and serves as a collagen-specific molecular chaperone that plays a crucial role in collagen metabolism. Abnormal collagen accumulation and autoimmunity are characteristics of systemic sclerosis (SSc). We determined the presence and prevalence of autoantibodies to HSP47 in patients with SSc and also in tight-skin (TSK/+) mice, an animal model for SSc. Anti-HSP47 autoantibodies were present in SSc patients with a frequency of 26%, while patients with systemic lupus erythematosus, those with dermatomyositis, those with keloid and healthy subjects did not have anti-HSP47 antibodies. IgG1 and IgG2 were the major Ig isotypes of the autoantibodies. Patients positive for anti-HSP47 had a significantly shorter duration of disease than those who were negative. Anti-HSP47 autoantibodies were also positive in 79% of TSK/+ mice. Thus, autoantibodies to HSP47 were present in the sera from SSc patients as well as those from TSK mice, and may be associated with the pathogenesis of SSc.

Autoantibodies directed against the protease inhibitor calpastatin in psoriasis

Psoriasis is believed to be a T cell-mediated autoimmune disease, but also exhibits autoantibody production. Calpastatin is an endogenous inhibitor of calpain, a ubiquitous protease that regulates inflammatory processes. Anti-calpastatin autoantibody was first identified as an autoantibody specific to rheumatoid arthritis, but has been also detected in other autoimmune diseases. In this study, we examined the presence and levels of anti-calpastatin antibody in 77 psoriasis patients by enzyme-linked immunosorbent assay. Compared with normal controls, psoriasis patients exhibited significantly elevated IgG anti-calpastatin antibody levels that were similar to those found in rheumatoid arthritis patients. Remarkably, IgG anti-calpastatin autoantibody in sera from psoriasis patients inhibited calpastatin activity. Calpain II expression was up-regulated in psoriasis skin lesions compared with normal skin while calpastatin expression was normal. The results of this study reveal the presence of anti-calpastatin autoantibody in psoriasis.

Up regulated expression of fractalkine/CX3CL1 and CX3CR1 in patients with systemic sclerosis

BACKGROUND

Fractalkine expressed on endothelial cells mediates activation and adhesion of leucocytes expressing its receptor, CX(3)CR1. Soluble fractalkine exhibits chemotactic activity for leucocytes expressing CX(3)CR1.

OBJECTIVE

To determine the role of fractalkine and its receptor in systemic sclerosis (SSc) by assessing their expression levels in patients with this disease.

METHODS

The expression of fractalkine and CX(3)CR1 in the skin and lung tissues was immunohistochemically examined. Circulating soluble fractalkine levels were examined by enzyme linked immunosorbent assay (ELISA). Blood samples from patients with SSc were stained for CX(3)CR1 with flow cytometric analysis.

RESULTS

CX(3)CR1 levels on peripheral monocytes/macrophages and T cells were found to be raised in patients with diffuse cutaneous SSc. The numbers of cells expressing CX(3)CR1, including monocytes/macrophages, were increased in the lesional skin and lung tissues from patients with diffuse cutaneous SSc. Fractalkine was strongly expressed on endothelial cells in the affected skin and lung tissues. Soluble fractalkine levels were significantly raised in sera and were associated with raised erythrocyte sedimentation rates, digital ischaemia, and severity of pulmonary fibrosis.

CONCLUSIONS

Up regulated expression of fractalkine and CX(3)CR1 cooperatively augments the recruitment of mononuclear cells expressing CX(3)CR1 into the affected tissue of SSc, leading to inflammation and vascular injury.

Localized scleroderma is an autoimmune disorder

OBJECTIVES

There have been many studies suggesting that localized scleroderma has a strong autoimmune background, although the lesions are usually limited to the skin and subcutaneous tissue. Here we summarize previous data on the autoimmunity of localized scleroderma, mostly published in the last two decades, because there has not been a review paper summarizing autoimmunity in this disorder.

METHODS

We classified the previous reports into three categories: antinuclear antibodies; cytokine and soluble receptors; and cell adhesion molecules and cell surface molecules. In each category, we introduce the important investigations.

RESULTS

High frequencies of antinuclear antibodies, detected by the indirect immunofluorescence method using cultured cells, are confirmed by many groups. The major autoantigens have been revealed to be histones. Recently, anti-topoisomerase II alpha antibody has been found to be detected highly frequently in localized scleroderma, while anti-topoisomerase I antibody, which is highly specific for systemic sclerosis, has not been detected in any case of localized scleroderma. In other studies, elevated serum cytokines and cell adhesion molecules suggest the immunoactivation of localized scleroderma.

CONCLUSIONS

Many previous studies conclude that localized scleroderma involves autoimmune abnormalities and is one of the organ-specific autoimmune disorders targeting mainly skin, although the types of autoimmune abnormality are different from systemic sclerosis.

Autoantibody against matrix metalloproteinase-3 in patients with systemic sclerosis

Systemic sclerosis (SSc) is characterized by multi-organ fibrosis with an autoimmune background. Although autoantibodies are detected frequently in SSc patients, the role of autoantibody in the development of fibrosis remains unknown. Connective tissue homeostasis is a balance between the synthesis and degradation of the extracellular matrix (ECM); ECM degradation is regulated mainly by matrix metalloproteinases (MMPs). Anti-MMP-1 antibody is suggested to inhibit MMP-1 and be involved in the development of the fibrosis in SSc. However, the accumulation of various ECM components in the tissue of SSc cannot be explained by the anti-MMP-1 antibody alone. In this study, we examined the presence or levels of antibody to MMP-3, a protein which degrades various ECM components relevant to SSc fibrosis. Enzyme-linked immunosorbent assay (ELISA) using human recombinant MMP-3 revealed that IgG anti-MMP-3 autoantibody levels were elevated significantly in the sera from SSc patients, but not in patients with active systemic lupus erythematosus or dermatomyositis. IgG and IgM anti-MMP-3 antibody levels were significantly higher in diffuse cutaneous SSc, a severe form, than those in limited cutaneous SSc. Consistently, IgG anti-MMP-3 antibody levels correlated significantly with fibrosis of the skin, lung and renal blood vessels. The presence of IgG anti-MMP-3 autoantibody in sera from SSc patients was confirmed by immunoblotting analysis. Remarkably, MMP-3 activity was inhibited by IgG anti-MMP-3 antibody. These results suggest that anti-MMP-3 antibody is a serological marker that reflects the severity of SSc and also suggest that it may contribute to the development of fibrosis by inhibiting MMP-3 activity and reducing the ECM turnover.