AB0113 ANTIBODIES AGAINST HELICOBACTER PYLORI ANTIGENS IN PATIENTS WITH PSORIATIC ARTHRITIS AND PSORIASIS

Background:

Psoriasis (Ps) and Psoriatic Arthritis (PsA) are inflammatory diseases of unknown etiology. Helicobacter pylori (Hp) infection has been hypothesized as one of the microbial agents that can lead to development of immune-mediated psoriatic disease, but the nature of the specific Hp antigens involved remains unclear.

Objectives:

To asses antigen specific antibody responses against immunodominant Hp antigens in patients with psoriatic diseases.

Methods:

Ninety-one patients with Ps (35 females; median age 51.9, age range 25-87), 47 patients with PsA (25 females; median age 52.9, age range 25-87) and 60 demographically matched healthy controls (HC) were studied. Reactivity to Hp-specific antigens were tested by Western immunoblotting (in combination with line immunoassay for anti-CagA and anti-VagA antibody testing) (Euroimmun AG, Lübeck, Germany).

Results:

Positivity against Hp was comparable between PsA (38.3%), Ps (39.6%) and HCs (50%). Anti-p66-UreB, anti-p54-flagelin and anti-p29-UreA abs were more frequent in psoriatic patients compered to healthy controls (p66: 94.4% in Ps vs 69.7% in HC, p=0.017; p54: 66.7% in Ps vs 33.3% in HC, p=0.012; p29 72.2% in Ps vs 45.5% in HC, p=0.044) and anti-p29-UreA abs were detected in higher frequency in PsA patients compered to HC (94.4% vs 45.5%, p=0.002). Reactivities against the remaining Hp antigens were comparable between Ps and PsA patients and HC.

Conclusion:

Antibody responses against p66-UreB, p29-UreA, and p54-flagelin are more prevalent in patients with psoriatic disease, suggesting their potential involvement in PsA and Ps.

Disclosure of Interests:

Eleni Patrikiou: None declared, George Efthymiou: None declared, Christos Liaskos: None declared, Niki Ntavari: None declared, Efterpi Zfiriou: None declared, Theodora Simopoulou: None declared, Thomas Scheper, Employee of: Employee of EUROIMMUN AG, Lubeck, Germany, Wolfgang Meyer Employee of: Employee of EUROIMMUN AG, Lubeck, Germany, Aggeliki Roussaki-Schulze: None declared, Dimitrios Bogdanos: None declared

Anti-C1q autoantibodies are frequently detected in patients with systemic sclerosis associated with pulmonary fibrosis

BACKGROUND

Anti-C1q autoantibodies (autoAbs) are associated with systemic lupus erythematosus (SLE), but their presence in other rheumatic diseases has not been adequately investigated.

OBJECTIVES

We aimed to assess anti-C1q autoAbs and circulating immune complexes (CICs) in systemic sclerosis (SSc).

METHODS

In total 124 patients with SSc were studied; 106 were female and the median age was 59·4 years (range 25-81·4). Overall 75 (60·5%) had limited cutaneous SSc and 49 (39·5%) had diffuse cutaneous SSc. Also included were 25 patients with Sjögren syndrome (SjS), 29 with rheumatoid arthritis (RA), 38 with SLE and 53 healthy controls. Enzyme-linked immunosorbent assays with high- and low-salt buffers were used to measure anti-C1q antibodies and CICs. The former allows only anti-C1q antibody binding to C1q and the latter also allows IgG Fc to bind to C1q.

RESULTS

Anti-C1q antibodies were present in 20 of 124 (16·1%) patients with SSc: five had high levels (> 80 RU mL^-1 ) and 10 (50%) had moderate levels (40-80 RU mL^-1 ). Anti-C1q antibodies were also present in one of 25 (4%) patients with SjS, one of 29 (3%) with RA (P < 0·05 for both) and three of 53 (6%) healthy controls (P < 0·01). Anti-C1q antibodies were detected in 13 of 38 (34%) patients with SLEs. Anti-C1q antibodies were more frequent in male than female patients with SSc (P = 0·005); this association remained after multivariate regression analysis. Anti-C1q antibody level was the most important factor in predicting the presence of pulmonary fibrosis, and the second most important in predicting pulmonary arterial hypertension. Fourteen patients with SSc (11·3%) had CICs.

CONCLUSIONS

Anti-C1q autoAbs were frequently detected in patients with SSc, and their high levels predict the co-occurrence of pulmonary fibrosis or pulmonary arterial hypertension.

Differential expression of leptin and leptin's receptor isoform (Ob-Rb) mRNA between advanced and minimally affected osteoarthritic cartilage; effect on cartilage metabolism

OBJECTIVE

To investigate leptin's effect on cartilage metabolism and the pathophysiology of osteoarthritis (OA).

METHODS

Messenger RNA (mRNA) expression and protein levels of leptin and leptin's receptor isoforms were measured by real-time reverse transcription-PCR and Western blot in osteoarthritic and normal cartilage. Osteoarthritic cartilage samples were obtained from two locations of the knee (n=11) and hip (n=6); from the main defective area (advanced OA) and from adjacent macroscopically and histological intact regions (minimal OA). Paired serum and synovial fluid (SF) leptin levels were measured. The effect of leptin was evaluated on chondrocyte proliferation, IL-1beta (interleukin-1beta), NO and metalloproteinases 9 and 13 (MMP-9, MMP-13) protein expression.

RESULTS

Leptin's and leptin's receptor (Ob-Rb) expression levels were significantly increased in advanced OA cartilage compared to minimal. Leptin was significantly increased in SF than serum samples. Also, leptin had a detrimental effect on chondrocyte proliferation and induced IL-1beta production and MMP-9 and MMP-13 protein expression. Furthermore, leptin's mRNA expression in advanced OA cartilage was significantly correlated with BMI of the patients.

CONCLUSION

The increased leptin levels in SF point toward a local effect of leptin in articular cartilage, while the observed intrajoint differences of leptin and Ob-Rb mRNA expression may be related to the grade of cartilage destruction. The observed production of IL-1beta, MMP-9 and MMP-13 by chondrocytes after leptin treatment indicates a pro-inflammatory and catabolic role of leptin on cartilage metabolism. Furthermore, the observed correlation of leptin's mRNA expression with BMI suggests that leptin may be a metabolic link between obesity and OA.

Lectin-like oxidized low density lipoprotein receptor 1 (LOX-1) expression in human articular chondrocytes

OBJECTIVE

To investigate the involvement of oxidized low density lipoprotein (ox-LDL) and the expression of its receptor lectin-like oxidized low density lipoprotein receptor 1 (LOX-1) in osteoarthritis, by determining the ox-LDL in synovial fluid and the expression of LOX-1 mRNA and protein in osteoarthritic as well as normal cartilage. In addition, the effect of ox-LDL on chondrocyte viability and the effect of ascorbic acid (a well-known anti-oxidant) on LOX-1 expression were studied.

METHODS

Fifteen patients were included in the study. Osteoarthritic articular cartilage was obtained from two distinct locations in the knee (n = 10) and hip (n = 5), specifically from weight-bearing and non-weight-bearing areas of the same joints. Five individuals were used as controls. mRNA and protein expression were studied by RT-PCR and immunofluorescence, respectively. Ox-LDL was measured in the synovial fluid and in paired serum samples from the patients using the ELISA method.

RESULTS

Ox-LDL was detected in the synovial fluid and its receptor LOX-1 was detected in cartilage from both weight-bearing and non-weight-bearing areas, whereas no LOX-1 expression was found in normal cartilage. Ox-LDL reduced chondrocyte viability in cell cultures, while the addition of ascorbic acid to osteoarthritic chondrocytes resulted in a decrease in LOX-1 mRNA expression.

CONCLUSION

The detection of LOX-1 mRNA and protein expression in osteoarthritic cartilage drawn from both weight-bearing and non-weight-bearing regions of the same patients suggest that LOX-1 may be involved in the progression and pathogenesis of osteoarthritis.