Franco Schiavon

Acetylcholine biosensor involving entrapment of acetylcholinesterase and poly(ethylene glycol)-modified choline oxidase in a poly(vinyl alcohol) cryogel membrane.

A bienzymatic sensor for the determination of acetylcholine was prepared by physical coimmobilization of acetylcholinesterase and poly(ethylene glycol)-modified choline oxidase in a poly(vinyl alcohol) cryogel membrane obtained by a cyclic freezing-thawing process. The enzyme-modified polymer was applied on a platinum electrode to form an amperometric sensor, based on the electrochemical detection of enzymatically developed hydrogen peroxide. The analytical characteristics of this sensor, including calibration curves for choline and acetylcholine, pH, and temperature effects, and stability are described.

Clinical and laboratory manifestations of elderly onset psoriatic arthritis: a comparison with younger onset disease

OBJECTIVE Although the influence of age on clinical and laboratory features has been widely demonstrated in many arthropathies, studies on elderly onset (> 60 years) psoriatic arthritis (EOPsA) are rare. This study compares manifestations at onset and two year outcome of EOPsA with those of younger onset PsA (YOPsA). PATIENTS AND METHODS Sixty six consecutive PsA patients with disease duration < 1 year, 16 EOPsA (>60 years) and 50 YOPsA (⩽60 years) were admitted to a prospective study. Clinical, laboratory, and radiographic assessment were carried out at admission and after two years. HLA class I and bone scintigraphy were also recorded. In 10 patients with EOPsA and 24 with YOPsA it was possible to obtain synovial fluid, which was subsequently analysed for local inflammatory indices, including interleukin (IL) 1β, IL6, and IL8. RESULTS Presenting manifestations of EOPsA differed from YOPsA in number of active joints (mean (SD)) (12.2 (6.3) v 6.7 (4.6), p<0.001), foot bone erosions (2.7 (1.2) v1.1 (1.1), p<0.001), erythrocyte sedimentation rate (64.2 (35.3)v 30.5 (30.0) mm 1st h, p<0.001), C reactive protein (3.9 (2.0) v 1.3 (1.3) mg/dl, p<0.001) and synovial fluid IL1β (8.0 (4.7)v 3.0 (3.0) pg/ml, p<0.001) and IL6 (828.2 (492.6) v 469.3 (201.4) pg/ml, p<0.005). No differences were found in the number of subjects with dactylitis, pitting oedema, HLA-B27, or signs of sacroiliac and sternoclavicular joint involvement at bone scintigraphy. After two years, progression was more evident in EOPsA than in YOPsA, as the number of new erosions in the hands and also the C reactive protein were higher in EOPsA patients. CONCLUSION PsA has a more severe onset and a more destructive outcome in elderly people (onset >60 years) than in younger subjects. This behaviour may be influenced by immune changes associated with aging, as suggested by the higher concentrations of IL1β and IL6 found in the synovial fluid of EOPsA than in YOPsA.

PEG-modified glucose oxidase immobilized on a PVA cryogel membrane for amperometric biosensor applications

Poly(ethylene glycol)-modified glucose oxidase was immobilized in a poly(vinyl alcohol) cryogel membrane, obtained by a freezing-thawing cyclic process, to obtain a suitable amperometric glucose sensor. The covalent linkage between PEG and GOD molecule improved the physical immobilization of enzyme in the polymeric matrix, by decreasing its loss in time. Sensor behaviour was evaluated electrochemically with a hydrogen peroxide electrode. The glucose content in standard solutions was determined and linear calibration curves in the 5x10(-5)-5x10(-3) mol l(-1) range were obtained. The kinetic parameters in the immobilized system were evaluated and analytical characteristics of sensor, including stability and influence of pH and temperature, were determined.

Intravenous immunoglobulins control scleromyxoedema

Background: Scleromyxoedema is a variant of papular mucinosis affecting the skin and internal organs. The different therapeutic approaches proposed for scleromyxoedema are still unsatisfactory. Intravenous immunoglobulin (IVIg) has been successfully employed in the treatment of connective tissue diseases and vasculitides. Patients: The successful treatment of three cases of scleromyxoedema with IVIg is reported here. Conclusions: The relatively low risk of the drug and the high effectiveness seen in three patients suggest that IVIg is a new treatment potentially useful in scleromyxoedema.

Rheumatoid arthritis is the major risk factor for septic arthritis in rheumatological settings.

Septic arthritis (SA) is a clinical emergency with considerable morbidity and mortality that can lead to rapid joint destruction and irreversible functional loss. The reported incidence varies from 2-5 cases/100,000 person-years in the general population to 70 cases/100,000 person-years among patients with rheumatoid arthritis. In fact, individuals with rheumatoid arthritis are at particular risk for developing SA. This may be due to several reasons: joint disease predisposes to bacterial joint colonization and RA itself and its treatment with corticosteroids, disease-modifying antirheumatic drugs (DMARDs) and biological therapies may decrease the immune function required for protection from pathogens. Steroids and DMARDs seem to affect the leukocyte synovial count; indeed, RA patients with SA have a leukocyte count in synovial fluid (SF) lower than patients with SA without underlying rheumatic diseases. The diagnosis of SA in RA patients can be difficult because the development of a hot painful joint is often confused with a relapse of the underlying joint disease leading to delay in diagnosis. For this reason the microscopic analysis and culture of synovial fluid are crucial to exclude septic arthritis.

Protective effect of superoxide dismutase and polyethylene glycol-linked superoxide dismutase against renal warm ischemia/reperfusion injury

The protective effect of oxygen free radical scavenger superoxide dismutase (SOD) against the warm ischemic damage that occurs in kidneys harvested from non-heart-beating donors is controversial because of its short half-life. In this model, we compared the protective effect of SOD and two longer lasting polyethylene glycol (PEG)-linked forms of SOD in a model of renal ischemia induced by 60 min of arterial clamping in rats. Rats treated with PEG1-SOD and PEG2-SOD had a better renal function than controls, with significantly lower serum creatinine levels throughout the follow-up period and a significantly higher creatinine clearance on postoperative days 1, 2, and 4. In native SOD treated-rats, serum creatinine was lower than in controls, though not significantly so, and creatinine clearance was significantly higher on postoperative day 4. Our results indicate that the protective effect of SOD against renal warm ischemia can be enhanced by prolonging its half-life by binding the enzyme to PEG.

The 158VV Fcgamma receptor 3A genotype is associated with response to rituximab in rheumatoid arthritis: results of an Italian multicentre study

Objective The polymorphism 158V/F of Fc fragment of IgG (FCGR) type 3A may influence the response to rituximab (RTX) in rheumatoid arthritis (RA). We investigated the FCG3A polymorphism in a large cohort of RA patients treated with RTX, also by considering the possible loss of response from month +4 to +6 after RTX and the presence of established predictors of response. Methods The study analysed 212 RA patients. European League Against Rheumatism (EULAR) response was evaluated at months +4 and +6 after the first RTX infusion. The FCGR3A polymorphism was analysed by PCR followed by Sanger sequencing. Results The FCGR3A genotypes were associated with EULAR response (good or moderate) at month +6 (response in 34/38 (89.5%) VV vs 70/106 (66%) VF and in 51/77 (66.2%) FF patients; p=0.01), but not at month +4 (response in 32/37 (86.5%) VV vs 69/102 (67.6%) VF and 53/73 (72.6%) FF patients; p=0.09). Loss of response was observed only in VF and FF carriers ((VV vs VF vs FF: 0/37 (0%) vs 11/102 (10.8%) vs 12/73 (16.4%); p=0.02)). Probability of response at month +6 was very high when at least two of the three following items selected by multivariate analysis were present: positive rheumatoid factor and/or anticyclic citrullinated peptide antibodies, previous treatment with ≤1 anti-tumor necrosis factor (TNF) agent, and 158VV FCGR3A genotype (p<0.0001; OR 7.9, 95% CI 4.1 to 15.1). Conclusions The 158VV FCGR3A genotype was associated with response to RTX in a large cohort of RA patients. Patient genotyping may be helpful to plan RTX treatment, and may be integrated with clinical predictors.

Pegylated enzyme entrapped in poly(vinyl alcohol) hydrogel for biocatalytic application.

A procedure for enzyme entrapment into matrices suitable for biocatalytic applications is reported. The method, which takes advantage of the stable formation of polyvinyl alcohol (PVA) hydrogels by freezing and thawing PVA aqueous solutions, was assayed using lipase as model enzyme. The leakage of lipase was minimised by using high molecular weight PVA and by previous conjugation of the enzyme to PEG. The immobilised PEG enzyme maintained its catalytic activity in organic solvents also, thus allowing enzymatic activity towards water insoluble substrates. The activity was largely increased reducing the diffusional constrain by cutting the matrices into slices of micron size. Matrix-entrapped lipase-PEG, when used in the hydrolysis of acetoxycoumarins, showed a conversion rate of about 10 times lower than the enzyme-PEG in the free form, and maintained regioselectivity when a diacetylated product was used as substrate.

The TTTT B lymphocyte stimulator promoter haplotype is associated with good response to rituximab therapy in seropositive rheumatoid arthritis resistant to tumor necrosis factor blockers

OBJECTIVE To investigate the polymorphisms in the promoter region of the B lymphocyte stimulator (BLyS) gene as markers of response to rituximab (RTX) in rheumatoid arthritis (RA). METHODS The study was first conducted in 152 Italian RA patients and then replicated in an additional 117 RA patients (73 Italian, 44 British). The European League Against Rheumatism response criteria were used to evaluate the response rate at months 4 and 6 after the first cycle of RTX, by means of the Disease Activity Score in 28 joints using the erythrocyte sedimentation rate; patients were classified according to the best response shown between months 4 and 6. BLyS promoter polymorphisms were analyzed by polymerase chain reaction followed by the analysis of the restriction fragments, BLyS promoter haplotypes were analyzed using the expectation-maximization algorithm, and BLyS serum levels were analyzed using enzyme-linked immunosorbent assay. Odds ratios (ORs) were calculated with 95% confidence intervals (95% CIs). RESULTS The TTTT BLyS promoter haplotype appeared to be significantly associated with response to RTX only in the subset of seropositive patients (those positive for rheumatoid factor and/or anti-cyclic citrullinated peptide). The replication study confirmed that this association was limited to seropositive RA patients in whom treatment with anti-tumor necrosis factor (anti-TNF) agents had previously failed. In the whole series of seropositive patients in whom anti-TNF agents had previously failed, patients carrying the TTTT BLyS promoter haplotype were more prevalent in good responders (18 of 43 [41.9%]) than in moderate responders (20 of 83 [24.1%]) or in nonresponders (1 of 21 [4.8%]) (for good responders versus nonresponders, OR 14.4 [95% CI 1.77-117.39], P=0.0028). Furthermore, multivariate analysis selected the TTTT BLyS promoter haplotype as an independent marker of good response to RTX (for good responders versus nonresponders, OR 16.2 [95% CI 1.7-152.5], P=0.01; for good responders versus moderate responders and nonresponders combined, OR 3.1 [95% CI 1.2-7.8], P=0.02). The relationship between BLyS polymorphisms and BLyS serum levels remained unclear. CONCLUSION BLyS promoter genotyping may be suitable for identifying seropositive RA patients who may have a good response to RTX after anti-TNF agents have failed.

Septic Arthritis Caused by Rothia dentocariosa in a Patient with Rheumatoid Arthritis Receiving Etanercept Therapy

To the Editor: Rothia dentocariosa is a pleomorphic gram-positive rod normally found in the human mouth that has been associated with dental cavities, periodontal disease1, and, rarely, as a cause of systemic infection2,3. We describe a case of septic arthritis due to R. dentocariosa in a 46-year-old woman admitted to our Rheumatology Unit in December 2008. She had been diagnosed with polyarticular rheumatoid arthritis (RA) 10 years before, and for 2 years arthritis was treated with etanercept (25 mg twice weekly) and oxaprozin. She underwent a meniscectomy and synovectomy of the right knee in March 2008. Tumor necrosis factor (TNF) inhibitor was stopped 2 weeks before and started again 2 weeks after surgery. Levofloxacin was administered for 2 weeks after surgery. Three months later the knee suddenly became swollen and painful. The patient had no fever; laboratory investigation showed only a mild increase of erythrocyte sedimentation rate (ESR; 57 mm/h). Arthritis was diagnosed as a rheumatoid flare and treated with corticosteroid infiltrations, unsuccessfully, with no other therapeutic change. On admission, … Address correspondence to Prof. Schiavon; E-mail: f.schiavon{at}unipd.it