Clinical associations in patients with hand osteoarthritis.

OBJECTIVES: To investigate the clinical associations of hand osteoarthritis (HOA) and their relationships with radiographic features. METHODS: A total of 446 patients with hand osteoarthritis (HOA; 233 with erosive HOA (EHOA) and 213 with non-EHOA) and 307 controls were evaluated. Demographic and clinical data from patients and controls were recorded based on medical records/clinical reports and an anamnesis of drug consumption. Posteroanterior radiographs of both hands were obtained from all HOA patients and were assessed using the Kellgren and Lawrence (K&L) and Kallman scoring systems. RESULTS: After adjustment for age, gender, and body mass index (BMI), HOA patients showed a significantly increased odds ratio (OR) for hypercholesterolaemia [OR 2.10, 95% confidence interval (CI) 1.39-3.16, p < 0.0005] and autoimmune thyroiditis (OR 4.85, 95% CI 1.77-13.29, p = 0.002), as well as for knee (OR 1.63, 95% CI 1.09-2.44, p = 0.018) and hip OA (OR 1.87, 95% CI 1.07-3.27, p = 0.029). No significant increase for systemic hypertension, ischaemic heart disease, and diabetes mellitus was found. Patients with EHOA and non-EHOA showed similar risks for the above-mentioned co-morbidities. A similar occurrence of clinical associations was also observed in patients with HOA alone and in those with generalized OA. No association between radiographic scores and clinical associations was observed. CONCLUSIONS: Patients with HOA present a direct association with hypercholesterolaemia (and autoimmune thyroiditis) but do not show increased ischaemic cardiovascular manifestations compared to controls. No significant association between radiographic scores and co-morbidities was found.

Development and validation of low-intensity pulsed ultrasound systems for highly controlled in vitro cell stimulation.

This work aims to describe the development and validation of two low-intensity pulsed ultrasound stimulation systems able to control the dose delivered to the biological target. Transducer characterization was performed in terms of pressure field shape and intensity, for a high-frequency range (500 kHz to 5 MHz) and for a low-frequency value (38 kHz). This allowed defining the distance, on the beam axis, at which biological samples should be placed during stimulation and to exactly know the intensity at the target. Carefully designed retaining systems were developed, for hosting biological samples. Sealing tests proved their impermeability to external contaminants. The assembly/de-assembly time of the systems resulted ~3 min. Time-domain acoustic simulations allowed to precisely estimate the ultrasound beam within the biological sample chamber, thus enabling the possibility to precisely control the pressure to be transmitted to the biological target, by modulating the transducer's input voltage. Biological in vitro tests were also carried out, demonstrating the sterility of the system and the absence of toxic and inflammatory effects on growing cells after multiple immersions in water, over seven days.

Interleukin-4/interleukin-4 receptor gene polymorphisms in hand osteoarthritis.

OBJECTIVE: IL-13/IL-4/IL-4R system has strong chondroprotective activity. We investigated polymorphisms in these genes as potential hand osteoarthritis (OA) susceptibility loci by performing a case-control association study. METHODS: Eighteen common single nucleotide polymorphisms (SNPs) (nine in IL-4R, five in IL-4 and four in IL-13) were genotyped in 403 patients (380 females) with hand OA and 322 healthy controls (308 females). RESULTS: Two SNPs (rs1805013 and rs1805015), mapping to the IL-4R gene, were associated with P-values of 0.0116 and 0.0305 respectively in the whole sample. As far as the non-erosive hand OA group (n=159) is concerned, the significance level of association of SNP rs1805013 is increased. After correction for multiple testing (correction for the 54 tests) the significance was not retained. None of the IL-13 SNPs analyzed showed association with hand OA. Some of the analyzed SNP within the IL-4 gene showed significant association with hand OA only when considering subgroups of patients. With respect to the CMC1 OA group, two SNPs in IL-4 (rs2243250 and rs2243274) showed association with a P-value of 0.027 and 0.018 respectively. None of these associations remained after correction for multiple testing. CONCLUSIONS: The present study shows a trend to an association between non-erosive hand OA in Caucasian population and a genetic variant in the coding region of IL-4R gene. Our results, in keeping with previous data on hip OA, confirm the suggestion that IL-4/IL-4R system plays a role in OA pathogenesis. Further confirmation studies on different populations are necessary.

Circulating RANKL/OPG in polymyalgia rheumatica.

OBJECTIVE: To evaluate whether RANKL/OPG balance is modified in PMR patients, either in the active phase of the disease or during corticosteroid treatment. METHODS: Circulating levels of RANKL and OPG were assayed by enzyme-linked immunosorbent assay in PMR patients with active untreated disease and in patients treated by corticosteroids over a 12-month follow-up period. RESULTS: We found no statistically significant differences in circulating levels of OPG between PMR patients either in the active phase of the disease or during all follow-up period compared to normal controls. On the other hand, systemic production of sRANKL is increased and is not modulated by corticosteroid treatment. CONCLUSION: In PMR increased levels of sRANKL may be related to bone osteoporosis. Further investigations are necessary to evaluate the relationship between the RANK/RANKL/OPG system and bone turnover in PMR patients.

Synovial expression of vasoactive intestinal peptide in polymyalgia rheumatica.

OBJECTIVE: Polymyalgia rheumatica (PMR) is an inflammatory disease that typically affects elderly people. Its clinical hallmark is the severity of pain in the shoulder and pelvic girdle. Mild to moderate synovitis and/or bursitis of the joints involved has been described. Neuropeptides are involved in nociception and modulation of inflammatory reaction. To evaluate whether neuropeptides have a role in PMR pathophysiology, we studied the expression of substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP) and somatostatin (SOM) in shoulder synovial tissues of PMR patients. METHODS: Synovial expression of neuropeptides was investigated by immunohistochemical analysis, in two groups of PMR patients: the first one at the onset of disease and the second one after corticosteroid treatment, and in other joint diseases, rheumatoid arthritis (RA) and osteoarthritis (OA). RESULTS: The only significant expression of VIP was found in PMR and, to a lesser extent, in RA synovial tissue. In PMR, we observed VIP immunostaining both in the lining layer and in the sublining area. In patients on corticosteroid treatment VIP lining layer expression was not significantly different while VIP positive cells in the sublining area were almost absent. CONCLUSION: Local VIP production in PMR synovial tissue might contribute to the typical musculoskeletal discomfort and it may have a role in the immunomodulation of synovial inflammation.

Vascular endothelial growth factor activities on osteoarthritic chondrocytes.

OBJECTIVE: Evaluation of the role of VEGF in cartilage pathophysiology. METHODS: VEGF release from chondrocytes in the presence of IL-1beta, TGFbeta and IL-10 was detected by immunoassay. VEGF receptor -1 and -2 expression and VEGF ability to modulate caspase -3 and cathepsin B expression were detected by immunohistochemistry on cartilage biopsies and cartilage explants. VEGF effects on chondrocyte proliferation was analysed by a fluorescent dye that binds nucleic acids. RESULTS: VEGF production by osteoartritis (OA) chondrocytes was significantly reduced by IL-1beta while it was increased in the presence of TGFbeta. Cartilage VEGFR-1 immunostaining was significantly downregulated in 'early' OA patients compared to normal controls (NC). VEGFR-2 expression was negligible both in OA and in NC. VEGF decreased the expression of caspase-3 and cathepsin B, whereas it did not affect proliferation. CONCLUSION: VEGF is able to down-modulate chondrocyte activities related to catabolic events involved in OA cartilage degradation.

Chemokine production by peripheral blood mononuclear cells in elderly subjects.

The function of chemokines in promoting and modulating leukocyte migration is essential for a prompt and efficacious inflammatory response and in host defence against infections. In order to investigate whether this important aspect of immunological response is influenced by ageing, we evaluated the basal levels as well as the ability of peripheral blood mononuclear cells from young and healthy elderly subjects to produce chemokines (IL-8, MCP-1, MIP-Ialpha, RANTES) in response to stimulation with anti-CD3 monoclonal antibody and lipopolysaccharide (LPS), a gram negative bacterial endotoxin. Our main findings are a spontaneous chemokine production; a 20% decrease of proliferative response to anti-CD3 monoclonal antibody accompanied by an age related increase of MIP-Ialpha and RANTES production and by a general increase of all chemokine production compared to unstimulated conditions; a proliferative defect of monocytes to LPS challenge associated with an increase of chemokine production compared to basal conditions with a progressive age-related increase of MIP-lalpha. In conclusion, this study suggests that chemokines could have a compensatory role in balancing the impaired mechanisms involved in 'specific' immune response during ageing. The successful activation of this strategy could contribute to the good performance of immune system so maintaining healthy status in elderly.

Different IL-8 production by T and NK lymphocytes in elderly subjects.

A gradual decline in the functional activity of the immune system is described with advancing age. The adaptive immune system seems the most severely affected, but some age-associated modifications also occurs in NK cells. Several studies investigated the age related changes of cytokine production, while little is known about chemokines, whose importance in regulating immune-response becomes even more evident. In this study we investigated whether the ability of T lymphocytes and NK cells to produce IL-8, either spontaneously or after activation, respectively with anti-CD3 monoclonal antibody or interleukin 2 (IL-2) was affected by age. We demonstrated that: (a) T lymphocytes and NK cells spontaneously produced detectable amounts of IL-8; (b) anti-CD3 stimulation of T lymphocytes significantly increased IL-8 production and the increment was more evident in the nonagenarian subjects; (c) similarly, IL-2 stimulation of NK cells rose the production of IL-8 but the amount produced by the old was lower than the one produced by the young group. Because of the co-stimulatory role of chemokines on NK responses and given the demonstrated importance of NK cells in defence against viral infections, the decreased production of IL-8 can be involved in the defective functional activity of NK cells from old subjects.

Biological parameters influencing the immunological response to plasma derived and recombinant hepatitis B vaccines.

Personnel (1856 subjects) belonging to local health units (medical and paramedical staff) that have been vaccinated since 1984 against hepatitis B virus (HBV) with HBsAg plasma purified preparations (Hevac-B and H-B-Vax) or recombinant DNA preparation (Engerix-B) were followed in plasma anti-HBs antibody levels. At the end of the protocols, different seroconversion percentages and different anti-HBs levels were reached: the best results were obtained with Engerix-B. Sex and principally age influenced the antibody production: women generally reached highest protective antibody levels and the 21-30 year group was more responsive than other groups. The injection of a supplementary 4th or 5th dose in low or non-responders could restore the specific immunity in the majority of the subjects and increase the anti-HBs level. The time course after the immunization of antibody levels depended on the level reached at the end of vaccination schedule. These data suggest that different antibody level monitorings of vaccinated subjects, planned on the basis of the antibody level reached at the end of vaccination, could prevent a loss of protection against the HBV infection.

Evaluation of prognostic significance of circulating interleukin-6 in patients with accident spine injuries.

Our study aimed to verify whether patients with spine accident injury present altered plasma levels of IL-6 and whether the levels of this cytokine are related with the production of acute phase proteins which are elevated after trauma and infection. 34 subjects admitted to an Intensive Care Unit for spine injuries were examined: 26 presented fever over 38.5 degrees C and in 13 of them blood or local cultures were positive for pathogenic bacteria. IL-6, C-reactive protein (CRP), haptoglobin (HPT), alpha 2-macroglobulin (alpha 2Mg), C3c and C4 Complement factors were determined on admission and in the course of their hospital stay. No changes in IL-6 systemic levels were present in the subjects examined and only CRP was constantly high. Although within the normal range IL-6 levels inversely correlated with fever. Our results show the difficulty to utilize the IL-6 circulating levels as prognosis parameter in patients subjected to spine accident injuries.

Elevated serum levels of soluble interleukin-4 receptor in osteoarthritis.

OBJECTIVE: To test the importance of the interleukin-4 (IL-4)/IL-4 receptor (IL-4R) system in osteoarthritis (OA) we evaluated soluble IL-4R (sIL-4R) levels in sera of patients with different forms of OA and healthy individuals. METHODS: We recruited: 141 patients with hand OA, 70 with nodal and 71 with erosive hand OA; 64 patients undergoing total joint replacement, 34 with hip and 30 with knee OA; and 38 ethnically and geographically age-matched healthy individuals [normal controls (NC)]. RESULTS: Serum sIL-4R concentration was found to be significantly higher in all OA patients than that in NC. When patients were divided into four subgroups (nodal, erosive, hip and knee OA) significant differences were present when comparing NC with each subgroup. This was true also when small-joint OA groups were compared with large-joint OA groups, the latter being associated with higher IL-4R levels. CONCLUSIONS: We found increased levels of sIL-4R in OA patients compared with healthy individuals. We speculate that this reduces availability of IL-4, and its effects on chondrocytes.

Distribution of IgG subclasses after anti-hepatitis B virus immunization with a recombinant vaccine.

To assess whether a different IgG subclass distribution was elicited in "low" and "high responders" after vaccination with recombinant hepatitis B virus surface antigen, we selected from 360 vaccine recipients 30 "low-responder" subjects, with anti-HBs levels of 10-160 mIU/ml, and 40 "high-responder" subjects, with anti-HBs levels greater than 10,000 mIU/ml. In both groups all IgG subclasses were elicited in the anti-HBs response and the greatest contribution was that of IgG1, followed by IgG2. IgG1 was significantly less represented after the second (58%) and third doses (61%) of vaccine in "low responders" compared with "high responders" (65% and 69%). The relative percentage of IgG2 was significantly higher after the second (33%) and third (30%) doses of vaccine in "low responders" than in "high responders" (29% and 26%). In "low responders" the age of vaccine recipients significantly influenced the anti-HBs IgG subclass distribution: IgG2 and IgG4 production was positively correlated with age, whereas the opposite was observed for IgG1. These data support the evidence that: (1) IgG1 and IgG2 subclasses are mainly involved in the specific anti-HBs response both in "high" and "low responders"; (2) the relative contribution of specific IgG2 to vaccination is higher in low responders and progressively increases with age.

A mathematical model predicting anti-hepatitis B virus surface antigen (HBs) decay after vaccination against hepatitis B.

The determination of serum levels of antibodies against hepatitis B virus surface antigen (anti-HBs) after hepatitis B vaccination is currently the only simple test available to predict the decay of protection and to plan the administration of booster doses. A total of 3085 vaccine recipients of plasma-derived and recombinant vaccine have been followed for 10 years to determine the kinetics of anti-HBs production and to construct a mathematical model which could efficiently predict the anti-HBs level decline. The anti-HBs peak level was reached 68 days after the last dose of recombinant vaccine and 138 days after the last dose of plasma-derived vaccines. The age of vaccinees negatively influenced the anti-HBs levels and also the time necessary to reach the anti-HBs peak. A bilogarithmic mathematical model (log10 level, log10 time) of anti-HBs decay has been constructed on a sample of recombinant vaccine recipients and subsequently validated on different samples of recombinant or plasma-derived vaccine recipients. Age, gender, type of vaccine (recombinant or plasma-derived), number of vaccine doses (three or four) did not influence the mathematical model of antibody decay. The program can be downloaded at the site: http:@www2.stat.unibo.it/palareti/vaccine.htm . Introducing an anti-HBs determination obtained after the peak, the program calculates a prediction of individual anti-HBs decline and allows planning of an efficient booster policy.

Epitope specificity of Th0/Th2 CD4+ T-lymphocyte clones induced by vaccination with rHBsAg vaccine.

BACKGROUND & AIMS: Different amino acid sequences of hepatitis B virus surface antigen (HBsAg) are involved in the activation of CD4+ lymphocytes needed to induce an optimal antiviral function. The aim of this study was to characterize the CD4-mediated response to immunodominant HBsAg epitopes in hepatitis B virus (HBV) vaccine recipients by defining minimal sequences recognized by T cells, cytokine profiles, and HLA restriction of peptide recognition. METHODS: T-lymphocyte lines and clones specific for HBsAg were isolated from the peripheral blood of subjects immunized with recombinant HBsAg and stimulated in vitro with synthetic peptides spanning the whole HBsAg sequence. RESULTS: Four immunodominant epitopes (sequences 21-40, 136-155, 156-175, and 211-226) were identified. Using panels of truncated peptides of different length, sequences 21-28, 165-172, and 215-223 were shown to correspond to the minimal epitopes recognized by T cells. The antigen-specific T-lymphocyte proliferation was HLA class II restricted, and each peptide could be presented in association with different HLA class II determinants. Th0/Th2 cytokine patterns were induced on peptide stimulation. CONCLUSIONS: These results indicate the presence of at least four immunodominant epitopes within HBsAg that represent potential candidates for the design of anti-HBV synthetic vaccines.

Vascular endothelial growth factor production in polymyalgia rheumatica.

OBJECTIVE: To evaluate peripheral production and synovial expression of vascular endothelial growth factor (VEGF) in polymyalgia rheumatica (PMR). METHODS: Circulating levels of VEGF in PMR (serum concentration and in vitro release by peripheral blood mononuclear cells [PBMC]) were investigated by enzyme-linked immunosorbent assay. Local expression of VEGF in shoulder synovial tissue was investigated by immunohistochemical analysis. Investigations were performed in patients with active, untreated disease and in patients treated with corticosteroids. RESULTS: VEGF serum concentrations were significantly higher in untreated PMR patients than in normal control subjects. During steroid treatment, VEGF serum concentrations reached their lowest level after the sixth month of treatment. PBMC isolated from untreated PMR patients spontaneously secreted a higher amount of VEGF compared with PBMC from control subjects. Corticosteroid therapy did not affect the ability of PBMC to produce VEGF. Immunohistochemical staining performed on shoulder synovial tissue showed VEGF expression in both the lining layer and the sublining area. In 3 of 4 treated patients, no VEGF staining was found in synovial tissue during corticosteroid therapy. VEGF expression correlated with vessel density, but was not associated with alphavbeta3 and alphavbeta5 integrin expression. CONCLUSION: Peripheral and local VEGF releases have different responses to steroid treatment in PMR. The lack of response to corticosteroids by peripheral VEGF production supports the hypothesis that systemic involvement is dominant in PMR. At the synovial level, VEGF production is linked to vascular proliferation and is thus directly involved in the pathogenesis of synovitis.

Chemokine production by human chondrocytes.

OBJECTIVE: To evaluate the role of chondrocytes in producing CXC chemokines [interleukin 8 (IL-8), growth related gene product (GRO-alpha)] and CC chemokines [monocyte chemoattractant protein (MCP-1), macrophage inflammatory protein (MIP-1alpha), RANTES] in patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and subjects after traumatic injury (PT). METHODS: Articular cartilage specimens were obtained from 38 patients with OA and 18 with RA undergoing joint replacement surgery. Healthy human cartilage was obtained from femoral condyles removed after trauma in 11 subjects with no history of joint pathology (PT cases). Chondrocytes were isolated from articular cartilage by sequential enzymatic digestion and cultured in vitro. Chemokine production was investigated in unstimulated condition and after 72 h incubation with proinflammatory [IL-1beta, tumor necrosis factor-alpha (TNF-alpha)] and antiinflammatory [transforming growth factor-beta1 (TGF-beta1), IL-10] mediators. Chemokine concentrations in cell supernatants were evaluated by ELISA. RESULTS: Chondrocytes produce all these chemokines to a different extent. IL-1beta was a more potent stimulus than TNF-alpha in inducing production of all chemokines except MCP-1. We found no statistical differences among chondrocytes isolated from OA, RA, and PT for chemokine production in either basal conditions or after cytokine stimulation. IL-1beta induced chemokine production can be modulated by TGF-beta1 in different ways according to the various chemokines, while IL-10 does not affect IL-1beta induced chemokine production. CONCLUSION: Chondrocytes produce IL-8, GRO-alpha, MCP-1, MIP-1alpha, and RANTES. Proinflammatory factors (IL-1beta, TNF-alpha) effectively upregulate chemokine production, but production is scarcely modulated by the antiinflammatory mediators TGF-beta and IL-10. Chondrocyte derived chemokines may play a role in triggering the mechanisms involved in pathogenesis and persistence of joint diseases.

Down-modulation of chemokine receptor cartilage expression in inflammatory arthritis.

OBJECTIVE: To evaluate in vivo expression of chemokine receptors in cartilage tissue samples from healthy and diseased joints. METHODS: Presence and distribution of several chemokine receptors in cartilage samples from patients with osteoarthritis (OA) or inflammatory arthritis (IA) and from multi-organ donors were assessed by immunohistochemistry. The expression of messenger RNA (mRNA) for chemokine receptors was also analysed by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Normal and OA-affected cartilage showed a moderate to high expression of chemokine receptors, while staining of IA samples ranged from low to absent. Differences between OA and IA samples were present for all receptors but CCR2 and CXCR4. Moreover, mRNAs for CCR1, CCR5 and CXCR1 were found both in normal and pathological chondrocytes, suggesting that chemokine receptor down-modulation seen in IA samples could be a post-transcriptional event. CONCLUSION: Data on normal and pathological chondrocytes underline the role of chemokines in cartilage homeostasis and suggest an imbalance towards catabolic processes in inflammatory conditions.

Differential roles of nitric oxide and oxygen radicals in chondrocytes affected by osteoarthritis and rheumatoid arthritis.

Osteoarthritis and rheumatoid arthritis are characterized by focal loss of cartilage due to an up-regulation of catabolic pathways, induced mainly by pro-inflammatory cytokines, such as interleukin-1 (IL-1) and tumour necrosis factor alpha (TNFalpha). Since reactive oxygen species are also involved in this extracellular-matrix-degrading activity, we aimed to compare the chondrocyte oxidative status responsible for cartilage damage occurring in primarily degenerative (osteoarthritis) and inflammatory (rheumatoid arthritis) joint diseases. Human articular chondrocytes were isolated from patients with osteoarthritis or rheumatoid arthritis, or from multi-organ donors, and stimulated with IL-1beta and/or TNFalpha. We evaluated the oxidative stress related to reactive nitrogen and oxygen intermediates, measuring NO(-)(2) as a stable end-product of nitric oxide generation and superoxide dismutase as an antioxidant enzyme induced by radical oxygen species. We found that cells from patients with osteoarthritis produced higher levels of NO(-)(2) than those from patients with rheumatoid arthritis. In addition, IL-1beta was more potent than TNFalpha in inducing nitric oxide in both arthritides, and TNFalpha alone was almost ineffective in cells from rheumatoid arthritis patients. We also observed that the intracellular content of copper/zinc superoxide dismutase (Cu/ZnSOD) was always lower in rheumatoid arthritis chondrocytes than in those from multi-organ donors, whereas no differences were found in intracellular manganese SOD (MnSOD) or in supernatant Cu/ZnSOD and MnSOD levels. Moreover, intracellular MnSOD was up-regulated by cytokines in osteoarthritis chondrocytes. In conclusion, our results suggest that nitric oxide may play a major role in altering chondrocyte functions in osteoarthritis, whereas the harmful effects of radical oxygen species are more evident in chondrocytes from patients with rheumatoid arthritis, due to an oxidant/antioxidant imbalance.