Can adipokines serum levels be used as biomarkers of hand osteoarthritis?

PURPOSE: To evaluate serum levels of visfatin, resistin and adiponectin in patients with erosive (E) and non-erosive (NE) osteoarthritis (OA) of the hand (HOA) compared to normal controls (NC). METHODS: 94 outpatients with E HOA and NE HOA and 21 NC were enrolled. The radiological assessment of both hands was performed according to the Kellgren-Lawrence and Kallman score. Patients were divided into two subsets (lone HOA or generalized OA) based on clinically OA involvement of knee and hip. Serum visfatin, resistin and adiponectin levels were determined by ELISA assay. RESULTS: Visfatin was significantly higher in E HOA patients in comparison to NC and NE HOA group. Resistin showed a significant increase in both E HOA and NE HOA groups versus NC, in particular in generalized OA. No significant differences among groups were found in adiponectin. The Kallman score was more severe in the two subsets of E HOA patients compared to NE HOA. CONCLUSIONS: This study showed increased levels of resistin in erosive and non-erosive HOA, and higher visfatin levels in E HOA in comparison to NE HOA. These data suggest the adipokines possible role in the pathogenesis of HOA and their potential usefulness as biomarkers of the disease.

Ultrasound detected inflammation is associated with the development of new bone erosions in hand osteoarthritis: a longitudinal study over 3.9 years.

OBJECTIVE: To evaluate the association between ultrasound (US) detected inflammation at baseline and the subsequent development of new bone erosions at follow-up in patients with hand osteoarthritis (HOA). METHOD: 32 of the 35 (10 controls, 12 patients with non erosive HOA (non-EHOA), 13 with EHOA subjects originally studied were re-evaluated 3.9 years after the initial study, by means of standard radiography and US examination. Kellgren-Lawrence (K-L) and Kallman scores were utilized to evaluate 576 interphalangeal (IP) joints. US detected synovial inflammation features were scored as present/absent. US detected bone erosions were also investigated. The association between synovial inflammation features at baseline and the development of new bone erosions was evaluated using the generalized linear mixed model (GLMM) after adjustment for patient effect, age, gender, body mass index. RESULTS: In HOA patients, radiographic scores worsened and bone erosions progressed. In HOA patients similar percentages of joints with Power Doppler Signal (PDS) and gray scale (GS) synovitis were found comparing baseline and follow-up examinations, whilst a significant increase was found in the joints with effusions. Only a minority of joints were positive on both occasions (between 2 and 6 %), the majority fluctuated between positive and negative and vice versa. PDS positivity was associated with new radiographic central erosions and US-detected bone erosions, whereas GS synovitis and effusion were not. CONCLUSIONS: Radiographic scores and bone erosions increased over a period of about 4 years. Synovial inflammation as detected by PDS was associated with the appearance of new bone erosions.

Tocilizumab in glucocorticoid-naïve large-vessel vasculitis.

Glucocorticoids (GC) are the mainstay of treatment of large-vessel vasculitis (LVV), but a sizeable number of patients relapse upon tapering the GC dose or after discontinuation of GC therapy. In addition, GC cause numerous adverse events. Therefore, in patients with longstanding disease and in those at risk for GC-related adverse events, the use of alternative therapeutic agents should be considered. Interleukin-6 (IL-6) is a key player in the pathogenesis of LVV. Preliminary data suggest the efficacy of the IL-6 receptor inhibitor tocilizumab (TCZ) in patients with LVV. We report 2 treatment-naïve patients with a recent diagnosis of LVV who received monthly TCZ infusions (8 mg/kg body weight) for 6 consecutive months as monotherapy because of relative contraindications and patients' reluctance to take GC. In both cases we observed a complete clinical response and normalisation of inflammatory markers as well as a decrease in vascular FDG uptake and SUV ratio on fluorodeoxyglucose positron emission/computerised tomography. Serum IL-6 and soluble IL-6 receptor (sIL-6R) levels rose in both patients after TCZ therapy. TCZ may be an effective alternative to GC treatment for LVV patients at risk for GC-related adverse events. Larger studies are required to confirm our findings.

[Disease activity assessment in large vessel vasculitis]. / Valutazione dell'attività di malattia nelle vasculiti dei grandi vasi.

Disease activity assessment in large vessel vasculitis (LVV) is often challenging for physicians. In this study, we compared the assessment of disease activity based on inflammatory markers, clinical indices (Indian Takayasu Activity Score [ITAS] and the Kerr/National Institute of Health indices [Kerr/NIH]), and 18F-Fluorodesossiglucose (FGD) vascular uptake at positron emission tomography (Pet). We found that Pet results did not statistically correlate with the clinical indices ITAS and Kerr/NIH, because FDG uptake was increased (grade>2 on a 0-3 scale in at least one evaluated vascular segment) in many patients with inactive disease according to clinical and laboratory parameters (i.e., negative ITAS and Kerr/NIH indices as well as normal erythrocyte sedimentation rate (ESR) and C-reactive protein (PCR)). Similarly, interleukin- 6 and its soluble receptor did not statistically correlate with disease activity. In contrast, clinical indices showed a significant correlation between each other and with inflammatory markers (VES and PCR). These data suggest that while clinical indices and inflammatory markers may be useful to assess disease activity, Pet may be more sensitive.

Serum levels of long pentraxin PTX3 in patients with polymyalgia rheumatica.

OBJECTIVES: To evaluate PTX3 feasibility to provide a prognostic tool in PMR clinical practice. METHODS: Circulating PTX3 levels were measured in 93 PMR patients at disease onset and during corticosteroid therapy and in 46 normal controls (NC) by ELISA. RESULTS: No difference in PTX3 concentrations was observed between NC and PMR either at disease onset and during follow-up or between groups of patients defined according to the presence of recurrence/relapse. CONCLUSIONS: PTX3 serum levels do not increase significantly in active PMR. Further studies on patients with giant-cell arteritis could evaluate whether large vessel involvement may be associated to increased PTX3 levels.

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.

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.

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.

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.

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.

High in vivo expression of interleukin-17 receptor in synovial endothelial cells and chondrocytes from arthritis patients.

OBJECTIVE: To evaluate the presence of interleukin-17 (IL-17) and the expression of IL-17 receptor (IL-17R) in joint tissues from subjects with different arthritides. METHODS: Immunohistochemistry was used on frozen synovial and cartilage biopsies to identify cells expressing IL-17 and IL-17R. RESULTS: IL-17 staining was present only in synovial biopsies of rheumatoid arthritis (RA) (seven out of nine cases). IL-17R was expressed by all synovial biopsies evaluated except for three cases of post-traumatic arthritis (PTA). Vascular endothelial cells mainly expressed IL-17R. The percentage of IL-17R(+) vessels was the highest in RA synovium and the lowest in PTA. Chondrocytes from all types of arthritides were negative for IL-17 staining, but expressed IL-17R; the highest percentage of positive chondrocytes was found in seronegative spondylarthritis and the lowest in RA. CONCLUSIONS: IL-17-positive cells are found exclusively in RA. On the other hand, synovial endothelial cells and chondrocytes expressing IL-17R are found in the majority of patients with different types of arthritis. This finding suggests a role for a second ligand for IL-17R, which could be either a different cytokine or a different isoform of IL-17.

Absence of the association with CC chemokine receptor 5 polymorphism in polymyalgia rheumatica.

OBJECTIVE: Elevated RANTES serum levels are present in polymyalgia rheumatica (PMR) patients with active disease. Chemokines may contribute to the inflammatory PMR process through their binding to CC chemokine receptor 5 (CCR5). The aim of this study was to examine if the 32 base pair deletion allele in CCR5 (CCR5 delta 32 allele) might be associated with PMR susceptibility and influence the disease outcome. METHODS: We enrolled 88 consecutive patients with PMR residing in the Reggio Emilia area (Italy) who had a follow-up duration of at least one year. As a control group we used 86 healthy blood donors from the same geographic area. The CCR5 genotype of all PMR patients and controls was studied by polymerase chain reaction amplification of the region which includes the 32 deletion (CCR5 delta 32). RANTES serum levels were measured by commercial ELISA kits in CCR5 delta 32 heterozygous and CCR5 homozygous PMR patients at diagnosis before starting corticosteroid therapy and again after 6 months of therapy, as well as in 28 healthy subjects over 50 years of age. RESULTS: Frequencies of the CCR5 and CCR5 delta 32 alleles in patients and controls did not differ significantly. Homozygosity for CCR5 delta 32 was not detected in PMR patients and was detected in only one of the controls. No significant differences were observed between the patients carrying the CCR5 delta 32 allele and those homozygous for the normal CCR5 allele when we compared sex, presence of distal synovitis and systemic signs and/or symptoms, initial and cumulative prednisone dose, duration of therapy, ESR at diagnosis, frequency of relapse/recurrence and RANTES serum levels at diagnosis and after 6 months of corticosteroids. CONCLUSION: These results indicate that the frequency of the 32 deletion of the CCR5 receptor was not significantly different between PMR patients and healthy controls, and this genotype does not appear to be associated with the susceptibility to or severity of PMR.

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.

Corticosteroid injections in polymyalgia rheumatica: a double-blind, prospective, randomized, placebo controlled study.

OBJECTIVE: To determine the efficacy and safety of shoulder corticosteroid injections in polymyalgia rheumatica (PMR). METHODS: Twenty consecutive patients with active PMR were randomized into a 7 month, double blind, placebo controlled study. Patients received either bilateral shoulder injections of 40 mg of 6-methylprednisolone acetate or placebo (1 ml saline solution). Responders were treated weekly with the same regimen for a total of 4 bilateral injections and then followed for 6 months. Response was defined as a 70% reduction in visual analog scale (VAS) score for pain and for patient and physician global assessment, and duration of morning stiffness. Bilateral shoulder magnetic resonance imaging (MRI) was performed at different times to evaluate the response of lesions to therapy. RESULTS: All 10 corticosteroid treated patients responded to the first injection with a significant reduction in duration of morning stiffness, VAS pain scale, patient and physician global assessment, erythrocyte sedimentation rate, and C-reactive protein. Interleukin 6 serum levels were significantly reduced after the 2nd injection. In 5 patients, the response persisted throughout the followup period. The other 5 withdrew within 4 weeks after the 4th injection due to recurrence of symptoms. None of the 10 patients of the placebo group responded to the first injection. The difference between the 2 groups was significant (p = 0.03). No side effects were recorded. MRI showed marked improvement of shoulder lesions one week after first injection and an almost complete resolution one week after last injection in the responders. CONCLUSION: Shoulder corticosteroid injections seem to be an effective and safe therapy for PMR.

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.