Receptor activator of nuclear factor kappa-B ligand (RANKL) but not sclerostin or gene polymorphisms is related to joint destruction in early rheumatoid arthritis

Honey: A Promising Therapeutic Supplement for the Prevention and Management of Osteoporosis and Breast Cancer

Osteoporosis and breast cancer are serious diseases that have become a significant socioeconomic burden. There are biochemical associations between the two disorders in terms of the amended function of estrogen, receptor activator of nuclear factor kappa beta ligand, oxidative stress, inflammation, and lipid accumulation. Honey as a functional food with high antioxidant and anti-inflammatory properties can contribute to the prevention of various diseases. Its health benefits are mainly related to the content of polyphenols. This review aims to summarize the current knowledge from in vitro, animal, and human studies on the use of honey as a potential therapeutic agent for osteoporosis and breast cancer. Preclinical studies have revealed a beneficial impact of honey on both bone health (microstructure, strength, oxidative stress) and breast tissue health (breast cancer cell proliferation and apoptosis, tumor growth rate, and volume). The limited number of clinical trials, especially in osteoporosis, indicates the need for further research to evaluate the potential benefits of honey in the treatment. Clinical studies related to breast cancer have revealed that honey is effective in increasing blood cell counts, interleukin-3 levels, and quality of life. In summary, honey may serve as a prospective therapeutic supplement for bone and breast tissue health.

Increased circulating sclerostin levels in rheumatoid arthritis patients: an updated meta-analysis

BACKGROUND

Sclerostin, a regulator of bone metabolism and vascular calcification involved in regulating the Wnt/β-catenin signaling pathway, has been shown to be involved in the pathogenesis of rheumatoid arthritis (RA). However, current results regarding the circulating sclerostin level of RA patients are debatable. This study aimed to evaluate the circulating level of sclerostin in RA patients and briefly summarize its role.

METHOD

PubMed, EMBASE, and the Cochrane Library databases were systematically searched till May 27, 2021, for eligible articles. Useful data from all qualified papers were systematically extracted and analyzed using Stata 12.0 software (Stata Corp LP, College Station, TX, USA).

RESULTS

Overall, 13 qualifying studies including 1030 cases and 561 normal controls were analyzed in this updated meta-analysis. Forest plot of this meta-analysis showed that RA patients had higher circulating sclerostin levels (P < 0.001, standardized mean difference [SMD] = 0.916, 95% CI: 0.235-1.597) compared to normal controls. Subgroup analyses implied that age, region, and assay method were associated with sclerostin level in RA patients.

CONCLUSION

RA patients have higher circulating sclerostin levels, and these was influenced by age, region, and assay method.

The association of serum RANKL levels with disease activity and hematological parameters in Syrian patients with rheumatoid arthritis

Our study aims to detect whether the serum RANKL could be a novel potential biomarker for activity and diagnosis of rheumatoid arthritis (RA). It included fifty-eight of RA patients and thirty of equal age and sex matched controls. Disease activity was determined by using DAS28-ESR. Serum Levels of RANKL were assayed by ELISA and compared with parameters such as ESR, CRP, Rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (ACPA). The serum RANKL levels were higher in RA patients compared to controls. There was an increase in its levels mean among post-menopausal patients compared to post-menopausal healthy group. RANKL levels were also higher in ACPA positive patients than ACPA negative. Our study found a correlation between RANKL levels and some parameters: DAS28, ACPA, CRP, and symptom duration. There was a moderate inverse correlation between RANKL levels and BMD. By ROC curve, our results displayed that the best cut-off value of RANKL was 178.99 pg/ml (sensitivity 79.31%; specificity 90%) to differentiate between RA patients and controls. In conclusion, elevated serum RANKL can be used as an indicator of disease activity and a diagnostic new biomarker in patients with early RA.

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Rheumatoid arthritis (RA) is categorized by chronic synovitis leads to cartilage degradation, and bone erosions.

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RANKL/RANK/OPG pathway stimulates osteoclasts and bone resorption.

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ACPA are associated with bone erosions.

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Serum RANKL correlates disease activity of Rheumatoid Arthritis.

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Serum RANKL is an innovative indicator in of Rheumatoid Arthritis patients.

Pathomechanisms of bone loss in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease, in which the inflammatory processes involve the skeletal system and there is marked destruction of the bones and the surrounding structures. In this review, we discuss the current concepts of osteoimmunology in RA, which represent the molecular crosstalk between the immune and skeletal systems, resulting in the disruption of bone remodeling. Bone loss in RA can be focal or generalized, leading to secondary osteoporosis. We have summarized the recent studies of bone loss in RA, which focused on the molecular aspects, such as cytokines, autoantibodies, receptor activator of nuclear kappa-β ligand (RANKL) and osteoprotegerin (OPG). Apart from the above molecules, the role of aryl hydrocarbon receptor (Ahr), which is a potential key mediator in this process through the generation of the Th17 cells, is discussed. Hence, this review highlights the key insights into molecular mechanisms of bone loss in RA.

Comparison of Romosozumab Versus Denosumab Treatment on Bone Mineral Density After One Year in Rheumatoid Arthritis Patients with Severe Osteoporosis: A Randomized Clinical Pilot Study

OBJECTIVES

To investigate the effect of romosozumab versus denosumab treatment on bone mineral density (BMD), disease activity, and joint damage in patients with rheumatoid arthritis (RA) and severe osteoporosis.

METHODS

Fifty-one postmenopausal women were enrolled and randomized equally into two groups to receive either romosozumab or the denosumab. Changes (Δ) in the BMD (at lumbar spine, total hip, and femoral neck), disease activity score in 28 joints (DAS28)-erythrocyte sedimentation rate (ESR), and van der Heijde-modified Total Sharp Score (TSS) from baseline to 12 months after treatment were evaluated.

RESULTS

The ΔBMD at 12 months in the romosozumab and denosumab groups were 10.2 ± 5.6% and 5.0 ± 3.1% (p = 0.002) for the lumbar spine, 3.7 ± 4.9% and 3.5 ± 3.0% (p = 0.902) for total hip, and 3.6 ± 4.7% and 3.2 ± 4.9% (p = 0.817) for femoral neck, respectively. The ΔDAS28-ESR at 12 months in the romosozumab and denosumab groups was 0.14 and 0.22 (p = 0.643), respectively, whereas, the ΔTSS at 12 months was 0.33 and 0.29 (p = 0.927), respectively.

CONCLUSIONS

Our results suggest that romosozumab treatment was more effective in increasing the BMD at the lumbar spine than denosumab, and may be selected for patients who require a significant increase in the lumbar spine BMD. Moreover, romosozumab may be not affect disease activity and joint damage in patients with RA.

MIF-mediated NF-κB signaling pathway regulates the pathogenesis of polycystic ovary syndrome in rats

Polycystic ovary syndrome (PCOS) resulting from abnormal glucose metabolism is a relatively common and complex endocrine disorder among women in their reproductive years, However, the pathogenesis of PCOS is still unclear. The purpose of this study is to investigate the macrophage migration inhibitory factor (MIF) involvement of the nuclear factor (NF)-κB in rats with PCOS. Results indicated that testosterone promoted the increase in the levels of MIF and luteinizing hormone (LH) but inhibited the increase in the level of follicular stimulating hormone (FSH). The MIF antibody could alleviate the process of PCOS to a certain extent. Testosterone promoted the expression of interleukin 1-beta (IL-1β), interleukin 6 (IL-6), Inducible nitric oxide synthase (iNOS), and tumor necrosis factor alpha (TNF-α); the MIF antibody could reverse this effect. Testosterone could inhibit the expression of NF-κB protein whereas MIF antibody could promote the expression in the ovarian cytoplasm. Testosterone promoted the expression of NF-κB protein in the nucleus, this effect also could be reversed by the MIF antibody. Hyperandrogenism activated the NF-κB pathway. After using the MIF antibody, this effect was reversed. This finding suggested that hyperandrogenism activated the NF-κB pathway through MIF. In short, increased MIF levels activated the NF-κB pathway in ovaries, leading to inflammation and the increase in the levels of relevant inflammatory indicators, which might be one of the important factors in the pathogenesis of PCOS.

The role of renin angiotensin system in the pathophysiology of rheumatoid arthritis

BACKGROUND

In rheumatoid arthritis (RA) and osteoarthritis (OA), chronic inflammatory processes lead to progresive joint destruction. The renin-angiotensin system (RAS) is involved in the pathogenesis of RA and OA. The aim of this mini-review article is to summarize evidence on the role of RAS in RA and OA.

METHODS

A non-systematic search in Pubmed included terms as "rheumatoid arthritis", "renin angiotensin system", "osteopenia", "RANKL", "DKK-1", "MMP", "inflammation", "angiogenesis", "local renin-angiotensin system", "angiotensin converting enzyme", "AT2 receptor", "Ang-(1-7)", "VEGF", "angiotensine receptor blocker", "angiotensin converting enzyme inhibitors", "renin inhibitors".

RESULTS

Both RAS axes, the classical one, formed by angiotensin converting enzyme (ACE), angiotensin (Ang) II and AT1 receptor (AT1R) and the counter-regulatory one, composed by ACE2, Ang-(1-7) and the Mas receptor, modulate inflammation and tissue damage. Ang II activates pro-inflammatory mediators and oxidative stress. Conversely, Ang-(1-7) exerts anti-inflammatory actions, decreasing cytokine release, leukocyte attraction, density of vessels, tissue damage and fibrosis. Angiogenesis facilitates inflammatory cells invasion, while osteopenia causes joint dysfunction. Up-regulated osteoclastogenisis and down-regulated osteoblastogeneses were associaed with the activation of the classical RAS axis. Three different pathways, RANKL, DKK-1 and MMPs are enhanced by classical RAS activation. The treatment of RA included methotrexate and corticosteroids, which can cause side effects. Studies with angiotensin receptor blockers (ARBs), angiotensin converting enzyme inhibitors (ACEi) and renin inhibitors have been conducted in experimental and clinical RA with promising results.

CONCLUSION

The classical RAS activation is an important mechanism in RA pathogenesis and the benefit of ARB and ACEi administration should be further investigated.

Aliskiren, tadalafil, and cinnamaldehyde alleviate joint destruction biomarkers; MMP-3 and RANKL; in complete Freund's adjuvant arthritis model: Downregulation of IL-6/JAK2/STAT3 signaling pathway

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease, which is accompanied by progressive joint damage and disability. The intolerability of conventional antirheumatic drugs by some patients necessitates the search for effective antirheumatic agents having better tolerability. In the current work, we aimed to investigate the efficacy of cinnamaldehyde, tadalafil, and aliskiren as potential antirheumatic candidates and to explore their modulatory effects on joint destruction, inflammatory response, and intracellular signaling. Arthritis was induced in female Wistar rats by complete Freund's adjuvant (CFA) 0.4 ml s.c. on days 1, 4, and 7. Treated groups received their respective drugs, starting from day 13, daily for 3 weeks. Methotrexate and prednisolone were the standard antirheumatic drugs, while cinnamaldehyde, tadalafil, and aliskiren were the test agents. Treatment with cinnamaldehyde, tadalafil, or aliskiren reduced serum levels of rheumatoid factor, and pro-inflammatory cytokines; tumor necrosis factor-alpha and interleukin-6 (IL-6), along with elevated level of IL-10 which is an anti-inflammatory cytokine. Besides, cartilage and bone destruction biomarkers; matrix metalloproteinase-3 (MMP-3) and receptor activator of nuclear factor-kappa B ligand (RANKL); were significantly reduced after treatment with the test agents, which was further confirmed by histopathological investigation. The elevated protein expressions of phosphorylated-Janus kinase 2 (p-JAK2), phosphorylated-signal transducer and activator of transcription 3 (p-STAT3), and inducible nitric oxide synthase (iNOS) in articular tissue were markedly attenuated after treatment with cinnamaldehyde, tadalafil, or aliskiren, while that of endothelial nitric oxide synthase (eNOS) was greatly enhanced. In addition, oxidative stress and inflammatory markers such as malondialdehyde, nitric oxide, and myeloperoxidase were reduced in joint tissue after treatment with the test agents, while glutathione content was elevated. Furthermore, the renin inhibitor aliskiren produced effects close to those of the normal and methotrexate, the gold standard antirheumatic drug, in most of the measured parameters.

Collectively, these findings led to the assumption that the downregulation of IL-6/JAK2/STAT3 signaling by cinnamaldehyde, tadalafil, and aliskiren could alleviate joint destruction by MMP-3 and RANKL, reduce iNOS, and enhance eNOS expressions. Moreover, aliskiren could be a promising therapeutic agent for RA, because of its ability to normalize most of the measured parameters after CFA-induced arthritis.

Polymorphisms within the RANK and RANKL Encoding Genes in Patients with Rheumatoid Arthritis: Association with Disease Progression and Effectiveness of the Biological Treatment

Inconsistency of the results regarding the genetic variability within genes coding for receptor activator of nuclear factor κB (RANK) and its ligand (RANKL) in rheumatoid arthritis (RA) prompted us to study the RANK and RANKL polymorphisms as potential biomarkers associated with disease predisposition and response to anti-TNF treatment in a group of Polish patients with RA. This study enrolled 318 RA patients and 163 controls. RANK (rs8086340, C > G; rs1805034, C > T) and RANKL (rs7325635, G > A; rs7988338 G > A) alleles were determined by real-time PCR with melting curve analysis and related with clinical parameters. In addition, RANKL serum levels were measured by ELISA. The RANK rs8086340-G allele was overrepresented among patients as compared to controls (OD = 1.777, p = 0.038). C-reactive protein (CRP) levels were significantly (p < 0.05) associated with RANK rs8086340 polymorphism and were higher in the CC-homozygotes at the baseline while lower in the GG-carriers at the 12th week of the treatment. At the latter time point RANKL rs7325635-GG-positive patients also showed significantly lower CRP concentrations. Higher alkaline phosphatase levels before induction of anti-TNF therapy were observed in RANK rs8086340 and RANK rs1805034 CC homozygotes (p = 0.057 and p = 0.035, respectively). The GG homozygosity of both RANKL single nucleotide polymorphisms was significantly associated with the number of swollen joints (rs7988338 and rs7325635, before and at the 12th week of therapy, respectively, p < 0.05 in both cases). These results imply that polymorphisms within the RANK and RANKL genes affect RA susceptibility and anti-TNF treatment outcome.

Risk of Osteoporotic Fracture in Patients with Breast Cancer: Meta-Analysis

Background

The fracture risk induced by anti-estrogen therapy in patients with breast cancer remains controversial. The aim of this study was to perform a meta-analysis and systematic review to evaluate the risk of osteoporotic fracture in patients with breast cancer.

Methods

A systematic search was performed to identify studies that included any osteoporotic fracture (hip fracture and vertebral fracture) in patients breast cancer. Main outcome measures were occurrence and risk of osteoporotic fractures including hip and vertebral fractures in patients and controls.

Results

A systematic search yielded a total of 4 studies that included osteoporotic fracture outcomes in patients with breast cancer. Meta-analysis showed a higher risk of osteoporotic fracture in patients with breast cancer. Analysis of these 4 studies involving a total of 127,722 (23,821 cases and 103,901 controls) patients showed that the incidence of osteoporotic fractures was higher in the breast cancer group than in the control group. The pooled estimate of crude relative risk for osteoporotic fracture was 1.35 (95% confidence interval, 1.29-1.42; P<0.001).

Conclusions

Although studies were limited by a small number, results suggested a possible association between anti-estrogen therapy and increased risk of osteoporotic fractures in patients with breast cancer.

Immunoexpression of canonical Wnt and NF-κB signaling pathways in the temporomandibular joint of arthritic rats

OBJECTIVE

To investigate the participation of canonical Wnt and NF-κB signaling pathways in an experimental model of chronic arthritis induced by methylated bovine serum albumin (mBSA) in rat temporomandibular joint (TMJ).

MATERIALS AND METHODS

Wistar rats were sensitized by mBSA+Complete Freund Adjuvant (CFA)/Incomplete Freund Adjuvant (IFA) on the first 14 days (1 ×/week). Subsequently, they received 1, 2 or 3 mBSA or saline solution injections into the TMJ (1 ×/week). Hypernociceptive threshold was assessed during the whole experimental period. 24 h after the mBSA injections, the TMJs were removed for histopathological and immunohistochemical analyses for TNF-α, IL-1β, NF-κB, RANKL, Wnt-10b, β-catenin and DKK1.

RESULTS

The nociceptive threshold was significantly reduced after mBSA injections. An inflammatory infiltrate and thickening of the synovial membrane were observed only after mBSA booster injections. Immunolabeling of TNF-α, IL-1β and Wnt-10b was increased in the synovial membrane in arthritic groups. The immunoexpression of nuclear β-catenin was significantly higher only in the group that received 2 booster TMJ injections. However, NF-κB, RANKL and DKK1 immunoexpression were increased only in animals with 3 mBSA intra-articular injections.

CONCLUSION

Our results suggest that canonical Wnt and NF-κB signaling pathways participate in the hypernociception and inflammatory response in TMJ synovial membrane during the development of rheumatoid arthritis in rats.

The RANKL-RANK Axis: A Bone to Thymus Round Trip

The identification of Receptor activator of nuclear factor kappa B ligand (RANKL) and its cognate receptor Receptor activator of nuclear factor kappa B (RANK) during a search for novel tumor necrosis factor receptor (TNFR) superfamily members has dramatically changed the scenario of bone biology by providing the functional and biochemical proof that RANKL signaling via RANK is the master factor for osteoclastogenesis. In parallel, two independent studies reported the identification of mouse RANKL on activated T cells and of a ligand for osteoprotegerin on a murine bone marrow-derived stromal cell line. After these seminal findings, accumulating data indicated RANKL and RANK not only as essential players for the development and activation of osteoclasts, but also for the correct differentiation of medullary thymic epithelial cells (mTECs) that act as mediators of the central tolerance process by which self-reactive T cells are eliminated while regulatory T cells are generated. In light of the RANKL-RANK multi-task function, an antibody targeting this pathway, denosumab, is now commonly used in the therapy of bone loss diseases including chronic inflammatory bone disorders and osteolytic bone metastases; furthermore, preclinical data support the therapeutic application of denosumab in the framework of a broader spectrum of tumors. Here, we discuss advances in cellular and molecular mechanisms elicited by RANKL-RANK pathway in the bone and thymus, and the extent to which its inhibition or augmentation can be translated in the clinical arena.

Effect of NF-kB signaling pathway on the expression of MIF, TNF-α, IL-6 in the regulation of intervertebral disc degeneration

OBJECTIVE

Τo investigate the effect of NF-kB signaling pathway on the expression of MIF, TNF-α, and IL-6 in the regulation of disc degeneration.

METHODS

The disc tissue was taken from 56 patients with cervical spondylosis. According to the preoperative MRI and intraoperative disc herniation, the patients were divided into two groups: degeneration group and herniation group. The control group was 34 patients with cervical trauma with no history of cervical spondylosis. According to the preoperative JOA scores of cervical spondylosis, patients were divided into three groups: mild, moderate and severe. ELISA was used to detect the expression of MIF, IL-6, and TNF-α in the cervical intervertebral disc. NF-kB mRNA expression in the intervertebral disc was detected by qRT-PCR.

RESULTS

The expression levels of NF-kB mRNA, MIF, IL-6 and TNF-α in the control group were significantly higher than those in the degeneration group and the herniation group (p⟨0.05). There was a positive correlation between the expression of NF-kB mRNA, MIF, IL-6, TNF- and cervical intervertebral disc degeneration. The expression of MIF, IL-6, and TNF-α in the mild, moderate, and severe group was negatively correlated with the JOA score.

CONCLUSIONS

The expressions of NF-kB, MIF, IL-6, and TNF-α in intervertebral disc tissue in patients with disc herniation were increased and related to the degree of disc herniation. It may play an important role in the pathophysiological process of disc herniation.

Association Between Marginal Jawbone Loss and Onset of Rheumatoid Arthritis and Relationship to Plasma Levels of RANKL

OBJECTIVE

To investigate whether periodontitis, characterized by marginal jawbone loss, precedes the onset of symptoms of rheumatoid arthritis (RA), and to analyze plasma levels of RANKL (a cytokine that is crucial for bone resorption) and anti-citrullinated peptide antibodies (ACPAs) in presymptomatic individuals compared with matched referent controls.

METHODS

Marginal jawbone loss was measured on dental radiographs of the premolar/molar regions in the jaws in 176 subjects, 93 of whom subsequently developed RA. Among these participating subjects, 46 had documented radiographs predating symptom onset, and 45 cases could be matched to controls, according to sex, age, and smoking status. Plasma RANKL concentrations were analyzed using enzyme-linked immunosorbent assay. A receiver operating characteristic curve was used to define the cutoff value for RANKL positivity.

RESULTS

Bone loss was significantly greater in presymptomatic subjects classified as never smokers compared with that in controls, and increasing levels of bone loss were associated with a higher risk of the subsequent development of RA (hazard ratio 1.03, 95% confidence interval 1.01-1.05). No association between jawbone loss and RA was observed in smokers. A significantly greater extent of marginal jawbone loss was detected in RANKL-positive presymptomatic subjects, and even more pronounced jawbone loss was observed in those who were positive for both RANKL and ACPA.

CONCLUSION

Marginal jawbone loss preceded the clinical onset of RA symptoms, but this was observed only in nonsmokers. Moreover, marginal jawbone loss was significantly greater in RANKL-positive presymptomatic subjects compared with RANKL-negative presymptomatic subjects and was highest in presymptomatic subjects positive for both ACPA and RANKL.

An increased concentration of receptor activator of nuclear factor kappa-B ligand pre-dates the onset of rheumatoid arthritis

Objectives

RANK ligand (RANKL) is involved in destruction and osteoporosis in RA. In this study, the relationships between RANKL and ACPA, anti-carbamylated protein antibodies (anti-CarP), cytokines and chemokines were analysed in individuals before the onset of RA symptoms, and their associations with radiological findings at disease onset were assessed.

Methods

This was a case-control study performed within the Medical Biobank of Northern Sweden that included 470 pre-symptomatic individuals [334 women and 136 men; mean (s.d.) age 52.3 (9.4) years] using blood samples donated before symptom onset (pre-dating time; 5.0 years) and 96 controls (60 women and 36 men). Plasma was analysed for RANKL (BioVendor, Karasek, Brno, Czech Republic), anti-CCP2 antibodies (Eurodiagnostics, Malmö, Sweden), anti-CarP antibodies (in-house ELISA), ACPA specificities (ISAC-platform, Phadia AB, Uppsala, Sweden) and cytokines/chemokines (Meso Scale Discovery methods, Rockville, MD, USA). Radiographs of hands and feet were graded using the Larsen score.

Results

The concentration of RANKL was higher in the pre-symptomatic individuals compared with controls; mean (s.e.m.): 0.50 (0.03) vs 0.22 (0.02) nmol/l (P < 0.001). The concentration increased gradually over time until symptom onset but appeared later than ACPA/RF/anti-CarP antibodies. Positivity for these antibodies yielded higher levels of RANKL compared with seronegativity (P < 0.001). RANKL concentrations were significantly associated with IL-6 and IL-10 concentrations. The combination of positivity for RANKL and anti-CarP antibodies resulted in a higher Larsen score at diagnosis β = 6.18 (95% CI: 0.93, 11.43; P = 0.022).

Conclusion

RANKL concentrations were increased several years before symptom onset for RA, particularly in ACPA/RF/anti-CarP-positive individuals, all detectable earlier than RANKL. Positivity for RANKL and anti-CarP antibodies yielded the highest Larsen score at disease onset.

Association of tumor necrosis factor-α (G-308A) genetic variant with matrix metalloproteinase-9 activity and joint destruction in early rheumatoid arthritis

Matrix metalloproteinases (MMPs) are the key enzymes responsible for the joint destruction. Their activity is regulated by the level of proinflammatory cytokines. The aim of this study was to examine the impact of TNF-α G-308A polymorphism on MMP-9 levels in blood plasma (BP) and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and their role in progression of joint destruction. One hundred thirty-four subjects were enrolled in this study. TNF-α G-308A polymorphism was determined using PCR-RFLP method. ELISA assay was used for the detection of MMP-9 activity in BP and SF. Joint damage was estimated by hands and feet radiography. Larsen score and annual changes in LS were used for quantitative evaluation of joint destruction and radiographic progression of disease. MMP-9 activity in BP and SF was significantly higher in RA compared to controls, as well as in SF of patients with erosive compared to nonerosive RA. Faster radiographic progression and increased MMP-9 activity in BP and SF were detected in the group A (GA or AA genotype carriers) compared to the group G (GG genotype carriers). However, statistical significance was revealed only for MMP-9 activity in SF (p < 0.05). MMP-9 activity in BP and SF is significantly higher in RA patients compared to patients with osteoarthritis. The presence of TNF-α-308A allele is associated with increased MMP-9 activity in SF of patients with early RA and may be a predictor of rapid radiographic progression of disease.