Nailfold capillaroscopy in the rheumatological current clinical practice in Italy: results of a national survey.

This cross-sectional online study was designed by the study group on Capillaroscopy and Microcirculation in Rheumatic Diseases (CAP) of the Italian Society of Rheumatology (SIR) to provide an overview of the management of nailfold capillaroscopy in Italian rheumatology centers. Therefore, SIR distributed the survey to its members in July 2021, and each center's physician with the most expertise in capillaroscopy completed the questionnaire. The survey was completed by 102 centers, with at least one representative from each Italian region. Ninety-three centers perform capillaroscopy, and 52 (56) conduct more than 200 investigations annually. Seventy-eight (84%) of respondents have more than five years of experience with the technique, and 75 centers (80.6%) have received certification from specific national or international training courses. In 85 centers, a videocapillaroscope with 200x magnification is employed (91.4%). The average waiting period for the examination is 2.4 months, and less than 3 months in 64 of the locations (68.8%). The study demonstrates that capillaroscopy is an integral part of both the diagnostic phase of Raynaud's phenomenon and the monitoring of autoimmune connective tissue diseases (CTDs). However, the reporting methods and timing of patient followup are heterogeneous.

Translation and cross-cultural adaptation into Italian of the self-administered FLARE-RA questionnaire for rheumatoid arthritis.

The aim was to provide a translation into Italian with cross-cultural adaptation of the French FLARE-Rheumatoid Arthritis (RA) questionnaire, and to test its acceptability, feasibility, reliability and construct validity in a single-centre cohort study. The French version of the FLARE-RA questionnaire was cross-culturally adapted and translated into Italian following an established forward-backward translation procedure, with independent translations and backtranslations. To validate the Italian version we tested the internal validity with Cronbach's alpha, test-retest reliability with the intraclass correlation coefficient, agreement between assessments with Bland-Altman plots and construct validity with Spearman's correlation coefficients. The questionnaire was tested on 283 consecutive RA outpatients (mean age 56.1±13.9 years, 226/283 females, median disease duration 12.6 years ranging from 0.2 to 70.6). For the global score (11 items) the Cronbach's alpha coefficient was 0.94. The intraclass correlation coefficient was 0.87 (95% CI, 0.76-0.96). The correlation of FLARE-RA global score was 0.59 (95% CI, 0.50-0.66) with the Disease Activity Score on 28 joints, 0.63 (95% CI, 0.55-0.71) with the Simplified Disease Activity Index, 0.77 (95% CI, 0.71-0.83) with the RA Impact of Disease and 0.67 (95% CI, 0.59-0.73) with the Health Assessment Questionnaire. The Italian version of the FLARE-RA is feasible, brief and easy to administer. The translated and cross-cultural adapted showed accordingly to be valid and reliable. This questionnaire has some practical advantages, such as clarity, comprehensiveness, simplicity, and a minimum filling time. The development of cross-cultural adapted questionnaires in different languages is of pivotal importance to obtain standardized and comparable data across countries.

Health-related quality of life burden in scleroderma patients treated with two different intravenous iloprost regimens.

Systemic sclerosis (SSc)-related Raynaud's phenomenon (RP) and digital ulcers (DU) can impair health-related quality of life (HRQoL). The aim of our study was to estimate HRQoL in SSc patients treated with two different intravenous (IV) iloprost (ILO) regimens and in patients not treated with IV ILO. 96 consecutive SSc patients were enrolled in a pragmatic, prospective and non-randomized study, and divided into 3 groups: not requiring therapy with IV ILO (N=52), IV ILO once monthly (N=24) or IV ILO for 5 consecutive days every 3 months (N=20). Patients were followed up for three months. We assessed HRQoL using the generic preference-based questionnaire EQ-5D-5L. We conducted multiple regression analyses to estimate, in each treatment group, the mean general health (GH) and the mean utility index of the EQ-5D-5L, adjusting for possible confounders. The mean adjusted utility index and GH score, after three months' follow-up, were not different in the three groups: IV ILO was able to make patients requiring IV ILO similar to those not requiring it. Moreover, there was no difference in this model between the two ILO regimens (1 day monthly vs 5 consecutive days every 3 months). The two different IV ILO regimens (the most appropriate regimen was decided according to patients' characteristics and needs) were able to stabilize HRQoL in RP secondary to SSc non-adequately controlled by oral therapy.

Smac127 Has Proapoptotic and Anti-Inflammatory Effects on Rheumatoid Arthritis Fibroblast-Like Synoviocytes.

Rheumatoid arthritis (RA) is characterized by synovial inflammation and hyperplasia. Fibroblast-like synoviocytes (FLSs) are apoptosis-resistant and contribute to the pathogenesis of RA by producing cytokines and proteolytic enzymes, which degrade the extracellular matrix. We evaluated the proapoptotic and anti-inflammatory activity of the small molecule Smac127 on RA-FLSs cultured in synovial fluid (SF), in order to reproduce the physiopathological environmental characteristic of RA joints. In this context, Smac127 induces apoptosis by inhibiting apoptosis proteins (IAPs). This inhibition activates caspase 3 and restores the apoptotic pathway. In addition, Smac127 induces a significant inhibition of the secretion of IL-15 and IL-6, stimulation of pannus formation, and damage of bone and cartilage in RA. Also the secretion of the anti-inflammatory cytokine IL-10 is dramatically increased in the presence of Smac127. The cartilage destruction in RA patients is partly mediated by metalloproteinases; here we show that the MMP-1 production by fibroblasts cultured in SF is significantly antagonized by Smac127. Conversely, this molecule has no significant effects on RANKL and OPG production. Our observations demonstrate that Smac127 has beneficial regulatory effects on inflammatory state of RA-FLSs and suggest a potential use of Smac127 for the control of inflammation and disease progression in RA.

Proapoptotic activity of a monomeric smac mimetic on human fibroblast-like synoviocytes from patients with rheumatoid arthritis.

Inhibitors of apoptosis proteins (IAPs) block cell death in response to diverse stimuli. The mitochondrial protein, second mitochondria-derived activator of caspase (Smac), negatively regulates IAP inhibition of caspase activity. We investigated the proapoptotic activity of a synthetic Smac (Smac 066) on fibroblast-like synoviocytes (FLS) derived from patients with active rheumatoid arthritis (RA). We found that Smac 066 induced significant apoptosis in all RA-FLS samples. Furthermore, IAPs, which are upregulated in RA-FLS, were downregulated by Smac 066. This suggested that IAPs upregulation was responsible for RA-FLS sensitivity to Smac 066. Next, we analysed caspase activation and found that Smac 066 was associated with caspase 8 and caspase 3 activities. We then investigated the mechanism underlying Smac 066 downregulation of IAPs in RA-FLS with an apoptotic pathway array. Interestingly, Smac 066 significantly upregulated IGFBP-5, a protein involved in differentiation, apoptosis, and osteoblastic activation. Smac 066 may represent a new therapeutic approach to RA treatment.

[Health related quality of life assessment in patients with systemic sclerosis]. / La valutazione della qualità della vita nei pazienti con sclerodermia.

OBJECTIVE: Health-related quality of life (HRQoL) in patients with systemic sclerosis (SSc), a chronic disabling disease associated to physical and psychological impairment, is often left behind in clinical practice and research. This is due to the use of tools that are not complete or mainly designed for the physical condition only. We tested EQ-5D, a valid, simple and brief questionnaire for HRQoL that has never been validated in SSc. METHODS: Thirty-three consecutive SSc patients referring to our Rheumatology Department and undergoing treatment have been asked to fulfill EQ-5D together with HAQ. RESULTS: EQ-5D demonstrated good acceptability, feasibility and validity in patients affected by SSc. Conceptually equivalent domains of EQ-5D demonstrated a good correlation with HAQ correspondent domains. CONCLUSIONS: We suggest the use of EQ-5D in SSc patients as a HRQoL measure in clinical practice, as well as an out come parameter in randomized clinical trials and/or in pharmaco-economic evaluations.

Anti-tumor necrosis factor alpha therapy normalizes fibrinolysis impairment in patients with active rheumatoid arthritis.

OBJECTIVES: Rheumatoid arthritis (RA) is associated with increased cardiovascular risk and involvement of inflammation, coagulation and fibrinolysis. Treatment with infliximab, a tumour necrosis factor-alpha (TNF-alpha) blocking chimeric monoclonal antibody, induces a long-term reduction of inflammation and coagulation, but its effect on fibrinolysis is still unknown. We carried out an observational study investigating plasma biomarkers of inflammation and fibrinolysis in RA patients before and after 14 weeks of infliximab treatment given according to the therapeutic guidelines for RA. METHODS: We studied 20 selected patients with active RA and without any other atherosclerosis risk factor as well as 40 healthy controls. Patients, treated with a stable dose of methotrexate, received infliximab (3 mg/kg) at week 0, 2, 6 and 14. At week 0 and 14, we assessed clinical, inflammatory and fibrinolyitic parameters. RESULTS: At baseline, plasminogen activator inhibitor (PAI-1) antigen, PAI-1 activity and tissue-type plasminogen activator (t-PA) antigen were significantly higher in RA patients than in controls (p=0.01, p=0.001 and p=0.0001 respectively). After 14 weeks of infliximab treatment, the levels of PAI-1 antigen, PAI-1 activity and t-PA antigen significantly decreased till normalization (p=0.0001). Plasma levels of C reactive protein (CRP) and interleukin-6 (IL-6) were directly correlated with levels of PAI-1 antigen (p=0.011 and p=0.0001), PAI-1 activity (p=0.013 and p=0.027) and t-PA antigen (p=0.017 and p=0.040). CONCLUSIONS: This study provides evidence that TNF-alpha blockade by infliximab not only decreases inflammation, but also reduces the inhibition of fibrinolysis. Such a combined effect may be pivotal in reducing the whole thrombotic risk in these patients.

Hand impairment in systemic sclerosis: association of different hand indices with organ involvement.

OBJECTIVE: To evaluate the association between the assessment tools used to quantify hand impairment and organ involvement in patients with systemic sclerosis (SSc). METHODS: Eighty consecutive SSc patients were assessed for hand impairment using the Hand Anatomic Index (HAI), finger-to-palm distance in flexion (FTP), and the Hand Mobility in Scleroderma (HAMIS) test. Cluster analysis was used to identify patients having similar characteristics on the basis of the pattern of organ involvement in order to create clinically homogeneous groups, and to correlate these clusters with the measures of hand involvement. Finally, we evaluated the discriminating ability of the indices to identify the patients whose clinical condition was more severe. RESULTS: Two major clusters were identified by cluster analysis on the basis of organ involvement. The first (cluster A) included 61 patients and the second (cluster B) 19 patients characterized by minor and major extent of organ involvement, respectively. The extent of organ involvement and the hand impairment were related. The scores of hand indices were lower in cluster B. The area under the receiver operating characteristic (ROC) curve (C-index) for the logistic model including all three indices was 0.85 (95% confidence interval 0.74­0.95). CONCLUSION: The seriousness of hand involvement as measured by the three indices was associated with the extent of organ involvement. Further studies of hand impairment scales are needed to provide validated guidance as meaningful clinical measures.

[Nailfold capillaroscopic report: qualitative and quantitative methods]. / La refertazione dell'esame capillaroscopico: metodi di valutazione qualitativi e quantitativi.

Nailfold capillaroscopy (NVC) is a simple and non-invasive method used for the assessment of patients with Raynaud's phenomenon (RP) and in the differential diagnosis of various connective tissue diseases. The scleroderma pattern abnormalities (giant capillaries, haemorrages and/or avascular areas) have a positive predictive value for the development of scleroderma spectrum disorders. Thus, an analytical approach to nailfold capillaroscopy can be useful in quantitatively and reproducibly recording various parameters. We developed a new method to assess patients with RP that is capable of predicting the 5-year transition from isolated RP to RP secondary to scleroderma spectrum disorders. This model is a weighted combination of different capillaroscopic parameters (giant capillaries, microhaemorrages, number of capillaries) that allows physicians to stratify RP patients easily using a relatively simple diagram to deduce prognosis.

Primary antiphospholipid syndrome associated with small aorta syndrome: a case report.

It has been widely accepted that the antiphospholipid syndrome (APS) is an autoimmune hypercoagulability syndrome in which a variety of venous and arterial thrombotic events may occur. Peripheral obliterating arterial disease characterized by aortoiliac steno-occlusion occurring in young women, is reported in the literature under the name of Small Aorta Syndrome (SAS). Although it remains unclear whether SAS represents a separate entity, the small size of the distal aorta increases the risk for aortoiliac occlusive disease. A 41-year old white woman was admitted with acute digital ischemia of the left foot. She had positive lupus anticoagulant and IgG anti-cardiolipin antibodies (61 UI/mL), but antinuclear antibodies and anti-ds-DNA antibodies were negative. She previously had two deep venous thromboses of the legs and, despite the oral anticoagulant therapy, pulmonary embolism occurred. Shortly thereafter, abdominal angio-magnetic resonance imaging suggested that the infra-renal aorta was narrowed more than 50%, without thrombotic occlusion of the terminal aorta and common iliac arteries. These findings were compatible with the features of SAS. There were no atherosclerotic changes in the artery wall and no other prediposing risk factors such as smoking, oral contraceptive or hyperlipidemia. After adequate anticoagulation and intravenous prostacyclin treatment the patient's symptoms and the ischemic lesions improved markedly. To our knowledge this is the first report of the association of SAS and primary APS. The occurrence of SAS in patients with APS may dramatically increase the risk of trombothic events.

Capillaroscopic observations in childhood rheumatic diseases and healthy controls.

OBJECTIVE: To describe, by using video nailfold capillaroscopy (NFC), microvascular abnormalities in children with rheumatic diseases and to evaluate the capillary changes over a follow up period. METHODS: 118 children suffering from rheumatic diseases: 55 juvenile idiopathic arthritis (JIA), 7 mixed connective tissue disease (MCTD), 6 primary Raynaud's phenomenon (PRP), 34 systemic lupus erythematosus (SLE), 8 juvenile systemic sclerosis (JSSc) and 8 juvenile dermatomyositis (JDM) were included in the study. Patients with major capillaries abnormalities or scleroderma pattern were followed up for at least 12 months. 70 age- and sex-matched healthy controls (HC) were also examined. RESULTS: In HC there was a significant correlation between age and capillary length (p = 0.001). JIA patients showed capillary number, size, shape and arrangement similar to HC. Minor abnormalities were frequently observed. The percentage of major abnormalities were significantly increased compared to HC in MCTD (p = 0.008), SLE (p = 0.0002) and JDM patients (p < 0.0001). 5/8 of JSSc had a scleroderma pattern from the onset of the disease. The serial observations in connective tissue diseases also showed that the evolution of capillaroscopic pattern was not unidirectional. In fact, in some nailfolds there was an increase in capillary loss and in avascular areas, whereas sometimes it remained stable on repeated examination. CONCLUSION: NFC can be used as a simple, inexpensive, non-invasive method to evaluate the microvascular abnormalities in childhood rheumatic conditions, and it may be useful in early recognition and monitoring scleroderma spectrum disorders.

Paget's disease and cochlear implantation.

Paget's disease of bone is a common disorder of unresolved etiology characterized by excessive bone resorption followed by excessive bone formation. If the skull is affected this may result in hearing loss and eventually develop into profound deafness. To date, no cases of cochlear implantation in patients with Paget's disease have been reported. The authors present a case of radiographically confirmed Paget's disease of the skull in a 77-year-old man with a 20-year history of progressive bilateral sensorineural hearing loss who underwent cochlear implantation. A successful insertion of the Nucleus 24 Contour electrode array was achieved without surgical and postoperative complications. At the 10 months' postoperative evaluation, the patient had gained useful open-set speech perception. In quiet conditions, his performance scores on the word and sentence recognition tests were 100 and 98 per cent, respectively. In the presence of noise (at +10 dB. signal-to-noise ratio), his performance scores on the word and sentence recognition tests were 96 and 94 per cent, respectively.

Autoantibodies to chromatin: prevalence and clinical significance in juvenile rheumatoid arthritis.

OBJECTIVE: To determine the prevalence of anti-chromatin antibodies (Abs) in juvenile rheumatoid arthritis (JRA) and to assess any association between the presence of anti-chromatin Abs and clinical subsets of the disease. METHODS: IgG anti-chromatin Abs and anti-extractable nuclear antigens (ENA) Abs were detected by an enzyme-linked immunosorbent assay (ELISA), and antinuclear Abs (ANA) by indirect immunofluorescence in sera of 89 children with JRA. Ten children with systemic, 32 with polyarticular and 47 with pauciarticular disease onset (uveitis occurred in 17/47 children) were studied. As a control group, 12 sera of patients suffering from idiopathic uveitis and 31 age- and-sex-matched healthy children (HC) were examined. RESULTS: Abs to chromatin were detected in 14/47 (29.8%) of children suffering from pauciarticular onset JRA and in this group the higher prevalence of anti-chromatin Abs has been found in children with chronic uveitis (p = 0.002). Anti-chromatin positivity was observed in 2/10 (20%) of systemic and in 3/32 (9.3%) of polyarticular onset JRA. Furthermore, none of the patients with idiopathic uveitis and HC had Abs to chromatin. anti-chromatin Abs titers remained relatively stable over a 6-month control period. CONCLUSION: Our results confirm previous data about the presence of circulating anti-chromatin Abs in juvenile arthritis. Interestingly, anti-chromatin Abs were significantly higher in the group of patients with pauciarticular onset with past or present history of uveitis, than in patients without ocular involvement. A long-term follow-up study could be useful to demonstrate the potential utility of these autoantibodies in diagnosing, classifying and treating children affected.

[Raynaud's phenomenon]. / Il fenomeno di Raynaud.

Raynaud's phenomenon (RP) is a vasospastic disorder characterized by episodic color changes of blanching, cyanosis, and hyperemia in response to cold and/or emotional stress. Although most typically noted in the fingers, the circulation of the toes, ears, nose and tongue is also frequently affected. Population studies have shown that RP in adults is more common in women than men, with prevalence estimates ranging from 4% to 30%. Geographic variations in the prevalence reflect differences in climate. RP may be a primary or a secondary process. LeRoy and Medsger suggested criteria for primary RP: symmetric attacks, the absence of tissue necrosis, ulceration or gangrene, the absence of a secondary cause, negative antinuclear antibodies, normal nailfold capillaroscopy and a normal erythrocyte sedimentation rate. Secondary RP is characterized by an age of onset of more than 30 years, painful and asymmetric attacks, ischemic skin lesions, positive autoantibodies, capillaroscopic abnormalities and/or clinical features suggestive of connective tissue diseases (CTDs). Among the CTDs, systemic sclerosis has the highest frequency of RP. Finding a cause for RP requires a knowledge of the patient's occupational, smoking, drug history, physical examination, nailfold capillaroscopy, routine laboratory tests and autoantibodies. Furthermore, RP should be distinguished from acrocyanosis, a condition characterized by continuous cyanosis of the hands or feet that is aggravated by cold temperature. The most important instruction to the patient is abstinence from any smoking, offending drugs should be discontinued, and abrupt changes in temperature. If these measures are inadequate, calcium-channel blockers are the most widely used (nifedipine 30 mg up to 90 mg daily). Alternatively, sympatholytic agent (prazosin), angiotensin II -receptor type I antagonist (losartan), selective sertonin-reuptake inhibitor (fluoxetine) may be useful. In the severe cases the role of prostaglandins is well established, but standard therapeutic protocols are not jet available.

[Anti-chromatin antibodies in juvenile rheumatoid arthritis]. / Anticorpi anti-cromatina in corso di artrite reumatoide giovanile.

OBJECTIVE: to evaluate the prevalence and clinical significance of anti-chromatin antibodies (Abs) in juvenile rheumatoid arthritis (JRA). METHODS: IgG anti-chromatin Abs were detected by an enzyme-linked immunosorbent assay (ELISA), in sera of 94 children with JRA (10 children with systemic, 38 with polyarticular and 46 with oligoarticular disease onset). As control group, 33 age- and-sex-matched healthy children (HC) were also examined. RESULTS: Abs to chromatin were detected in 24/94 (25.5%) of children suffering from JRA. Particularly, the higher prevalence of anti-chromatin Abs has been found in children with oligoarticular (30,4%) and polyarticular (23.7%) onset JRA. In these groups Abs titers were significantly higher compared to systemic JRA and HC (p=0.003). Anti-chromatin Abs were observed more frequently in patients with oligoarticular disease and chronic uveitis (21.7%). Furthermore, higher levels of anti-chromatin Abs has been found in all the patients treated with anti-TNF-alpha therapy (p< 0.0001). CONCLUSIONS: our results confirm previous data about the prevalence of anti-chromatin Abs in JRA. These Abs were significantly higher in the group of patients with oligoarticular onset with past or present history of ocular involvement and in the group with polyarticular JRA treated with biologic therapy. A long-term follow-up study could be useful to evaluate the potential utility of these autoantibodies.

[Role of cell migration in the pathogenesis of rheumatoid arthritis: in vivo studies in SCID mice transplanted with human synovial membrane]. / Ruolo della migrazione cellulare nella patogenesi dell'artrite reumatoide: studi in vivo in topi SCID trapiantati con membrana sinoviale umana.

OBJECTIVE: Adhesion mechanisms play a central role in the recruitment of leukocytes which characteristically infiltrate rheumatoid synovium. Therefore, we adapted an animal model, in which human rheumatoid synovium was transplanted into severe combined immunodeficient (SCID) mice, to study the effects of Tumor Necrosis Factor-alpha (TNF-alpha) in modulatine leukocyte migration and to investigate the chemotactic potential of Stromal Derived Factor-1 alpha (SDF-1 alpha). MATERIALS AND METHODS: Human synovium samples, obtained from patients undergoing joint replacement, were divided into two parts. One was analysed by immunohistology and the other was implanted subcutaneously into SCID mice under general anaesthesia. Four weeks post-transplantation, grafts were injected with optimal dose of SDF-1, TNF-alpha or saline (negative control). At the same time, animals were injected iv with fluorescently labelled cells. 48 hours later mice were sacrificed and grafts removed for cryo-hystology. The number of cells migrating to the grafts was determined by UV-microscopy and the results expressed as cells per high power field. RESULTS AND CONCLUSIONS: In these studies we provide the evidence that: 1) the animal model, in which human tissues are grafted into SCID mice, can be used to study cell migration under controlled experimental conditions; 2) direct intragraft injection of TNF-alpha increases lymphocytes migration and up-regulates the expression of human adhesion molecules (CAMs) and 3) SDF-1 alphainjected intragraft increases the migration of the pro-myelo-monocytic U937 cells to synovial transplants, even more efficiently than TNF-alpha, but without modifications of CAMs' expression.

[Role of chemokines in the pathogenesis of chronic synovitis during rheumatoid arthritis]. / Ruolo delle chemochine nella patogenesi della sinovite cronica in corso di artrite reumatoide.

Chemokines play a central role in the pathogenesis of rheumatoid arthritis (RA) synovitis which is characterised by new blood vessel formation, thickening of the lining layer and infiltration of immune cells. The inflammatory infiltrate is generated by a series of events which include the recruitment of leukocytes from the blood stream into the tissue, their local retention and activation to effector cells. All these processes are finely regulated by the interplay of different cell adhesion molecules (CAMs) and chemoattractant factors called chemokines (CK). CK are a superfamily of small proteins that play a crucial role in immune and inflammatory reactions. These chemoattractant cytokines share structural similarities including four conserved cysteine residues which form disulphide bonds in the tertiary structure of the proteins. CK mediate their effects by binding specific receptors (CK-R) characterised by a domain structure which spans the cell membrane seven times and signal through heterotrimeric GPT-binding proteins. Activation of the CK network results in an amplification of the inflammatory cascade and consequently in the progressive destruction of RA joints. The recognition of the central role of CK in inflammation has paved the way to the development of new agents capable of interfering with CK and CK-R. This review will focus in particular on the role of CK in regulating leukocyte trafficking in RA joints.

Stromal cell-derived factor 1 (CXCL12) induces monocyte migration into human synovium transplanted onto SCID Mice.

OBJECTIVE: The mechanisms by which monocyte/macrophage cells migrate to the joint involve a series of integrated adhesion and signaling events in which chemokines and their receptors are strongly implicated. This study was undertaken to investigate the hypothesis that stromal cell-derived factor 1 (SDF-1), a CXC chemokine (CXCL12), plays a critical role in monocyte/macrophage localization to synovium. METHODS: SDF-1 and CXC receptor 4 (CXCR4) expression in rheumatoid arthritis (RA) and osteoarthritis synovium and graft SDF-1, tumor necrosis factor alpha (TNF alpha), and human and murine vascular markers were examined by immunohistochemistry and double-immunofluorescence. The functional capacity of SDF-1 to modulate monocyte migration into joints was investigated by examining the localization of pro-myelomonocytic U937 cells into synovial tissue transplanted into SCID mice. SDF-1, TNF alpha, or saline was injected into graft sites and response determined by the number of fluorescently labeled U937 cells (injected intravenously) detected in grafts by ultraviolet microscopy. RESULTS: SDF-1 and CXCR4 were highly expressed in CD68+ cells in the RA synovium. SDF-1 induced U937 cell migration in vitro and in vivo in a dose-dependent manner and, in vivo, SDF-1 was more effective than TNF alpha. In contrast to TNF alpha, SDF-1 did not induce intracellular adhesion molecule 1 in transplant microvasculature. Furthermore, intragraft injection of SDF-1 did not up-regulate TNF alpha, or vice versa. CONCLUSION: This study demonstrates, for the first time, that SDF-1 is functional in vivo when injected into synovial grafts. In addition, SDF-1 is more potent than TNF alpha, and its mechanisms of action appear to be autonomous. Therefore, SDF-1 may be an important TNF-independent molecule involved in the migration to and retention of inflammatory effector cells in the joint.