Evolution of bone metastases in patients receiving at least three months of checkpoint inhibitors.

BACKGROUND: To investigate the evolution of bone metastases in patients receiving immune checkpoint inhibitors (ICI). METHODS: A single-center retrospective study included cancer patients with bone metastases treated with ICI at our institution between January 2014 and September 2019. Clinical and biological data were collected from medical records and independent expert review of imaging was performed. Target and non-target lesions were identified and followed up to 1 year. Patients were then classified as bone responder or non-responder. Comparisons between groups were performed with Student's t test or Mann-Whitney test. RESULTS: Among 1108 patients screened, 192 patients had bone metastases and 48 patients were included in the final analysis, with lung cancer, renal carcinoma and melanoma as most represented cancer type. Half of the patients experienced stability, condensation or peripheral sclerosis of bone lesions. Initial progression before stabilization with or without sclerosis of bone lesion occurred for 19% of patients (pseudoprogression). There was an association between bone response and global oncological outcomes. Bone responder patients had a significant decrease in morphine and co-analgesic prescription as well as a significant decrease in alkaline phosphatases compared to non-responder patients. CONCLUSION: Bone response was observed in half of patients with available imaging and follow-up after 3 months of ICI treatment, with sclerosis observed in one-third of bone lesions at month 3, in all tumor types. Up to 20% of patients experienced a pseudoprogression of bone lesions such as previously described in primary tumor and other metastatic sites. Bone response was associated with improvement of pain and survival.

Association between RANK, RANKL and OPG polymorphisms with ACPA and erosions in rheumatoid arthritis: results from a meta-analysis involving three French cohorts.

OBJECTIVES: The RANK/RANKL/osteoprotegerin (OPG) system plays a central role in the pathogenesis of bone erosions in rheumatoid arthritis (RA). The aim of this study was to test the association between 11 single-nucleotide polymorphisms (SNPs) located on RANK, RANKL and OPG genes and anticitrullinated peptide antibody (ACPA) presence or erosions in RA. PATIENTS: This work was performed on three independent samples of French patients with RA: the Etude de Suivi des PolyArthrites Indifférenciées Récentes (ESPOIR) (n=632), Rangueil Midi-Pyrénées (RMP) (n=249) and French Rheumatoid Arthritis Genetic Consortium (FRAGC) (n=590) cohorts. Genotyping: the genotyping of 11 SNPs located on RANK, RANKL and OPG were performed by PCR. STATISTICAL ANALYSES: The association between the genotypes with ACPA or erosions was first tested in the ESPOIR cohort using a χ(2) test and, in the case of significant association, replicated in the RMP and FRACG cohorts. A meta-analysis on the three cohorts was performed using the Mantel-Haenszel method. RESULTS: One SNP on RANK (rs8086340) and three SNPs on RANKL (rs7984870, rs7325635, rs1054016) were significantly associated with ACPA presence, while one SNP on OPG (rs2073618) and one SNP on RANKL (rs7325635) were significantly associated with erosions in the ESPOIR cohort. Following meta-analysis performed on the three samples, the SNP on RANK and the GGG haplotype of the three SNPs located on RANKL were both significantly associated with ACPA presence, while only the SNP on OPG remained significantly associated with erosions. CONCLUSIONS: This study identified one SNP located on RANK, one haplotype on RANKL associated with ACPA presence, and one SNP located on OPG associated with erosions in three different samples of French patients with RA.

Predictive risk factors of serious infections in patients with rheumatoid arthritis treated with abatacept in common practice: results from the Orencia and Rheumatoid Arthritis (ORA) registry.

OBJECTIVES: Little data are available regarding the rate and predicting factors of serious infections in patients with rheumatoid arthritis (RA) treated with abatacept (ABA) in daily practice. We therefore addressed this issue using real-life data from the Orencia and Rheumatoid Arthritis (ORA) registry. METHODS: ORA is an independent 5-year prospective registry promoted by the French Society of Rheumatology that includes patients with RA treated with ABA. At baseline, 3 months, 6 months and every 6 months or at disease relapse, during 5 years, standardised information is prospectively collected by trained clinical nurses. A serious infection was defined as an infection occurring during treatment with ABA or during the 3 months following withdrawal of ABA without any initiation of a new biologic and requiring hospitalisation and/or intravenous antibiotics and/or resulting in death. RESULTS: Baseline characteristics and comorbidities: among the 976 patients included with a follow-up of at least 3 months (total follow-up of 1903 patient-years), 78 serious infections occurred in 69 patients (4.1/100 patient-years). Predicting factors of serious infections: on univariate analysis, an older age, history of previous serious or recurrent infections, diabetes and a lower number of previous anti-tumour necrosis factor were associated with a higher risk of serious infections. On multivariate analysis, only age (HR per 10-year increase 1.44, 95% CI 1.17 to 1.76, p=0.001) and history of previous serious or recurrent infections (HR 1.94, 95% CI 1.18 to 3.20, p=0.009) were significantly associated with a higher risk of serious infections. CONCLUSIONS: In common practice, patients treated with ABA had more comorbidities than in clinical trials and serious infections were slightly more frequently observed. In the ORA registry, predictive risk factors of serious infections include age and history of serious infections.

Comparison of the long-term outcome for patients with rheumatoid arthritis with persistent moderate disease activity or disease remission during the first year after diagnosis: data from the ESPOIR cohort.

OBJECTIVE: To investigate if patients with early RA with persistent moderate disease activity during the first year after diagnosis have a worse 3-5 year outcome than those who achieve sustained clinical remission within the first year, in a daily life setting. METHODS: The ESPOIR cohort included patients with early arthritis of <6 months' duration. Treatment was the standard of care. We had 5-year follow-up data for 573 patients. This study compared patients who had persistent moderate disease activity (Disease Activity Score in 28 joints (DAS28)>3.2 and ≤5.1) at both the 6- and 12-month visits, with those who were in sustained DAS28 remission. The primary outcome was radiographic progression at the 36-month visit. Secondary endpoints were clinical remission (DAS28 score, Simplified Disease Activity Index, ACR/EULAR criteria), Health Assessment Questionnaire-Disability Index (HAQ-DI) and number of missed workdays at months 36 and 60. A Fisher exact test was used to compare categorical variables, and the Kruskal-Wallis test for quantitative variables. Logistic regression analysis was used to determine predictors of outcome. RESULTS: Patients were aged 48.1±12.5 years and their duration of symptoms was 103.2±52.1 days. Mean baseline DAS28 was 5.1±1.3. Persistent moderate disease activity (107 patients) rather than sustained remission (155 patients) during the first year was associated with increased radiographic disease progression at 3 years (OR=1.99 (95% CI 1.01 to 3.79)), increased HAQ-DI at 3 and 5 years (5.23 (2.81 to 9.73) and 4.10 (2.16 to 7.80), respectively), a 7-11 times smaller chance of achieving clinical remission and a five times greater number of missed workdays. CONCLUSIONS: Patients with early RA with persistent moderate disease activity during the first year had a worse outcome than patients who achieved sustained clinical remission. Persistent moderate disease activity affects long-term structure, remission rate and functional and work disability. Such patients may benefit from intensive treatment.

Identification of patients with gout: elaboration of a questionnaire for epidemiological studies.

OBJECTIVES: In France, the prevalence of gout is currently unknown. We aimed to design a questionnaire to detect gout that would be suitable for use in a telephone survey by non-physicians and assessed its performance. METHODS: We designed a 62-item questionnaire covering comorbidities, clinical features and treatment of gout. In a case-control study, we enrolled patients with a history of arthritis who had undergone arthrocentesis for synovial fluid analysis and crystal detection. Cases were patients with crystal-proven gout and controls were patients who had arthritis and effusion with no monosodium urate crystals in synovial fluid. The questionnaire was administered by phone to cases and controls by non-physicians who were unaware of the patient diagnosis. Logistic regression analysis and classification and regression trees were used to select items discriminating cases and controls. RESULTS: We interviewed 246 patients (102 cases and 142 controls). Two logistic regression models (sensitivity 88.0% and 87.5%; specificity 93.0% and 89.8%, respectively) and one classification and regression tree model (sensitivity 81.4%, specificity 93.7%) revealed 11 informative items that allowed for classifying 90.0%, 88.8% and 88.5% of patients, respectively. CONCLUSIONS: We developed a questionnaire to detect gout containing 11 items that is fast and suitable for use in a telephone survey by non-physicians. The questionnaire demonstrated good properties for discriminating patients with and without gout. It will be administered in a large sample of the general population to estimate the prevalence of gout in France.

Safety of surgery after rituximab therapy in 133 patients with rheumatoid arthritis: data from the autoimmunity and rituximab registry.

OBJECTIVE: We used data from the AutoImmunity and Rituximab (AIR) registry to investigate the safety of surgery for patients with rheumatoid arthritis receiving rituximab (RTX) in routine care. METHODS: Data for patients included in the AIR registry and undergoing surgery during the year following an infusion of RTX were reviewed to describe the frequency of postsurgical complications, compare patients with and without complications, and identify factors associated with complications. RESULTS: We examined data for 133 patients with a known date of surgery and at least 1 followup visit, corresponding to 140 procedures, including 94 orthopedic surgeries (67%) and 23 abdominal surgeries (16.5%). The median delay between surgery and the last RTX infusion was 6.4 months (interquartile range 4.3­ 8.7 months), without any difference between patients with and without complications. Nine patients (6.7%) experienced 12 complications (8.5%), including 8 surgical site infections (5.7%) and 1 death due to septic shock. Postoperative complications occurred after 4.3% of abdominal surgeries (1 of 23) and 7.4% of orthopedic surgeries (7 of 95). On univariate analysis, spine surgery was associated with postoperative complications (P = 0.048). CONCLUSION: In common practice, the risk of complications may be more important in case of spine surgery, but does not seem to be linked to the time between the last RTX infusion and surgery.

Imatinib mesylate in scleroderma-associated diffuse skin fibrosis: a phase II multicentre randomized double-blinded controlled trial.

BACKGROUND: Imatinib mesylate is a potent inhibitor of platelet-derived growth factor and transforming growth factor-ß signalling pathways which may play a role in systemic sclerosis (SSc)-associated skin changes. OBJECTIVES: We aimed primarily at assessing the efficacy of imatinib mesylate in scleroderma skin fibrosis. METHODS: We performed a phase II double-blinded trial on patients with scleroderma with either morphoea involving > 20% of body surface area or SSc with extensive skin involvement: modified Rodnan Skin Score (mRSS) ≥ 20/51. Each patient was randomized to receive either imatinib mesylate 400 mg or placebo daily for a total of 6 months, and then was followed up 6 months after therapy discontinuation. Skin fibrosis was assessed by mRSS and measurement of the dermal thickness using skin biopsies performed at inclusion and at 6 months of treatment. In addition, quality of life (Dermatology Life Quality Index and modified Health Assessment Questionnaire for Scleroderma) was recorded at each visit, and pulmonary function before and after intervention. RESULTS: Twenty-eight patients were included in the study with a mean age of 48·9 years (range 30-71): 25 had a diagnosis of a SSc and three of diffuse cutaneous scleroderma. Demographic data, frequency of organ involvement of SSc and mRSS were comparable between groups. At 6 months, the proportion of variation of mRSS from inclusion was not statistically significantly different between the two groups (median +0·10 in imatinib group vs. -0·16 in placebo group, P = 0·098). Similarly, changes in dermal thickness, quality of life and diffusion capacity for carbon monoxide were not significantly different between groups. CONCLUSIONS: This study failed to demonstrate the efficacy of imatinib 400 mg daily to improve skin fibrosis of diffuse scleroderma after 6 months of treatment based on validated outcome measurements.

Positivity for anti-cyclic citrullinated peptide is associated with a better response to abatacept: data from the 'Orencia and Rheumatoid Arthritis' registry.

OBJECTIVES: Very limited data are available regarding the efficacy of abatacept (ABA) in real life. The aims of this study were to determine the efficacy of ABA in rheumatoid arthritis and predicting factors of efficacy in common practice. METHODS: The Orencia and Rheumatoid Arthritis" (ORA) prospective registry, promoted by the French Society of Rheumatology, has included 1003 patients with RA. RESULTS: 773 patients had already fulfilled the 6-month follow-up visit. Only 21.3% of patients would have fulfilled inclusion criteria used in pivotal controlled trials. The European League Against Rheumatism (EULAR) response, was observed in 330 (59.1%) of the 558 assessed patients (good response: 20.4%, moderate response: 38.7%) and was similar in patients who did and in patients who did not fulfill inclusion criteria of controlled trials. Among EULAR responders, initial 28-joint disease activity score (5.4 (4.7-6.5) in responders vs 4.9 (4.0-6.0) in non responders, p< 0.0001), the proportion of rheumatoid factor (75.6% vs 66.7%, p= 0.03) and the proportion of anti-cyclic citrullinated peptide antibody (anti-CCP)-positivity (75.9% vs 62.2%, p= 0.001) were significantly higher. In multivariate analysis adjusted on initial 28-joint disease activity score and CRP, anti-CCP positivity was associated with EULAR response (OR=1.9;95% CI=1.2 to 2.9, p=0.007), but not rheumatoid factor (OR=1.0;95% CI=0.6 to 1.6, p=0.9). Anti-CCP positivity was also significantly associated with a higher ABA retention rate at 6 months. CONCLUSIONS: Real life efficacy of ABA in the ORA registry was similar as that reported in clinical trials. Anti-CCP positivity was associated with a better response to ABA, independently from disease activity.

Safety and efficacy of rituximab in nonviral cryoglobulinemia vasculitis: data from the French Autoimmunity and Rituximab registry.

OBJECTIVE: Management of nonviral cryoglobulinemia vasculitis has yet to be defined. Rituximab has emerged as a novel and promising therapeutic alternative, but data are scarce. Our objective was to evaluate the safety and efficacy of rituximab in nonviral cryoglobulinemia vasculitis in off-trial real-life patients. METHODS: Prospective data from the French AutoImmunity and Rituximab (AIR) registry, which includes data on patients with autoimmune disorders treated with rituximab in off-label conditions, were analyzed. RESULTS: Twenty-three patients received treatment with rituximab for cryoglobulinemia vasculitis. Tolerance was marked by the occurrence of side effects in almost half of the patients, including severe infections in 6 (26%) of 23, with a rate of 14.1 per 100 patient-years. These infections occurred in a particular subset of patients ages>70 years, with essential type II mixed cryoglobulinemia and renal failure with a glomerular filtration rate of <60 ml/minute, and receiving high-dose corticosteroids. Three of these patients died. In contrast, clinical and immunologic efficacy was noted in all evaluable patients. Clinical relapses occurred in half of the patients after a median time of 13.5 months following rituximab administration, and were more frequent in patients refractory to previous immunosuppressive therapy than in previously untreated patients. CONCLUSION: Data from the AIR registry show a dramatic efficacy and a steroid-sparing effect of rituximab, but also show the occurrence of severe infections in elderly patients with renal failure and high-dose steroids. The role of rituximab in nonviral cryoglobulinemia vasculitis remains to be defined in well-designed randomized controlled trials.

Risk factors for severe infections in patients with rheumatoid arthritis treated with rituximab in the autoimmunity and rituximab registry.

OBJECTIVE: The risk of severe infection is a crucial factor in the assessment of the short-term risk:benefit ratio of biologic drugs in rheumatoid arthritis (RA). There is no increase in severe infections in RA patients treated with rituximab (RTX) in controlled trials, but this has not yet been assessed in daily practice. We undertook this study to investigate the occurrence of and risk factors for severe infections in off-trial patients using data from the AutoImmunity and Rituximab (AIR) registry. METHODS: The AIR registry was set up by the French Society of Rheumatology. The charts of patients with severe infections were reviewed. RESULTS: Of the enrolled patients, 1,303 had at least 1 followup visit at 3 months or later, with a mean ± SD followup period of 1.2 ± 0.8 years (1,629 patient-years). Eighty-two severe infections occurred in 78 patients (5.0 severe infections per 100 patient-years), half of them in the 3 months following the last RTX infusion. Multivariate analysis showed that chronic lung disease and/or cardiac insufficiency (odds ratio 3.0 [95% confidence interval 1.3-7.3], P = 0.01), extraarticular involvement (odds ratio 2.9 [95% confidence interval 1.3-6.7], P = 0.009), and low IgG level (<6 gm/liter) before initiation of RTX treatment (odds ratio 4.9 [95% confidence interval 1.6-15.2], P = 0.005) were significantly associated with increased risk of a severe infection. CONCLUSION: The rate of severe infections in current practice is similar to that reported in clinical trials. The risk factors for severe infections include chronic lung and/or cardiac disease, extraarticular involvement, and low IgG before RTX treatment. This suggests that serum IgG should be checked and the risk:benefit ratio of RTX discussed for patients found to have low levels of IgG.

Lymphoma in patients treated with anti-TNF: results of the 3-year prospective French RATIO registry.

OBJECTIVE: To describe cases of lymphoma associated with anti-TNF therapy, identify risk factors, estimate the incidence and compare the risks for different anti-TNF agents. METHODS: A national prospective registry was designed (Research Axed on Tolerance of bIOtherapies; RATIO) to collect all cases of lymphoma in French patients receiving anti-TNF therapy from 2004 to 2006, whatever the indication. A case-control analysis was conducted including two controls treated with anti-TNF per case and an incidence study of lymphoma with the French population was used as the reference. RESULTS: 38 cases of lymphoma, 31 non-Hodgkin's lymphoma (NHL) (26 B cell and five T cell), five Hodgkin's lymphoma (HL) and two Hodgkin's-like lymphoma were collected. Epstein-Barr virus was detected in both of two Hodgkin's-like lymphoma, three of five HL and one NHL. Patients receiving adalimumab or infliximab had a higher risk than those treated with etanercept: standardised incidence ratio (SIR) 4.1 (2.3-7.1) and 3.6 (2.3-5.6) versus 0.9 (0.4-1.8). The exposure to adalimumab or infliximab versus etanercept was an independent risk factor for lymphoma in the case-control study: odds ratio 4.7 (1.3-17.7) and 4.1 (1.4-12.5), respectively. The sex and age-adjusted incidence rate of lymphoma was 42.1 per 100 000 patient-years. The SIR was 2.4 (95% CI 1.7 to 3.2). CONCLUSION: The two to threefold increased risk of lymphoma in patients receiving anti-TNF therapy is similar to that expected for such patients with severe inflammatory diseases. Some lymphomas associated with immunosuppression may occur, and the risk of lymphoma is higher with monoclonal-antibody therapy than with soluble-receptor therapy.

Cytokine imbalance with increased production of interferon-alpha in psoriasiform eruptions associated with antitumour necrosis factor-alpha treatments.

BACKGROUND: Psoriasiform eruptions occur in association with antitumour necrosis factor (TNF)-alpha treatments in autoinflammatory diseases. The major reported clinical presentation is palmoplantar pustulosis, sometimes accompanied with plaque-like psoriasis. In some reports, histological findings suggest psoriasis whereas others favour a lichenoid drug reaction. We present a case series with a comprehensive clinical, histopathological and immunohistochemical study. OBJECTIVES: To investigate the mechanism involved in psoriasiform eruptions in patients receiving anti-TNF-alpha inhibitors. METHODS: Between July 2004 and May 2008, 13 patients with psoriasiform eruptions arising under anti-TNF-alpha treatment were enrolled in the study. Punch biopsy specimens of lesions were processed for standard and immunohistochemical analyses using antibodies against CD3, CD4, CD8, CD20, CD1a, KP1, CXCR3, CXCL9, Tia1 and MxA, which is specifically induced by type I interferons (IFNs). Additionally, we analysed biopsies from lesional skin of patients with cutaneous discoid lupus erythematosus, lichen planus and psoriasis. Control biopsies were taken from unaffected skin. RESULTS: All patients developed psoriasiform plaques on the body accompanied with palmoplantar keratoderma or pustulosis in three patients. Histological and immunohistochemical findings showed a psoriasiform pattern with focal lichenoid and spongiotic features. We detected strong production of the MxA protein in inflammatory cells, indicating involvement of type I IFNs, and the expression was higher than in control psoriasis samples. Expression of MxA was closely associated with the recruitment of CXCR3+ lymphocytes in the skin bearing markers of cytotoxic capacity. CONCLUSIONS: Results support the hypothesis that psoriasiform eruptions are a new model of drug reaction characterized by an increased expression of type I IFNs induced by anti-TNF-alpha.

Incidence and risk of fatal myocardial infarction and stroke events in rheumatoid arthritis patients. A systematic review of the literature.

BACKGROUND: There is substantial evidence of excess cardiovascular morbidity and mortality in rheumatoid arthritis (RA) patients, but the related studies showed important variations in the estimation of the risk. We conducted a meta-analysis to evaluate more accurately the incidence of cardiovascular events, and the excess of cardiovascular risk in a population of RA patients. METHODS: The authors searched for observational studies accounting for the number of myocardial infarction or stroke events, using Medline, and congress abstracts published until February 2006. The populations studied were adults and RA diagnosis was based on the American College of Rheumatology (ACR) criteria. We calculated the incidence of myocardial infarction and cerebrovascular fatal events in RA patients and estimated the cardiovascular risk increase for RA patients compared with the control group. RESULTS: 17 publications and abstracts were identified, 15 were selected for the meta-analysis (two publications were excluded because of the lack of person-years information). The incidence of fatal myocardial infarction was 13.3 for 1000 RA patients-year (IC95%=[13-13.6]). The incidence of fatal cerebrovascular accident was 4.5 for 1000 RA patients-year (IC95%=[4.3-4.7]). Risk of myocardial ischemia in RA patients was about 1.63 compared to the general population (OR=1.63, IC95%=[1.34-2]). No excess was found for the risk of stroke event in RA patients. CONCLUSION: RA patients were reported to present an excess risk of fatal myocardial infarction compared to the general population. The prevention of cardiovascular complications, including management of cardiovascular risk factors and control of systemic inflammation, should be taken into account by the rheumatologist.

Influence of FCGR3A-V212F and TNFRSF1B-M196R genotypes in patients with rheumatoid arthritis treated with infliximab therapy.

OBJECTIVE: Anti-TNF-alpha therapies are widely used in rheumatoid arthritis (RA) patients. Despite their clearly proven efficacy, some discrepancies were observed in the treatment response with 40% of non-responder patients. The aim of this study is to determine whether two functional single-nucleotide polymorphisms, V212F in the FCGR3A, and M196R in the TNFRSF1B genes correlate with rheumatoid arthritis susceptibility and response to anti-TNF-alpha therapy. METHODS: The population study was composed of a French cohort of 78 RA patients and 70 healthy controls. Allele and genotype frequencies were compared between patients and controls, according to their response to infliximab therapy, using the American College of Rheumatology (ACR) response criteria. RESULTS: No association was found between these two SNPs and RA susceptibility. A significant correlation was found between 196R allele carriers and low response to infliximab therapy. CONCLUSION: This is the first report of a statistically significant association between the TNFRSF1B-M196R SNP and response to infliximab in a French cohort. Larger studies are needed to confirm the relevance of this association.

Anti-nuclear antibodies, anti-DNA and C4 complement evolution in rheumatoid arthritis and ankylosing spondylitis treated with TNF-alpha blockers.

OBJECTIVE: To investigate autoantibody induction in rheumatoid arthritis (RA) and ankylosing spondylitis (AS) in a cohort of French patients treated with TNF-alpha blockers. METHODS: We tested the serum of patients for antinuclear antibodies (ANA), anti-DNA antibodies and C4 complement at baseline, and for each infusion for infliximab, and at month 3, 6 and 12 for etanercept. We looked for all signs suggesting a drug-induced lupus. We tried to correlate ANA and anti-DNA development with various clinical data, especially the response to treatment. RESULTS: 229 patients were included in the study. 159 were treated with infliximab (98 RA and 61 AS) and 125 with etanercept (116 RA and 9 AS). In the infliximab group, 43.6% of RA patients and 27.1% of AS had significant levels of ANA at baseline. This proportion increased during the follow up to 73% in RA patients and 52% in AS patients. The proportion of patients positive for anti-DNA antibodies increased from 0% to 9.5% in RA group, and from 0% to 2% in AS group. In the etanercept group, 58.5% of these patients had significant levels of ANA at baseline; this proportion raised to 63.3% in patients previously treated with infliximab, and fell to 20.6% in the patients who never received TNF-alpha blockers. No significant variation of ANA, anti-DNA and C4 levels was observed in the etanercept group. Only three patients developed clinical manifestations (chilblain lupus) possibly related to these auto-antibodies, two with infliximab and one with etanercept. CONCLUSION: The ANA induction was only observed under infliximab therapy. Thus, ANA induction seems not to be a therapeutic class effect. This difference between infliximab and etanercept treatment may be the consequence of differential capacity of a monoclonal antibody and a soluble receptor in inducing apoptotic cell death of the cells expressing TNF on their membrane.

The effect of imatinib (Glivec) on scleroderma and normal dermal fibroblasts: a preclinical study.

BACKGROUND: Scleroderma skin overexpresses the platelet-derived growth factor receptor beta-subunit (PDGFR-beta) in dermal vessels and PDGFR-beta messenger RNA in cultured fibroblasts. Moreover, increased levels of PDGF and stimulatory autoantibodies to PDGFR have been identified in the serum of scleroderma patients. OBJECTIVE: Imatinib being an inhibitor of tyrosine kinase receptors such as PDGFR, its effect on scleroderma fibroblasts was evaluated in vitro as a preclinical therapeutic step. METHODS: The effect of imatinib on fibroblasts grown from normal or involved/uninvolved scleroderma skin was studied by Western blot and the methyltetrazolium test. The pattern of distribution of PDGFR-beta in scleroderma versus normal skin was studied by immunohistochemistry. RESULTS: In vitro, imatinib inhibited the proliferation of normal dermal and scleroderma fibroblasts at least partly via the inhibition of the phosphorylation of PDGFR. PDGFR-beta was expressed in the epidermis and adnexae in 5 lesional scleroderma biopsies and not in controls. CONCLUSION: This study suggests that imatinib can serve as therapy to limit dermal fibroblast proliferation in scleroderma.