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Luc Mouthon

Publications and source records attributed to Luc Mouthon.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Intravenous immunoglobulin therapy].

Intravenous immunoglobulins (IVIg) are therapeutic preparations of normal human IgG that are obtained from pools of healthy blood donors. They can be used at low dose in the substitutive therapy of patients with primary or secondary immune deficiencies, or at high dose as an immunomodulatory agent in a large number of autoimmune and/or systemic inflammatory diseases, particularly in hematologic or neurologic diseases. Tolerance to IVIg is excellent in most of the cases and the risk of transmission of an infectious agent is only theoretical. Mechanisms of action of IVIg are multiple and complicated. The development of new therapeutic trials in association with analyses of mechanisms of action should help to define new indication of IVIg therapy.

Autoimmune Diseases↗
PubMed2005

Early detection of pulmonary arterial hypertension in systemic sclerosis: a French nationwide prospective multicenter study.

OBJECTIVE: Screening allows for early management of pulmonary arterial hypertension (PAH), a severe complication of systemic sclerosis (SSc). Since no consensus has been reached on the method and criteria for optimal screening, we sought to develop an algorithm based on symptoms, Doppler echocardiography, and right heart catheterization (RHC) for application to a nationwide multicenter SSc population in France. METHODS: This prospective study was conducted from September 2002 to July 2003 by experts at 21 SSc centers. At each center, SSc patients without severe pulmonary function abnormalities underwent Doppler echocardiography by an experienced cardiologist. Patients with a peak velocity of tricuspid regurgitation (VTR) of >3 meters/second or 2.5-3 meters/second with unexplained dyspnea were asked to undergo RHC to confirm PAH according to international guidelines. RESULTS: Of the 599 patients analyzed, 29 had known PAH and 33 had suspected PAH, based on Doppler echocardiography, and underwent RHC. Of these 33, 18 were found to have PAH, 3 had left ventricular dysfunction, and 12 had no PAH. Newly diagnosed cases of PAH were of mild severity (mean +/- SD pulmonary artery pressure [mPAP] 30 +/- 9 mm Hg, mean +/- SD total pulmonary resistance [TPR] 524 +/- 382 dynes x second/cm(5)). Hemodynamic findings in patients with known PAH were mPAP 49 +/- 17 mm Hg and TPR 1,007 +/- 615 dynes x second/cm(5). The estimate of PAH prevalence was 7.85% (95% confidence interval 5.70-10.00). CONCLUSION: This screening algorithm, based on dyspnea, Doppler echocardiographic evaluation of VTR, and RHC, enabled early detection of PAH at a mild stage. Whether mild PAH will evolve to severe PAH in reported cases and whether this early diagnosis translates into improved prognosis for patients with mild PAH will be evaluated in the ongoing 3-year followup of this cohort.

Adult↗
PubMed2005

Anti-annexin V antibodies: are they prothrombotic?

Annexin V inhibits prothrombin activation and is able to prevent thrombus formation under normal venous and arterial blood flow conditions. Antibodies to annexin V have been identified in association with several pathological conditions, including systemic lupus erythematosus (SLE) with or without anti-phospholipid syndrome, recurrent spontaneous abortions and systemic sclerosis (SSc). These antibodies are suspected to exert a detrimental role and interfere with annexin V function. Thus, they have been associated with the occurrence of foetal loss and venous and/or arterial thrombosis in SLE patients, as well as digital ischemia in SSc patients. However, their true pathogenic role remains to be proven.

Abortion, Habitual↗
PubMed2005

Analysis of autoantibody repertoires in small- and medium-sized vessels vasculitides. Evidence for specific perturbations in polyarteritis nodosa, microscopic polyangiitis, Churg-Strauss syndrome and Wegener's granulomatosis.

In order to identify new antibody reactivities, we have used a quantitative immunoblotting technique on extracts of normal human tissues to analyze the repertoires of serum IgM, serum IgG and purified IgG autoantibodies of patients with systemic vasculitides. Patients fulfilled the American College of Rheumatology and Chapel Hill criteria for the diagnosis of polyarteritis nodosa (PAN) (n=8), PAN related to hepatitis B virus (HBV) infection (n=5), Wegener's granulomatosis (WG) (n=6), microscopic polyangiitis (MPA) (n=18) or Churg-Strauss syndrome (CSS) (n=8). Sera from patients with chronic HBV infection without PAN (n=5) and age- and gender-matched healthy individuals (n=45) were used as controls. In the lung extract, IgM from 12/18 MPA patients reacted with high intensity with a 50 kDa band and serum IgG from 3/8 CSS patients bound to a 70 kDa protein band. In the artery extract, serum IgG from 6/18 MPA patients bound to an 85 kDa antigen, whereas purified IgG from all WG patients tested bound to a 28 kDa protein band and IgM from CSS patients bound to 2 main antigens of 38 and 60 kDa. These results provide evidence for the specificity of autoantibody repertoires from patients with PAN, WG, CSS and MPA.

Adolescent↗
PubMed2005

[Interstitial lung disease in connective tissue disorders].

Interstitial lung diseases (ILD) associated with connective tissue disorders differ from idiopathic ILD in several aspects, although most of them are comparable. In most patients, ILD occurs during the course, or at the time of diagnosis of connective tissue disease. Opportunistic pulmonary infections, together with adverse effects of treatment should always be discussed. The prevalence of ILD varies among the different connective tissue disorders. Thus, ILD is frequently encountered in patients with systemic sclerosis and to a lesser degree in patients with myositis. As compared to idiopathic ILD, histopathological aspects of ILD associated with connective tissue diseases are more frequently those of non-specific interstitial pneumonia, whereas usual interstitial pneumonia is rare. Other ILD, such as organized pneumonia, interstitial lymphoid pneumonia, diffuse alveolar damage and alveolar hemorrhage are occasionally encountered. ILD must be detected early in the course of collagen disorders by performing computed tomodensitometry and pulmonary function tests. The prognosis of connective tissue associated ILD is better than that of idiopathic ILD. The treatment requires corticosteroids and/or immunosuppressants, depending on the nature of the associated connective tissue disease and ILD progression.

Adrenal Cortex Hormones↗
PubMed2005

Deaths occurring during the first year after treatment onset for polyarteritis nodosa, microscopic polyangiitis, and Churg-Strauss syndrome: a retrospective analysis of causes and factors predictive of mortality based on 595 patients.

Although combining corticosteroids and cyclophosphamide has greatly improved the prognoses of severe necrotizing vasculitides, some patients continue to have fulminating disease and die within the first year of diagnosis. To evaluate the characteristics of these patients, we retrospectively studied the files of 60 patients who died within the first year (20 patients with hepatitis B virus-associated polyarteritis nodosa [HBV-PAN], 18 with non-HBV PAN, 13 with microscopic polyangiitis [MPA], and 9 with Churg-Strauss syndrome [CSS]) and 535 first-year survivors (89 patients with HBV-PAN, 182 with non-HBV PAN, 140 with MPA, and 124 with CSS), 85 of whom died during a mean follow-up of 6.4 years. The 2 groups were compared for prognostic factors defined by the five-factor score (FFS) and Birmingham Vasculitis Activity Score at baseline, clinical signs, treatment, outcome, and causes of death. For first-year nonsurvivors, the clinical signs predictive of death were as follows: renal involvement (hazard ratio [HR], 1.6; 95% confidence intervals [CI], 1.09-2.3) or central nervous system involvement (HR, 2.3; 95% CI, 1.5-3.7), and a trend toward cardiomyopathy (HR, 1.4; 95% CI, 1.000-2.115). Older patients died earlier (HR, 1.04; 95% CI, 1.023-1.051). Gastrointestinal symptoms were most frequently associated with early death from HBV-PAN, while 83% of CSS patients died of cardiac involvement. Treatment had no significant impact on early death, except for patients with FFS > or = 2, for whom steroids alone were associated (p < 0.05). The major cause of early death was uncontrolled vasculitis (58%), followed by infection (26%). Cyclophosphamide-induced cytopenia and infection were responsible for 2 deaths. Despite these iatrogenic complications, early deaths were more frequently the consequence of insufficient or inappropriate therapy.

Adolescent↗
PubMed2004

Intravenous immunoglobulins in autoimmune- or parvovirus B19-mediated pure red-cell aplasia.

Pure red-cell aplasia (PRCA) is defined as the absence of mature erythroid precursors in a bone marrow that otherwise exhibit normal cellularity. Acquired PRCA may occur in association with neoplasms (such as lymphoproliferative disorders), thymoma, autoimmune disorders, pregnancy, or as a consequence of chronic human parvovirus B19 (B19) infection in an immunologically incompetent host. PRCA may also develop after exposure to drugs (erythropoietin or tacrolimus). PRCA of autoimmune origin was first treated successfully with intravenous immunoglobulins (IVIg) more than 20 years ago. Since then, B19-associated PRCA in solid-organ transplant recipients and in human immunodeficiency virus (HIV)-infected patients has also been successfully treated with IVIg. Routine maintenance therapy is probably not indicated in HIV-infected patients with CD4+ counts above 300/microL, whereas repeated infusions might be necessary if CD4+ count is below 80.

Autoimmune Diseases↗
PubMed2004

[Immunomodulatory effects of intravenous immunoglobulins].

Intravenous immunoglobulins (IVIg) are therapeutic preparations of normal human IgG obtained from pools of more than 1000 healthy blood donors. They are currently used in the treatment of a wide range of auto-immune diseases, whether associated with auto-antibodies or auto-reactive T lymphocytes, as well as in the treatment of systemic inflammatory diseases. Several mechanisms of action have been identified during the last 20 years, including: (i) modulation of Fc receptors expression on leukocytes and endothelial cells; (ii) interaction with complement proteins; (iii) modulation of cytokines and chemokines synthesis and release; (iv) modulation of cell proliferation and apoptosis; (v) remyelinisation; (vi) neutralisation of circulating autoantibodies; (vii) selection of repertoires of B and T lymphocytes; (viii) interaction with other cell-surface molecules on lymphocytes and monocytes; (ix) corticosteroid sparing. These mechanisms of action are multiple and often intricate. However, they are still little known and further investigations are warranted.

Apoptosis↗
PubMed2004

Predicting mortality in systemic Wegener's granulomatosis: a survival analysis based on 93 patients.

OBJECTIVE: To determine predictors of survival of patients with systemic Wegener's granulomatosis (WG). METHODS: We retrospectively studied 93 patients (median age 52 years, male/female ratio 1.7) with systemic WG. All subjects received cytotoxic drugs. Survival was evaluated as a function of the main clinical and laboratory parameters and 2 disease activity scores assessed at diagnosis. Statistical analyses used the multivariate Cox proportional hazards regression model. RESULTS: The mean followup was 4.5 years; 25 (27%) patients died. According to univariate analysis, a pejorative prognostic value was attributed to serum creatinine >160 micromole/liter (P < 0.001); age >52 years (P < 0.002); absence of ear, nose, and throat (ENT) involvement (P < 0.001); and hemoglobin < or =11.8 gm/dl (P = 0.02). Multivariate analysis retained age >52 years (hazard ratio [HR] = 3.40, P = 0.04) as an independent predictor of poor outcome, whereas the presence of ENT involvement was associated with a longer survival (HR = 0.31, P = 0.02). CONCLUSION: Our results suggest that an older age and the absence of ENT involvement at diagnosis independently predict an increased risk of mortality for WG patients. These findings could indicate that the prognosis of WG might be governed by the balance between the granulomatosis as opposed to the vasculitic disease process.

Adolescent↗
PubMed2004

IgG reactivity with a 100-kDa tissue and endothelial cell antigen identified as topoisomerase 1 distinguishes between limited and diffuse systemic sclerosis patients.

We have analyzed antibody (Ab) reactivities of patients with limited systemic sclerosis (SSc) and anti-centromere Ab, patients with diffuse SSc and anti-topoisomerase 1 (anti-topo 1) Ab, patients with diffuse SSc without anti-topo 1 or anti-centromere Ab and age- and gender-matched healthy controls with normal human tissue and endothelial cell (EC) antigens. IgG reactivities with tissue antigens differed significantly between patients with anti-topo 1 Ab and patients with anti-centromere Ab. One 100-kDa band identified as topoisomerase 1 in macrovascular and microvascular EC extracts was recognized by IgG from patients with anti-topo 1 Ab and 50% of patients without specific Ab. IgG from patients with limited SSc and anti-centromere Ab, but not those of other patients or controls specifically recognized a 80-kDa band only in microvascular EC. Our results indicate that Ab from patients with limited or diffuse SSc with or without anti-topo 1 Ab exhibit specific and mutually exclusive reactivity patterns.

Autoantibodies↗
PubMed2004

Intrasinusoidal cytotoxic CD8+ T cells in nodular regenerative hyperplasia of the liver.

Diffuse nodular regenerative hyperplasia (NRH) of the liver is an acquired architectural disturbance that can lead to portal hypertension. Although frequently associated with autoimmune or hematologic malignancies, its exact pathogenesis remains largely unknown. We observed CD8+ cytotoxic T cells in the liver sinusoids of 14 of 44 NRH patients and explored possible relationships between these lymphocytes and vascular damage. The immunophenotype of intrahepatic lymphocytes was determined using immunohistochemical analysis and endothelial injury using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method for apoptosis combined with endothelial cell labeling. Controls for the quantitative analysis of liver-infiltrating lymphocytes consisted of patients with chronic hepatitis C or normal liver (n = 13 and n = 6, respectively). Liver specimens from the 14 patients dislayed intrasinusoidal infiltrate composed of CD3+ and CD8+ lymphocytes, located near atrophic liver cell plates. Significantly more granzyme B+ and CD57+ lymphocytes were observed in NRH than chronic hepatitis C samples with quantitatively similar CD8+ infiltrates. Double-labeling revealed apoptotic endothelial sinusoidal cells in CD8+ T-cell-infiltrated areas in all NRH samples but never in chronic hepatitis C or normal livers. T-cell receptor rearrangement or immunoscope analysis suggested liver-specific polyclonal or oligoclonal T-cell expansions. Clinical and biological characteristics of the 14 patients were similar to those observed in the 30 patients with NRH devoid of lymphocytic infiltration. We report here that CD8+ cytotoxic T cells infiltrated the liver sinusoids of a high percentage (32%) of NRH patients and suggest that some NRH cases might result from chronic, cytotoxic CD8+ T-lymphocyte targeting of sinusoidal endothelial cells.

Adult↗
PubMed2004

Pathogenesis of hemophagocytic syndrome (HPS).

Hemophagocytic syndrome (HPS) is a clinicopathologic entity characterized by increased proliferation and activation of benign macrophages with hemophagocytosis throughout the reticuloendothelial system. Uncontrolled T-lymphocyte activation is responsible for increased T(H)1 cytokines secretion such as IFN-gamma, IL-12 and IL-18 that promotes macrophage activation. Genetic defects specific for cytotoxic T lymphocytes (CTL) and natural killer (NK) cells have been identified in patients with primary HPS that are responsible for altered cell death and apoptosis induction or target killing. HPS may be secondary to malignancy, infection or autoimmune disease, and mechanisms involved are poorly understood. However, in adult-onset Still's disease, juvenile chronic arthritis and probably systemic lupus erythematosus, IL-18 might play a role in initiating macrophage activation.

Autoimmune Diseases↗
PubMed2004

Churg-strauss syndrome.

First described in 1951 as an allergic and granulomatous angiitis, Churg-Strauss syndrome (CSS) is a small-vessel vasculitis. Mean age at the time of diagnosis is approximately 50 years, with a sex ratio around 1. Asthma is the central feature of CSS and precedes the systemic manifestations in almost all cases, whereas 70% of the patients have maxillary sinusitis, allergic rhinitis, and/or sinus polyposis. General symptoms are frequent, and associated with pulmonary infiltrates in 38 to 77% of the patients; peripheral neuropathy, usually mononeuritis multiplex, in 64 to 75%; skin involvement in 40 to 70%; and gastrointestinal tract symptoms in 37 to 62%. Cardiac involvement is common, with pericarditis in 23% of the patients and myocarditis in 13%, and represents the primary cause of mortality. Hypereosinophilia is the main biological feature of CSS, whereas antineutrophil cytoplasm antibodies (ANCA), especially anti-myeloperoxidase (MPO), are found in one third to one half of the patients. Triggering factors, such as vaccination, desensitization, or exposure to leukotriene-receptor antagonists, have been suspected as contributing to the development of CSS, but its etiology has not yet been fully elucidated. T-helper type 2 (Th2) lymphocytes, by analogy with the pathogenesis of asthma, eosinophils infiltrating tissues, and anti-MPO ANCA are probably implicated in the pathogenesis of vasculitic lesions. CSS usually responds rapidly to corticosteroids. Adjunction of cyclophosphamide is indicated when at least one factor of poor prognosis is present. With treatment, remission is obtained in more than 80% of the patients, but it is often impossible to withdraw corticosteroids completely because of residual asthma. Relapses occur in 25% of the patients, half during the first year. The 10-year survival rate was 79% for our patients, with 73% of them requiring low-dose prednisone maintenance therapy for persistent asthma.

Journal Article↗
PubMed2004

Medical cure of plasma cell granuloma of the thyroid associated with Hashimoto's thyroiditis: a case report and review.

Plasma cell granuloma (PCG) is a rare, benign inflammatory tumor composed of myofibroblasts, abundant plasma cells, and lymphocytes combined with collagen. A thyroid localization of PCG is extremely rare, and surgical therapy is indicated. We report the case of a 35-yr-old woman with a thyroid PCG, associated with Hashimoto's thyroiditis, that was responsible for tracheal compression. Surgery was performed, but the thyroid could not be removed because of the fibrotic process. The patient was treated with corticosteroids and immunosuppressive therapy. Dyspnea and dysphagia improved within 1 month, whereas thyroid volume returned to normal within 3 yr. We also review other reports of thyroid PCG in the literature and discuss the differential diagnosis and treatment. Although the use of immunosuppressive therapy has never been reported for thyroid PCG until now, this treatment may represent a good alternative to surgery in life-threatening, unresectable PCG.

Adrenal Cortex Hormones↗
PubMed2003

Microscopic polyangiitis and polyarteritis nodosa: how and when do they start?

OBJECTIVE: To describe initial clinical symptoms attributable to microscopic polyangiitis (MPA) or polyarteritis nodosa (PAN). METHODS: We retrospectively reviewed the medical files of 72 patients (mean followup 6.7 years) with biopsy-proven MPA (n = 36) or PAN (n = 36). RESULTS: Initial manifestations were similar in both entities except for peripheral neuropathy (P = 0.02) and gastrointestinal tract involvement (P = 0.006), which were significantly more frequent in PAN, and general signs alone in MPA (8%; P = 0.02). The mean time to diagnosis was 9.8 +/- 19.4 months; 35% of the patients died and 26% relapsed; significantly more MPA than PAN patients relapsed (P = 0.03). Time to diagnosis >/=90 days was associated with a trend toward more patients relapsing (P = 0.12), but not with an increased risk of mortality. CONCLUSION: Initial symptoms of MPA and PAN are usually nonspecific and last for several months before the diagnosis is made. A longer time to diagnosis is associated with a tendency to a higher relapse rate.

Adolescent↗
PubMed2003

Treatment of polyarteritis nodosa and microscopic polyangiitis with poor prognosis factors: a prospective trial comparing glucocorticoids and six or twelve cyclophosphamide pulses in sixty-five patients.

OBJECTIVE: Because the optimal cyclophosphamide (CY) treatment duration for severe polyarteritis nodosa (PAN) without virus infection and microscopic polyangiitis (MPA) has not been established, we conducted a trial to compare the effectiveness of 6 versus 12 CY pulses given in combination with corticosteroids (CS). METHODS: Sixty-five (18 PAN, 47 MPA) previously untreated patients were randomized to receive 12 (n = 34) or 6 (n = 31) CY pulses combined with CS. PAN and MPA were histologically proven or met ACR criteria. All patients presented >or=1 factor of severity according to the five factor score (FFS). CY pulses were administered every 2 weeks for 1 month, then every 4 weeks. The end point of the study was the number of events (relapses and/or deaths) occurring in each group, analyzed according to an intention-to-treat strategy. The outcome was evaluated by Cox proportional hazards analysis. RESULTS: The baseline characteristics were similar for both groups. The mean (+/- SD) followup was 32 +/- 21 months. Survival analysis showed a significantly lower relapse probability (P = 0.02; hazards ratio [HR] = 0.34) and higher event-free survival (P = 0.02, HR = 0.44) for the 12 CY-pulse group while the mortality rates were not significantly different (P = 0.47). CONCLUSION: These results suggest that 6 CY pulses are less effective than 12 CY pulses to treat severe PAN and MPA, particularly with respect to the risk of relapses.

Adult↗
PubMed2003

Intravenous immunoglobulin abrogates dendritic cell differentiation induced by interferon-alpha present in serum from patients with systemic lupus erythematosus.

OBJECTIVE: Alterations in the function of dendritic cells (DCs) may explain the systemic autoimmune responses that characterize systemic lupus erythematosus (SLE). Even though several reports have documented the beneficial effect of intravenous immunoglobulin (IVIG) in SLE, the underlying mechanisms of action remain poorly understood. Considering the effect of serum factors, including interferon-alpha (IFNalpha), on the activity of DCs, we investigated the effects of IVIG on the differentiation of DCs mediated by serum from SLE patients. METHODS: DCs were differentiated from peripheral blood monocytes obtained from SLE patients and from healthy blood donors, in the presence of SLE serum. IVIG was used at a concentration of 0.15 mM. A functional assay was performed to assess the inhibitory effect of IVIG on the uptake of nucleosomes by DCs. RESULTS: IVIG interfered with the differentiation of DCs from SLE patients and healthy donors cultured in the presence of SLE serum. Treatment of DCs with IVIG inhibited the ingestion of nucleosomes by immature DCs, by up to 36%. CONCLUSION: The present findings indicate that IVIG, by down-regulating the IFNalpha-mediated differentiation of DCs and by inhibiting uptake of nucleosomes, may exert an essential immunoregulatory effect in SLE patients at the onset of the immune response, at the DC level. Given the critical role of HLA molecules and the costimulatory signals delivered by CD80 and CD86 in optimal antigen presentation and T cell activation, inhibition of expression of HLA and CD80/CD86 on DCs by IVIG offers a plausible explanation for the efficacy of IVIG in SLE and other immune-mediated inflammatory conditions.

Adult↗