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Biomedical subjects

Luc Mouthon

Publications and source records attributed to Luc Mouthon.

At least 19 recordsLinked to original sources

Sjogren's syndrome is associated with and not secondary to systemic sclerosis.

OBJECTIVES: When Sjögren's syndrome (SS) is secondary to rheumatoid arthritis, the sicca syndrome is less serious and anti-SSA/SSB antibodies are found less frequently than in primary SS (pSS). When SS is associated with systemic lupus erythematosus, clinical and serological patterns are similar to those of pSS. We aimed to determine whether SS, accompanying systemic sclerosis (SSc), could be considered secondary to or associated with SSc and whether the coexistence of both modifies the severity and the outcome of each disease. PATIENTS AND METHODS: A retrospective multicentric study was conducted to compare (i) characteristics and complications of SS between 27 patients with SS and SSc (SS-SSc) and 202 patients with pSS, and (ii) the characteristics of SSc and complications between the SS-SSc group and 94 patients with SSc alone. RESULTS: SS features were similar in both SS-SSc and pSS patients, except for peripheral neuropathy and arthritis, which was more common in SS-SSc than in the pSS patients (P = 0.02 and 0.05, respectively). SSc appears to be less severe in patients with SS-SSc than SSc alone with a lower frequency of lung fibrosis (P = 0.05). Compared with patients with pSS or SSc alone, SS-SSc patients were more likely to have another autoimmune disorder and other autoantibodies (SS-SSc vs pSS, P = 0.02 and P = 0.03, respectively). CONCLUSION: SS seems to be associated with and not secondary to SSc. SS associated with SSc has the same features as pSS, but SSc seems to be less serious. Moreover, the association of SS and SSc is frequently accompanied by a spreading of autoimmunity.

Adult↗

Marked efficacy of a therapeutic strategy associating prednisone and plasma exchange followed by rituximab in two patients with refractory myopathy associated with antibodies to the signal recognition particle (SRP).

We report two patients with myopathy associated with anti-signal recognition particle Ab, refractory to conventional therapy, who were treated with prednisone and plasma exchange, followed by rituximab. A marked response was observed in both patients, with partial to complete recovery of muscle strength, which was sustained.

Adult↗

Anti-endothelial cell antibodies from patients with limited cutaneous systemic sclerosis bind to centromeric protein B (CENP-B).

By using a quantitative immunoblotting technique on protein extracts of human macrovascular and microvascular endothelial cells, we have analyzed the self-reactive repertoires of IgG from 20 patients with limited cutaneous SSc, 40 patients with diffuse SSc and 60 age- and sex-matched healthy controls. Serum IgG from 15/20 patients with limited cutaneous SSc and anti-centromere antibodies bound to at least one of the two 75- and 85-kDa protein bands in the different endothelial cell extracts, whereas IgG from healthy controls or patients with diffuse SSc did not. N-terminal sequencing of the 75- and 85-kDa bands identified CENP-B as the sole antigen in both bands. Moreover, IgG from all of the SSc patients who recognized the 75- and/or 85-kDa bands bound to a full-length recombinant CENP-B protein as assessed by ELISA, whereas IgG from other SSc patients did not. The main target of anti-endothelial cell antibodies in patients with limited cutaneous SSc is the nuclear and ubiquitous protein CENP-B.

Antibody Specificity↗

[Bosentan for treatment of active digital ulcers in patients with systemic sclerosis].

OBJECTIVES: To describe the effect of bosentan and its dual inhibition of endothelin-1 ETA and ETB receptors on digital ulcers in patients with systemic sclerosis (SSc). METHODS: Patients receiving bosentan for SSc-related digital ulcers were identified in eight centers, and their characteristics and follow-up were recorded. RESULTS: Nine (six with diffuse and three with limited cutaneous forms of SSc) patients (median age: 54 years) had received bosentan for digital ulcers. Complete healing occurred in seven (median time to improvement: 4 weeks). Another experienced a significant decrease in the number of ulcers (from 22 to 5) in 8 weeks, while one had no improvement. After a median follow-up of 24.3 months, only one recurrence was observed. Raynaud phenomenon improved in all but one patient. DISCUSSION: These data suggest that some patients may benefit from bosentan to treat digital ulcers. The short time to healing in these patients with rather chronic ulcers argues strongly in favor of its use. These results also strengthen the evidence that endothelin-1 plays an important role in the vascular manifestations of SSc. CONCLUSION: Bosentan can be effective in the treatment of digital ulcers in some SSc patients with SSc, probably especially those involving substantial ischemia. Bosentan is not a first-line drug in this indication yet and must be carefully used by specialists in SSc. Forthcoming results from the international RAPIDS-2 study should clarify the indications for bosentan in the treatment of SSc-related digital ulcers.

Adult↗

[Mandibular resorption, an underdiagnosed manifestation of systemic scleroderma].

INTRODUCTION: Systemic sclerosis (SSc) is sometimes associated with bone resorption that can reach the mandible. CASES: We report here the cases of two women (aged 47 and 57 years) with SSc diagnosed 13 and 26 years earlier, respectively. Both presented marked mandibular bone resorption. The first had prominent interstitial lung disease, and the second, who died within a few months, had severe left ventricular dysfunction due to SSc. DISCUSSION: Mandibular resorption is a rare but probably underdiagnosed manifestation of SSc. In addition to its esthetic effects, it can cause severe disability.

Bone Resorption↗

[Indications for intravenous immunoglobulins].

Intravenous immunoglobulins (IgIV) are therapeutic preparations of polyclonal human IgG, obtained from a pool of plasma from more than 1000 healthy donors. This article discusses only some of the recognized indications (Group I) and some of those currently under evaluation (Group II) for the treatment of autoimmune and systemic inflammatory diseases. Perspectives for IgIV use are approached through three diseases, each providing a different model of immune system modulation: ocular cicatricial pemphigoid, where an autoimmune reaction is modulated; alloimmunization of chronic hemodialysis patients, where alloreactivity can be modulated; and streptococcal toxic shock, where anti-infectious immunity may be modulated.

Acquired Immunodeficiency Syndrome↗

[Diagnosis of lymphocytopenia].

Lymphopenia is defined as a peripheral lymphocyte count lower than 1500/mm3 in adults and 4500/mm3 in children younger than eight months of age. We propose a classification of lymphopenia according to the mechanism involved: lymphocyte production defects, including primary immune deficiencies and immune deficiencies secondary to malnutrition or zinc deprivation; excess catabolism, due to causes including radiotherapy, chemotherapy, immunosuppressive therapy, HIV infection, and systemic lupus erythematosus; abnormal lymphocyte trapping, including mainly splenomegaly, certain viral infections, septic shock, extended burns, systemic granulomatosis, and corticosteroids; other causes of lymphocytopenia, with mechanisms that remain poorly understood: ethnicity (Ethiopians), lymphoma, renal insufficiency, and idiopathic CD4 lymphocytopenia.

Humans↗

[Diagnosis of primary immunodeficiency in adult patients].

The molecular bases of approximately one hundred primary immune deficiencies (PID) have been identified over the last 15 years. In adults, the diagnosis of PID cannot be evoked before ruling out acquired immunodeficiencies, which are far more frequent. The search for specific PIDs may be oriented by the type of agent responsible for severe and/or recurrent infection. More rarely, other clinical manifestations such as granulomatosis, autoimmune manifestations, hemophagocytic syndrome, lymphoproliferation, or solid tumors may also lead to the identification of PID.

Adult↗

[Systemic sclerosis: pathophysiology of a multifaceted disease].

Systemic sclerosis is a rare disease characterized by vascular hyperreactivity and collagen deposition. Endothelial cell, fibroblast and lymphocyte abnormalities have been reported in systemic sclerosis. Fibroblast dysfunction is characterized by uncontrolled activation of the transforming growth factor-beta (TGF-beta) pathway and excess synthesis of both connective tissue growth factor (CTGF) and free radicals. These promote the accumulation of extracellular matrix. Endothelial cells produce excess quantities of endothelin 1 and inducible NO synthase. They also undergo early apoptosis. Oxidative stress appears to play a major role in disease progression. Increased levels of interleukin 4, a profibrotic cytokine, have been detected in plasma and skin of systemic sclerosis patients. Autoantibodies are detectable in the serum of almost all systemic sclerosis patients. Some are directed against well-identified ubiquitous nuclear proteins and have no demonstrated pathogenic role. Other autoantibodies bind to endothelial cells or fibroblasts and may have a pathogenic role.

Adult↗

[Interstitial lung disease in systemic sclerosis].

Interstitial lung diseases (ILD) associated with systemic sclerosis (SSc) are mainly encountered in patients with diffuse disease, although they may also be seen in patients with limited cutaneous SSc. ILD screening must be performed regularly, with high-resolution computed tomography and pulmonary function tests (TLCO). Up to 75% of patients with diffuse SSc develop a form of ILD. ILD remains stable in most patients and does not worsen. The nonspecific nature of SSc-associated ILD makes it different from idiopathic ILD and helps to explain its better prognosis. Nonetheless, ILD is one of the two leading causes of death in SSc patients. Treatment of SSc-associated ILD is not yet well codified. Antifibrotic treatments have not proved beneficial, and the efficacy of cyclophosphamide, which has been used to treat this condition for 15 years, has been shown to be very limited against SSc-associated ILD. A subgroup of patients with rapidly progressive ILD might benefit from intravenous cyclophosphamide pulses in association with 15 mg/d prednisone.

Anti-Inflammatory Agents↗

[Scleroderma renal crisis].

Scleroderma renal crisis (SRC) occurs in patients with systemic sclerosis (SSc) and is defined by otherwise unexplained rapidly progressive renal insufficiency associated with oliguria or rapidly progressive arterial hypertension or both. SRC is a rare and severe complication of SSc, most often encountered during the first 4 years of disease, almost only in patients with diffuse SSc. Factors predicting SRC were identified, including high-dose corticosteroid administration. Use of angiotensin-converting enzyme inhibitors (ACEI) has dramatically impressed the prognosis of SRC, but it mortality rate is still high. Treatment aims at normalizing blood pressure as soon as possible. ACEI should always be used, and additional anti-hypertensive agents, including calcium channel blockers and alpha- and beta-blockers, may be useful. Renal replacement therapy may be needed, but often (for almost half of patients) only temporarily.

Acute Kidney Injury↗

[Therapeutic management of systemic sclerosis].

UNLABELLED: Improved understanding of the pathophysiology of systemic sclerosis (SSc) opens new therapeutic avenues in its treatment. The efficacy of disease-modifying agents remains limited however, and none has yet demonstrated its ability to improve survival in a prospective randomized trial. RESULTS: of traditional antifibrotic agents such as colchicine and D-penicillamine are disappointing. Cyclophosphamide (CYC) seems to be beneficial in interstitial lung disease associated with SSc. Organ-specific therapies may produce dramatic benefits. Examples include angiotensin-converting enzyme inhibitors for renal failure and epoprostenol for primary pulmonary hypertension. Several new therapeutic approaches are currently under evaluation, including high-dose CYC followed by peripheral stem cell transplantation, vasodilators, and antiinflammatory and antifibrotic agents. Physical therapy and rehabilitation may help to treat disability and loss of function in SSc patients.

Acute Kidney Injury↗

Celiprolol-induced lupus-like syndrome.

Systemic lupus erythematosus can be idiopathic or drug-induced. Although a number of beta-blockers have been reported to induce a lupus-like syndrome, to the best of our knowledge, no such case has been described following celiprolol therapy. We diagnosed a lupus-like syndrome in a 67-year-old female patient who developed febrile polyarthritis, percarditis, antinuclear and anti-histone antibodies after taking celiprolol for 2 years. Despite drug withdrawal, prolonged corticotherapy was needed to obtain clinical and biological remission.

Aged↗

A mimic of p21WAF1/CIP1 ameliorates murine lupus.

Systemic lupus erythematosus (SLE) is a progressive autoimmune disease characterized by the production of high levels of affinity-matured IgG autoantibodies to dsDNA and, possibly, visceral involvement. Pathogenic autoantibodies result from the activation and proliferation of autoreactive T and B lymphocytes stimulated by epitopes borne by nucleosomal histones. To inhibit the proliferation of autoreactive cells and abrogate the development of SLE, a novel tool, cell cycle inhibiting peptide therapy, was used. Thus, a peptidyl mimic of p21WAF1/CIP1 that inhibits the interaction between cyclin-dependent kinase 4 and type D cyclins abrogated the in vitro proliferative response of T cells to histones and T-independent and T-dependent proliferative responses of B cells. The WAF1/CIP1 mimic also abrogated the in vitro production of total and anti-dsDNA IgG Abs by B cells. Similarly, the p21WAF1/CIP1 construct inhibited the ex vivo T and B cell proliferative responses to histones and decreased the numbers of activated/memory B and T spleen cells. The alterations in the balance of spleen cell subsets resulted from proapoptotic effects of the p21WAF1/CIP1)construct on activated splenocytes. Finally, in vivo, four i.v. injections of the p21WAF1/CIP1 mimic were sufficient to inhibit the progression of the lupus-like syndrome in (NZB x NZW)F1 mice. The levels of anti-dsDNA IgG autoantibodies and the incidence and severity of renal involvement were lower in treated mice than in nontreated mice. Those observations open new avenues for the treatment of SLE and prompt us to evaluate the potential interest of peptidic therapy in human SLE.

Amino Acid Sequence↗

Antineutrophil cytoplasmic antibodies and the Churg-Strauss syndrome.

BACKGROUND: Since testing for antineutrophil cytoplasmic antibodies (ANCA) became available for routine evaluation, no large homogeneous cohort of patients with the Churg-Strauss syndrome has been studied. OBJECTIVE: To define the clinical and biological characteristics of newly diagnosed Churg-Strauss syndrome, according to the presence or absence of ANCA. DESIGN: Cross-sectional analysis of manifestations of participants who were enrolled in treatment trials between December 1995 and December 2002. SETTING: Multicenter study in 63 clinical centers in France, Belgium, Latvia, and the United Kingdom, coordinated by the French Vasculitis Study Group. PARTICIPANTS: 112 patients with Churg-Strauss syndrome that was recently diagnosed on the basis of current classifications. MEASUREMENTS: The authors compared principal demographic, clinical, and laboratory features according to ANCA status at diagnosis. RESULTS: The authors detected ANCA in 43 (38%) patients. Positive ANCA status at diagnosis was associated with renal involvement, peripheral neuropathy, and biopsy-proven vasculitis, whereas negative ANCA status was associated with heart disease and fever. LIMITATIONS: The authors assessed ANCA by immunofluorescence, but they did not assess ANCA centrally or systematically retest if ANCA was undetected at diagnosis. CONCLUSIONS: Phenotypically, ANCA-positive and ANCA-negative Churg-Strauss syndrome might differ. The association of ANCA positivity with clinical symptoms that indicate inflammation and necrosis of small vessels might characterize a predominantly vasculitic pattern of the Churg-Strauss syndrome.

Adolescent↗