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Louis Dubertret

Publications and source records attributed to Louis Dubertret.

At least 37 records · Page 2Linked to original sources
PubMed2004

Foxp3 expressing CD4+CD25(high) regulatory T cells are overrepresented in human metastatic melanoma lymph nodes and inhibit the function of infiltrating T cells.

Dominant tolerance is mediated by regulatory T cells (T(reg)) that control harmful autoimmune T cells in the periphery. In this study, we investigate the implication of T(reg) in modulating infiltrating T lymphocytes in human metastatic melanoma. We found that CD4(+)CD25(high) T cells are overrepresented in metastatic lymph nodes (LNs) with a 2-fold increased frequency compared with both tumor-free LNs and autologous PBMCs. These cells express the Foxp3 transcription factor, display an activated phenotype, and display a polyclonal TCR Vbeta chain repertoire. They inhibit in vitro the proliferation and cytokine production of infiltrating CD4(+)CD25(-) and CD8(+) T cells (IL-2, IFN-gamma) through a cell-contact-dependent mechanism, thus behaving as T(reg). In some cases, the presence of T(reg) type 1/Th3-like lymphocytes could also be demonstrated. Thus, T(reg) are a major component of the immunosuppressive microenvironment of metastatic melanoma LNs. This could explain the poor clinical response of cancer patients under immunotherapeutic protocols, and provides a new basis for future immunotherapeutic strategies counteracting in vivo T(reg) to reinforce local antitumor immune responses.

CD4-Positive T-Lymphocytes↗
PubMed2004

[Therapeutic negotiation in psoriasis].

The patient based medicine joins together all the medical techniques making possible to adapt to a particular individual the scientific knowledge obtained through the study of broad populations. It rests on four successive phases: questions, explanations, negotiation and prescription. The purpose of these successive phases in the relation doctor-patient is to identify and take into account in the therapeutic decision, all the facets of the personality of the patient, the pathologies and treatments associated, the therapeutic experiments already carried out by this patient and his personal evaluation of his quality of life and of the impact of the treatments and the disease on this quality of life. These techniques are essential to efficiently treat chronic diseases. Their progressive development represents a therapeutic revolution resounding on the teaching of medicine, the development of new drugs and on the rights of the patients.

Decision Making↗
PubMed2004

Treatment of refractory pemphigus vulgaris with rituximab (anti-CD20 monoclonal antibody).

BACKGROUND: Pemphigus vulgaris (PV) is a severe antibody-mediated autoimmune blistering disease. Because some patients with PV do not enter into remission, despite the use of high-dose corticosteroid therapy and immunosuppressive adjuvant treatments, new effective and safer agents are warranted to treat refractory PV. Rituximab, a monoclonal anti-CD20 antibody, induces depletion of B cells in vivo and has shown efficacy in patients with refractory antibody-mediated autoimmune disorders. We describe herein 3 patients treated with rituximab for severe PV. OBSERVATIONS: Three patients with refractory PV were treated with rituximab, resulting in a clinical response in all patients, which was complete in 2 patients. A decline in titers of circulating antiepidermis autoantibodies paralleled disease activity, while circulating B cells remained undetectable for 6 to 10 months. Two patients experienced bacterial infection in the weeks following the rituximab course. A clinical relapse occurred in 2 patients, at 6 and 10 months. A second course of rituximab controlled the disease in one of them. CONCLUSION: These patients' response suggests that rituximab may be a valuable treatment for refractory PV and warrants further studies to evaluate the risk-benefit ratio in patients with PV showing resistance to classic therapy.

Adult↗
PubMed2004

Vulvar lichen sclerosus: effect of long-term topical application of a potent steroid on the course of the disease.

BACKGROUND: Lichen sclerosus is an inflammatory disease of unknown etiology affecting the anogenital skin and associated with the development of squamous cell carcinoma. It is not known whether long-term topical treatment with a potent steroid can cure this disease and thus prevent malignant evolution. OBJECTIVES: To analyze the rates of remission, recurrence, and chronic evolution of vulvar lichen sclerosus (VLS) treated with 0.05% clobetasol propionate ointment and determine whether this treatment can decrease the risk of malignant evolution. DESIGN: Prospective study, conducted between 1981 and 2001, of 83 women with VLS who were treated until complete clinical and histologic remission and followed up for evidence of clinical and histologic recurrence (median follow-up, 4.7 years). SETTING: Dermatology department of a large urban teaching hospital. RESULTS: Complete remission was obtained in 45 patients (54%). The probability of remission was significantly associated with age (P<.001). The estimated incidence of remission at 3 years was 72% in women younger than 50 years, 23% in women aged between 50 and 70 years, and 0% in women older than 70 years. The incidence of relapse was estimated to be 50% at 16 months (95% confidence interval, 30%-64%) and 84% at 4 years (95% confidence interval, 57%-94%). Age had no effect on relapse prevalence. The 8 observed vulvar squamous cell carcinomas (9.6%) occurred in previously untreated or irregularly treated VLS lesions. CONCLUSIONS: Treatment with a potent steroid cream can improve but does not cure VLS in women older than 70 years, probably because of a long disease evolution. In younger patients who achieve complete remission, it seems to have only a temporary effect. Although a protective effect from malignant evolution is suggested (carcinoma developed only in nontreated or irregularly treated VLS lesions), the number of seemingly protected patients was too small to be statistically significant.

Administration, Cutaneous↗
PubMed2004

Prognostic value of blood eosinophilia in primary cutaneous T-cell lymphomas.

OBJECTIVE: To investigate the prognostic value of initial characteristics including blood eosinophilia in patients with primary cutaneous T-cell lymphoma. DESIGN: A retrospective inception cohort, patients included from date of diagnosis (1982-1998). SETTING: Two dermatology departments of a university hospital. Patients A total of 104 patients with cutaneous T-cell lymphoma, including patients with mycosis fungoides (n = 69), Sézary syndrome (n = 13), and nonepidermotropic cutaneous lymphoma (n = 22). The following variables were recorded: age, sex, diagnosis according to the European Organization for Research and Treatment of Cancer (EORTC) classification, type of skin involvement at the time of diagnosis, initial eosinophil absolute count, lactate dehydrogenase value, date of disease progression, and cause and date of death or date of last contact. MAIN OUTCOME MEASURES: Time from diagnosis to disease progression and to disease-specific death. RESULTS: The median follow-up was 43 months (range, 7-197 months). Estimated rates of disease progression and disease-specific death for 3 years were 19.5% (95% confidence interval [CI],11.3%-27.6%) and 9.9% (95% CI, 2.8%-13.6%), respectively. Univariable analysis of initial variables possibly influencing disease progression revealed significant prognostic value for diagnosis according to EORTC classification (hazard ratio [HR], 2.77; 95% CI, 1.04-7.41; P =.04), type of skin involvement (HR, 2.70; 95% CI, 1.00-7.25; P =.04), raised blood eosinophil absolute count (HR, 7.33; 95% CI, 2.84-18.91; P<.001), and raised serum level of lactate dehydrogenase (HR, 3.72; 95% CI, 1.58-8.78; P =.001). Concerning disease-specific death, significant prognostic indicators were diagnosis according to the EORTC classification (HR, 6.62; 95% CI, 1.68-26.12; P =.007) and a raised blood eosinophil absolute count (HR, 10.57; 95% CI, 2.28-49.0; P<.001). In multivariable analysis, only blood eosinophilia was associated with disease progression and disease-specific death. CONCLUSION: These results strongly suggest that blood eosinophilia at baseline is a prognostic factor in patients with primary cutaneous T-cell lymphoma.

Adult↗
PubMed2004

High frequency of cholestasis in generalized pustular psoriasis: Evidence for neutrophilic involvement of the biliary tract.

Generalized pustular psoriasis is a rare form of psoriasis that is sometimes associated with extracutaneous manifestations. Evidence for biliary involvement has been suggested in isolated cases. We investigated the prevalence and nature of liver abnormalities occurring in this disease. Twenty-two patients consecutively admitted for generalized pustular psoriasis who underwent liver biological tests at the time of the attack and during the following weeks were included. Twenty patients (90%) had at least one abnormal biological liver parameter. Eleven patients (50%) had pronounced abnormalities: jaundice (4/22), gammaglutamyl transferase higher than 5 times the normal value (10/22), alkaline phosphatase higher than twice the normal value (7/22), and/or aminotransferases higher than 3 times the normal value (7/22). These abnormalities returned to normal range at the time of remission of pustular psoriasis, suggesting that severe liver abnormalities could be associated with severe cutaneous disease. Neutrophilic cholangitis was observed on liver biopsy. Persistent magnetic resonance cholangiopancreatography features similar to those observed in sclerosing cholangitis were found in 3 of the 4 patients studied. No causal factor other than pustular psoriasis could be identified. In conclusion, our results demonstrate the high frequency of liver abnormalities in patients with generalized pustular psoriasis. Biliary involvement related to neutrophilic cholangitis should be added to the spectrum of extracutaneous manifestations of this disease, and physicians should be aware of such a complication.

Adult↗
PubMed2004

Infrared radiation affects the mitochondrial pathway of apoptosis in human fibroblasts.

We have previously observed that near-infrared (IR) pre-irradiation protects normal human dermal fibroblasts from ultraviolet (UV) cytotoxicity in vitro. Here, we show that IR pre-irradiation of human fibroblasts inhibited UVB activation of caspase-9 and -3, leading us to study early events in the mitochondrial apoptotic pathway after IR irradiation. IR irradiation led to a partial release of cytochrome c and Smac/Diablo but not apoptosis-inducing factor (AIF). This was accompanied by a slight but transient decrease in the mitochondrial membrane potential (Deltapsim) and by the insertion of Bax into mitochondrial membrane. Early apoptotic events in the mitochondrial pathway thus occurred after IR irradiation despite a lack of caspase-9 and -3 activation. This could be explained by the induction by IR of the expression of heat shock protein Hsp27, which is known to prevent apoptosome assembly. Furthermore, the balance between pro-apoptotic (i.e., Bax) and anti-apoptotic (i.e., Bcl-2 or Bcl-xL) proteins, which was rather pro-apoptotic after IR exposure, became anti-apoptotic 24 h later, suggesting a protective effect. Together, these actions could also contribute to prepare the cell to resist UVB-triggered apoptosis. Finally, isolated rat liver mitochondria-released cytochrome c in response to IR, demonstrating that mitochondria were a primary target of IR radiation.

Adolescent↗
PubMed2004

ERK activation by mechanical strain is regulated by the small G proteins rac-1 and rhoA.

Physical forces play an important role in regulating cell functions. We applied mechanical strain to human fibroblasts by magnetic attraction of superparamagnetic arginine-glycine-aspartic acid (RGD)-coated beads. We confirmed that the MAP kinases Erk and p38 are activated by mechanical strain, and went further by demonstrating the activation of Elk-1 by mechanical strain, mainly through a MEK-Erk pathway. Transfection of a dominant negative form of the G protein rac-1 (rac T17N), and inhibition of PI3K, an effector of rac-1, efficiently prevented Elk-1 activation by mechanical forces. Transfection with C3 transferase, known to inhibit rhoA, and inhibition of rock (a downstream effector of rhoA), gave similar results. However, contrary to the active form of rhoA (rho G14V), transfection of the active form of rac-1 (rac G12V) induced Elk activation and mimicked the effects of mechanical strain. These results point out that the two small G proteins rhoA and rac-1 participate in cell sensitivity to mechanical strain and lead to the modulation of the Erk pathway.

Amino Acid Substitution↗
PubMed2003

Differential molecular profiling between skin carcinomas reveals four newly reported genes potentially implicated in squamous cell carcinoma development.

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are skin tumors with different invasive potential. In this work, we analysed mRNA differential expression between seven BCC and five SCC and their normal skin counterparts using 1176 cDNA macroarrays and verification by RT-PCR to identify genes modulated in each tumor type. We identified 37 genes commonly modulated in both tumors and four genes specifically modulated in SCC. Among these latter RhoC and EMMPRIN genes seem to be of particular interest and could participate in SCC aggressivity.

Carcinoma, Squamous Cell↗
PubMed2003

Randomized trial and local biological effect of autologous platelets used as adjuvant therapy for chronic venous leg ulcers.

OBJECTIVES: Platelet products have been proposed as adjuvant therapy for wound healing. We undertook this study to determine the healing effect of topically applied frozen autologous platelets (FAP) on chronic venous ulcers, compared with effect of placebo, and whether use of topical FAP modifies local expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), interleukin 8 (IL-8), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in wound fluid. METHODS: This randomized, placebo-controlled, double-blind trial was carried out in institutional practice, with ambulatory patients with proved chronic venous leg ulcers. In all patients, whole venous blood was drawn for preparation of FAP. FAP or normal saline solution was applied three times per week for up to 12 weeks, together with hydrocolloids and standardized compression bandages. Leg ulcer surface was assessed with numerical pictures. IL-8, VEGF, KGF, and TIMP-1 levels were determined (enzyme-linked immunosorbent assay) in wound fluid after each 4 weeks of treatment. RESULTS: Fifteen patients were randomized into two groups with comparable leg ulcer characteristics. Mean percent reduction in ulcer area was 26.2% in the FAP group versus 15.2% in the placebo group (P =.94). One ulcer in each group was completely healed at study end. Levels of TIMP-1 increased significantly during FAP treatment. IL-8 concentration was significantly lower in wound fluid of healing ulcers than in the fluid of nonhealing ulcers, in both FAP and placebo groups. Growth factor levels were not modified with FAP treatment. CONCLUSION: Topical autologous platelets have no significant adjuvant effect on healing of chronic venous leg ulcers and increased wound fluid TIMP-1 concentration. Ulcer healing is associated with a decrease in wound fluid IL-8.

Administration, Topical↗
PubMed2003

Follow-up of the T-cell clonality in Sezary patients treated by extracorporeal photopheresis using a new assay: the immunoscope technique.

Sezary syndrome is a leukemic form of epidermotropic cutaneous T-cell lymphoma related to the malignant proliferation of clonal CD4+ T-cells. Extracorporeal photochemotherapy (ECP) may induce a transient improvement of the clinical signs but it's efficiency is discussed. In order to investigate the T-cell clonality in the peripheral blood of patients with Sezary syndrome and to monitor its evolution in 8 patients treated by ECP, we used the Immunoscope technique. In one patient, we observed a decrease of the T-cell clonality from 15.6% to 0%, paralleling a complete remission of the clinical disease with a disappearance of the circulating Sezary cells. In the other cases, the evolution of the relative frequency paralleled the clinical status of the patient. In 3 cases, we observed a quick-acting direct cytotoxicity of the association 8MOP + UVA on the T-cell clone present in the cellular product. Immunoscope technique appears to be an efficient assay to appreciate the amount of tumoral cells and monitor the evolution of the clonal component in Sezary syndrome.

Aged↗
PubMed2003

Risk of malignancies in psoriasis patients treated with cyclosporine: a 5 y cohort study.

This prospective long-term cohort study investigated the incidence of malignancies in severe psoriasis patients treated with cyclosporine. A total of 1252 patients were followed prospectively for up to 5 y. Malignancies were recorded prospectively. Incidence rates for malignancies were compared with the general population using standardized incidence ratios. The effect of duration of exposure to cyclosporine and to previously administered anti-psoriatic treatments on the incidence of malignancies was investigated using Poisson regression models. The mean age of patients was 43 y and on average, patients received cyclosporine for 1.9 y. Malignancies were diagnosed in 47 patients (3.8%), 49% of them had skin malignancies. The standardized incidence ratio in the study cohort was 2.1 as compared with the general population. The higher incidence of malignancies was attributed to a 6-fold higher incidence of skin malignancies, most of which were squamous cell carcinoma. The incidence of nonskin malignancy overall was not significantly higher in this study than in the general population. Duration of exposure to cyclosporine, exposure to psoralen and ultraviolet A, exposure to methotrexate, and exposure to immunosuppressants showed a significant effect on the incidence of nonmelanoma skin malignancies. In conclusion, treatment of psoriasis with cyclosporine is associated with an increased risk of nonmelanoma skin cancer. Patients treated for more than 2 y with cyclosporine were shown to have a higher risk. In addition, exposure to psoralen and ultraviolet A and to other immunosuppressants was shown to contribute to the overall risk.

Adult↗
PubMed2003

Arsenic trioxide induces apoptosis of cutaneous T cell lymphoma cells: evidence for a partially caspase-independent pathway and potentiation by ascorbic acid (vitamin C).

Arsenic trioxide (As2O3) displays apoptogenic properties against various types of hematopoietic malignancies. We investigated the effects of As2O3 on the viability of the cutaneous T cell lymphoma cell lines HuT-78, SeAx, and Myla, and of peripheral blood mononuclear cells from patients with Sézary syndrome, by using propidium iodide and annexin-V staining, terminal deoxyuridine triphosphate nick end labeling (TUNEL), cell cycle analysis, mitochondrial transmembrane potential (delta psi(m)) alterations, cytochrome c release, and detection of processed caspase-3. We also report in vivo effects of As2O3 in two patients with cutaneous T cell lymphoma. The results show that As2O3 induces apoptosis of cutaneous T cell lymphoma lines and of Sézary cells from patients in a time- and concentration-dependent manner in vitro, as demonstrated by annexin-V staining, mitochondrial depolarization, and DNA fragmentation. Ascorbic acid 100 microM potentiated As2O3-induced Sézary cell death, whereas interferon-alpha had no synergistic effect. As2O3-induced Sézary cell death involves activation of caspase-3, cleavage of poly(ADP-ribose)polymerase, and cytochrome c release, but was only partially inhibited by the pancaspase inhibitor Z-VAD.fluoromethylketone. Finally, As2O3 was administered to two patients with cutaneous T cell lymphoma, allowing us to obtain a partial response in one case, whereas stability was observed in the second patient. These results demonstrate that As2O3 synergizes with ascorbic acid to induce Sézary cell death at clinically achievable concentrations, through a caspase-partially independent pathway, and provide a rationale for further in vivo studies addressing the therapeutic efficacy of As2O3 in cutaneous T cell lymphoma patients.

Aged↗
PubMed2003

Mizolastine in primary acquired cold urticaria.

BACKGROUND: Treatment of primary acquired cold urticaria (CU) is quite difficult because of variable clinical effectiveness and side effects of classic antihistamines. OBJECTIVE: The objective of the study was to assess the efficacy and safety of mizolastine, an antihistaminic with antiallergic properties, versus placebo in primary acquired CU. METHODS: This study was a phase II, multicenter, randomized, double-blind, crossover, placebo-controlled study of mizolastine (10 mg, once daily) versus placebo in 28 patients with primary acquired CU. Efficacy was measured by the cold-stimulation time test, the wheal response, and pruritus intensity after an ice-cube test. RESULTS: Mizolastine delayed the cold-induced wheal reaction, reduced wheal response at 3 and 10 minutes, and reduced pruritus intensity. Statistically significant differences were observed versus placebo for the cold-stimulation time test, wheal response at 3 and 10 minutes, and pruritus intensity (P =.006,.015,.009, and.005, respectively). No clinically relevant adverse events were reported. CONCLUSIONS: Mizolastine (10 mg, once daily) was shown to be superior to placebo for both delaying and reducing the cold-induced wheal reaction without significant adverse events. Results suggest that mizolastine may be effective in the treatment of CU.

Adolescent↗
PubMed2003

Scytalidiosis in Paris, France.

BACKGROUND: Scytalidium dimidiatum and S hyalinum are molds responsible for human skin and nail infections in tropical areas. OBJECTIVE: We sought to examine the epidemiology of cutaneous infections caused by Scytalidium species in a temperate country. METHODS: We conducted a retrospective study of patients with Scytalidium spp. infection diagnosed in our laboratory in Paris, France, from 1994 to 1999. RESULTS: Cutaneous Scytalidium infections were diagnosed in 332 patients, all of whom were from the tropics, especially the West Indies and Africa. S hyalinum and S dimidiatum were isolated in 53.6% and 43.9% of cases, respectively, and were associated with dermatophytes in 30 patients. Skin and nail lesions were found in, respectively, 65.3% and 34.7% of cases, and the feet were involved in 90.6% of cases. CONCLUSION: Cutaneous infections caused by Scytalidium species are far from rare in France, a temperate country, and must not be mistaken for dermatophytosis, given the resistance of S hyalinum and S dimidiatum to most antifungal drugs. Mycologic examination is, thus, required to identify Scytalidium spp in patients returning from or residing in tropical areas.

Adult↗