Search PubMed⌕ Search

Biomedical subjects

P Musette

Publications and source records attributed to P Musette.

At least 19 recordsLinked to original sources
PubMed2006

[Rituximab treatment for immune thrombocytopenia associated with systemic lupus erythematosus].

BACKGROUND: Immune thrombocytopenic purpura is an autoimmune disorder occasionally associated with systemic lupus erythematosus for which oral corticosteroids constitute the first-line treatment. Therapy may be complex, particularly in the event of a contraindication to the standard treatment, namely corticosteroids, splenectomy or immunosuppressants. We report the case of a patient with systemic lupus associated with immune thrombocytopenic purpura and multisystem tuberculosis. Because of a contraindication to corticosteroids, the patient was successfully treated with rituximab (anti-CD20 antibody). This medication (Mabthera) is indicated in the treatment of relapsing or refractory follicular lymphoma. CASE REPORT: A 31-year-old North African woman had been treated for 10 years with prednisone, hydroxychloroquine, methotrexate and non-steroidal anti-inflammatory drugs for systemic lupus erythematosus. She presented severe immune thrombocytopenic purpura (platelet count: 4G/l) 3 months after initiation of antitubercular treatment for multisystem tuberculosis. The patient was unsuccessfully treated at the outset with 3 infusions of intravenous immunoglobulin. Since thrombocytopenia remained under 5 G/l, she was given rituximab 375 mg/m2/week for 4 weeks. Thrombocytopenia and native anti-DNA antibody levels decreased after the third infusion (D16). No side effects of treatment were observed. The patient did not experience any relapse during the 29 months following the final infusion. DISCUSSION: In the present case, rituximab was used because of multisystem tuberculosis. Rituximab appears to constitute a safe and effective treatment for refractory immune thrombocytopenic purpura associated with SLE in patients having a contraindication to or refractory to conventional therapy.

Adult↗
PubMed2005

[Molecular advances in pathogenesis of autoimmune blistering skin diseases].

Autoimmune blistering skin diseases are characterized by the production of autoantibodies directed against adhesive structures of the skin. These organ specific autoimmune diseases included pemphigus in which autoantibodies target proteins of the desmosomal complex, and subepidermal autoimmune diseases characterized by autoantibodies directed against structural proteins of the dermoepidermal junction. Binding of autoantibodies to their targets induces a loss of adhesion between keratinocytes in pemphigus and alterations of the dermoepidermal junction in subepidermal autoimmune diseases. Progresses during the last twenty years had allowed the identification of target autoantigens and the characterization of their adhesive functions, a better understanding of the pathogenesis of these diseases and the development of new diagnostic tools.

Autoantibodies↗
PubMed2004

Determinants of severity for superficial cellutitis (erysipelas) of the leg: a retrospective study.

BACKGROUND: Superficial cellulitis (erysipelas) of the leg is a frequent infectious disease with a favorable outcome, whereas some patients present a serious disease. The determinants of severity for superficial cellulitis (erysipelas) of the leg have not yet been clearly established. In order to determine the characteristics of patients presenting with severe superficial cellulitis of the leg, we analyzed patients with favorable and unfavorable outcome. METHODS: The records of 167 patients referred to Rouen University Hospital for non-superficial cellulitis of the leg were analyzed. Two severity groups of patients were retrospectively defined. Patients in the severe group either died secondary to infection during hospital stay or were hospitalized for a duration at least equal to the 90th percentile (i.e., >21 days of hospitalization). The remaining patients were considered as presenting with non-severe cellulitis. Potential determinants of severity were analyzed by univariate and multivariate analysis based on logistic regression. RESULTS: From univariate analysis, the following general factors were positively associated with severity: advanced age, arterial hypertension, diabetes mellitus, elevated leukocytosis, and elevated neutrophilia. The local factors associated with severity were ulcer of the leg and arteriosclerosis obliterans of the leg. From multivariate analysis, only age (P=0.004), diabetes mellitus (P=0.01), and leukocytosis (P=0.04) appeared to be independently associated with severity. A close to significant association was also found with arteriosclerosis obliterans of the leg (P=0.07). Whereas general complications occurred more frequently in the severe group, no such difference was observed for local complications. CONCLUSIONS: Determinants of severity for superficial cellulitis of the leg include high age and associated medical conditions. Aged patients and patients with diabetes mellitus, elevated leukocytosis, or possibly arteriosclerosis obliterans of the leg should preferably be hospitalized for specific care of associated conditions to avoid the occurrence of general complications.

Journal Article↗
PubMed2002

Preferential survival of an MBP-specific T cell clone in an HLA-DR2 multiple sclerosis patient.

Anti-myelin basic protein (MBP) autoreactive T cells play a key role in the pathogenesis of multiple sclerosis. Thus, we applied the Immunoscope strategy to cerebrospinal fluid (CSF) and peripheral blood lymphocytes (PBLs) of an HLA-DR2 patient. Both compartments showed major expansion for the V(beta)13S5 chain, which was associated in peripheral blood with significant proliferation of PBLs in response to MBP and the 84-102 HLA-DR2-restricted peptide. Sequencing revealed a unique nucleotide sequence in the CSF that gives rise to the amino acid sequence V(beta)13S5-RPGQGDQETQ-J(beta)2.5 if translated. This CDR3 sequence had already been reported to be reactive against the 84-102 peptide. This specific sequence was not detected in PBLs on day 0, whereas it was readily detectable on day 6 culture samples. Thus, cell culture may lead to enrichment in a T cell clone identified as autoreactive.

Adult↗
PubMed2001

[Cutaneous lupus erythematosus following argon laser treatment].

BACKGROUND: It is well known that exposure to ultraviolet light can trigger lupus manifestations. Other light sources may have the same effect. We report a case of argon laser-induced lupus erythematosus. CASE REPORT: A 59-year-old women developed an erythematous edematous infiltrated and sensitive lesion over the right cheek ten days after an argon laser treatment of the retina. The lesion spread towards the chin despite antibiotic treatment. Histology examination of a biopsy specimen and direct immunofluorescence suggested the diagnosis of cutaneous lupus erythematosus. The lesions regressed in one month with hydroxychloroquine (400 mg/d) treatment. DISCUSSION: Our patient developed argon laser induced cutaneous lupus erythematosus. It is known that ultraviolet light and non-ultraviolet frequencies (x-rays, visible light) can induce lupus manifestations. One case of discoid lupus erythematosus after argon laser has been reported. In our case, due to a technical error the laser beam was directed onto the ipsilateral cheek during the laser treatment of the retina. The low-energy beams used in ophthalmology would explain the absence of local burn but would be sufficient to trigger lupus. This case demonstrates that argon laser, a visible blue or green beam, can provoke cutaneous lupus erythematosus even if there is no heat-induced burn. It is important to be aware of this adverse effect due to the widespread use of lasers in dermatology, particularly for the treatment of cutaneous lupus lesions.

Argon↗
PubMed2000

Comparison of the T cell patterns in leprous and cutaneous sarcoid granulomas. Presence of Valpha24-invariant natural killer T cells in T-cell-reactive leprosy together with a highly biased T cell receptor Valpha repertoire.

The T-cell-reactive (eg, tuberculoid and reversal) forms of leprosy represent a well-defined granulomatous reaction pattern against an invading pathogen. The immune response in cutaneous sarcoidosis is a granulomatous condition that pathologically is very similar to T-cell reactive leprosy. However, it lacks a defined causative agent. In view of the role of NKT cells in murine granulomas induced by mycobacterial cell walls, we have searched for the presence of NKT cells in the cutaneous lesions of both leprosy and sarcoidosis. These cells were present in T-cell-reactive leprosy but were undetectable in cutaneous sarcoidosis. We have also studied the TCR Valpha repertoire in the two diseases. In addition to Valpha24(+) NKT cells, all patients with T-cell-reactive leprosy showed a very restricted T-cell-reactive Valpha repertoire with a strong bias toward the use of the Valpha6 and Valpha14 segments. Valpha6 and Valpha14(+) T cells were polyclonal in terms of CDR3 length and Jalpha usage. In contrast, most sarcoidosis patients showed a diverse usage of Valpha chains associated with clonal or oligoclonal expansions reminiscent of antigen-driven activation of conventional T cells. Thus the origin and perpetuation of the two kinds of granulomatous lesions appear to depend on altogether distinct T-cell recruiting mechanisms.

Adolescent↗
PubMed2000

A paraneoplastic mixed bullous skin disease: breakdown in tolerance to multiple epidermal antigens.

We report a new type of paraneoplastic mixed bullous skin disease in a patient with a B-cell lymphoma associated with monoclonal IgM kappa paraproteinaemia. The patient's clinical and histological features were reminiscent of bullous pemphigoid. Characterization of antiepidermal antibodies by immunoblotting and indirect immunoelectron microscopy demonstrated a novel pattern of reactivity: IgG antibodies were directed against desmoplakins I-II and BPAG2, and were associated with antidesmoglein 3 polyclonal IgM antibodies. Such an autoreactive pattern involving antidesmoplakins, anti-BPAG2 and antidesmoglein 3 antibodies has not been previously reported. It reflects the breakdown of tolerance to multiple epidermal antigens observed in some patients with malignancy.

Autoantibodies↗
PubMed1999

Immune-mediated destruction of melanocytes in halo nevi is associated with the local expansion of a limited number of T cell clones.

The beta-chain repertoire of the T cells that infiltrate spontaneously regressing nevi (the halo nevus phenomenon) was studied. In addition to the infiltration of the halo nevi by cutaneous lymphocyte-associated Ag-positive lymphocytes, oligoclonal expansion of T cells was observed in all halo nevi of all patients. T cells using the same TCR beta-chain were observed in distinct halo nevi of the same patient but not in his peripheral blood, demonstrating a local expansion of common clones that are most likely activated by the Ag(s) shared by independent halo nevi of the same patient.

Amino Acid Sequence↗