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Impact of corticosteroids in the inflammatory process of muscle biopsies of dermatomyositis and polymyositis

Grant number: 14/09079-1
Support type:Regular Research Grants
Duration: June 01, 2015 - May 31, 2017
Field of knowledge:Health Sciences - Medicine - Medical Clinics
Principal researcher:Samuel Katsuyuki Shinjo
Grantee:Samuel Katsuyuki Shinjo
Home Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Assoc. researchers:Sueli Mieko Oba Shinjo ; Suely Kazue Nagahashi Marie


Idiopathic inflammatory myopathies are a heterogeneous group of rare chronic systemic autoimmune myopathies associated with high morbidity and functional disability. This groups is subdivided into dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM), juvenile dermatomyositis (JDM), autoimmune necrotizing myopathy, among others. These diseases exhibit specific epidemiological, histological, immunohistochemical and pathological features on evaluation.For a definitive diagnosis of DM / PM, besides the presence of symmetrical proximal muscle weakness of the limbs, elevated serum muscle enzymes, and electromyography indicating the presence of myopathy limbs, it is essential to identify inflammation in muscle biopsy samples from these patients. In this case, there is generally a predominance of CD8+ T cell infiltration into the PM muscle tissues and IBM as well as infiltration of CD4+ cells associated with B lymphocytes in DM. The function of these T cells (CD4+ and CD8+ cells), in turn, is determined by major histocompatibility complex (MHC). These cells recognize antigen bound to MHC class I or II. In the case of MHC I, antigen presentation is derived from an endogenous protein or peptides to T lymphocytes, CD8+ T cells expressing glycoproteins, whereas MHC II molecules present antigens derived from endogenous or exogenous proteins to T cells expressing CD4. MHC II molecules are mainly expressed in macrophages, monocytes and B lymphocytes, whereas MHC I are expressed in most cells.In general, treatment of DM / PM is based on different types of glucocorticoids and immunosuppressants (methotrexate, azathioprine, cyclosporin, etc). Early introduction of these medications, particularly corticosteroids, can allow for faster and more effective control of the activity of these diseases, thus improving their prognosis and reducing morbidity. In contrast, although not scientifically proven, it is believed that early introduction of corticosteroids can directly interfere with the inflammatory process found in muscle tissue of patients with DM / PM. To circumvent this obstacle, the introduction of drug therapy into clinical practice before the muscle biopsy has been postponed. Following this same reasoning, performing biopsies in individuals already use of corticosteroids has been avoided in medical practice, for fear of that not visualizing signs suggestive of inflammatory myopathies and subjecting patients to unnecessary surgery.Moreover, we do not know the impact of glucocorticoid in the gene expression of protein involved in inflammatory process and also in the MHC I and II expressions and in phenotyping distribuition finding in the muscle biopsies. (AU)

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Scientific publications (8)
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
BEHRENS PINTO, GUSTAVO LUIZ; CARBONI, RENATA CASSEB DE SOUZA; DE SOUZA, FERNANDO HENRIQUE CARLOS; SHINJO, SAMUEL KATSUYUKI. A prospective cross-sectional study of serum IL-17A in antisynthetase syndrome. CLINICAL RHEUMATOLOGY, v. 39, n. 9, p. 2763-2771, SEP 2020. Web of Science Citations: 0.
SILVA, M. G.; OBA-SHINJO, S. M.; MARIE, S. K. N.; SHINJO, S. K. Serum interleukin-17A level is associated with disease activity of adult patients with dermatomyositis and polymyositis. CLINICAL AND EXPERIMENTAL RHEUMATOLOGY, v. 37, n. 4, p. 656-662, JUL-AUG 2019. Web of Science Citations: 0.
SHINJO, SAMUEL KATSUYUKI; ELIAS SALLUM, ADRIANA MALUF; OBA-SHINJO, SUELI MIEKO; SILVA, MARILDA GUIMARAES; SILVA, CLOVIS ARTUR; NAGAHASHI MARIE, SUELY KAZUE. Comparison between treatment naive juvenile and adult dermatomyositis muscle biopsies: difference of inflammatory cells phenotyping. ADVANCES IN RHEUMATOLOGY, v. 58, OCT 26 2018. Web of Science Citations: 0.
PIRES BORGES, ISABELA BRUNA; SILVA, MARILDA GUIMARAES; SHINJO, SAMUEL KATSUYUKI. Prevalence and reactivity of anti-melanoma differentiation-associated gene 5 (anti-MDA-5) autoantibody in Brazilian patients with dermatomyositis. ANAIS BRASILEIROS DE DERMATOLOGIA, v. 93, n. 4, p. 517-523, JUL-AUG 2018. Web of Science Citations: 1.
PIRES BORGES, ISABELA BRUNA; SILVA, MARILDA GUIMARES; MISSE, RAFAEL GIOVANE; SHINJO, SAMUEL KATSUYUKI. Lipid-lowering agent-triggered dermatomyositis and polymyositis: a case series and literature review. RHEUMATOLOGY INTERNATIONAL, v. 38, n. 2, p. 293-301, FEB 2018. Web of Science Citations: 6.
ISABELA BRUNA PIRES BORGES; MARILDA GUIMARÃES SILVA; SAMUEL KATSUYUKI SHINJO. Prevalence and reactivity of anti-melanoma differentiation-associated gene 5 (anti-MDA-5) autoantibody in Brazilian patients with dermatomyositis. ANAIS BRASILEIROS DE DERMATOLOGIA, v. 93, n. 4, p. -, Ago. 2018.
DE SOUZA, F. H. C.; MIOSSI, R.; SHINJO, S. K. Necrotising myopathy associated with anti-signal recognition particle (anti-SRP) antibody. CLINICAL AND EXPERIMENTAL RHEUMATOLOGY, v. 35, n. 5, p. 766-771, SEP-OCT 2017. Web of Science Citations: 3.
SAMUEL KATSUYUKI SHINJO; SUELI MIEKO OBA-SHINJO; MIYUKI UNO; SUELY KAZUE NAGAHASHI MARIE. The expression of gene ANKRD1 correlates with hypoxia status in muscle biopsies of treatment-näive adult dermatomyositis. MedicalExpress (São Paulo, online), v. 4, n. 4, p. -, Ago. 2017.

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