Published on July 31, 2008
Internal MedicineClinical Pathological Conference : Internal MedicineClinical Pathological Conference July 18, 2008 Diagnostic Procedure : Diagnostic Procedure Right thigh skeletal muscle biopsy Further Evaluation: : Further Evaluation: Further Evaluation: : Further Evaluation: Thoracentesis Transudative fluid AFB sputum negative x 3 EMG Sensory and motor neuropathy, but cannot exclude myopathy Modified Barium Swallow Examination Moderate dyshphagia with unilateral left pharyngeal weakness Key Features: : Key Features: Clinical Proximal muscle weakness Arthralgia Dysphagia Absence of rash Radiology Bilateral interstitial fibrosis Transudative effusion Laboratory Elevated creatine kinase Elevated Anti-Jo1 Elevated ESR, CRP Transaminitis EMG Neuropathy Idiopathic Inflammatory Myopathy : Idiopathic Inflammatory Myopathy Subclassified Polymyositis Dermatomyositis Inclusion body myositis Histological: endomysial inflammation and activation of the immune response Idiopathic Inflammatory Myopathy : Idiopathic Inflammatory Myopathy Epidemiology Annual incidence: 2-10 per million Polymyositis: Disease of adult; rare in people younger than 20 years old Dermatomyositis: Two peaks: 5-10 years old and 50 years old Female to male – 2:1 Inclusion body myositis Older than 50 years of age Polymyositis/Dermatomyositis : Polymyositis/Dermatomyositis Diagnostic criteria, Bohan and Peter, 1975 Symmetrical, proximal muscle weakness Elevation of serum skeletal muscle enzymes CK, LDH, AST, ALT, and Aldolase Muscle biopsy with evidence of myositis EMG pattern of myopathy Typical rash of dermatomyositis- photosensitive rash, heliotrope rash, and gottron papules Gottron Papules Heliotrope rash Polymyositis/ Dermatomyositis : Polymyositis/ Dermatomyositis Esophageal involvement (8-30%), inflammation of cardiac muscle Interstitial Lung disease (50%) Nonspecific interstitial pneumonia (NSIP) Usual interstitial pneumonia (UIP) Anti-Jo 1 and Anti-Mi2 Anti- Jo-1 commonly have Interstitial lung disease Anti-M1 have skin findings Increase cancer risk 7-10% of polymyositis 15-20% of dermatomyositis Polymyositis/ Dermatomyositis : Polymyositis/ Dermatomyositis Cellular immunity Polymyositis- Class II HLA antigen DR3, predominant CD8 T cells Dermatomyositis- Predominant B cells and CD4 T cells in inflammatory infiltrates Inclusion Body Myositis : Inclusion Body Myositis May be asymmetric and involves distal muscles Dysphagia is prominent( 40-80%) Muscle enzyme is only mildly elevated EMG- Myopathic and Neuropathic Biopsy- mononuclear infiltrates and red-rimmed vacuoles in muscle cells with inclusion bodies Mild response to conventional steroid treatment Inclusion Body Myositis: Pathogenesis : Inclusion Body Myositis: Pathogenesis Engel and Arahata 1984 Endomysial infiltrates are composed of primarily CD8+ T Cells Engela and Engel 1988; Orimo 1994; Schmidt 2004 CD8+ T Cells surrounds MHC class I myofibers and express perforin Cupler 1996; Saperstien 1999; Tsuruta 2001; Dalakas 2006 Association with chronic viral infection Inclusion Body Myositis: Pathogenesis : Inclusion Body Myositis: Pathogenesis Hypothesis- Dalakas 2006 Disease begins with viral infection HIV, HTLV-1, Hepatitis C Clonal expansion of CD 8+ T cells and T-cell mediated, MHC class I cytotoxicity via perforin pathway leading to necrosis Cytokines upregulate MHC class I molecules leading to MHC-peptide loading complex and endoplasmic reticulum (ER) stress ER stress leads to activation of transcription factor NFkB, further stimulating MHC/CD 8 complex and induce a self-sustain inflammatory response Dalakas, 2006 Treatment : Treatment Polymyositis/ Dermatomyositis High dose corticosteroids- respond within 6 weeks Methotrexate, cyclosporine, and IVIG Inclusion body myositis Most immunotherapeutic agents are ineffective Age appropriate cancer screening FINAL DIAGNOSIS: : FINAL DIAGNOSIS: Inclusion Body Myositis Dermatomyositis sine dermatitis Slide 16: Viral Infection Proximal muscle Weakness, myalgia Dysphagia Cough Interstitial lung disease Elevated serum muscle enzymes Rash Complex with MHC class I Cytotoxicity via perforin pathway causing necorsis Skeletal muscle inflammation Recurrent Aspiration Clonal expansion of CD 8+ T Cell Cytokine release Inclusion Body Myositis Dermatomyositis Endoplasmic reticulum stress and Intracellular peptide loading complex B cells and CD4 T cells in inflammatory infiltrates Skeletal muscle inflammation Epidermal and dermal destruction Pathogenesis of Patient’s disease Case Follow-up : Case Follow-up Patient was started on empiric antibiotics for aspiration pneumonia Started on prednisone 30mg bid Pt transferred to subacute inpatient rehabilitation CPK=5675, AST=237, ALT=252 after one week of prednisone therapy Pt with improvement in deltoid strength and proximal muscle strength Case Follow-up : Case Follow-up Eventually discharged with outpatient rheumatology follow up Initially, clinical symptoms improved and patient was maintained on daily steroid for about 1 year Patient was found to have rising CK, and Azathioprine was added to his regimen Azathioprine did not improve his CK levels, and was switched to Mycophenolate mofetil Patient was electively admitted 2 weeks ago for IVIG as CK levels continue to be elevated THANK YOU! : THANK YOU! Medical Student Discussants Michael Goldman Juan Lado Megan Mcgill Nekee Pandya Moderator: Martin Blaser, MD Faculty Discussant: Peter Izmirly, MD Radiology Speaker: Dr. David Naidich , MD Pathology Speaker: David Zagzag, MD SPECIAL THANKS: Christina Yoon , MD, Harry Shen, MD and Jean Park, M.D.
CPC CONFERENCE CPC CONFERENCE . Presented by: Manavjyot S. Heer, MD (R2) Discussion: James Ampil, MD . Presbyterian Hospital of Dallas.
Internal Medicine Clinical Pathological Conference Further Evaluation: TEST . REFERENCE RANGE . Anti- RNP ab . Negative . Negative . RF (U/mL) <15 <10
Internal Medicine Clinical Pathological Conference July 18, 2008 * * * * * * * * Diagnostic Procedure Right thigh skeletal muscle biopsy Further Evaluation ...