title: Overlapping features of polymyositis and inclusion body myositis in HIV-infected patients.
abstract: OBJECTIVE
  To characterize patients with myositis with HIV infection.
  
  
  METHODS
  All HIV-positive patients with myositis seen at the Johns Hopkins Myositis Center from 2003 to 2013 were included in this case series. Muscle biopsy features, weakness pattern, serum creatine kinase (CK) level, and anti-nucleotidase 1A (NT5C1A) status of HIV-positive patients with myositis were assessed.
  
  
  RESULTS
  Eleven of 1,562 (0.7%) patients with myositis were HIV-positive. Myositis was the presenting feature of HIV infection in 3 patients. Eight of 11 patients had weakness onset at age 45 years or less. The mean time from the onset of weakness to the diagnosis of myositis was 3.6 years (SD 3.2 years). The mean of the highest measured CK levels was 2,796 IU/L (SD 1,592 IU/L). On muscle biopsy, 9 of 10 (90%) had endomysial inflammation, 7 of 10 (70%) had rimmed vacuoles, and none had perifascicular atrophy. Seven of 11 (64%) patients were anti-NT5C1A-positive. Upon presentation, all had proximal and distal weakness. Five of 6 (83%) patients followed 1 year or longer on immunosuppressive therapy had improved proximal muscle strength. However, each eventually developed weakness primarily affecting wrist flexors, finger flexors, knee extensors, or ankle dorsiflexors.
  
  
  CONCLUSIONS
  HIV-positive patients with myositis may present with some characteristic polymyositis features including young age at onset, very high CK levels, or proximal weakness that improves with treatment. However, all HIV-positive patients with myositis eventually develop features most consistent with inclusion body myositis, including finger and wrist flexor weakness, rimmed vacuoles on biopsy, or anti-NT5C1A autoantibodies.
authors.affiliation: From the Johns Hopkins University School of Medicine (T.E.L., E.H.M., L.C.-S., N.S., A.L.M.), Baltimore; and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (I.P.-F., K.P., A.L.M.), National Institutes of Health, Bethesda, MD.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Lloyd
authors.affiliation: From the Johns Hopkins University School of Medicine (T.E.L., E.H.M., L.C.-S., N.S., A.L.M.), Baltimore; and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (I.P.-F., K.P., A.L.M.), National Institutes of Health, Bethesda, MD.
authors.forename: Iago
authors.initials: I
authors.lastname: Pinal-Fernandez
authors.affiliation: From the Johns Hopkins University School of Medicine (T.E.L., E.H.M., L.C.-S., N.S., A.L.M.), Baltimore; and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (I.P.-F., K.P., A.L.M.), National Institutes of Health, Bethesda, MD.
authors.forename: E Harlan
authors.initials: EH
authors.lastname: Michelle
authors.affiliation: From the Johns Hopkins University School of Medicine (T.E.L., E.H.M., L.C.-S., N.S., A.L.M.), Baltimore; and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (I.P.-F., K.P., A.L.M.), National Institutes of Health, Bethesda, MD.
authors.forename: Lisa
authors.initials: L
authors.lastname: Christopher-Stine
authors.affiliation: From the Johns Hopkins University School of Medicine (T.E.L., E.H.M., L.C.-S., N.S., A.L.M.), Baltimore; and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (I.P.-F., K.P., A.L.M.), National Institutes of Health, Bethesda, MD.
authors.forename: Katherine
authors.initials: K
authors.lastname: Pak
authors.affiliation: From the Johns Hopkins University School of Medicine (T.E.L., E.H.M., L.C.-S., N.S., A.L.M.), Baltimore; and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (I.P.-F., K.P., A.L.M.), National Institutes of Health, Bethesda, MD.
authors.forename: Ned
authors.initials: N
authors.lastname: Sacktor
authors.affiliation: From the Johns Hopkins University School of Medicine (T.E.L., E.H.M., L.C.-S., N.S., A.L.M.), Baltimore; and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (I.P.-F., K.P., A.L.M.), National Institutes of Health, Bethesda, MD. andrew.mammen@nih.gov.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Mammen
mesh_terms: D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood; D015331:Cohort Studies; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018979:Myositis, Inclusion Body / Q000097:blood / Q000209:etiology*; D017285:Polymyositis / Q000097:blood / Q000209:etiology*; D055815:Young Adult
chemical_list: D000974:Antibodies, Antinuclear; C046750:Jo-1 antibody; D003402:Creatine Kinase