Predictors of myositis in mixed connective tissue disease: A multicentre retrospective study
Keywords
Objectives: We aimed to identify clinical and serological predictors of myositis in mixed connective tissue disease (MCTD).
Methods: We performed a nationwide, retrospective, multicentre study including adult-onset MCTD patients fulfilling at least one of the following diagnostic criteria: Sharp’s, Kasukawa, Alarcón-Segovia, or Kahn’s. Univariate analysis was performed using Chi-square, Fisher exact, Student’s t or Mann-Whitney U tests, as appropriate. Multivariate analysis was performed using binary logistic regression.
Results: Ninety-eight patients were included. Myositis was observed in 43.9% of patients, of whom 60.5% had myositis at disease onset.
Proximal muscle weakness was described in 30 patients with muscle involvement (70%). Gastrointestinal involvement was identified in 28% and respiratory involvement in 29% of myositis patients. In the same subgroup of patients, 41.7% had a myopathic pattern on electromyography, and 47.1% had histological myositis features in the muscle biopsy.
Fever (OR=6.96, p=0.022) was an independent predictor of myositis, regardless of sex, age at diagnosis, ancestry, and respiratory involvement. African ancestry (OR=8.39, p=0.019), leukopenia at the disease onset (OR 6.24, p=0.021), and younger age at diagnosis (OR=1.07/year, p=0.035) were identified as independent predictors of myositis at disease onset, regardless of sex and scleroderma pattern in capillaroscopy.
Conclusions: Myositis is a common manifestation of MCTD, even at the disease onset. African ancestry, leukopenia at the disease onset, younger age at diagnosis, and fever should prompt a thorough evaluation for myositis.
Carlos Costa
Centro Hospitalar Trás-os-Montes e Alto Douro, Vila Real, Portugal
Tiago Beirão
Centro Hospitalar Vila Nova de Gaia/Espinho, Gaia, Portugal
Carolina Furtado
Hospital do Divino Espírito Santo, Ponta Delgada, Portugal
Pedro Abreu
Unidade Local de Saúde de Castelo Branco, Castelo Branco, Portugal
Nikita Khmelinskii
Centro Hospitalar Universitário Lisboa Norte, Centro Académico de Medicina de Lisboa, Lisbon, Portugal
Daniela Oliveira
Centro Hospitalar Universitário São João, Porto, Portugal
Jorge Lopes
Hospital Garcia de Orta, Lisboa, Portugal
André Saraiva
Centro Hospitalar Universitário de Coimbra, Coimbra, Portugal
Ana Gago
Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal
Margarida Correia
Hospital de Braga, Braga, Portugal
Ana Lúcia Fernandes
Centro Hospitalar Universitário do Algarve, Faro, Portugal
Sara Dinis
Unidade Local de Saúde da Guarda, Guarda, Portugal
Rafaela Teixeira
Centro Hospitalar Tondela-Viseu, Viseu, Portugal
Susana Pinto Silva
Centro Hospitalar do Baixo Vouga, Aveiro, Portugal
Joana Martins-Martinho
Centro Hospitalar Universitário Lisboa Norte, Centro Académico de Medicina de Lisboa, Lisbon, Portugal
Francisca Guimarães
Unidade Local de Saúde do Alto Minho, Ponte de Lima, Portugal
Eduardo Dourado
Centro Hospitalar do Baixo Vouga, Aveiro, Portugal
Ana Teresa Melo
Centro Hospitalar Universitário Lisboa Central, Lisbon, Portugal
Manuel Silvério-António
Centro Hospitalar Universitário Lisboa Norte, Centro Académico de Medicina de Lisboa, Lisbon, Portugal
Centro Hospitalar Trás-os-Montes e Alto Douro, Vila Real, Portugal
Tiago Beirão
Centro Hospitalar Vila Nova de Gaia/Espinho, Gaia, Portugal
Carolina Furtado
Hospital do Divino Espírito Santo, Ponta Delgada, Portugal
Pedro Abreu
Unidade Local de Saúde de Castelo Branco, Castelo Branco, Portugal
Nikita Khmelinskii
Centro Hospitalar Universitário Lisboa Norte, Centro Académico de Medicina de Lisboa, Lisbon, Portugal
Daniela Oliveira
Centro Hospitalar Universitário São João, Porto, Portugal
Jorge Lopes
Hospital Garcia de Orta, Lisboa, Portugal
André Saraiva
Centro Hospitalar Universitário de Coimbra, Coimbra, Portugal
Ana Gago
Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal
Margarida Correia
Hospital de Braga, Braga, Portugal
Ana Lúcia Fernandes
Centro Hospitalar Universitário do Algarve, Faro, Portugal
Sara Dinis
Unidade Local de Saúde da Guarda, Guarda, Portugal
Rafaela Teixeira
Centro Hospitalar Tondela-Viseu, Viseu, Portugal
Susana Pinto Silva
Centro Hospitalar do Baixo Vouga, Aveiro, Portugal
Joana Martins-Martinho
Centro Hospitalar Universitário Lisboa Norte, Centro Académico de Medicina de Lisboa, Lisbon, Portugal
Francisca Guimarães
Unidade Local de Saúde do Alto Minho, Ponte de Lima, Portugal
Eduardo Dourado
Centro Hospitalar do Baixo Vouga, Aveiro, Portugal
Ana Teresa Melo
Centro Hospitalar Universitário Lisboa Central, Lisbon, Portugal
Manuel Silvério-António
Centro Hospitalar Universitário Lisboa Norte, Centro Académico de Medicina de Lisboa, Lisbon, Portugal