1 - Unidade de Reumatologia Pediátrica, Pediatria Médica, Hospital Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, Lisboa
- 29th Paediatric Rheumatology European Society Congress
- Poster
- Publication in a form of abstract
Introduction: Mixed Connective Tissue Disease (MCTD) is a rare immune-mediated disorder characterized by overlapping features of juvenile idiopathic arthritis, systemic lupus erythematosus (SLE), systemic sclerosis, and dermatomyositis (DM)/polymyositis, associated with high titers of anti-U1 ribonucleoprotein antibodies (U1RNP). The heterogeneity of clinical manifestations, both at presentation and over time, present a diagnostic challenge. Furthermore, no classification criteria for MCDT have been validated for children.
Objectives: Characterization of patient demographics, clinical and complementary findings, and treatment in children with MCTD.
Methods: A single centre retrospective case series of children diagnosed with MCTD from 2008 to 2022. We identified children fulfilling both classification criteria for MCTD proposed by Alarcón-Segovia and Kasukawa.
Results: Eight patients were identified (7 female), median age at diagnosis of 10 years (5-15 years) and median time to diagnosis of 12 months (m) (4-36m).At onset, all had Raynaud phenomenon (RP) and arthritis, 6/8 had systemic symptoms, 6/8 had skin manifestations (puffy fingers 3/8, DM rash 2/8, SLE rash 1/8 and one with digital erythema), 3/8 had myositis (one with muscle weakness), 2/8 presented with serositis, and 1/8 with aseptic meningitis. All presented an abnormal nailfold capillaroscopy. During follow-up, two additional patients developed puffy fingers and digital erythema; of the others, two evolved with digital ulcers, one with sclerodactyly, and two with SLE rash. 4/8 patients showed reduced Diffusing Capacity for Carbon Monoxide; none had interstitial lung disease on CT. One had gastroesophageal reflux disease. All patients showed elevated ESR and hypergammaglobulinemia as well as positive ANA (≥1:160) and anti-U1RNP antibodies. One had hypocomplementemia. 4/8 had positive RF (2 with polyarticular arthritis; 2 with oligoarthritis); other positive antibodies were: anti-SSA (1/8), anti-Ro52 (2/8), anti-dsDNA (1/8), and anti-RP155 (1/8). During disease course, 6/8 patients had anaemia, 5/8 leukopenia, and 5/8 lymphopenia. At diagnosis, all patients were treated with hydroxychloroquine, corticosteroids, and calcium channel blockers for RP management; 7/8 started methotrexate but 2 switched to azathioprine. 1/8 patient was treated with cyclophosphamide followed by maintenance therapy with mycophenolate mofetil.
Conclusion: Our findings are in accordance with MCTD literature, regarding the age of onset and time until diagnosis, female predominance and clinical manifestations, with RP, arthritis and skin disease associated
Palavras Chave: Mixed Connective Tissue Disease, anti-U1 ribonucleoprotein antibodies