Long-term outcome in juvenile-onset mixed connective tissue disease: a nationwide Norwegian study.
OBJECTIVE
To describe the characteristics, outcome and predictive factors of juvenile mixed connective tissue disease (JMCTD) in a nationwide cohort of patients.


METHODS
We examined 55 patients with JMCTD after a mean disease duration of 16.2 years (SD 10.0). Patients were registered according to Kasukawa's criteria. Remission criteria were defined according to those for juvenile idiopathic arthritis, plus absence of cytopenia, myositis, progressive sclerodactyly, lung and oesophageal manifestations. Organ damage was assessed with the Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index and the Juvenile Arthritis Damage Index (JADI). Medical records were reviewed for early predictors for outcome, which were assessed by multivariate logistic regression analyses.


RESULTS
Three patients developed systemic lupus erythematosus (SLE). Fifty-two patients had continuous JMCTD; the most common manifestations were: Raynaud (100%), arthritis (94%), puffy hands (77%) and pulmonary manifestations (58%). SLE-like, systemic sclerosis (SSc)-like and polymyositis (PM)-like findings were found in 98%, 77% and 48%, respectively. Over time, SLE-like and PM-like manifestations decreased, and SSc-like findings increased. At follow-up, 35 patients (67%) had active disease and 17 (33%) were in remission. In 34 patients (65%), SLICC or JADI≥1 assessments indicated organ damage. Active disease was associated with higher anti-ribonucleoprotein antibody titres at follow-up and positive rheumatoid factor (RF) at diagnosis and follow-up.


CONCLUSIONS
Most patients with JMCTD had active disease and organ damage after a mean follow-up of 16.2 years. Active disease was associated with higher anti-ribonucleoprotein antibody levels and positive RF. The presence of RF at diagnosis predicted persistent disease activity.
Department of Rheumatology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
Siri Opsahl
SO
Hetlevik
Department of Rheumatology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.|Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
Berit
http://orcid.org/0000-0001-9178-1583
B
Flatø
Department of Pediatrics, St Olavs Hospital, Trondheim, Norway.|Department of Laboratory Medicine, Children's and Women's Health, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Marite
M
Rygg
Department of Pediatrics, University Hospital of North Norway, Tromsø, Norway.|Institute of Clinical Medicine, UiT-the Arctic University of Norway, Tromsø, Norway.
Ellen Berit
EB
Nordal
Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Ullevål, Oslo, Norway.
Cathrine
C
Brunborg
Department of Rheumatology, Hospital of Southern Norway, Kristiansand, Norway.
Helene
H
Hetland
Department of Rheumatology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
Vibke
V
Lilleby
D000293:Adolescent; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000974:Antibodies, Antinuclear / Q000097:blood; D002648:Child; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008947:Mixed Connective Tissue Disease / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology / Q000276:immunology; D009664:Norway / Q000453:epidemiology; D017063:Outcome Assessment, Health Care / Q000379:methods; D017285:Polymyositis / Q000175:diagnosis / Q000453:epidemiology; D011379:Prognosis; D012042:Registries; D012217:Rheumatoid Factor / Q000097:blood; D012261:Ribonucleoproteins / Q000276:immunology; D012595:Scleroderma, Systemic / Q000175:diagnosis / Q000453:epidemiology; D012720:Severity of Illness Index
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000974:Antibodies, Antinuclear; D007166:Immunosuppressive Agents; D012261:Ribonucleoproteins; D012217:Rheumatoid Factor
Autoimmune Diseases; Disease Activity; Outcomes research