The magnitude of early response to methotrexate therapy predicts long-term outcome of patients with juvenile idiopathic arthritis.
OBJECTIVE
To investigate the relationship between the magnitude of clinical response in the first 6 months of methotrexate (MTX) therapy and long-term outcome in children with juvenile idiopathic arthritis (JIA).


METHODS
The clinical charts of 125 JIA patients who were started with MTX and then followed for at least 5 years were reviewed. Based on the level of American College of Rheumatology (ACR) Pediatric response at 6 months, patients were divided in four mutually exclusive groups: (1) non-responders, (2) responders at 30%, (3) responders at 50%, and (4) responders at 70%. The long-term outcome in each response group was evaluated by calculating the percentage change in active and restricted joint counts from baseline to 1, 2 and 5 years and the frequency of inactive disease at 5 years.


RESULTS
At 6 months, 42 patients were classified as non-responders, 24 as 30% responders, 26 as 50% responders, and 33 as 70% responders. Patients who had achieved a 70% response showed a significantly greater percentage improvement in active joint count between baseline to 5 years compared with non-responders and 30% responders, and a significantly greater percentage improvement in restricted joint count between baseline to 5 years compared with 30% responders. The 70% responders also had a greater frequency of inactive disease at 5 years compared with 30% responders,


CONCLUSIONS
Our results show that the achievement of an ACR Pediatric 70 response at 6 months after start of MTX therapy predicts a more favorable long-term outcome of patients with JIA.
Istituto di Ricovero e Cura a Carattere Scientifico Policlinico S. Matteo, Pavia, Italy.
M
M
Bartoli
M
M
Tarò
S
S
Magni-Manzoni
A
A
Pistorio
F
F
Traverso
S
S
Viola
A
A
Magnani
C
C
Gasparini
A
A
Martini
A
A
Ravelli
D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001171:Arthritis, Juvenile / Q000188:drug therapy* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use*; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
D018501:Antirheumatic Agents; D007166:Immunosuppressive Agents; D008727:Methotrexate