Predictors of poor response to methotrexate in polyarticular-course juvenile idiopathic arthritis: analysis of the PRINTO methotrexate trial.
OBJECTIVE
To determine whether baseline demographic, clinical, articular and laboratory variables predict methotrexate (MTX) poor response in polyarticular-course juvenile idiopathic arthritis.


METHODS
Patients newly treated for 6 months with MTX enrolled in the Paediatric Rheumatology International Trials Organization (PRINTO) MTX trial. Bivariate and logistic regression analyses were used to identify baseline predictors of poor response according to the American College of Rheumatology pediatric (ACR-ped) 30 and 70 criteria.


RESULTS
In all, 405/563 (71.9%) of patients were women; median age at onset and disease duration were 4.3 and 1.4 years, respectively, with anti-nuclear antibody (ANA) detected in 259/537 (48.2%) patients. With multivariate logistic regression analysis, the most important determinants of ACR-ped 70 non-responders were: disease duration > 1.3 years (OR 1.93), ANA negativity (OR 1.77), Childhood Health Assessment Questionnaire (CHAQ) disability index > 1.125 (OR 1.65) and the presence of right and left wrist activity (OR 1.55). Predictors of ACR-ped 30 non-responders were: ANA negativity (OR 1.92), CHAQ disability index > 1.14 (OR 2.18) and a parent's evaluation of child's overall well-being < or = 4.69 (OR 2.2).


CONCLUSIONS
The subgroup of patients with longer disease duration, ANA negativity, higher disability and presence of wrist activity were significantly associated with a poorer response to a 6-month MTX course.
Vilca
Iris
I
IRCCS G Gaslini, Pediatria II, Reumatologia, PRINTO, Genova, Italy.
Munitis
Pablo Garcia
PG
Pistorio
Angela
A
Ravelli
Angelo
A
Buoncompagni
Antonella
A
Bica
Blanca
B
Campos
Lucia
L
Häfner
Renate
R
Hofer
Michael
M
Ozen
Seza
S
Huemer
Christian
C
Bae
Sang Cheol
SC
Sztajnbok
Flavio
F
Arguedas
Olga
O
Foeldvari
Ivan
I
Huppertz
Hans Iko
HI
Gamir
Maria Luz
ML
Magnusson
Bo
B
Dressler
Frank
F
Uziel
Yosef
Y
van Rossum
Marion A J
MA
Hollingworth
Peter
P
Cawkwell
Gail
G
Martini
Alberto
A
Ruperto
Nicolino
N
D000293:Adolescent; D000974:Antibodies, Antinuclear / Q000032:analysis; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001171:Arthritis, Juvenile / Q000188:drug therapy* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use*; D011379:Prognosis; D016896:Treatment Outcome
D000974:Antibodies, Antinuclear; D018501:Antirheumatic Agents; D007166:Immunosuppressive Agents; D008727:Methotrexate