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.
IRCCS G Gaslini, Pediatria II, Reumatologia, PRINTO, Genova, Italy.
Iris
I
Vilca
Pablo Garcia
PG
Munitis
Angela
A
Pistorio
Angelo
A
Ravelli
Antonella
A
Buoncompagni
Blanca
B
Bica
Lucia
L
Campos
Renate
R
Häfner
Michael
M
Hofer
Seza
S
Ozen
Christian
C
Huemer
Sang Cheol
SC
Bae
Flavio
F
Sztajnbok
Olga
O
Arguedas
Ivan
I
Foeldvari
Hans Iko
HI
Huppertz
Maria Luz
ML
Gamir
Bo
B
Magnusson
Frank
F
Dressler
Yosef
Y
Uziel
Marion A J
MA
van Rossum
Peter
P
Hollingworth
Gail
G
Cawkwell
Alberto
A
Martini
Nicolino
N
Ruperto
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