Nonspecific interstitial pneumonia in refractory systemic juvenile idiopathic arthritis responded to tocilizumab treatment.

Background: Nonspecific interstitial pneumonia (NSIP) is a rare pulmonary complication in systemic juvenile idiopathic arthritis (SJIA).
Objective: To present a case with NSIP in SJIA.
Methods: Case report.
Results: We report the case of a 4-year-old boy with SJIA complicated by macrophage activation syndrome (MAS) refractory to conventional therapy, and who later developed NSIP confirmed by high-resolution computerized tomography of the chest and lung histopathology. The patient received tocilizumab, a monoclonal antibody to interleukin-6 receptor, to control his disease. Data relating to tocilizumab treatment of NSIP in refractory SJIA is limited.
Conclusions: The data from this case report suggests that NSIP could be a pulmonary complication of SJIA complicated by MAS that is refractory to conventional therapy. Early initiation of tocilizumab should be considered to achieve disease remission in this pediatric patient population.