Mesenchymal Stromal Cell Infusions Appear Safe in Refractory JIA

Investigators evaluated the efficacy of infusing mesenchymal stromal cells in refractory juvenile idiopathic arthritis and assessed subsequent adverse events.

Infusions of mesenchymal stromal cell (MSC) for juvenile idiopathic arthritis (JIA) have demonstrated safety among a small population, according to study results recently published in Rheumatology (Oxford); however, macrophage activation syndrome flare remains a risk among persons with systemic onset JIA.

This single-center, phase 1b, open-label intervention study included 6 individuals with JIA whose median disease duration was 9.2 years. All participants had active arthritis, and corticosteroids, methotrexate, and a median of 5 biological treatments had all been ineffective. All participants visited the study center 9 times and were given intravenous infusions of allogeneic MSC (2 million/kg) derived from bone marrow.

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The number of adverse events per 3-month postinfusion period compared with the previous 3 months constituted the primary outcome. The Fisher’s exact test was used to compare adverse events before and after infusion, and a 2-tailed Wilcoxon signed Ranks test was used to compare end-of-study results with baseline.

Of the study’s participants, all received an initial MSC infusion and 3 participants received a second infusion. No severe infusion reactions occurred, and adverse events decreased between pretreatment and posttreatment; however, one participant with systemic onset JIA experienced a macrophage activation syndrome flare 7 weeks after the infusion and 9 weeks after discontinuing tocilizumab, but this participant had a medical history with the syndrome.

Eight weeks after a single infusion, Visual Analogue Scale (VAS) well-being decreased significantly from 75 to 56, Juvenile Arthritis Disease Activity Score-71 (JADAS-71) decreased from 24.5 to 11, and Clinical Juvenile Arthritis Disease Activity Score-10 (cJADAS10) decreased from 18 to 10.6.

The study researchers concluded that “Four of six patients showed a decrease of clinically active joints 8 weeks after the first MSC administration, with a decrease of [C-reactive protein] and [erythrocyte sedimentation rate] in three of the four patients with an elevated value at the start. In the six study patients, only JADAS-71, cJADAS10 and the VAS well-being decreased significantly in that short period. The median scores of the patient reported outcome measures of VAS pain, Childhood Health Assessment Questionnaire and Quality of Life all improved non-significantly during that same episode.”


Swart JF, de Roock S, Nievelstein RAJ, et al. Bone-marrow derived mesenchymal stromal cells infusion in therapy refractory juvenile idiopathic arthritis patients [published online April 27, 2019]. Rhematology (Oxford). doi:10.1093/rheumatology/kez157