Allogeneic haematopoietic stem-cell transplantation for children with refractory systemic juvenile idiopathic arthritis and associated lung disease: outcomes from an international, retrospective cohort study.

BACKGROUND

Systemic juvenile idiopathic arthritis-related lung disease (sJIA-LD) is a severe complication in patients with treatment-refractory systemic juvenile idiopathic arthritis (sJIA). The objective of this study was to evaluate the effect of allogeneic haematopoietic stem-cell transplantation (HSCT) in a cohort of children with sJIA-LD.

METHODS

This international, retrospective cohort study was performed in nine hospitals across the USA and Europe in children with sJIA-LD who had received allogeneic HSCT. Patients' medical charts were reviewed and their data extracted using a standardised form. The outcomes assessed were allogeneic HSCT outcomes (eg, engraftment and donor chimerism, and transplant-related complications), pulmonary outcomes (eg, oxygen dependence, chest CT findings, and pulmonary function test results), and overall outcomes (eg, death, complete response, or partial response). A complete response was defined as resolution of signs of sJIA without the need for systemic immunomodulatory therapy, in addition to discontinuation of supplemental oxygen.

FINDINGS

Between Jan 18, 2018, and Oct 17, 2022, 13 patients with sJIA-LD, who were refractory to immunosuppressive treatment and who had received an average of six different treatment agents, underwent allogeneic HSCT. Ten (77%) of 13 patients were female and three (23%) were male. The median age at diagnosis of sJIA-LD was 4·8 years (IQR 2·9-14·8) and the median age at transplantation was 9·0 years (5·0-19·0). Pre-HSCT chest CT revealed characteristic sJIA-LD. Five patients required supplemental oxygen before transplantation. Patients received various reduced toxicity or intensity conditioning regimens. Grafts were from 10/10 HLA-matched (n=6) or 9/10 HLA-mismatched (n=5) unrelated donors, a 7/10 related donor (n=1), and a matched sibling (n=1). All patients engrafted. One patient had secondary graft failure and received a second transplant from a different donor. Post-transplantation complications included acute graft-versus-host disease (n=5), bacteraemia (n=8), cytomegalovirus reactivation (n=6), and post-transplantation macrophage activation syndrome (n=3). Four patients died; two from cytomegalovirus pneumonitis, one from intracranial haemorrhage, and one from progressive sJIA-LD. At a median follow-up of 16 months (IQR 6-24), all nine surviving patients had a complete response, with no active features of sJIA, no biological therapy or corticosteroid use, and no supplemental oxygen dependence.

INTERPRETATION

Allogeneic HSCT might be a valuable treatment option for patients with refractory sJIA and sJIA-LD and should be considered for children with worsening oxygen dependence or severe treatment-related morbidity.

FUNDING

National Institute of Arthritis and Musculoskeletal and Skin Diseases (R01-AR079525).