Phenotype and cytokine profile in a TRAPS Syndrome family with TNFRSF1A p.(Thr79Met): Association with sacro-iliitis.

OBJECTIVE

A comparative retrospective and analytic study was performed in 13 members of a family, affected or not by tumor necrosis factor TNF-α receptor-associated periodic syndrome (TRAPS), including one patient with sacro-illitis.

METHODS

Clinical features and TNFRSF1A gene analysis were reported for each family member, symptomatic or asymptomatic. Biological features including CRP/SAA, IgD and ex vivo T lymphocytes and myeloid-derived cytokine profile (IL1-β, IL-1α, IL-1ra, IL-4, IL-10, IL-17, IFN-γ, TNF-α, IL-6) were characterized for all family members. CRP and IgD only were compared with those of 13 axial SA patients with TNF-blockade indication.

RESULTS

Symptomatic TRAPS patients presented p.(Thr79Met) variant and generally complained of abdominal pain. They displayed higher SAA/IgD levels and IL-6/IL-1RA/IL-10 production by PBMC compared to asymptomatic family members. IgD serum level was higher in symptomatic members compared to SA patients. The patient with sacro-iliitis displayed the highest cytokine production and IgD serum levels.

CONCLUSION

This study describes clinical heterogeneity in a family examined for TRAPS syndrome and reports the first sacro-iliitis in a patient with pathogenic TNFRSF1A variant. Dysregulated PBMC-derived cytokine and Il-10/IgD dysregulation in the patient with sacro-iliitis raises the issue of sacro-iliitis pathophysiology.