SAMHD1 associates with inflammation and vasculitis in paediatric-onset systemic lupus erythematosus.

OBJECTIVES

In this study, we aimed to explore the expression of the Aicardi-Goutières syndrome (AGS) mutant gene SAMHD1 in paediatric-onset systemic lupus erythematosus (pSLE), its correlations with clinical and laboratory parameters, and the relationship between its expression and the type 1 interferon (IFN) signalling pathway.

METHODS

Peripheral blood from 98 pSLE patients and 44 gender and age-matched healthy individuals were examined. Gene expression levels of SAMDH1 and interferon-stimulated genes (ISGs; MxA, IRF3 and IRF7) were evaluated using real-time RT-PCR assays.

RESULTS

SAMHD1 levels in pSLE patients were significantly increased compared to those in healthy donors (p<0.001). SAMHD1 was associated with serum ferritin (r=0.221, p=0.042) in pSLE patients. SAMHD1 levels were significantly increased (p<0.05) in pSLE patients with butterfly erythema, alopecia, and photosensitivity. SAMHD1 was positively correlated with MxA, IRF3 and IRF7 levels, indicating that SAMHD1 was associated with the type 1 IFN signalling pathway.

CONCLUSIONS

SAMHD1 was significantly increased and correlated with MxA, IRF3 and IRF7 in pSLE patients.