Olfactory impairment in patients with primary Sjogren’s syndrome and its correlation with organ involvement and immunological abnormalities

Abstract

Objective Patients with autoimmune diseases often present with olfactory impairment. The aim of the study was to assess the olfactory functions of patients with primary Sjögren’s syndrome, and to correlate these findings with their disease activity.Methods Fifty-two patients with primary SS and 52 sex- and age- matched healthy control subjects were included. All of them underwent clinical and laboratory examination. Olfactory functions were evaluated using olfactory function assessment by computerized testing including the three stages of smell: threshold, identification and memory of the different odors. Results All the olfactory scores (olfactory threshold, identification and memory) in patients with pSS were significantly decreased than the control group (all P<0.01). Patients had higher proportion of anosmia (13.5% vs 0%) and hyposmia (19.2% vs 11.5%) than controls (χ2 =10.526, P <0.01). Multivariable regression analysis revealed that ESSDAI and the symptoms of dryness, fatigue and limb pain had negative influence on olfactory function (adjusted R2=0.381, 0.387, 0.513 and 0.614, respectively). ESSPRI showed significantly negative association with olfactory threshold, identification, memory and total scores. Olfactory identification and memory scores were decreased in pSS patients with thyroid dysfunction or hypocomplementemia (P<0.05). Smell threshold scores were decreased in pSS patients with anti-SSA antibody or anti-nuclear antibody compared with those without those autoantibodies (P<0.01). Conclusion Our findings indicate that olfactory functions are impaired in pSS patients. There was close correlation between olfactory dysfunction with disease severity and immunological abnormalities. Immune and systemic inflammation dysregulation might play a role in the mechanism of this defect.