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 a close correlation between olfactory dysfunction and disease severity and immunological abnormalities. Immune and systemic inflammation dysregulation might play a role in the mechanism of this defect.

Smell and Taste Function and Their Disturbances in Sjögren’s Syndrome

“…In addition to general taste perception, some studies revealed various degrees of dysfunction for the main types of taste in SS patients. Sweet taste was the least affected, while bitter was the most impaired in the SS group [12]. Similar results were obtained by Kamel et al, who reported that within the SS group, the threshold for sweet taste was much less affected than the threshold for sour, salty and bitter [6].…”

“…In the SS group, the self-reported taste and smell scores on VAS were significantly lower than those of healthy controls [1]. Ageusia, hypogeusia, anosmia, and hyposmia were more frequent in the SS group than in healthy people [1,12]. Although the main types of taste and smell disorders were hyposmia and hypogeusia, anosmia, and ageusia were relatively common in the SS group [1].…”

“…Although the main types of taste and smell disorders were hyposmia and hypogeusia, anosmia, and ageusia were relatively common in the SS group [1]. It is postulated that anosmia is exclusively presented in the SS group compared to the control [12]. Furthermore, a high proportion of SS patients complained of dysgeusia [1].…”

Chemosensory dysfunction in primary Sjögren’s syndrome: a topical review

“…Furthermore, Xu et al recently shown in a study including 52 pSS patients versus matched healthy control subjects, impaired olfactory functions (assessed by odors threshold, identification, and memory tests) in pSS patients (all p ≤ 0.01); they found more anosmia and hyposmia in pSS patients. They also highlight a close correlation between olfactory dysfunction and pSS severity or activity (evaluated by ESSDAI and ESSPRI scores) and immunological abnormalities (Table 2 ) [ 4 ]. However, we have not identified any specific longitudinal studies on olfactory disorders in SS patients, to further strengthen these results.…”

“…Today, chemosensory dysfunction remains rarely investigated during the medical follow-up of patients although the recent COVID-19 pandemic reveal that it could be a strong and clear sign of systemic condition [ 2 , 3 ]. Chemosensory dysfunction has been seldom reported in primary Sjögren’s syndrome (pSS) [ 4 ].…”