Sense of smell reduced in lupus patients

The sense of smell is diminished in patients with systemic lupus erythematosus (SLE) and the extent of this loss correlates with disease activity and nervous system involvement, a small study has found. Prior research carried out by the authors had indicated that neuropsychiatric SLE-like manifestations and olfactory impairment might be induced in mice by autoimmune mechanisms, which target specific areas of the brain. Until now, however, no studies have evaluated olfactory function in patients with SLE. The levels of olfactory functions were evaluated in 50 patients with SLE and in 50 age- and sex-matched controls by using a test based on a pen-like odour-dispensing device that measured the threshold, discrimination, and identification of various odours. The authors found that male gender and older age were predictive of olfactory deficits in both groups. A reduced sense of smell was identified in 46% of SLE patients compared with just 25% of controls (p < 0.02). Anosmia was noted in 10% of SLE patients, but was totally absent in the control group. The researchers discovered that as the smelling deficit increased, so did SLE disease activity (p < 0.001) and CNS manifestations (p < 0.03). “Olfaction is hardly a familiar subject for rheumatologists and immunologists. However, based on the literature on smell deficits, data from our mouse model, and results of the current study, a possible role of an autoimmune mechanism in the pathogenesis of olfactory impairment may exist,” the researchers concluded. "Smell decrement has been found to be an early and predictive sign in several CNS diseases, and therefore, might be a useful and easy tool for the physician in early diagnosis of CNS involvement in autoimmune diseases," they added....