Hemorheological profile in primary Sjögren's syndrome: a case-control study

Rheological blood behavior in primary Sjögren's syndrome (SS) has been scarcely investigated. We evaluated the rheological profile (blood viscosity, plasma viscosity, erythrocyte deformability, erythrocyte aggregation, erythrocyte aggregation time and erythrocyte disaggregation threshold) along with fibrinogen, high-sensitive C reactive protein, plasma lipids, immunoglobulins, total proteins and erythrocyte sedimentation rate in 22 patients with primary SS (2 males, 20 females, aged 58 ± 9 years) and in 22 healthy volunteers (3 males, 19 females, aged 57 ± 5 years). Patients showed statistically higher plasma viscosity, erythrocyte sedimentation rate and G immunoglobulin (IgG) levels and lower total cholesterol than controls (p = 0.006, p = 0.023, p = 0.034, p = 0.036, respectively). Three patients with extraglandular involvement showed the highest plasma viscosity values: 1.98 cP, 1.70 cP and 1.65 cP, respectively. No differences were observed for the other rheological parameters analyzed. In a multivariate regression analysis, only fibrinogen, triglycerides and IgG were independent determinants for plasma viscosity values (beta coefficient: 0.335; p = 0.001; beta coefficient: 0.242; p = 0.019; beta coefficient: 0.660; p < 0.001, respectively). Our results indicate that patients with primary SS show increased plasma viscosity, mostly related with IgG levels without other alterations in the rheological profile. Further research with a larger sample size achieved by multicenter studies would be desirable.