Psoriasis and hemorheology. Influence of the metabolic syndrome.

Psoriasis is a systemic inflammatory disorder with increased cardiovascular risk which has been partly attributed to the increased prevalence of the metabolic syndrome (MS). However, the contribution of rheological alterations to cardiovascular risk has been scarcely investigated. In 91 psoriasis patients and in 101 healthy volunteers, we determined the rheological profile (fibrinogen, blood viscosity and erythrocyte aggregation), along with lipidic and inflammatory parameters. Patients showed statistically higher BMI, waist, triglycerides, insulin, c-reactive protein (CRP), neutrophils, lower HDL-cholesterol and a higher MS prevalence (p<0.05). When subjects with MS were excluded from the study, patients with psoriasis still showed a worse inflammatory, lipidic and rheological profile in the above-mentioned variables compared with controls without MS (p<0.05). The logistic regression analysis revealed that abdominal obesity and fibrinogen>384 mg/dL were independent predictors of psoriasis (OR 3.75 95% CI 1.77-7.94, p<0.001; OR 2.95 95% CI 1.14-7.64, p=0.025), respectively. Patients on biologics, showed less inflammation and a better rheological profile than those not on biological treatment. In conclusion, patients with psoriasis show an altered rheological profile, which may contribute to increased cardiovascular risk. Although the presence of MS worsens this profile, psoriasis per se shows rheological alterations due to both inflammation and altered metabolic parameters. Anti TNF-α treatment markedly improves the rheological profile by mostly decreasing inflammation.

Erythrocyte deformability in macrocytosis determined by means of ektacytometry techniques.

There is little information regarding the behaviour of red blood cell deformability in macrocytosis. We have determined in 114 patients with macrocytosis (MCV > 97 fL) and in 115 age and sex-matched subjects with normocytosis (VCM < 97 fL) erythrocyte deformability by means of ektacytometric techniques (Rheodyn SSD) measuring the erythrocyte elongation index (EEI) at 12, 30 and 60 Pa. Patients with macrocytosis showed statistically higher EEI at all the shear stresses tested when compared with controls (p < 0.001). When patients with macrocytosis were classified according to their main diagnosis as hepatic or renal disease, HIV and miscellaneous, 66.7%, 41.7%, 36.7% and 33.3% of patients, respectively, showed a EEI 60 higher than 61.8% (mean value of the control group + 2 SD). Linear regression analysis demonstrates that MCV, bilirubin, triglycerides and alanine aminotransferase were the main variables influencing EEI 60. An increased surface/volume ratio of the red blood cells may be the main cause related with a higher erythrocyte deformability in a relevant percentage of macrocytosis. Further research is required to confirm our findings by designing case-control pathology-specific studies.