Clinical Hemorheology and Microcirculation - Volume 47, issue 4

Authors: van der Loo, Bernd | Spring, Silviana | Koppensteiner, Renate

Article Type: Research Article

Abstract: Background: Statins are used for the treatment of hypercholesterolemia. Although they are well known to have pleiotropic effects, their dose-dependent influence on platelet aggregation, hemorheologic properties and the plasma levels of homocysteine in patients with peripheral arterial disease (PAD) has not been thoroughly investigated so far. Methods and results: From a total of 100 patients with PAD 48 patients were randomized to a treatment with atorvastatin 80 mg/d for six months, and 52 patients served as controls who continued their medication including statins in lower doses. At baseline and at six months' follow up we assessed platelet aggregation upon stimulation …with ADP, collagen and epinephrine using light transmission aggregometry. Furthermore, we determined major hemorheologic variables as well as the plasma levels of homocysteine, folic acid, and vitamin B6 and B12. No patient had obtained folic acid or B vitamin supplement. Platelet aggregation upon agonist-induced stimulation did not differ between patients under high-dose atorvastatin therapy and controls at baseline and after six months (p > 0.05). All hemorheologic parameters (plasma viscosity, red cell aggregation, whole blood viscosity, hematocrit, platelets, leucocytes) measured at baseline and after six months were not significantly different between both groups, too. After therapy with 80 mg atorvastatin homocysteine levels were significantly elevated as compared with baseline values (p = 0.0007), whereas levels remained unchanged in the control group. Folic acid levels were higher in the patients receiving high-dose atorvastatin as compared with controls both at baseline (p = 0.002) and at six months' follow up (p = 0.034). No significant difference in vitamin B6 and B12 levels both at baseline and after six months could be detected in either group. Conclusions: Treatment with 80 mg atorvastatin did not affect platelet aggregation and major hemorheologic parameters. The finding of an increase of homocysteine plasma levels in the presence of rather elevated levels of folic acid needs further investigation. Show more

DOI: 10.3233/CH-2011-1386

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 4, pp. 241-251, 2011

Authors: Bowers, A.S. | Pepple, D.J. | Reid, H.L.

Article Type: Research Article

Abstract: The determination of an optimal haematocrit (H0 ) has important clinical implications if such a level can be attained, and more importantly, maintained. This is defined as a haematocrit level, above or below which oxygen delivery is deleteriously affected. This study is designed to determine an optimal haematocrit in normal (AA), sickle cell trait (AS) and sickle cell disease (SS) subjects. Twenty-seven apparently healthy subjects having normal haemoglobin genotype, 24 with sickle cell trait and 42 with homozygous sickle cell disease were recruited into the study. Whole blood viscosity (WBV) was measured by a Wells Brookfield Cone and Plate Viscometer …at a shear rate of 230 sec−1 . Haematocrit was determined by an AC.Tron Coulter Counter. The optimal haematocrit was calculated as the inverse of a constant, K, which was derived from the haematocrit and viscosity data. Our findings showed that the H0 varied significantly among the 3 haemoglobin genotypes, in the order AA vs SS and AS vs SS. Additionally, the data indicated an increased H0 in subjects with sickle cell trait, suggesting a possible impairment in oxygen delivery in these individuals. Show more

Keywords: sickle cell disease, normal haemoglobin, sickle cell trait, optimal haematocrit, shear rate

DOI: 10.3233/CH-2011-1387

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 4, pp. 253-260, 2011

Authors: Tripette, Julien | Hardy-Dessources, Marie-Dominique | Beltan, Eric | Sanouiller, Alain | Bangou, Jacqueline | Chalabi, Tawfik | Chout, Roger | Hedreville, Mona | Broquere, Cédric | Nebor, Danitza | Dotzis, Grégory | Hue, Olivier | Connes, Philippe

Article Type: Research Article

Abstract: Purpose: The aim of this study was to clarify whether exercising in a tropical climate induces blood rheology alterations despite ad libitum hydration. Methods: Hematological, biochemical and hemorheological changes were investigated in young healthy adults (N = 9 men, 20.7 ± 0.8 yrs) after a 10-km race in hot and humid conditions. Subjects' maximal aerobic abilities were tested using a maximal ramp exercise. Blood was sampled at rest (TR ), at the end of the race (TEx ), and after 24 hours of recovery (T24 ). Ad libitum hydration was allowed during the race. Blood viscosity (ηb), red blood cell …deformability (EI), aggregation (AI) and disaggregation shear rate (γ) were measured. Results: Hematocrit, hemoglobin and plasma concentration of chlorine, sodium and potassium did not change in response to exercise. No functional consequence was observed on RBC deformability since EI remained unchanged. Percentages of echinocytes, schizocytes and stomatocytes remained in the subclinical range at all times. AI, γ and ηb did not present change. Conclusion: Running exercise in tropical climate with ad libitum hydration does not alter the main rheological properties of blood. Show more

Keywords: Exercise, hot environment, hydration, hemorheology

DOI: 10.3233/CH-2011-1388

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 4, pp. 261-268, 2011

Authors: Wenzel, Folker | Günther, Wiebke | Baertl, Anja | Lasshofer, Roland | Rox, Jutta | Fischer, Johannes Christian | Giers, Günther

Article Type: Research Article

Abstract: Introduction: Soluble CD40L (sCD40L) is expressed by platelets and is involved in the stabilization of arterial thrombi. Additionally, it was shown that sCD40L accumulation occurred in stored blood products triggering adverse transfusion reactions like TRALI. To study the influence of the preparation technique on sCD40L accumulation and platelet function we examined CD40L concentrations in prestorage pooled platelet concentrates compared to apheresis products. In addition, sCD40L release capacity was determined as a marker for platelet viability. Material and methods: sCD40L concentrations were determined in prestorage pooled platelet concentrates (n = 8) and in platelet apheresis concentrates (n = 8) before and …after platelet stimulation (recalcification and clot formation) at day 1, 3 and 5 under routine storage conditions. sCD40L concentrations were determined by a commercially available ELISA kit. Results: sCD40L concentrations in storage medium increased over time in prestorage pooled platelet concentrates (from 1,185 pg/mL ± 87 pg/mL at day 1 to 4,464 pg/mL ± 212 pg/mL at day 5) as well as in apheresis products (from 581 pg/mL ± 124 pg/mL at day 1 to 2,718 pg/mL ± 154 pg/mL at day 5) in a hyperbolic manner. Recalcification and clot formation caused an increase in sCD40L concentrations (for example 3,842 pg/mL ± 769 pg/mL before platelet activation to 31,219 pg/mL ± 2,063 pg/mL after platelet activation at day 3), and we observed comparable release capacities for both preparation techniques, however, decreasing over storage time up to 50% (day 5) of the respective control value (day 1). Conclusions: Amounts of sCD40L accumulation and release capacity during storage of platelet concentrates were dependent on storage duration, but showed no relevant differences regarding the preparation technique. After 5 days of storage, CD40L basal levels were increased, in contrast sCD40L release capacity was decreased. By recalcification and clot formation sCD40L release capacity could be easily induced and is assumed to be used as a marker for platelet viability. Show more

DOI: 10.3233/CH-2011-1407

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 4, pp. 269-278, 2011

Authors: Spengler, M.I. | Svetaz, M.J. | Leroux, M.B. | Bertoluzzo, S.M. | Carrara, P. | Van Isseldyk, F. | Petrelli, D. | Parente, F.M. | Bosch, P.

Article Type: Research Article

Abstract: Systemic Lupus Erythematosus (SLE) is an autoimmune, chronic inflammatory, non-organ specific disease. SLE patients present a high prevalence of thrombotic and arteriosclerotic disease. The aim of the present work was to study the erythrocyte aggregation kinetics, and the effect of plasma factors, namely, immunoglobulin and fibrinogen concentration, as well as cell factors such as deformability and erythrocyte membrane lipid fluidity on the erythrocyte aggregation, in SLE patients and healthy controls. The results show that SLE patients red blood cells aggregate at higher rate and the aggregates size are also greater than controls due to an increase of immunoglobulin and plasma …fibrinogen. The negative correlation between aggregation parameters and rigidity index could point out that the altered deformability diminishes the erythrocyte aggregation. Correlation between rigidity index and anisotropy suggests that the decrease of membrane lipid fluidity might be a cause of deformability decrease. The erythrocyte aggregation increase in these patients could induce a decreased flow that might contribute to the thromboembolic process present in SLE patients. Show more

Keywords: Systemic Lupus Erythematosus, erythrocyte aggregation, membrane fluidity, erythrocyte deformability

DOI: 10.3233/CH-2011-1409

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 4, pp. 279-285, 2011

Authors: Vayá, Amparo | Suescun, Marta | Micó, Luisa | Todolí, Jose | Ricart, Jose M.

Article Type: Research Article

Abstract: 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. Show more

Keywords: Hemorheology, cardiovascular risk factors, primary Sjögren syndrome

DOI: 10.3233/CH-2011-1410

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 4, pp. 287-293, 2011

Authors: Baskurt, Oguz K. | Uyuklu, Mehmet | Ozdem, Sebahat | Meiselman, Herbert J.

Article Type: Research Article

Abstract: A new method is described in this paper that allows measurement of red blood cell (RBC) aggregation indexes in disposable glass tubes within minutes. Light transmission through the RBC suspension filled into a microhematocrit capillary at stasis is recorded during RBC aggregation; a novel method assures an initial dispersion of aggregates in the capillary. The resulting light transmittance-time data are analyzed to calculate various parameters. Measurement of erythrocyte sedimentation rate (ESR) and RBC aggregation using well established methods and the newly developed capillary tube aggregometer in blood samples with a wide range of RBC aggregation indicated significant correlations between these …parameters. Additionally, light transmittance during complete disaggregation allows estimating hematocrit, thereby enabling hematocrit correction of the measured and calculated parameters. The newly developed capillary tube RBC aggregometer is suitable for use as a method to rapidly monitor disease activity and the acute phase response, especially at the point-of-care (e.g., health care facilities, physician's office) and for field studies. Show more

Keywords: Acute phase response, disease activity, erythrocyte sedimentation rate, erythrocyte aggregation

DOI: 10.3233/CH-2011-1411

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 4, pp. 295-305, 2011