Sex differences in the expression of haemorheological determinants in individuals with atherothrombotic risk factors and in apparently healthy people.

BACKGROUND: Increased red cell aggregation can be detrimental, leading to slow capillary blood flow and tissue hypoxaemia. Sex differences in the degree of erythrocyte adhesiveness/aggregation in the peripheral blood have not been clearly shown. OBJECTIVES: To determine whether there are sex differences in the expression of erythrocyte adhesiveness/aggregation in the peripheral blood in individuals with atherothrombotic risk factors and in apparently healthy people. METHODS: From a cohort of 965 participants in the Tel Aviv Medical Centre inflammation survey, 192 pairs of different sex were matched for age, body mass index, hip and waist circumferences, cardiovascular risk factors, and the intake of active cardiovascular drugs. RESULTS: Women had an enhanced degree of red cell aggregation (p < 0.0005) as well as increased concentrations of inflammation sensitive proteins including fibrinogen and C reactive protein. Women had a lower haemoglobin concentration than men, but this did not affect the degree of erythrocyte adhesiveness/aggregation. CONCLUSIONS: The significant increase in red blood cell adhesiveness/aggregation in the peripheral blood of women with atherothrombosis could be relevant to the more eventful course that some women experience during and following acute ischaemic disease.

Capillary and venous leukocyte adhesiveness/aggregation to differentiate between viral and bacterial infection.

BACKGROUND: A simple capillary leukocyte adhesiveness/aggregation test (CAPLAAT) might be helpful in determining the intensity of inflammation in acute viral and bacterial infections. PATIENTS AND METHODS: We included 30 patients with acute bacterial infections, 14 with viral infections as well as 48 healthy controls. The leukocyte adhesiveness/aggregation test (LAAT) test was performed using a simple slide test and image analysis. RESULTS: The CAPLAAT had a similar discrimination power between bacterial and viral infections as both the white blood cell count (WBC) and the erythrocyte sedimentation rate (ESR). It was more sensitive than the WBC and the ESR (77%, 68% and 66%, respectively) for the detection of bacterial infections and had a comparable negative predictive value. By analyzing the size distribution of the aggregated leukocytes, we found that a venous leukocyte adhesiveness/aggregation test (VLAAT) of four cells and more had the best positive predictive value (94%) and specificity (95%) for diagnosis of an acute bacterial infection (from all the acute phase response variables examined). CONCLUSION: The CAPLAAT might be attractive for the detection of inflammation and for the assessment of its severity at points of care where the services of a clinical laboratory are not available around the clock.

Prognostic implications of admission inflammatory profile in acute ischemic neurological events.

OBJECTIVE: To reveal the potential prognostic implications of admission inflammatory markers in patients with acute ischemic neurological events. PATIENTS AND METHODS: Sixty patients with an acute ischemic neurological event who were examined within 24 h from the appearance of symptomatology. We determined the high-sensitive C-reactive protein (hs-CRP) concentrations, erythrocyte sedimentation rate (ESR), fibrinogen concentrations and degree of erythrocyte adhesiveness/aggregation. RESULTS: A significant correlation was noted between baseline hs-CRP concentrations, ESR as well as adhesiveness/aggregation and the outcome of the ischemic neurological event as determined by the modified Rankin scale 8-12 months following the insult. CONCLUSION: Admission inflammatory markers have long-term prognostic implications in patients with acute ischemic neurological events. These findings are relevant in view of the new therapeutic interventions now available for reducing the inflammatory response.

Rheological determinants of red blood cell aggregation in diabetic patients in relation to their metabolic control.

AIMS: To determine whether increased red blood cell adhesiveness/aggregation in diabetic patients is related to the extent of their metabolic control. METHODS: We measured erythrocyte adhesiveness/aggregation in a group of 85 adult patients with diabetes mellitus by using citrated venous whole blood and a simple slide test. The erythrocyte adhesiveness/aggregation was determined by measuring the size of the spaces that are formed between the aggregated erythrocytes. We divided the patients into those with either low or high erythrocyte adhesiveness/aggregation values. RESULTS: The erythrocyte adhesiveness/aggregation values of the two groups differed significantly in terms of their fibrinogen concentration, erythrocyte sedimentation rate, high sensitive C-reactive protein (CRP), total cholesterol and triglyceride concentrations. There was no difference between the two groups regarding the concentrations of HbA(1c). Logistic regression was applied to construct a model to predict the belonging of a patient in the low or high erythrocyte adhesiveness/aggregation group. A linear regression was applied to construct a model to predict the erythrocyte adhesiveness/aggregation values. Both models turned out to include gender, age, fibrinogen, triglyceride, retinopathy, coronary artery disease and age and gender interaction. Neither HbA(1c) nor CRP entered the models. CONCLUSIONS: The degree of erythrocyte adhesiveness/aggregation and several variables of the acute-phase response in patients with diabetes mellitus are not directly related to the degree of metabolic control as evaluated by means of HbA(1c) concentration. Diabetic patients might benefit from rheological or anti-inflammatory interventions regardless of their metabolic control.

The picture of inflammation: a new concept that combines the white blood cell count and erythrocyte sedimentation rate into a new hematologic diagnostic modality.

BACKGROUND: Physicians who work in small clinics, far away from medical centers, cannot obtain relevant information regarding the acute phase response at low cost and real time. METHODS: We adopted a simple slide test and image analysis to determine the number of white blood cells in the peripheral blood, their degree of adhesiveness/aggregation as well as that of the red blood cells. Three independent observers scored the images into categories of no (1), mild (2), moderate (3) or severe (4) inflammation. RESULTS: A substantial interobserver agreement was noted for all three observers. No patient classified as having no (1) inflammation was given a score of moderate (3) or severe (4) inflammation and vice versa. The one-way analysis of variance (age- and gender-adjusted) confirmed that the data obtained from the image analyzer are significantly different between the above-mentioned four categories. CONCLUSIONS: It is possible to use a simple slide test and image analysis to discriminate effectively between various degrees of inflammation intensity. Since it is possible to send the pictures via telephone, Inter- or Intranet to a physician somewhere else, it might be attractive for medical personnel who work in small clinics not equipped with sophisticated laboratory facilities. This technique is currently being evaluated for possible Telemedicine and E-Health uses.

The state of leukocyte adhesiveness/aggregation in the peripheral blood of patients with type 2 diabetes and ischemic vascular disease.

White blood cells have a potential role in the pathogenesis of vasculopathy in diabetic patients. We studied the circulating peripheral blood in a cohort of patients with documented ischemic heart or brain disease with and without type 2 diabetes by means of image analysis and flow cytometry. Our study showed that the state of leukocyte adhesiveness/aggregation is slightly increased in those who had concomitant diabetes but that there was no difference regarding the expression of CD11b/CD18 and CD62L antigens on the surface of the peripheral blood white blood cells. The finding of a significantly increased number of white blood cells in the peripheral blood of patients with ischemic vascular diseases is important insofar as it is associated with a poorer prognosis.

The feasibility of estimating the erythrocyte sedimentation rate within a few minutes by using a simple slide test.

The acute phase response is accompanied by the appearance of aggregated red blood cells in the peripheral blood. The Westergren erythrocyte sedimentation rate (ESR) is an indirect measurement of this enhanced aggregability. We adopted a simple slide test and image analysis to reveal the adhesiveness/aggregation of red blood cells. A significant correlation was found between the erythrocyte adhesiveness/aggregation test (EAAT) and the ESR. A predictive model for ESR based on EAAT and the age of the patients was created. This new approach will enable us to obtain within a few minutes a good estimate of whether a given individual has a mild moderate or significant acute phase response. With further development, we will be able to use a bedside small cartridge that will deliver the extrapolated ESR at low costs and within a couple of minutes.

Increased erythrocyte adhesiveness/aggregation in the peripheral venous blood of patients with ischaemic heart disease and an eventful course.

OBJECTIVE: To determine whether increased erythrocyte aggregability has prognostic implications in patients with established ischaemic heart disease. METHODS AND RESULTS: We have adopted a simple slide test and image analysis to reveal the state of erythrocyte adhesiveness/aggregation (EAA) in the peripheral blood of patients with ischaemic heart disease and an eventful course (n=46) as opposed to those with an uneventful (n=43) course. A significant correlation was noted between the results of the erythrocyte adhesiveness/aggregation test (EAAT) and either erythrocyte sedimentation or fibrinogen concentration. When we sampled the results of fibrinogen in the group of eventful course they were not significantly different from the results obtained in the uneventful one. This was the case with the results of the erythrocyte sedimentation rate. However, the variables of the EAAT showed a significant difference, the values in the eventful group being higher than those observed in the uneventful one. CONCLUSIONS: The EAAT is a valuable tool to disclose the presence of increased red blood cell aggregability in patients with ischaemic heart disease. Increased EAA might have prognostic implications in patients with ischaemic heart disease.

Combined leukocyte and erythrocyte aggregation in patients with acute myocardial infarction.

OBJECTIVES: To determine whether the increased aggregability of both white and red blood cells previously reported in acute myocardial infarction (aMI) correlates with each other. DESIGN: Cross-sectional study comparing two groups of patients and a group of healthy controls. SETTING: A tertiary university affiliated hospital (Intensive Cardiac Care Unit and Department of General Internal Medicine). PATIENTS: Consecutive patients with aMI, patients with chest pain and no infarction, and healthy controls. MEASUREMENTS AND RESULTS: We adapted a simple slide test and image analysis to reveal the state of both leukocyte and erythrocyte adhesiveness/aggregation in the peripheral blood of patients with aMI. A significant (P=0.0001) increment in the aggregation of both cellular populations was noted in 48 patients with aMI as opposed to the 141 patients with ischemic heart disease and no infarction and in 45 matched controls. In addition, a significant correlation was noted between the various variables of the leukocyte and erythrocyte adhesiveness/aggregation tests. CONCLUSIONS: The significant correlation between the aggregability of white and red blood cells in patients with aMI is suggestive of there being a commonly shared adhesive protein(s). The prompt identification of patients with increased aggregation might have clinical and therapeutic implications.

Image analysis for the detection of increased erythrocyte, leukocyte and platelet adhesiveness/aggregation in the peripheral blood of patients with diabetes mellitus.

Increased erythrocyte, leukocyte, and platelet adhesiveness and aggregation may contribute to the development of ischemic vascular conditions in diabetic patients. They have been described by using different diagnostic systems and following various ex vivo manipulations. We have adopted a simple slide test and image analysis to reveal the adhesiveness and aggregation of the three cellular elements in a picture that is obtained from one single citrated venous blood sample presented on a glass slide. A significant increment in the degree of adhesiveness/aggregation of erythrocytes, leukocytes and platelets was noted in 29 patients with diabetes mellitus as opposed to age- and gender-matched healthy controls. It is feasible to look at the increased state of adhesiveness/aggregation of erythrocytes, leukocytes and platelets present in their native milieu and following minimal manipulation by using an almost real time and low cost procedure.

The usefulness of telemedicine for the detection of infection/inflammation at the point of care.

The objective of this study is to examine the possibility of using Telemedicine to diagnose the presence of the inflammatory response and to assess its intensity at the point of care. One drop of citrated peripheral venous blood from 15 patients with infection/inflammation and 15 controls were used to prepare the slides. Unstained pictures were analyzed using a microscope, video camera and image analyzer (INFLAMETTM, Biovision, Tel Aviv, Israel). The jpg-compressed images were transferred via telephone to a physician in a remote location. A significant correlation was noted between the white blood cell count and the number of leukocytes per square mm by image analysis (r = 0.67 p < 0.0001 n = 30), between the degree of leukocyte adhesiveness/aggregation and the concentration of C-reactive protein (r = 0.42 p = 0.02 n = 29) and between the degree of erythrocyte aggregation and either fibrinogen concentrations (r = 0.73 p < 0.0001) or erythrocyte sedimentation (r = 0.83, p < 0.0001). No problems occurred during file transmission and there were no transfer errors. Physicians can successfully estimate the presence of an inflammatory response and its intensity using a simple slide test, image analysis, and Telemedicine technology.

The concomitant appearance of aggregated erythrocytes, leukocytes and platelets in the peripheral blood of patients with risk factors for atherothrombosis.

Risk factors for atherothrombosis including increased leukocyte count, hyperlipidemia, diabetes mellitus, hypertension as well as smoldering inflammation and hyperfibrinogenemia might affect the aggregability of peripheral blood erythrocytes, leukocytes as well as platelets. We have used a simple slide test and image analysis to reveal the presence of these aggregabilities obtained in one single drop of peripheral venous citrated blood in 48 individuals with risk factors for atherothrombosis. A significant correlation was noted between the state of adhesiveness/aggregation of all the above mentioned three cellular elements and the concentrations of total and LDL cholesterol. The correlation with triglycerides concentrations was more modest. A significant reduction of adhesiveness/aggregation was noted in 18 individuals following an intervention to reduce the concentration of cholesterol and triglycerides. This reduction might have a favorable hemorheologic effect. Our results are significant in that they show that it is possible to detect the above mentioned changes in whole blood, following a single step and minimal manipulations, at real time and low cost.

INFLAMET: an image analyzer to display erythrocyte adhesiveness/aggregation.

Background: Due to a lack of simple, inexpensive, and real-time methodology, the state of erythrocyte adhesiveness/aggregation is not measured in daily practice by most clinicians. Methods: We measured the state of erythrocyte adhesiveness/aggregation before and following the administration of intravenous high-dose gamma globulins in 18 patients with various autoimmune diseases using a simple slide test and image analysis system (INFLAMET). Results: A significant (P=0.01) increment in the state of erythrocyte adhesiveness/aggregation (from 2+/-3 to 8+/-9 arbitrary units) was noted in the entire study group despite a significant (P=0.008) decrement (from 350+/-97 to 323+/-127 mg%) in the concentration of fibrinogen and no significant change in the erythrocyte sedimentation rate (32+/-30 mm/h before and 35+/-29 mm/h following administration of gamma globulin). Conclusions: By using a simple slide test and image analysis, we were able to provide relevant rheological information that was not available from either of the routine indirect tests, i.e. the Westergren erythrocyte sedimentation rate and the concentration of fibrinogen.

Combined leukocyte and erythrocyte aggregation in the peripheral venous blood during sepsis. An indication of commonly shared adhesive protein(s).

We have used a simple slide test and image analysis to reveal the state of leukocyte and erythrocyte adhesiveness/aggregation in the peripheral blood of 28 patients with sepsis and 28 controls. A significant (P<0.00001) increment in both leukocyte and erythrocyte adhesiveness/aggregation was noted in patients compared with controls. Moreover, a significant (r=0.73, n=56, P<0.001) correlation was noted between the two adhesiveness/aggregation variables themselves, suggesting a common mechanism responsible for these adhesive phenomena. The significant correlation with fibrinogen suggests that this protein might be such a "non-specific glue." Our results indicate that a simple slide technique and image analysis can assess the aggregability of both white and red blood cells in septic patients. This might have clinical application when interventions to reduce cell aggregability are planned in order to improve blood flow in the microcirculation.

Correlated expression of adhesive properties for both white and red blood cells during inflammation.

The state of leukocyte and erythrocyte adhesiveness/aggregation was determined in the peripheral blood of 382 patients with infection/inflammation as well as in 72 controls by using a simple slide test and image analysis. A highly significant correlation (r = 0.4, n = 455, p < 0.001) was found between the state of leukocyte and erythrocyte adhesiveness/aggregation. The extent of both leukocyte and erythrocyte aggregation correlated with the concentration of fibrinogen. Significant aggregation of leukocytes with erythrocytes was noted as well. We conclude that both leukocyte and erythrocyte aggregation occur in the peripheral blood of patients with infection/inflammation. Such cell aggregation, which might have detrimental rheological consequences, can be detected by using our novel technique.