A Method for Evaluation of Membrane Permeability for Water by the Erythrocyte Osmotic Deformability Profiles

Comprehensive study of the rheological status and intensity of oxidative stress during the progression of type 2 diabetes mellitus to prevent its complications

BACKGROUND

Prevention of Type 2 diabetes mellitus (T2DM) requires a modifying effect on the pathological processes inducing the β-cell dysfunction.

OBJECTIVES

the comprehensive study of the violation of rheological parameters in patients with different stages of diabetes and identification of possible links between these alterations with the intensity of the oxidative stress in the patient's body.

METHODS

60 patients with IR, prediabetes, T2DM and healthy volunteers were included. Full range of the rheological parameters of the patients' blood - the indicators of erythrocytes aggregation index (EAI), the relative deformability of the erythrocytes membranes (ERDI), blood plasma viscosity (BPV), and oxidative stress intensity (OSI) were examined.

RESULTS

In patients with insulin resistance (IR), prediabetes, and T2DM the ERDI was statistically significantly lower and BPV - higher compared to control; a significant increase in EAI was detected in the patient group with prediabetes and T2DM compared to the control.

CONCLUSION

The level of rheological disorders in patients increases with the increase of the level of carbohydrate metabolism disorders and intensity of oxidative stress and reaches a maximum during manifested diabetes. Diagnosis of hemorheological disorders and OSI in T2DM can serve as an early marker of target organ damage possibility.

Dynamics of Deformation Properties of Erythrocytes in Wistar Rats during Postnatal Ontogeny

We performed a detailed analysis of changes in the profiles of osmotic deformability using the method of gradient ektacytometry. Changes in all determinants that form the deformation properties of red blood cells in Wistar rats in the juvenile period and before puberty were determined. The dynamics of the formation of the rheological properties of the blood after birth is characterized by a wave-like change in the studied determinants. The changes are explained by adaptive reactions to extrauterine life as a result of hematopoiesis activation and the transition of the red bone marrow to a new level of functioning with the predominant replacement of physiological reticulocytosis in newborns with mature erythrocytes. The most critical period is from 10 days to 1 month after birth. Starting from the second month, the deformation parameters of erythrocytes are stabilized.

Next-generation osmotic gradient ektacytometry for the diagnosis of hereditary spherocytosis: interlaboratory method validation and experience

Background:

Osmotic gradient ektacytometry is part of the laboratory diagnosis process of hereditary spherocytosis (HS) and other red blood cell (RBC) membrane disorders. We here present the experience of two independent institutions with a next-generation ektacytometer, the LoRRca MaxSis analyzer, in HS diagnostic settings.

Methods:

Inter- and intra-assay variability and sample stability were analyzed. Samples from patients with HS (n=40), probable HS (n=21), auto-immune hemolytic anemia (n=7), and other pathologies (n=37) were studied. Daily controls were run in parallel with patient samples. Results were expressed as percent of change compared to mean of controls.

Results:

Analytical performances showed an inter-assay variability between 0.2% and 3%. Samples were stable for 48–72 h depending of temperature storage and anticoagulant used. The following diagnostic cut-offs were established for HS: an increase of more than 21.5% for the osmolality point at the minimal elongation index (O min), a decrease of more than 8.5% for the maximal elongation index (EI max), and a decreased area under the curve (AUC) of more than 18.5% compared to the mean of controls.

Conclusions:

As the previous instrument, the next-generation ektacytometer is an efficient tool for laboratory diagnosis of HS. Sample stability and standardized reporting of results allow inter-laboratory exchange and comparison. The most useful parameters for HS diagnosis were AUC, EI max, and O min; unfortunately, this method does not differentiate between HS and auto-immune hemolytic anemia (AIHA), but it distinguishes HS from other hereditary membrane pathologies. It can thus be considered as an intermediate step between screening and diagnostic tests.

The impact of fist clenching and its maintenance during venipuncture on routine hematology testing

BACKGROUND

Prevention of a disturbance of the blood vessel allows phlebotomists to collect a blood specimen by venipuncture that will truly mirror the patient condition. This study was aimed to evaluate the impact of repeated fist clenching and maintenance of the fist during blood collection by venipuncture for routine hematology testing.

METHODS

Blood were collected from 16 healthy volunteers with two separate sequential procedures, entailing standard venipuncture with hand opened throughout blood collection, or clenching the fist six times before venipuncture and maintaining the fist until completion of blood collection. The parameters tested included red blood cell (RBC) count, hemoglobin, hematocrit, mean corpuscular volume (MCV), RBC distribution width, white blood cell count and differential, including neutrophils, lymphocytes, monocytes, eosinophils, basophils, large unstained cells, platelet count, mean platelet volume, and reticulocytes. The results were reported as median and interquartile range. The comparison of data obtained with the two different venipuncture procedures (i.e., with or without fist clenching and closed hand) was performed with Wilcoxon-Mann-Whitney ranked-pairs test. The degree of statistical significance was set at P<.01.

RESULTS AND CONCLUSION

Fist clenching and maintenance during blood collection for routine hematology testing was effective to increase the MCV by 1.2% (P<.001). All others hematological parameters were not significantly biased by fist clenching, though hematocrit, neutrophils, eosinophils, and reticulocytes displayed mindful of trends. We hence advise patients against clenching their fist before blood collection for hematology testing.