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In autoimmune haemolytic anaemia, the presence of antibodies on the erythrocyte membrane results in haemolysis through an immune process, but does it not alter the rheological properties of red blood cells (RBC), thus adding a mechanical factor to haemolysis? This study was designed to examine the rheological properties of erythrocytes sensitized with IgG-type antibodies. The study involved 20 patients with anaemia and positive direct antiglobulin test, including 12 with straightforward haemolysis, 10 samples sensitized in vitro, and 20 controls. The following haemorheological parameters were studied: erythrocyte filtration, blood and plasma viscosities, titration of adenosine triphosphate (ATP) and 2-3-DPG, erythrocyte morphology under scanning electron microscopy. The results showed increased erythrocyte rigidity (P less than 0.025) as well as higher blood viscosity compared to controls with similar haematocrit values, and unaltered ATP and 2-3-DPG (consistently with scanning electron microscope observations). These haemorheological disorders were more noticeable in patients with clear-cut haemolysis, and there was a correlation between the increase in erythrocyte rigidity indices and the haemolytic parameters, especially haptoglobin (P less than 0.001). The in vitro study confirmed the results obtained ex vivo. To conclude, the mechanical properties of antibody-coated erythrocytes are impaired, which may promote the immunological mechanism favouring haemolysis in the spleen.

Hemorheological parameters were studied in 218 subjects: 129 alcoholic liver diseases, 19 alcoholic patients without liver damage, 20 liver diseases without alcoholism and 50 controls. Whole blood filtration (WBF) is significantly decreased in the group of alcoholic patients; whole blood and plasma viscosity are increased in the groups of alcoholic patients as well as in the group of non alcoholic liver diseases. The liver damage seems not to be a determining factor to the genesis of filterability impairment. Alcohol and/or one of its metabolites induce erythrocytes morphological alterations (scanning electro-microscopy) correlated with some alterations of the RBC membrane lipids content (increased cholesterol/phospholipids ratio). It is suggested that these hemorheological patterns must be discussed in cases of alcoholic liver diseases as well as in following up alcohol withdrawal.

The authors have tested a new device that records the filtration pressure of a suspension of red blood cells (R.B.C.) passing through a 3 micron pore diameter filter. As the flow rate is constant, the pressure increase allows to appreciate an index of the R.B.C. deformability. In order to test the performances of this new equipment, the authors have studied the influence of the variation of the following parameters. Haematocrit from 0.5 to 2%, Buffer composition; time elapsing from drawing to measurement: from hour 0 to hour 3. This analysis has been performed on donors; on packed red cells preserved in CPD, from D0 to D21 and on patients specimens and the results have been compared to the whole blood filtration according to the Reid and Dormandy method. The following parameters were simultaniously measured: Whole blood viscosity by means of a Low Shear 30 viscosimeter, Intraerythrocyte ATP by bioluminescence, Membrane lipid composition (cholesterol, phospholipids), Scanning electron microscopy. This new apparatus, measuring the filtration pressure seems to be a more sensitive and reproductible method allowing to approach the RBC deformability, and quite usefull in clinical haemorheology.

A study was made of storage lesions of packed red cells stored in different preservative media: CPD, CPD-adenine, CPD-SAG, and CPD-pentoxifylline. The following chemical and physical parameters were studied: filterability, viscosity, ATP, 2-3,DPG pH, osmotic fragility, scanning electron microscopy pattern, blood gas levels. Tests were performed on days 0, 2, 4, 8, 16 and 24. The number and intensity of storage lesions in vitro give an indication of changes in oxygen-delivery capacity and flow characteristics of erythrocytes over a period of storage at 4 degrees C in different preservative media. CPD was found to maintain pertinent RBC properties up to Day 15. Adding adenine made little difference, whereas adding SAG gave better results. Pentoxifylline did not show appreciable effects in the initial concentrations used, which were close to those employed in medical practice. A preservative mixture ensuring maintenance of normal blood values during storage at 4 degrees C has yet to be found. Continued study of pentoxifylline should be conducted using higher concentrations of this additive.

Hybridomas secreting anti-mouse macrophage antibodies were obtained by fusing a routine plasmacytoma with lymphocytes of a rat immunized against mouse macrophages. An IgM, monoclonal antibody (3 A 35) reacted with mouse monocytes, macrophages and polymorphonuclear leucocytes. It did not bind appreciably to erythrocytes, platelets and unstimulated T or B lymphocytes. However, 3 A 35 bound to various murine T-derived leukaemic cells and to a small proportion of Con A-stimulated thymocytes. Cross absorption experiments confirmed the existence of a common antigenic determinant on macrophages and leukaemic cells. The possiblility that 3 A 35 identified a previously described antigen common to macrophages and normal or leukaemic T cells was investigated. The antibody was tested against thymocytes and macrophages of various mouse strains, some congenic for H-2 or Tla. The 3 A 35-detected antigen was found to be different from Ly5, Tla and Qa and did not represent a I-J encoded allotypic specificity. [ABSTRACT FROM AUTHOR]