White cells

A method for the fractionation of plasma, allowing albumin, y-globulin, and fibrinogen to become available for clinical use, was developed during World War II (see also Fractionation, blood-plasma fractionation). A stainless steel blood cell separation bowl, developed in the early 1950s, was the earhest blood cell separator. A disposable polycarbonate version of the separation device, now known as the Haemonetics Latham bowl for its inventor, was first used to collect platelets from a blood donor in 1971. Another cell separation rotor was developed to faciUtate white cell collections. This donut-shaped rotor has evolved to the advanced separation chamber of the COBE Spectra apheresis machine. 

Each component of blood has a function ia the body. Red cells transport oxygen and carbon dioxide between the lungs and cells ia the tissues. White cells function as defense of the body. Platelets are important for hemostasis, ie, the maintenance of vascular iategrity. Plasma, an aqueous solution containing various proteias and fatty acids, transports cells, food, and hormones throughout the body. Some proteias ia plasma play a role ia clotting, others are messengers between cells. 

The red cells also may be filtered to reduce the white cell content. This technique is needed if there is a chance of the patient developing graft versus host disease (GvHD), ie, transfused white cells attack the cells of the patient. 

White cell contamination of a platelet product can induce GvHD. It is beUeved that GvHD can be minimized by a contamination of less than 5 X 10 white cells per therapeutic dose of platelets, ie, 3-5 x 10. Blood cell separation technology is directed toward consistentiy achieving this goal. 

Beckman Elutriation Method. The Beckman elutriation method uses a chamber designed so that the centrifugal effect of the radial inward fluid flow is constant (Fig. 3). The separation chambers are made of transparent epoxy resin which faciUtates observation of the movements of the cell boundary in strobe light illumination. This enables detection of the radius at which the cells are separating. When a mixture of cells, eg, mononuclear white cells, enters the chamber, separation can be achieved by fine tuning centrifuge speed and inward fluid flow to the specific cell group. This is a laboratory method suitable for relatively small numbers of cells. Chambers are available in sizes to handle 2-3 x 10 , 1 2 x 10 , and 1 x 10 ° cells. The Beckman chambers can be appHed to collect mononuclear cells from bone marrow aspirates. 

The special design of the Latham bowl allows for a specific blood cell separation known as SURGE. This technique makes use of the principle of critical velocity. The Latham bowl is filled until the huffy coat, ie, layer of platelets and white cells, moves in front of the bowl optics. At this point the machine starts to recirculate plasma through the bowl at increasing rates. The smallest particles, ie, platelets, ate the first to leave the bowl. Their high number causes the effluent line to turn foggy. The optical density of the fluid in the effluent line is monitored by the line sensor. A special algorithm then determines when to open and close the appropriate valves, as well as the optimum recirculation rate. 

Filtration Filtration (qv) is appHed in blood cell separation to remove leukocytes from ted blood cell (RBC) and platelet concentrates. Centtifugational blood cell separators do not reduce white blood cells (WBC) in red cell and platelet products sufficiently to avoid clinical complications such as GvHD and alloimmunization. A post-apheresis filtration step is needed to further reduce the WBC load. Modem filters are capable of a 3-log reduction in white cell contamination of the blood product, eg, apheresis single-donor platelet units having a typical white cell contamination of 5 x 10 white cells in 4 x 10 platelets can be reduced to a 5 x 10 white cell contamination, a sufficiently low number to avoid severe transfusion reactions. 

The white cell adsorption filter layer is typically of a nonwoven fiber design. The biomaterials of the fiber media are surface modified to obtain an optimal avidity and selectivity for the different blood cells. Materials used include polyesters, eg, poly(ethylene terephthalate) and poly(butylene terephthalate), cellulose acetate, methacrylate, polyamides, and polyacrylonitrile. Filter materials are not cell specific and do not provide for specific filtration of lymphocytes out of the blood product rather than all leukocytes. 

Cell Activation. Several studies have shown that platelets and white cells undergo shape changes when adhering to filter media. The cells are activated by contact with the filter media and form pseudopods which attach to the filter media. The cells membranes may need a certain degree of viabihty to be able to actively attach to the filter media. When white cells are treated with metaboHc inhibitors, the capabiUty of leukocyte reduction by the filter is reduced. 

Technologies to purify cells from white cell concentrates are in the research stage. Principles used include antibodies covalently bound to a surface, antibody-coated microbeads in a column, magnetic microparticles that have been coated with antibodies, and hoUow fibers that have been coated with antibodies. 

Dactinomycin, an antineoplastic dmg, was discovered in 1943 and is made in rather pure form by StreptomjcesparvuUus. Dactinomycin has some bacteriostatic antibacterial and antifungal activity, but high toxicity limits its use to antineoplastic therapy. It may be used alone or with other antineoplastics, with or without surgery and synergistic x-ray therapy. Dose limiting bone marrow toxicity may result in low white cell and platelet count. Intestinal mucosal damage also occurs. Reviews of more detailed chemotherapeutic information are available (217—222). 

The basic aperture impedance method can produce three-part white cell differential counts. Impedance counters can distinguish three white cell types by size the LYMPHS, mid-range cells including MONOS and BASOS, and granulocytes including NEUTS and EOS. 

No clinical effects but small depletions in normal white cells count and in platelets likely within 2 days. 

Lackie, J.M., Wilkinson, P.C. (1984). Adhesion and locomotion of neutrophil leukocytes on 2-D substrata and in 3-D matrices. In White Cell Mechanics Basic Clinical Aspects (Meiselman, H.J., Lichtman, M.A., LaCelle, P.L., eds.), pp. 237-254. Alan R. Liss, New York. 

Cardio Gastro Hemato 260 M 260 M (elevated hemoglobin and white cell count) 260 M (biood pressure drop) ... 

Hematological Effects. Leukocytosis and decreased platelet counts were reported in a group of subjects shortly after they ingested an unknown amount of endosulfan (Blanco-Coronado et al. 1992). One subject from that study, who eventually died, had prolonged partial thromboplastin time and prothrombin time with thrombocytopenia, and decreased fibrinogen two days after being admitted to the hospital. Elevated white cell count was also observed in an additional case of fatal acute poisoning with... 

Hydrocortisone microspheres (108,109) and films (110) based on poly(lactic acid) have been investigated. A cage implant technique was used to study the performance of monolithic poly (DL-lactide) films loaded with hydrocortisone acetate (110). Films 1.5 x 0.6 cm were inserted into titanium wire-mesh cages 3.5 x 1.0 cm. The cages were implanted in the backs of rats and the inflammatory exudate was sampled periodically. The white cell concentration in the samples was lower than that of controls at all times during the 21-day test. 

Figure 2.60 Pictorial representation of the SLIC scheme showing the updating scheme for an upwind and a downwind cell. Cells filled with fluid 1 are indicated in gray, those with fluid 2 in white. Cells containing a mixture of both fluids are represented by hatched areas. In the right column the configuration at the new time step is shown, with interface positions depicted explicitly.

Urinalysis Midstream urine is analyzed microscopically for white blood cells and bacteria Urine should have no white cells or bacteria in it Urine with white cells and bacteria is suggestive of inflammation and infection if positive, urine is sent for bacteriologic culture... 

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