Plasmapheresis

Plasmapheresis. The separation of plasma from whole blood by continuous membrane filtration represents an improvement over conventional centrifugation techniques in terms of efficiency, safety and cost. In the past, plasmapheresis was carried out with blood donors by collecting their whole blood in plastic bags which were then centrifuged to separate the red cells from the plasma. The supernatant plasma was then decanted and the red cells returned to the donorenabling plasma to be drawn from the same person as frequently as three times per week. Most of this plasma is then processed to yield purified components such as albumin or anti-hemophilic factor (Factor VIII). 

Continuous flow plasmapheresis is a superior alternative. Whole blood is continuously withdrawn from the donor and red cells are returned while plasma is continuously removed. There are two major advantages  

Continuous flow centrifuges are now available with disposable rotating bowls. However, these devices are expensive and quite complex, requiring the attendance of skilled personnel during operation. Cross-flow filtration (CFF) is potentially a less expensive and simpler separation tool for continuous plasmapheresis. Large scale plasmapheresis of animal blood is also facilitated by CFF. 

The early attempts at membrane filtration of blood were disappointing. Stirred-cells were used to reduce the accumulation of blood cells on the membrane, but the stirring hemolyzed the red cells and the flux was low even at high stirring rates. 

Though most of the applications for plasmapheresis are medically related, some of the larger pharmaceutical houses are beginning to process pooled animal blood in a similar way but on a larger scale. The cellular components and the plasma are then processed separately to obtain the desired final products. 

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G. MyUyla, "Whole Blood and Plasma Procurement and the Impact of Plasmapheresis," in Ref 2. 

Plasma Collection. Human plasma is collected from donors either as a plasma donation, from which the red cells and other cellular components have been removed and returned to the donor by a process known as plasmapheresis, or in the form of a whole blood donation. These are referred to as source plasma and recovered plasma, respectively (Fig. 1). In both instances the donation is collected into a solution of anticoagulant (146) to prevent the donation from clotting and to maintain the stabiUty of the various constituents. Regulations in place to safeguard the donor specify both the frequency of donation and the volume that can be taken on each occasion (147). 

Procedures for the collection of whole blood are similar throughout the world. An interval from at least 8 weeks (United States) to 12 weeks (United Kingdom) is required between a donation of 450 mL blood, which yields about 250 mL plasma. In some countries a smaller volume of blood is collected, eg, 350—400 mL in Italy, Greece, and Turkey and as Httie as 250 mL in some Asian countries (147). Regulations concerning plasmapheresis donations vary more widely across the world eg, up to 300 mL of plasma can be taken in Europe in contrast to 1000 mL in the United States, both on a weekly basis. Consequentiy, both the mode of donation and the country in which it is given can have a profound effect on plasma collection (Table 6). 

Mononeuropathy multiplex (MM) is an infrequent complication that can occur in early HIV infection, because of dysimmune or vasculitic mechanisms (Gherardi et al. 1989 Chamonard et al. 1993 Bradley and Verma 1996 Schifitto et al. 1997 Mahadevan et al. 2001). Seroconversion-related MM has been described in a case report (Sngimoto et al. 2006). Most of these patients have a good prognosis as symptoms resolve spontaneously and treatment may not be necessary. In others, treatment has focused on intravenous immunoglobulin, judicious short-term use of steroids, and a combination of zidovudine and plasmapheresis (Chamouard et al. 1993 Cohen et al. 1993 Bradley and Verma 1996 Schifitto et al. 1997). 

Also known as antibody-mediated rejection, humoral rejection is the process of creating graft-specific antibodies.1,4 This type of rejection occurs less frequently than cell-mediated acute rejection. Humoral rej ection is characterized by deposition of immunoglobulins and complement in allograft tissues. Treatment for this type of rejection is not well defined, yet several reports have shown that treatments such as plasmapheresis, immunoglobulin therapy, rituximab, and/or antithymocyte globulin maybe effective. 

Plasmapheresis A process of separating blood cells from plasma. This process is used to remove monoclonal antibodies from the blood. 

Refsum s disease is an autosomal recessive peroxisomal disorder characterized by accumulation of phytanic acid and other 3-alkyl-branched fatty acids [55]. Patients develop hypertrophic demyelinative polyneuropathy, retinitis pigmentosa, ichthyosis and deafness. The disorder can be successfully treated by institution of a diet poor in phytanic acid, in conjunction with plasmapheresis to remove circulating phytanic acid. 

Most, and possibly all of these changes result from the tissue accumulation of phytanic acid. Phytanic is of dietary origin exclusively, and dietary restriction of phytanic and plasmapheresis are of clinical benefit. The defective gene and pathogenic mutations have been identified. The clinical manifestations can also be mimicked by defects of PEX7. 

General supportive measures, including acetaminophen as an antipyretic (aspirin or other nonsteroidal antiinflammatory drugs may displace bound thyroid hormone), fluid and electrolyte replacement, sedatives, digoxin, antiarrhythmics, insulin, and antibiotics should be given as indicated. Plasmapheresis and peritoneal dialysis have been used to remove excess hormone in patients not responding to more conservative measures. 

Plasmapheresis induces impressive reduction of Lp(a) levels and seems a very effective procedure (RIO). 

Treatment with guanidine may produce clinical improvement within 3 to 4 days. Side effects include paresthesia, gastrointestinal distress, renal tubular necrosis, and hyperirritability. The most serious effect is bone marrow depression, which is dose-related and potentially fatal. Aminopyridines have been used in clinical studies with some positive results. Corticosteroids and plasmapheresis may also be of some benefit, whereas anticholinesterase agents are only marginally effective. 

Keywords Laparoscopy Acute pancreatitis Plasmapheresis Oral sorption... 

In order to remove the endogenous toxicosis, we have applied various methods of detoxification in 22 patients. In 14 cases, one or two sessions of plasmapheresis were performed. Biochemical markers used for determining the level of toxemia were middle molecules . In six cases, against the background of intensive care, oral sorption (enterosorption) was administered 2-3 days after operative intervention. 

Plasmapheresis and Laser Therapy in Complex Treatment of Myasthenia and their Influence on Erythrocytes and Endothelium... 

Keywords Plasmapheresis Laser therapy Myasthenia Ultrastructure... 

Efferent methods of detoxification snch as haemosorption (haemoperfnsion), plasma sorption (plasma perfnsion) and plasmapheresis are the most effective ways to eliminate antibodies from the blood at myasthenia. Among these methods plasmapheresis is the preferred choice [3],... 

Fig. 30.4 Various forms of erythrocytes in Thick Drop at different conditions. (1). Control. Domination of discocytes in peripheral blood. 10x40. (2). Myasthenia. Nnmerons pathological forms of erythrocytes. 10x40. (3). Increase of the nnmber of pathological forms of erythrocytes after plasmapheresis. 10x40. (4). Decrease of the nnmber of pathological forms of erythrocytes after ELBI. 10x40...

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