Single-needle thrombo-cytapheresis with the Fresenius AS 104.

BACKGROUND: The Fresenius AS 104 cell separator has recently met some popularity in European apheresis units for the quality of the platelets obtained with the totally automated double-needle procedure. MATERIALS AND METHODS: Taking advantage of the machine's flexibility we have developed a new automated procedure for single-needle thrombocytapheresis (SNP). So far 61 SNP were carried out. From donors having a platelet precount of 2.74 x 10(5) an average of 3.8 x 10(11) cells were collected by processing 2.5 liters of blood in a run time of 83 min. RESULTS AND CONCLUSIONS: The leukocyte and erythrocyte contaminations were 2.7 x 10(7) and 3.5 x 10(7), respectively. Only 2 products did contain less than 3.5 x 10(11) platelets, and 7 procedures were complicated by minor signs of hypocalcemia. With minor modifications this SNP is presently offered on a routine basis to our platelet donors.

Apheresis for severe malaria complicated by cerebral malaria, acute respiratory distress syndrome, acute renal failure, and disseminated intravascular coagulation.

Malaria has become a very uncommon disease in Italy. Recently a variety of circumstances, such as travel to tropical countries as well as immigration from Asia and Africa, have combined to increase the number of malaria cases recorded annually. In this report we describe the use of red cell exchange transfusion and plasma exchange in the treatment of a patient with hyperparasitemic malaria (51% erythrocytes or more parasitized). When first observed the patient was in shock and had signs of cerebral malaria, disseminated intravascular coagulation, and acute respiratory distress syndrome, which in the following 2 days were complicated by acute renal failure. After mefloquine therapy combined with 3 red blood cell exchanges, 2 plasma exchanges, and 10 dialysis sessions over 14 days, the patient recovered completely. This case of severe malaria with multiple complications, treated with mefloquine in conjunction with both exchange transfusion and plasmapheresis, had a successful outcome and lends further support to the possible beneficial role of exchange transfusion in complicated malaria.

Plateletpheresis with the new Fresenius AS 104 blood cell separator.

Among the many blood cell separators introduced into the international market in these last few years, the Fresenius AS 104 represents an advanced and safe thrombocytapheresis machine whose development took advantage of extensive worldwide experience with blood cell separation. Nonetheless the AS 104 has generated most interest in West Germany and most, if not all, the studies published on its platelet collection efficiency have been carried out in that country. It is normally reported that from 2.7 to 3.5 x 10(11) platelets can be collected in approximately 80 minutes. Since these results could not be duplicated routinely in our hemapheresis unit, we set up a study by modifying the standard procedure. It was possible to reduce the procedure time and to collect platelet concentrates containing more than 4 x 10(11) cells on a routine basis by using the following procedure: ACD-A/blood ratio 1:10; Interface position 6:2; blood flow rate always exceeding 65 mL/min; rpm 1750; cell collection from 4 to 7 mL/min; volume of blood processed 3.6 L followed by the rinsing of the system with 200 ml of saline; extraction of the content of the secondary separation chamber by the action of the plasma pump working at 20 mL/min for 2 min. With this procedure the platelet yield in 34 collections exceeded 3.1 x 10(11) and averaged 4.06 x 10(11). The procedure time was reduced to 56.5 minutes with a mean blood flow rate of 62.3 mL/min. The leukocyte and erythrocyte contamination of the products were in the range of 1 x 10(7) and 1 x 10(8) respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Cyclosporin-induced hypertriglyceridemia with prompt response to plasma exchange therapy.

A case of severe cyclosporin-induced hypertriglyceridemia that prompted plasma exchange therapy is reported. Hyperlipemic retinitis, headache, stupor, and peripheral paresthesias became apparent when the level of triglycerides exceeded the 1,500 mg/dL level. Two plasma exchanges were required to halt disease progression. This is the second time that plasma exchange was used in a bone marrow transplanted patient on cyclosporin-A therapy. In both cases hypertriglyceridemia became apparent and symptomatic after approximately 7 months of therapy with cyclosporin.

Cascade filtration with reverse rinse of the secondary filter.

With cascade filtration (CF) secondary filter plugging may render some procedures difficult, particularly with cryoglobulinemia or macroglobulinemia patients, when filters are subjected to the most consistent burden. To prevent plugging, in the initial management of seven patients with cryoglobulinemia or macroglobulinemia we employed polymethylmethacrylate secondary filters produced by Toray Industries Inc., Tokyo, with pores calculated at 0.1 micron (QS-12-70). In the subsequent sessions, when circulating macroproteins were reduced to more acceptable levels, secondary filters with pores of 0.06 micron were used (QS-12-50). The filtration efficiency of both filters was maintained throughout the procedures with reverse rinses carried out when the transmembrane pressure from the values of 80-130 mm Hg reached the values of 250 mm Hg. With this improved technique, 2.6-3.31 liters of plasma could be treated, producing adequate clinical benefits. From a laboratory point of view, the differential sieving for albumin and macroglobulins was 61% for the QS-12-50 filters and 56% for the QS-12-70 models.

Preparation of small volume, leuko and erythrocyte very poor platelet concentrates.

Recently developed automated discontinuous flow centrifuge (DFC) separators can produce leuko- and erythrocyte-poor platelet concentrates (PC). According to general experience with these machines it is difficult to obtain more than 4 X 10(11) platelets, though a second program set up by Coffe et al. appears to produce PC containing approximately 5 X 10(11) platelets suspended in a plasma volume of 390 ml. At our center we employed a new Dideco cell separator equipped with the surge pump and a technique developed for the production of small volume, RBC and WBC-very poor PC. In 60 routine procedures we obtained the following results: mean processing time 87 +/- 11 minutes; final volume of PC 136 +/- 19 ml, with a mean platelet yield of 5.21 X 10(11) platelets. WBC contamination was 1.8 X 10(8) (93% lymphocytes) and RBC were 3.1 X 10(8). Plasma volume as well as WBC and RBC contamination were reduced by recirculating PC after the 6th pass. The demand for single donor platelet concentrates (PC) is increasing progressively. Recently developed automated cell separators can produce leukocyte (WBC) and erythrocyte (RBC) poor PC. With these machines it may be difficult to obtain PC containing at least 4 X 10(11) platelets and less than 1 X 10(9) leukocytes (1, 2, 3) since donor variables such as hematocrit, precounts, buffy coat formation and initial plasma light transmission are of paramount importance for the efficiency of the program. At our center a prototype discontinuous flow centrifuge (DFC) cell separator equipped with the surge pump was studied.(ABSTRACT TRUNCATED AT 250 WORDS)