DD293267B5 - Filter for selective leukocyte elimination - Google Patents

Abstract

Filter for selective elimination of leucocytes from blood, blood preparations or other leucocyte-contg. biological liq. comprises a sieve-like filter base and as column packing an adsorbent made from a framework of plant cell-walls. USE/ADVANTAGE - The method is esp. useful in transition medicine and haematology (removal of leucocytes avoids problems of non-haemolytic febrile reactions). It is simple and economical and the compsn. of the cellular and acellular blood components is not changed by passage through packing. The removal of leucocytes from preserved blood is over 90% and erythrocyte recovery about 10% (without any loss of viability or function).

Description

Methods WBC residual content I - % Zeitl. costs (US- of apparatus 7 expenditure Dollar) expenditure (χ ю ^э / і; 0.50 (Min) 16 * with NaCl washing processes 35 45 Cell washing centrifuge 0.65 32 refrigerated centrifuge * after cryopreservation 0.55 35 60 Cell washing centrifuge 0.00 17 2 refrigerated centrifuge * "Reverse centrifugation" 0.00 0 45 7 refrigerated centrifuge * Pall filter (spin-cool) 0 250 25 refrigerated centrifuge * Erypur filter 45 16 filter * Sepacell filter 20 filter

DE-AS 1 928 052 describes a method for removing storage-modified constituents from stored blood in which the blood comes into contact with a filter which constitutes a compressible fiber mass. This pulp has a large surface area, has a density of 0.1 to 0.4 g / cm ³ and the average fiber diameter is less than 60 microns.

From DD 263 921 a method for the separation of low molecular weight compounds from the blood is known in which the cellular blood components including the leukocytes pass without elimination through a pack of plant cell wall scaffolds. For this process, large vesicular fillers, which are made from the sprouts of the duckweed Wolffia arrhiza, used, resulting in relatively large flow channels.

Object of the invention

The object of the invention is an effective and economical device for the selective elimination of leukocytes from blood and blood preparations or other biological fluids.

Explanation of the essence of the invention

The invention has the object to develop a device for the selective elimination of leukocytes from blood and blood preparations or other biological fluids.

According to the invention the object is achieved in that the filter device is filled with an adsorbent from plant cell wall scaffolds in a simple or cascade-shaped package and is saturated before use with a buffer solution and an anticoagulant substance.

The adsorbent consists of a sieve-like filter bottom and a column packing. The column packing contains an adsorbent of cell wall scaffolds derived from the 0.1 to 0.2 mm cell aggregates of a plant cell suspension culture.

Blood or blood preparations are connected to the prepared filtration pack and passed continuously through the filtration material. The filtration is terminated only when the filtration volume reaches a multiple of the packing volume. The composition of the remaining cellular and / or acellular components is not significantly altered upon passage of the column packing.

The elimination of leucocytes from canned blood is surprisingly> 90% after passing through the filter. The recovery rate for erythrocytes is approximately 100%.

The biological compatibility of the used plant cell wall scaffolds is proven. Simple in vitro tests showed that the erythrocytes after filtration showed no limitations on life and functioning.

embodiments example 1

The random packings of Chenopodium album prepared by method DD 246 920 A1 suspension cells have an irregular and approximately isodiametric shape and a size of 0.1 to 0.4 mm.

The finished filling material was saturated in a Sörensen's phosphate buffer solution (0.066 mol / l, pH = 7.0) with the addition of 500 IU of heparin per 100 ml of buffer and filled into a column of siliconized gas. The final volume of the packed body was 8 ml. A blood bag (Human RBC concentrate, ARp 08/30/03) was connected through this filtration pack so that the packed RBC flowed continuously through the filtration pack by gravity.

The filtrate was collected fractionally and analyzed. The number of erythrocytes, leucocytes and platelets was determined by Coulter Counter in the erythrocyte concentrate and after filtration.

After an elution volume which corresponds to the dead volume of the filtration pack of vesicular plant packings (= 50% of the pack volume), an equilibrium is established in the cellular composition of the filtration material.

Table 2 shows the results of filtration of human erythrocyte concentrate.

Table 2

Comparative determination of hematological parameters in the human erythrocyte concentrate before and after simple passage of the filtration pack (WBC = leucocytes, PLT = platelets, RBC = erythrocytes, HB = hemoglobin, PCV = hematocrit, MCV = mean erythrocyte volume, MCH = mean HB content of the individual erythrocyte , MCHC = mean corpuscular HB concentration).

parameter (GPVI) before passage after passage % Elimination WBC (Gpt / D 4.1 0.5 87.8 PLT (Tpt / I) 64.0 3.0 95.3 RBC (Mmol / l) 6.93 7.22 HB 13.3 13.7 PCV (Fl) 0,619 0.653 MCV (Fmol) 90.1 90.4 MCH (Mmol / l) 1.92 1.90 MCHC 21.4 21.0

These hematological parameters remain constant even after filtration of a blood cell suspension whose volume is 3 times the volume of the package. Only then is there a slow increase in leukocyte concentration in the filtrate, which suggests a depletion of the elimination capacity of the filling material.

Example 2

The starting material for the filtration pack is the same material from plant cell wall scaffolds as used in Example 1. In order to increase the degree of elimination of leukocytes and to prevent a slowing down of the flow through the filter, a cascaded device was used.

For this purpose, the column pack was placed so that freshly drawn whole blood, heparinized, healthy blood donor was filtered through a two-piece, sequential pack of packing (each part of the pack had a volume of 3.0 ml).

The results of this filtration are shown in Table 3 (The determination of hematological parameters is analogous to Example 1.).

Table 3

Comparative determination of hematological parameters before and after cascaded filtration of heparin whole blood from healthy blood donors (abbreviations as in Table 2).

parameter Before passage Second attempt After passage Second attempt % Elimination Second attempt 1st attempt 6.6 1st attempt 0.4 I.Versuch 93.4 WBC (Gpt / I) 8.2 177 0.3 6 96.3 96.6 PLT (Gpt / I) N. G. 4.18 N. G. 5.0 N. G. RBC (TpVI) 4.75 8.40 3.83 10.6 HB (mmol / l) 9.01 0.390 8.49 0.501 PCV 0,435 2.01 0.344 1.97 MCH (fmol) 1.90 93.2 2.21 92.1 MCV (fl) 91.5 21.6 89.9 21.4 MCHC (fmol) 20.7 24.6

Leukocyte elimination using the filter achieves a leukocyte concentration of 0.3 χ 10 ⁹ / l which is below the maximum non-immunogenic dose and thus fully complies with the requirement of transfusion practice

 The use of such produced, leucocyte-poor blood and blood preparations in transfusion medicine and hematology has significant medical and economic effects, since with the help of these preparations in polytransfused patients NHFTR can be prevented or prevented by the transfusion of pure blood preparations of an alloimmunization. With respect to the known filters, the results obtained are approximately equivalent to leucocyte removal, and the plant cell wall scaffolds used as filtration material can be cheaper to produce.

Claims (1)

A filter for selective leukocyte elimination from blood, blood preparations or other biological leukocyte-containing fluids using an adsorbent of plant cell wall scaffolds comprising a sieve-like filter bottom and a column packing, characterized in that the column packing comprises an adsorbent of cell wall scaffolds selected from 0.1 to 0, 2 mm cell aggregates of a plant cell suspension culture emerged contains. Field of application of the invention The leukocyte-poor blood and blood preparations filtered through the filter are used for targeted hemotherapy in medicine and prevent a non-hemolytic febrile transfusion reaction (NHFTR) in the patient or prevent alloimmunization by transfusion. Characteristic of the known state of the art Part of the concept of blood component therapy (targeted hemotherapy) is the transfusion of pure blood as possible preparations to avoid in the transfusion an immunization of patients in the HLA and ΗΡΑ-system or to prevent existing antibodies of a NHFTR. According to consistent data in international literature, the maximum non-immunogenic dose is 0.25 χ 10 ⁹ WBC (threshold dose), for the prevention of NHFTR = 96% leukocyte elimination). The critical immunogenic dose is given as 0.002 χ 10 ⁹ leukocytes / l (threshold dose to prevent immunization = 99.9% leukocyte elimination). Numerous devices for the preparation of leukocyte-poor blood cell concentrates (overview in Tab. 1) are known, which reduce the total leukocyte count in the preparation with different effectiveness (elimination by 50-99%), the devices active principles such as density, density gradient separation, specific adsorption, selective osmotic Damage or cryoseelection or combinations of these methods. Removal of leucocytes by the methods described results in a 10-30% erythrocyte loss, which impairs the desired increase in hemoglobin in a transfusion with leukocyte-poor blood preparations prepared in this way. Table 1 Known devices and methods for reducing the total leukocyte count in red blood cell-containing preparations (according to Labmedica, Vol. 5, No. 3 [1988], p. 39-41)