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PubMed2002

Performance and costs of particle air filtration technologies.

This paper predicts the reductions in the indoor mass concentrations of particles attainable from use of filters in building supply airstreams and also from use of stand-alone fan-filter units. Filters with a wide efficiency range are considered. Predicted concentration reductions are provided for indoor-generated particles containing dust-mite and cat allergen, for environmental tobacco smoke (ETS) particles, and for outdoor air fine-mode particles. Additionally, this paper uses a simple model and available data to estimate the energy and total costs of the filtration options. Predicted reductions in cat and dust-mite allergen concentrations range from 20 to 80%. To obtain substantial, e.g. 50%, reductions in indoor concentrations of these allergens, the rate of airflow through the filter must be at least a few indoor volumes per hour. Increasing filter efficiencies above approximately ASHRAE Dust Spot 65% does not significantly reduce predicted indoor concentrations of these allergens. For ETS particles and outdoor fine-mode particles, calculations indicate that relatively large, e.g. 80%, decreases in indoor concentrations are attainable with practical filter efficiencies and flow rates. Increasing the filter efficiency above ASHRAE 85% results in only modest predicted incremental decreases in indoor concentration. Energy costs and total costs can be similar for filtration using filters with a wide range of efficiency ratings. Total estimated filtration costs of approximately $0.70 to $1.80 per person per month are insignificant relative to salaries, rent, or health insurance costs.

Air Movements↗
PubMed1976

Filtration of protein in the anti-glomerular basement membrane nephritic rat: a micropuncture study.

Production on an anti-glomerular basement membrane (anti-GBM) nephritis in the rat results in a 30-fold increase in glomerular membrane permeability to albumin. The concentration of albumin in glomerular filtrate, estimated from proximal tubular fluid samples, is ten times the normal value. Tubular reabsorption of albumin is not enhanced so that essentially the filtered load is excreted. A nephrotic syndrome develops rapidly. Total kidney glomerular filtration rate (GFR) is reduced to 40% of normal with a proportional reduction in filtration fraction. Glomerulo-tubular balance is maintained since proximal fractional reabsorption remains constant near control levels. Calculated efferent arteriolar plasma colloid osmotic pressure (COP) is about one-third normal. Sodium excretion, sharply curtailed in the first days of anti-GBM nephritis, returns to control values after the fourth postinjection day. Restoration of sodium balance despite reduced filtered load and constant proximal fractional reabsorption must be accomplished by adjustments at a distal site in the nephron.

Albuminuria↗
PubMed1981

Dependency of proximal tubular fluid transport on the load of glomerular filtrate.

In hydropenic rats, the reabsorption of glomerular filtrate by the proximal convoluted tubules was measured before and after reduction of its intratubular flow rate. Three different protocols were used. (1) In 26 tubules (14 rats), nephron glomerular filtration rate (SNGFR) was varied from 37.2 +/- 7.3 to 20.4 +/- 7.1 nl/min by microperfusing their loops of Henle at 0 to 5 nl/min and 40 nl/min, respectively. This 43% reduction of SNGFR was followed by a 36.0 +/- 23.3% reduction of volume reabsorption rate (P less than 0.001). Between both parameters a linear regression line can be calculated, which is given by y = 0.92 chi + 0.0017. (2) In 17 tubules (14 rats), SNGFR was altered again by feedback from 46.0 +/- 9.7 to 28.8 +/- 9.3 nl/min. The volume resorption from the first half of the proximal convoluted tubule was compared with the reabsorption in its late proximal segments, which were microperfused with proximal tubular fluid at a rate of 20 nl/min. The 36.8% reduction of SNGFR was followed by only a 28.2% reduction of volume reabsorption rate in the first half of the tubule. In the microperfused segments, however, reabsorption remained unaltered. (3) In 29 tubules (21 rats), at the midpoint of proximal convolutions, some of the tubule fluid was removed by a suction pump, and volume reabsorption rate in the late segments was compared with that in the early parts of this tubule, when SNGFR remained stable. The reduction of intratubular flow from 27.7 +/- 8.5 to 14.7 +/- 5.8 nl/min, which is 53% of control, were followed by a reduction of volume reabsorption rate in the late segment to 60.6% control. Between both parameters a regression line was calculated, which is given by y = 0.76 chi +/- 0.01. We conclude that the rate of volume reabsorption by the proximal tubule depends on its intratubular load of glomerular filtrate and, further, that this dependency accounts predominantly for the maintenance of glomerular tubular balance under conditions of hydropenia.

Absorption↗
PubMed1984

Foot process fusion and glomerular filtration rate in minimal change nephrotic syndrome.

Reduced glomerular filtration rate (GFR), not due to hypovolemia, has been reported in patients in the proteinuric phase of the minimal change nephrotic syndrome (MCNS). A group of children with MCNS was studied to investigate the possible relationship between the fusion of glomerular epithelial foot processes and the reduction in GFR. The degree of foot process fusion was estimated as the harmonic true mean of foot process width and the length density of epithelial slit pores as determined by quantitative electron microscopic stereology. In the patients investigated GFR ranged between 40 and 127 ml/min/1.73 m2 body surface area, the filtration fraction between 6.9 and 22.5%, and the serum albumin concentration between 14 and 46 g/liter. The mean foot process width, which varied between 330 and 870 nm, showed a close correlation with GFR (r = -0.859) and the filtration fraction (r = -0.812), as well as with the serum albumin concentration (r = -0.756). As expected, a reduction of epithelial slit pore length occurred concomitant with the broadening of the foot processes. These results agree with the hypothesis that the reduction in the total length of glomerular epithelial slit pores, due to the fusion of foot processes, results in a reduced glomerular capillary permeability to water and small solutes.

Adolescent↗
PubMed1985

Limitations of creatinine as a filtration marker in glomerulopathic patients.

To determine the reliability of creatinine as a measure of the glomerular filtration rate (GFR), we compared the simultaneous clearance of creatinine to that of three true filtration markers of graded size in 171 patients with various glomerular diseases. Using inulin (radius [rs] = 15 A) as a reference marker, we found that the fractional clearance of 99mTc-DTPA (rs = 4 A) was 1.02 +/- 0.14, while that of a 19 A rs dextran was 0.98 +/- 0.13, with neither value differing from unity. In contrast, the fractional clearance (relative to inulin) of creatinine (rs = 3 A) exceeded unity, averaging 1.64 +/- 0.05 (P less than 0.001), but could be lowered towards unity by acute blockade of tubular creatinine secretion by IV cimetidine. Cross-sectional analysis of all 171 patients revealed fractional creatinine secretion to vary inversely with GFR. This inverse relationship was confirmed also among individual patients with either deteriorating (N = 28) or remitting (N = 26) glomerular disease, who were studied longitudinally. As a result, changes in creatinine relative to inulin clearance were blunted considerably or even imperceptible. We conclude that true filtration markers with rs less than 20 A, including inulin, are unrestricted in glomerular disease, and that creatinine is hypersecreted progressively by remnant renal tubules as the disease worsens. Accordingly, attempts to use creatinine as a marker with which to evaluate or monitor glomerulopathic patients will result in gross and unpredictable overestimates of the GFR.

Creatinine↗
PubMed1990

Hyperplasia precedes increased glomerular filtration rate in rat remnant kidney.

Using 3H-thymidine (3H-T), we examined DNA synthesis in rats subjected to either uninephrectomy (UNI), five-sixths nephrectomy (R) or sham (S) surgery. Twenty-four, 48, or 72 hours later, animals were infused with 14C-inulin, PAH and 3H-T and clearances obtained. Prior to sacrifice, India ink was injected for glomerular counting. By 24 hours, glomerular filtration rate per nephron was significantly increased in UNI. However, in R, glomerular filtration rate per nephron was significantly lower than S until 72 hours. Total micrograms DNA per nephron was unchanged in UNI but significantly increased in R compared to S at all times. 3H-T incorporation into DNA was twice as great in UNI as in S was over five-fold greater at 24 hours in R than in S; this marked increase persisted in R at 48 and 72 hours. Autoradiographs confirmed that DNA was synthesized predominantly by renal tubular cells and not infiltrating cells. These results indicate that hyperplasia in compensatory renal growth is related to the quantity of tissue removed and that, in the remnant kidney, DNA synthesis precedes the compensatory increase in glomerular filtration rate per nephron.

Animals↗
PubMed2002

Protein restriction, glomerular filtration rate and albuminuria in patients with type 2 diabetes mellitus: a randomized trial.

OBJECTIVE: Protein restriction delays the progression of non-diabetic and type 1 diabetic renal disorders. This study assessed whether protein restriction delays the onset or early progression of renal disorders in type 2 diabetes. DESIGN: Randomized controlled trial. Outcomes were albuminuria (mg/24 h) and, as an estimate of the glomerular filtration rate, cimetidine-influenced creatinine clearance. SETTING: Primary care. SUBJECTS: Patients with type 2 diabetes and microalbuminuria or at least detectable albuminuria, or a diabetes duration >5 y. INTERVENTIONS: The experimental group received dietary counselling on protein restriction (n=63); a control group (n=68) received the usual dietary advice. The duration of intervention and follow-up was 28+/-7 months. RESULTS: After 6 months, protein intake differed only by 0.08 g/kg/day between the study groups. Subsequently, this difference decreased and eventually disappeared. An initial effect of protein restriction on albuminuria in favor of the experimental group was not sustained, and the glomerular filtration rate decreased in the experimental group at a 1.6+/-2.2 ml/min/1.73 m(2) y lower rate than in the control group (P=0.5). Comparison of patients in the experimental group with a decrease in protein intake of at least 0.20 g/kg/day, with controls with no decrease, indicated a similarly small and insignificant effect on glomerular filtration rate. CONCLUSIONS: It is concluded that, in the longer term prevention or delay of renal damage in patients with type 2 diabetes, protein restriction is neither feasible nor efficacious.

Aged↗
PubMed2006

Effects of glomerular filtration rate on Ficoll sieving coefficients (theta) in rats.

The purpose of the present study was to assess the role of diffusion and convection during filtration of Ficoll across the glomerular filter by comparing glomerular sieving coefficients (theta) to neutral fluorescein isothiocyanate (FITC)-Ficoll 70/400 obtained at low (hydropenic) vs raised (normal) glomerular filtration rates (GFRs). The theta for FITC-Ficoll was determined in anesthetized Wistar rats (304 +/- 18 g) following laparotomy and cannulation of the ureters, used for urine sampling. After surgery, GFR was 1.2 +/- 0.16 ml/min (+/- s.e.), assessed using the plasma to urine clearance of FITC-inulin and (51)Cr-ethylenediaminetetraacetic acid. FITC-Ficoll 70/400 was infused intravenously (i.v.) following an initial bolus dose. To raise GFR, to an average of approximately 2 ml/min, 5 ml of serum together with glucagon (3 microg/min) was given i.v. FITC-inulin and FITC-Ficoll were determined in plasma and urine using size-exclusion high-performance liquid chromatography. The theta for Ficoll as a function of Stokes-Einstein radius was significantly reduced in the range of 13-43 A when GFR was raised. The maximal theta lowering effect, in relative terms, of raising GFR was obtained for a Ficoll a(e) of approximately 32 A. For Ficoll(36 A) (cf. albumin), theta was reduced from 0.111+/- 0.009 to 0.081+/- 0.012 (P < 0.05; n = 7) for the GFR increment imposed. The reduction in theta for Ficoll after raising GFR indicates the presence of a high diffusive component of glomerular Ficoll filtration in rats in vivo and contradicts the notion of a significant concentration polarization effect in the glomerular filter upon Ficoll molecules < 50 A in radius.

Animals↗
PubMed1993

Effect of splenic congestion associated with haemolytic anaemia on filtration of 'spleen-homing' microspheres.

1. The surface of large model 125I-labelled polystyrene microspheres (220 nm in diameter) was coated with the polyoxyethylene/polyoxypropylene block co-polymer poloxamine-908. The coated microspheres were injected intravenously into rats. Up to 40% of the administered dose had accumulated in the spleen by a filtration mechanism, as compared with 5% for uncoated microspheres, at 3 h after administration. The enhanced splenic sequestration of microspheres was accompanied by a decrease in the liver uptake. In contrast, smaller poloxamine-908-coated microspheres (60 nm in diameter) effectively avoided uptake by both the liver and the spleen and remained in systemic circulation. 2. The effect of splenic congestion, associated with phenylhydrazine-induced haemolytic anaemia, on filtration of poloxamine-908-coated microspheres was studied. The enlarged spleen of the anaemic rats was incapable of efficiently filtering large poloxamine-908-coated microspheres when compared with the spleen of normal animals. This was suggested to be the result of extensive 'clogging' of the red pulp by damaged erythrocytes. However, the splenic filtration of large coated microspheres was still five-fold higher than that of uncoated microspheres of similar size in anaemic animals. 3. The potential use of large sterically stabilized colloids and drug carriers for selective spleen scanning and splenic drug delivery in pathological conditions, where anaemia prevails, is discussed. 4. Sterically stabilized microspheres may have potential for re-examining the microcirculatory pathways in healthy spleen and various splenomegalies.

Anemia, Hemolytic↗
PubMed1993

Renal uric acid handling in non-insulin-dependent diabetic patients with elevated glomerular filtration rates.

1. Hypouricaemia is prevalent in diabetic patients. In most of the studies, the diabetic patients had some degree of diabetic nephropathy as evidenced by a decreased glomerular filtration rate and proteinuria. Therefore we studied renal uric acid handling in a group of type II diabetic patients with elevated glomerular filtration rates. 2. Eighteen type II diabetic patients with normal kidney functions and elevated glomerular filtration rate and a group of 18 healthy, age- and weight-matched control subjects, were studied. Serum fructosamine, creatinine and uric acid levels were determined. Twenty-four hour urine collections were obtained, and microalbumin, glucose, creatinine and uric acid, were measured. 3. The creatinine clearance was higher and the serum uric acid concentration was lower in the diabetic patients (P < 0.05). The 24 h urinary uric acid excretion and filtered uric acid load were similar in both groups. However, the derived parameters of uric acid clearance and fractional excretion were significantly higher in the diabetic patients (P < 0.002 and P < 0.05, respectively). A negative correlation was apparent between serum fructosamine concentration and serum uric acid concentration (r = -0.76). A positive correlation was found between serum fructosamine concentration and fractional uric acid excretion (r = 0.64) and between serum fructosamine concentration and filtered uric acid load (r = 0.66). A positive correlation was found between creatinine clearance and 24 h uric acid excretion (r = 0.61) and between creatinine clearance and filtered uric acid load (r = 0.82).(ABSTRACT TRUNCATED AT 250 WORDS)

Creatinine↗
PubMed2001

A multicentre evaluation of a new filtration protocol for leucocyte depletion of high-haematocrit red blood cells collected by an automated blood collection system.

BACKGROUND AND OBJECTIVES: A multicentre trial was set up to evaluate the performance of a new leucodepletion protocol. MATERIALS AND METHODS: Filtration at high haematocrit was started during collection of red blood cell (RBC) products by apheresis with Trima. SAG-M was added after filtration through the filter. Haematocrits and haemoglobin of the filtered RBCs were measured. Residual leucocytes were determined by Nageotte counting. RESULTS: One-hundred and forty seven procedures were carried out. The haematocrit and haemoglobin contents were 57.3 +/- 3.0% and 55.1 +/- 4.3 g/unit, respectively. All products showed low residual leucocyte levels (< or = 0.75 x 106/unit; 99.31% < 1 x 106). CONCLUSION: Immediate, on-line, high-haematocrit filtration of red cells collected on Trima resulted in leucoreduced RBCs, which met the AABB and Council of Europe criteria.

Blood Cell Count↗
PubMed2001

An improved method of sperm selection by glass wool filtration.

An improved method of sperm selection by glass wool filtration is introduced. After incubation of glass wool filtrates for 30 min at 37 degrees C in a conical-shaped 1.5-ml tube, an enrichment of highly motile spermatozoa was found in the bottom layer of the tube. The effect turned out to be dependent on the conical shape of the tube, as it was not observed in flat-bottomed tubes. Native ejaculates (obtained from 30 men) and their glass wool filtrates were analysed by cell counter, computer-assisted sperm-motility analysis, morphological differentiation and supravital staining of spermatozoa. When 400 microl of ejaculate, diluted with 800 microl of medium, was applied to the top of a column consisting of a 1-ml disposable syringe barrel gently packed with 15 mg of glass wool to a depth of 6 mm, an enrichment of viable spermatozoa was found in the first three 100-microl fractions taken from the bottom of the tube. It is the simplicity of this technique that makes it so easily applicable.

Cell Adhesion↗
PubMed1999

Plasma total homocysteine and cysteine in relation to glomerular filtration rate in diabetes mellitus.

BACKGROUND: The plasma concentrations of total homocysteine (tHcy) and total cysteine (tCys) are determined by intracellular metabolism and by renal plasma clearance, and we hypothesized that glomerular filtration is a major determinant of plasma tHcy and tCys. We studied the relationships between the glomerular filtration rate (GFR) and plasma tHcy and tCys in populations of diabetic patients with particularly wide ranges of GFR. METHODS: We measured GFR, urine albumin excretion rate (UAER), plasma tHcy, tCys, methionine, vitamin B12, folate, C-peptide, and routine parameters in 50 insulin-dependent diabetes mellitus (IDDM) and 30 non-insulin-dependent diabetes mellitus (NIDDM) patients. All patients underwent intensive insulin treatment and had a serum creatinine concentration below 115 micromol/liter. RESULTS: Mean plasma tHcy in diabetic patients (0.1 micromol/liter) was lower than in normal persons (11.1 micromol/liter, P = 0.0014). Mean plasma tCys in diabetic patients (266.1 micromol/liter) was also lower than in normal persons (281.9 micromol/liter, P = 0.0005). Seventy-three percent of the diabetic patients had relative hyperfiltration. Plasma tHcy and tCys were closely and independently associated with GFR, serum folate, and serum B12. However, plasma tHcy was not independently associated with any of the 22 other variables tested, including age, serum creatinine concentration, UAER, total daily insulin dose, and glycemic control. CONCLUSIONS: Glomerular filtration rate is an independent determinant of plasma tHcy and tCys concentrations, and GFR is rate limiting for renal clearance of both homocysteine and cysteine in diabetic patients without overt nephropathy. Declining GFR explains the age-related increase in plasma tHcy, and hyperfiltration explains the lower than normal mean plasma tHcy and tCys concentrations in populations of diabetic patients.

Adult↗
PubMed1999

Changes in CD4+ T lymphocyte subsets in circulating blood and synovial fluid following filtration leukocytapheresis therapy in patients with rheumatoid arthritis.

The purpose of this study is to determine the changes in CD4+ T lymphocyte subsets in the circulating blood and synovial fluid following filtration leukocytapheresis (LCP) therapy for patients with rheumatoid arthritis (RA). A Cellsorba column packed with polyester fibers was used for the removal of circulating leukocytes. For patients with RA, filtration LCP or sham procedures were performed 3 times with 1 week intervals between procedures. T lymphocyte surface markers in the peripheral blood and synovial fluid were measured by flow cytometry. The proportions of activated CD4+ T cells (CD4+DR+, CD4+CD25+, and CD4+CD71+) and CD4+CD29+ T cells increased significantly in the peripheral blood, but the counts of these cells were significantly reduced in the synovial fluid after 2 treatment sessions in the LCP group. No significant changes were observed in the proportion of these cells in the control group. Our findings suggest that filtration LCP may cause a redistribution of activated T cells from affected joints into the circulating blood.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Efficiency of white cell filtration and a freeze-thaw procedure for removal of HIV-infected cells from blood.

Strategies for diminishing the risk of blood transfusion-associated transmission of HIV-1 were evaluated. HIV-1-infected peripheral blood mononuclear cells were added to blood that was subsequently filtered by using different white cell (WBC) filters (cellulose acetate and polyester). The average log reduction of infected cells with polyester filters was at least 2.5 as measured by ID50 titration and polymerase chain reaction. In two WBC filtration experiments with blood from seropositive donors diluted 1:4 with seronegative blood, log reductions of 2.4 and greater than 2.5 were observed. No cell-free virus was retained by the filter used. A freeze-thaw procedure applied to HIV-1-contaminated blood resulted in a minimal log reduction. These results indicate that the reduction of HIV-1 infectivity as a result of filtration is mainly due to the removal of HIV-1-infected WBCs, and that complete removal of infected WBCs cannot be achieved by the current filtration or freeze-thaw procedures. However, the development of filters with enhanced ability to remove (possibly infected) WBCs may have the added benefit of improving the safety of donor blood, especially in multiply transfused patients.

Blood↗
PubMed1993

Mechanisms of white cell reduction in red cell concentrates by filtration: the effect of the cellular composition of the red cell concentrates.

The effect of platelets on the removal of white cells (WBCs) from 16 to 24-hour-old red cell (RBC) concentrates by filtration was studied. RBC concentrates with various concentrations of platelets and WBCs were filtered on a cellulose acetate column filter and on three polyester flatbed filters. The microscopic study revealed that lymphocytes and most monocytes were captured in the smaller pores of the fiber network, irrespective of the brand of filter, the type of filter material, or the prefiltration platelet amount in the RBC concentrates. In contrast, efficient granulocyte depletion depended on granulocyte-platelet interaction and on the filter material. In the presence of platelets, granulocytes were captured in the top part of the column filter or in the coarse layers of two of the flatbed filters, where platelets covered the fibers. Platelet depletion of the RBC concentrates prior to filtration diminished the contribution of these parts of the filters to granulocyte capture. A larger part of the column filter or the fine layers of the flatbed filters were now required for granulocyte capture. In one of the flatbed filters, granulocyte-platelet interaction occurred mainly in the fine layers, which ended in blockage of this filter after the filtration of variable volumes (250-600 mL) of standard RBC concentrates. A quantitative estimation of the effect of platelets on the WBC-reduction capacity found that all three flatbed filters had a highly significant decrease (p = 0.001) in WBC-reduction capacity for platelet-depleted or buffy coat-depleted RBC concentrates, as compared with standard RBC concentrates.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Platelets↗
PubMed1993

Filtration through a polyester white cell-reduction filter of plasma-poor platelet concentrates prepared with an acetate-containing additive solution.

It is of practical importance to known whether the adsorption of platelets and contaminating white cells (WBCs) by the WBC-reduction filter is altered when platelet concentrates (PCs) are prepared in a plasma-poor condition with an acetate-containing additive solution (Seto sol). Plasma-poor PCs with 11-percent residual plasma were prepared from apheresis platelet-rich plasma by using a sterile docking device with steam-sterilized Seto sol. Seto sol contains 115 mM (115 mmol/L) NaCl, 4 mM (4 mmol/L) KCl, 3 mM (3 mmol/L) MgCl2, 10 mM (10 mmol/L) Na3PO4, 15 mM (15 mmol/L) acetate, 3 mM (3 mmol/L) Na3 citrate, and 10 mM (10 mmol/L) glucose (pH 7.1). The solution was steam-sterilized under nitrogen gas. On Days 1 and 5, pooled Seto sol PCs (2.4 x 10(11) platelets) were filtered with a polyester filter at a flow rate of 10 mL per minute. The WBC-removal rate was over 99.9 percent with a platelet recovery of 88 percent following Day 1 filtration. These values were very similar to those of plasma PCs, and 84-percent recovery was achieved following Day 5 filtration. However, when 1 unit of Seto sol PCs with half the number of platelets was filtered with the polyester filter, platelet recovery was about 16 to 17 percent less than that of plasma PCs. Platelet quality was maintained if pooled Seto sol PCs were filtered on Day 1 and stored for over 4 days. Filtration did not alter platelet function in 1-day-old or 5-day-old Seto sol PCs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorption↗
PubMed1998

Effect of filtration and storage of platelet concentrates on the production of the chemotaxins C5a, interleukin 8, tumor necrosis factor alpha, and leukotriene B4.

BACKGROUND: The production in platelet concentrates (PCs) of C3 activation products (C3bc), terminal complement complex (TCC), and chemotaxins C5a, interleukin (IL)-8, tumor necrosis factor alpha (TNFalpha), and leukotriene B4 (LTB4) and the proposed reduction in concentration of the chemotaxins by white cell reduction were examined. STUDY DESIGN AND METHODS: Samples were collected from supernatants of PCs produced by apheresis (apheresis PCs) or from buffy coats (BC PCs) immediately after the production, after white cell-reduction filtration on Day 1, and after 5-day storage, and examined by enzyme immunoassays. RESULTS: Complement was activated in all PCs during storage, and the concentration of activation products was not influenced by prestorage filtration. In prestorage white cell-reduced BC PCs, only C3bc levels increased. Levels of IL-8, TNFalpha, and LTB4 increased during storage of apheresis PCs, but not in filtered units, except for LTB4. In contrast, levels of IL-8 decreased after storage of filtered BC PCs. C5a correlated significantly with IL-8, which also correlated with TNFalpha and LTB4. CONCLUSION: Both C5a and TNFalpha generation in apheresis PCs seem to induce white cell IL-8 production, which mediates cellular LTB4 release. Prestorage white cell reduction is recommended for reducing chemotactic cytokine and leukotriene levels in all PCs. Production of BC PCs is recommended to achieve less complement activation, which is not affected by filtration.

Blood Platelets↗