Biomedical subjects

M Schoorl

Publications and source records attributed to M Schoorl.

At least 19 recordsLinked to original sources

PubMed2001

Predictive value of inflammatory and coagulation parameters in the course of severe ulcerative colitis.

Alterations in markers of coagulation have been found in patients with inflammatory bowel disease. Our aim was to study the predictive value of coagulation and inflammatory parameters in the course of severe ulcerative colitis. Twenty-seven patients were included. The disease course was followed for one year. Sensitivity, specificity, negative predictive value, positive predictive value, and likelihood ratio, as well as the clinical predictive value of laboratory variables were calculated. Inflammatory variables, such as ESR, CRP, and leukocyte and platelet count showed poor diagnostic accuracy. Several coagulation parameters, such as fibrinogen and fibrin(ogen) degradation products, were increased in patients with active ulcerative colitis, whereas coagulation factor XIII was decreased. No significant relationship between clinical course and coagulation parameters was demonstrated, though both inflammatory and coagulation parameters were useful in the assessment of disease activity in patients with active ulcerative colitis.

Adult↗

PubMed2001

Hemostatic imbalance in active and quiescent ulcerative colitis.

OBJECTIVE: In healthy conditions, factors inducing or inhibiting coagulation and factors inducing or inhibiting fibrinolysis are in balance. In ulcerative colitis, hypercoagulation is presumed, which may explain part of the clinical features of this disease. Therapy strategies affecting hemostasis may improve the course of ulcerative colitis. This study was conducted to evaluate the balance of coagulation and fibrinolysis in the course of treatment of active ulcerative colitis. METHODS: Patients with active ulcerative colitis were studied by serial determination of markers of the coagulation cascade (thrombin-antithrombin complexes and fibrin degradation products [FbDP]) and the fibrinolytic cascade (fibrinogen degradation products [FgDP]). Parameters of inflammation were also measured (C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], albumin, platelet count, and fibrinogen). Disease activity was assessed by endoscopic and histopathological scores. Follow-up measurement was performed in the course of treatment at the third or fourth month after baseline. Measurements were compared with healthy controls. RESULTS: Thirty-three patients and 22 healthy controls were included. During active ulcerative colitis, inflammatory parameters (CRP, ESR, platelet count) and hemostatic parameters (thrombin-antithrombin complexes, fibrinogen, FgDP, and FbDP) were elevated in comparison with healthy controls. Albumin was decreased and antithrombin-III remained unchanged. During treatment, disease activity decreased significantly endoscopically and histopathologically (p < 0.001). CRP, ESR, platelet count, and fibrinogen also decreased significantly. The hemostatic balance, expressed as the ratio between the plasmin-dependent generation of FgDP and coagulation-dependent generation of FbDP, increased from 0.69 to 1.12 during treatment, mainly because of a decrease of FbDP. In healthy controls, this ratio was CONCLUSIONS: The coagulation and fibrinolytic cascades were activated in active ulcerative colitis, with a hemostatic imbalance in favor of coagulation. This hypercoagulability persisted in 20% (7/33) of patients with ulcerative colitis in remission. The decrease of FbDP and the increase in the FgDP/FbDP ratio during reconvalescence of ulcerative colitis showed that the coagulation cascade was more activated than the fibrinolytic cascade in active disease.

Adult↗

PubMed2000

Activation of coagulation during treatment with haemodialysis.

Generation of factor XII, thrombin antithrombin complexes, prothrombin fragment 1+2 and thrombus precursor protein has been monitored in 16 subjects during haemodialysis. Immediately after starting treatment, contact of blood with the negatively charged surfaces of the polyacrylnitril membrane AN-69 resulted in a 9-45% decrease in factor XII activity. Peak concentrations for thrombin antithrombin complexes (50 to 120 microg/L) were observed 30 min after the start of haemodialysis. Establishment of thrombus precursor protein concentrations yielded steadily increasing results without any tendency to decrease during treatment. Determination of thrombin antithrombin complexes is considered to establish the most sensitive short-term reacting parameter indicating activation of coagulation. A steady generation of fibrin and fibrinogen-fibrin complexes during treatment with haemodialysis is indicated by increasing results for thrombus precursor protein. In order to prevent clotting during haemodialysis, an additional supplementation of anticoagulant is needed.

Adult↗

PubMed2000

Effects of dialyser and dialysate on the acute phase reaction in clinical bicarbonate dialysis.

BACKGROUND: In chronic haemodialysis (HD), morbidity may result from repetitive induction of the acute phase response, caused by a bioincompatible dialysis membrane and/or contaminated dialysate. In the present study, cytokine release (interleukin-6, IL-6) and subsequent production of acute phase proteins (C-reactive protein, CRP and secretory phospholipase A(2), sPLA(2)) were assessed to investigate whether the HD-induced acute phase reaction depends mainly on the type of membrane or on the sterility of the dialysate. METHODS: In 11 patients, IL-6, CRP and sPLA(2) levels were assessed in blood samples drawn before (t(0)), at the end (t(180)) and 24 h after the start of HD (t(1440)). All patients were dialysed on Cuprammonium (CU) and Polysulphon (PS) dialysers and seven patients underwent an additional HD session on CU plus a dialysate filter (CUf). RESULTS: IL-6 levels were increased significantly at t(180) compared with t(0) (P<0.02) with both CU and CUf. At t(1440), IL-6 levels had returned to baseline. In contrast, marked fluctuations did not occur during HD with PS. At t(180), IL-6 was significantly greater with CU and CUf devices, than with PS (P<0.02). Following HD with CU and CUf, a significant increase in CRP was observed at t(1440), compared with postdialysis values (P</=0.05). In addition, sPLA(2) values were markedly increased at t(1440), compared with t(180), but only significant in the case of CU (P=0.01). IL-6 levels at t(180) were significantly correlated with CRP (r=0.50, P<0.01) and sPLA(2) (r=0.47, P=0.01) values at t(1440). During HD with PS membranes, neither CRP nor sPLA(2) values were markedly changed. CONCLUSIONS: In contrast to PS, both CU and CUf resulted in elevated IL-6 plasma levels at the end of HD, compared with t(0), which correlated with increased CRP and sPLA(2) values 24 h later. Therefore, the type of membrane, rather than the bacterial quality of the dialysate, seems to be responsible for the induction of the acute phase response during clinical bicarbonate HD.

Acute-Phase Reaction↗

PubMed2000

Hemodialysis-induced degranulation of polymorphonuclear cells: no correlation between membrane markers and degranulation products.

BACKGROUND/AIMS: Degranulation of polymorphonuclear leukocytes (PMN) during hemodialysis (HD) is usually assessed by measuring degranulation products. However, this process might also be estimated by the assessment of cell surface markers. In this study, the relationship between the expression of PMN degranulation markers (CD63 and CD66b) and the release of degranulation products [myeloperoxidase (MPO) and lactoferrin (LF)] was investigated during clinical HD in order to evaluate cell surface markers as a useful index of PMN degranulation. METHODS: The expression of CD63 and CD66b on PMN and the release of MPO and LF were investigated in 10 chronic HD patients, during both heparin (HDhep) and trisodium citrate anticoagulation (HDcit), in a randomized order. Samples were drawn from both the efferent and afferent lines of the dialyzer at 0, 7.5, and 180 min. RESULTS: During HDhep at first passage, a major increase in MPO (from 158 +/- 32 to 448 +/- 177 microg/l, p = 0.001) and LF (from 134 +/- 52 to 260 +/- 120 microg/l, p = 0.01) was found across the dialyzer, whereas marked changes were not observed during HDcit. The expression of CD63 and CD66b increased across the dialyzer during both anticoagulation modalities, but was only significant in the case of HDhep (CD63: mean fluorescence intensity from 247 +/- 61 to 331 +/- 118, p < 0.01; CD66b: mean fluorescence intensity from 340 +/- 76 to 434 +/- 103, p = 0.01). During HDhep a correlation was noted between the degranulation products and markers of both azurophilic and specific granules (MPO and CD63: r = 0.35; p < 0.01; LF and CD66b: r = 0.39, p < 0.01). Significant differences in the expression of CD63 and CD66b between HDhep and HDcit were not observed. When analyzing the combined data for both HDhep and HDcit, no correlation was observed between degranulation products and markers. CONCLUSION: Our data suggest that the measurements of cell surface markers may not be a reliable indicator of the degree of HD-induced PMN degranulation.

Adult↗

PubMed1998

Time dependent increase of differential monocyte count on the Sysmex NE-8000.

During storage of whole blood samples the results of white blood cell counts on a Sysmex NE-8000 Hematology Analyser showed an apparent shift from the granulocytes towards monocytes. The effects of various storage conditions were investigated by incubating blood samples at different temperatures and time intervals. Granulocyte activation and degranulation during storage resulted in a false elevation of the automated monocyte differential counts. The phenomenon occurs at temperatures beyond ambient room temperature.

Artifacts↗

PubMed1998

[Decreased erythropoiesis and biochemical deviations in psychogeriatric patients].

Laboratory investigations were performed in group of 60 psychogeriatric patients on their admission into hospital, in order to elucidate the interdependence of erythropoiesis and the concentrations of albumin and several vitamins in blood or serum. The results of albumin concentration and ETK activity show that 47 out of 60 the patients (= 78%) are in a poor nutritional condition. In 13 of these 47 subjects (= 28%) deficiency with respect to vitamin B12 or folic acid is presumed from decreased serum concentrations. In 6 of the 47 patients in poor nutritional condition (= 13%) decreased reticulocyte concentrations are shown. Further evaluation of differences between the respective subgroups revealed significantly reduced ETK activity and lower reticulocyte concentrations in the group of delirium patients compared to the other patients groups and to the reference group.

Aged↗

PubMed1997

Mechanisms of intra-dialyser granulocyte activation: a sequential dialyser elution study.

INTRODUCTION: During haemodialysis (HD), an early and transient white blood cell (WBC) reduction is noted in the peripheral blood, which has been attributed mainly to the sequestration of polymorphonuclear cells (PMN) in the pulmonary vasculature. However, WBC also adhere to the dialyser, as demonstrated before in an elution study performed after HD. In the present study, we investigated if intradialyser WBC sequestration contributes to the WBC nadir in the blood shortly after the start of HD and whether or not different mechanisms underlie PMN adherence in dialyser and lung. In addition, PMN degranulation was analysed not only in peripheral blood but also in dialyser eluates (DE). SUBJECTS AND METHODS: Dialysers were eluted after 7 1/2 (DE-7 1/2) and 180 (DE-180) min of HD in eight patients. Blood samples were taken before HD (t0), and at t7 1/2 and t180. Besides WBC count and differentiation, PMN adhesion (CD11b and CD62L) and degranulation markers (CD63 and CD66b) were assessed by flow cytometry. RESULTS: In the blood, a WBC fall was noted at t7 1/2 (from 5.8 to 4.8 x 10(9)/l; absolute about 5 x 10(9) cells). DE contained 3.0 x 10(6) cells at t7 1/2, and 57.2 x 10(6) at t180 (P = 0.015). As for CD11b, at t7 1/2 both in the blood and DE an increased expression was observed, as compared to t0 (P = 0.01); CD11b expression in DE-7 1/2 was higher than in DE-180 (P = 0.025). In contrast, CD62L showed downregulation only in DE both at t7 1/2 (mean fluorescence intensity (MFI) PB 4172 and DE-7 1/2 2353, P = 0.01), and at t180 (MFI 794, P = 0.03 versus DE-7 1/2), when compared to blood at t0. As for degranulation markers, an increase was observed in blood at t7 1/2 (MFI CD63 from 357 to 506, P = 0.02; CD66b from 507 to 794, P = 0.001), in comparison with t0. Eluted PMN at t7 1/2 showed a higher expression of CD63 than PMN in blood at t7 1/2 and DE-180 (MFI in DE-7 1/2 1280 and blood 506, P = 0.003). The expression of CD66b was increased in DE-7 1/2 (MFI 1803 versus blood 794, P = 0.01), and even more in DE-180 (MFI 2763, P = 0.002), when compared to blood. CONCLUSIONS: From these data it is concluded first, that intradialyser PMN sequestration does not contribute markedly to the WBC nadir in the circulation. Second, intradialyser PMN trapping appears to result primarily from non-adhesion-molecule-mediated factors, as indicated by an increased expression of CD11b at t7 1/2 on eluted PMN associated with low cell numbers in DE, and normalized CD11b expression at t180 associated with considerably higher cell numbers in DE. Third, HD-induced degranulation seems to be a complex phenomenon. After a rapid transient onset, characterized by an early upregulation of CD63 and CD66b on PMN leaving the dialyser, degranulation continues within the device as indicated by an additional rise in the expression of CD66b on PMN in DE-180.

Adult↗

PubMed1997

Low polymorphonuclear cell degranulation during citrate anticoagulation: a comparison between citrate and heparin dialysis.

INTRODUCTION: Haemodialysis (HD)-induced bio-incompatibility includes alterations in both cellular elements and humoral factors. As far as polymorphonuclear (PMN) cells are concerned, an increase in both adhesion and degranulation has been reported. However, whereas increased PMN adherence and aggregation is highly linked with early transient complement activation, degranulation seems a continuous process, independent from the formation of complement degradation products. In the process of cell activation, including PMN degranulation, divalent cations (Ca2+) appear to play a pivotal role. As regionally administering citrate creates an almost Ca(2+)-free environment within the dialyser, it is tempting to speculate that Ca2+ dependent phenomena of bio-incompatibility, originating within the dialyser, can be attenuated by substituting conventional heparin for citrate. METHODS: Therefore, both anticoagulation modalities were compared in 10 stable patients, undergoing haemodialysis (HD) treatment with cellulose-triacetate membranes (CTA) only. Apart from the intracellular granule products myeloperoxidase (MPO) and lactoferrin (LF), the classical parameters of bio-incompatibility, peripheral blood neutropenia and complement activation, were measured. RESULTS: Analysis of MPO and LF gradients across the dialyser (concentration in efferent line-concentration in afferent line) suggested that degranulation is an early process, that occurs mainly within the extracorporeal circuit. Citrate abolished the release of MPO almost completely, whereas LF release was partially inhibited. Neither neutropenia, nor complement activation could be correlated with the occurrence of degranulation. CONCLUSIONS: HD-induced PMN degranulation seems largely independent from complement activation, but primarily reliant on Ca2+, at least in the case of CTA membranes.

Adult↗

PubMed1997

Cytokine profiles during clinical high-flux dialysis: no evidence for cytokine generation by circulating monocytes.

Secretion of cytokines by monocytes has been implicated in the pathogenesis of dialysis-related morbidity. Cytokine generation is presumed to take place in two steps: induction of mRNA transcription for cytokines by C5a and direct membrane contact, followed by lipopolysaccharide (LPS)-induced translation of mRNA (priming/second signal theory, Kidney Int 37: 85-93, 1990). However, the in vitro conditions on which this theory was based differed markedly from clinical dialysis. To test this postulate for routine hemodialysis, 13 patients were studied cross-over with high-flux cuprammonium (CU), cellulose triacetate (CTA), and polysulfon dialyzers, using standard bicarbonate dialysate, as well as CTA with filtered dialysate (fCTA). Besides leukocytes, C3a, C5a, and limulus amebocyte lysate reactivity, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-6, IL-1RA, soluble TNF receptors, and IL-1 beta mRNA were assessed. Only during dialysis with CU did C5a increase significantly (561 to 8185 ng/ml, P < 0.001). Endotoxin content of standard bicarbonate was higher than filtered dialysate (median, 24.3 and < 5 pg/ml respectively, P = 0.002), whereas limulus amebocyte lysate reactivity was not detected in the blood, except in the case of CU. TNF-alpha levels were elevated before, and remained stable during, dialysis, independent of the modality used. IL-1 beta, IL-6, and mRNA coding for IL-1 beta could not be demonstrated. IL-1RA and soluble TNF receptors (p55/p75) were markedly elevated compared with normal control subjects, but showed no differences between fCTA and CTA. To summarize, no evidence was found for production and release of cytokines by monocytes during clinical high-flux bicarbonate hemodialysis, neither with complement-activating membranes nor with unfiltered dialysate. Therefore, this study sheds some doubt on the relevance of the "priming/second signal" theory for clinical practice. The data presented suggest that reluctance to prescribe the use of high-flux dialyzers, as advocated in many reports, may not be warranted.

Adult↗

PubMed1997

Screening for EDTA-dependent deviations in platelet counts and abnormalities in platelet distribution histograms in pseudothrombocytopenia.

Screening for pseudothrombocytopenia caused by in vitro platelet clumping has been performed in 45,000 subjects attending a general hospital. In our region, the observed prevalence of EDTA-induced pseudothrombocytopenia in blood samples with an initial platelet count below 150 x 10(9)/l was estimated to amount to 0.1%. EDTA-induced pseudothrombocytopenia was confirmed by detection of platelet aggregates by means of microscopic evaluation from the blood smear. In routine investigations, pseudothrombocytopenia could be highly suspected when the Sysmex NE 8000 showed characteristic peculiarities in the white blood cell (WBC) scattergram and histogram. Platelet aggregation is avoided in such cases by the use of citrate as an anticoagulant instead of EDTA. Pseudothrombocytopenia was detected in 46 subjects. As a screening test for pseudothrombocytopenia, increased cut-off values derived from the WBC histogram demonstrated 90% sensitivity and 100% specificity. Automated flagging for platelet clumps, deviations reflecting MPV, or PDW abnormalities revealed lower scores with respect to sensitivity.

Anticoagulants↗

PubMed1997

Mean corpuscular volume-dependent deviations in red blood cell distribution width between Sysmex NE-8000 and SF-3000.

Values for red blood cell distribution width yield information concerning size heterogeneity of red blood cell populations. Comparative studies between various haematology analysers are obligatory to quantify apparatus-dependent deviations with respect to accuracy and subsequent consequences with respect to clinical interpretation of results. In this study a comparative assessment is performed between a Sysmex SF-3000 and NE-8000 Haematology Analyser. Fifty-four specimens with abnormal red blood cell volumes and a hundred specimens from apparently healthy subjects were assayed. Systematic deviations in values concerning red blood cell distribution width are demonstrated to show a tendency to decrease towards higher mean corpuscular volume values.

Anemia↗

PubMed1997

Evaluation of Sysmex SF-3000 performance concerning interpretive morphology flagging of the leucocyte differential count.

Results from the Sysmex SF-3000 automated haematology analyser are reported with special attention to leucocyte morphology flagging in pathological conditions. Results for leucocyte differential counts provided by the Sysmex SF-3000 were compared with those obtained from the Sysmex NE-8000 and a visual evaluation based on a differential count of 400 leucocytes. One hundred samples from apparently healthy subjects and 100 samples from patients with haematological abnormalities were examined. The SF-3000 yielded a rather high frequency of flagging inappropriately referring to blasts, immature granulocytes, left shift and nucleated red blood cells/platelet clumps. The presence of atypical lymphocytes was not indicated by appropriate flagging.

Data Interpretation, Statistical↗

PubMed1996

Ex vivo elution of hemodialyzers. An additional criterion for the assessment of bioincompatibility.

The analysis of hemodialysis (HD)-related bioincompatibility is focused mainly on phenomena observed in peripheral blood. However, since biocompatibility originates inside the dialyzer, white blood cells (WBC) adhering to the dialyzer are probably most subject to the influence of both dialyzer membrane and dialysate. In order to collect membrane-adherent cells, a reliable and reproducible elution technique was developed. After 3 h of HD, blood was returned to the patient with 0.9% NaCl. Then, dialyzers were eluted by recirculation of phosphate-buffered saline (PBS) or PBS/3 mM EDTA for 20 min, with or without prior flushing with 200 ml PBS. Finally, remaining adherent cells were collected by an afterwash with 10% trypsin. These solutions, as well as blood samples, were analyzed for WBC count, viability and differentiation. Random eluate samples were analyzed by flow cytometry, and the influence of elution on PMN activation was tested in a separate control experiment. WBC numbers decreased by flushing before elution, whereas cell numbers were maximal after elution with PBS/3 mM EDTA (30 x 10(6)). Trypsin afterwash resulted in a further yield of 12 x 10(6) cells. The eluates contained 81% PMN (blood 68%, p < 0.01), with a degranulated appearance, and only 12% lymphocytes (blood 21%, p < 0.05); cell viability in the eluates was > 95%. The eluted cells could be analyzed by flow cytometry, and the procedure itself induced only minimal PMN activation. In conclusion, a maximal number of adherent cells, consisting mainly of PMN, was obtained by direct elution with PBS/3 mM EDTA. The method itself did not induce marked PMN activation, and the cells obtained were suitable for further investigations, including flow cytometry.

Biocompatible Materials↗

PubMed1996

Lymphocyte subsets in dialyser eluates: a new parameter of bioincompatibility?

INTRODUCTION: During haemodialysis (HD), several adverse reactions in peripheral blood can occur, which have been attributed to the bioincompatibility of the dialyser membrane. Utilizing a dialyser elution technique, we have demonstrated that polymorphonuclear cells (PMN) manifested non-membrane dependent signs of activation during HD with cellulose triacetate (CTA), cuprammonium (CU) and polysulphone (PS) membranes. In the present study, we employed this elution technique to investigate the influence of HD with these membranes on lymphocytes. METHODS: Eight patients were studied during HD with CTA, CU, and PS dialysers in a randomized crossover design. Dialyser elution was performed after 3 h of HD. Besides total leukocyte count and differentiation, lymphocyte subpopulations and activation status in peripheral blood and dialyser eluates were analysed by flow cytometry. RESULTS: Only with CU was a significant leukocyte decrease observed in peripheral blood at 30 min (P<0.001). Neither the total number of lymphocytes nor the proportion of T(CD3+) and B(CD19+) cells had markedly changed after HD with either membrane. Meanwhile, all membranes induced a relative decline in natural killer cells -NK(CD3-/CD16+/56+)- at the end of dialysis, although this was only significant for CTA (P=0.04). As for the T-lymphocyte subsets, the proportion of CD4+ cells had markedly increased after three hours of HD with all three dialysers, CTA and PS being significant (P<0.05). Dialyser eluates contained 33.8-82.2 x 10(6) cells, CTA yielding the highest cell counts. The majority (81-91%) of the eluted cells consisted of PMN dialyser eluates versus peripheral blood: P<0.05), whereas only few lymphocytes were found (4-13%, absolute 2.6 x 10(6)). Lymphocyte subpopulations in dialyser eluates were comparable to peripheral blood at t 180 in case of CTA and CU. In contrast PS eluates contained significantly fewer T-cells (37%), but more B-cells (22%) and NK-cells (30%) in comparison with peripheral blood at 180 min (peripheral blood: 79, 6 and 16% respectively; P<0.05). The expression of activation markers on T-cells (HLA-DR, CD25) in dialyser eluates was comparable with peripheral blood. Conclusions. The absolute number of lymphocytes in dialyser eluates of CTA, CU, and PS dialysers was low (mean 2.6 x 10(6)) in comparison with peripheral blood (mean 1.4 x 10(9)/l). Whereas non-selective adhesion occurred in CU and CTA dialysers, a selective adhesion pattern of lymphocyte subpopulations was observed in case of PS, suggesting a difference in bioincompatibility. Apparent T-cell activation was not noted, either in peripheral blood or in dialyser eluates. Because PMN in the dialyser eluates of three different membranes showed similar activation patterns in a previous study, we hypothesize that eluted lymphocyte, rather than PMN, represent a preferable parameter of bioincompatibility.

Adult↗

PubMed1995

Fibrinolytic split products, fibrinolysis, and factor XIII activity in inflammatory bowel disease.

BACKGROUND: Factor XIII (F XIII), the last coagulation factor in the clotting cascade, plays a role in mucosal repair. Beneficial effects of F XIII supplementation in severe ulcerative colitis (UC) have been observed. The aim of this study was to relate plasma F XIII activity to the severity of inflammatory bowel disease (IBD). METHODS: A transversional and, in part, longitudinal study of F XIII activity and related clotting products was performed in 39 patients with UC, 31 patients with Crohn's disease (CD), and 20 controls. Disease activity was assessed with a combined activity score in UC and with the Dutch Activity Index in CD. RESULTS: F XIII activity was decreased in active UC (p < 0.05) and active CD (p < 0.05) and was inversely correlated with severity in both UC (r = -0.30) and CD (r = -0.46). In six patients with UC (15%) and six patients with CD (19%) F XIII activity was below the lower range of normal. In these patients apparent rectal bleeding was only found in severe UC. Hyperfibrinolysis was indicated by elevated levels of D-dimer (p < 0.001) notwithstanding increased concentrations of alpha-2 antiplasmin (p < 0.05). CONCLUSIONS: In active IBD we found decreased plasma F XIII activity and hyperfibrinolysis. Decreased F XIII activity was not associated with apparent rectal bleeding in IBD.

Adolescent↗

PubMed1995

Granulocyte sequestration in dialysers: a comparative elution study of three different membranes.

BACKGROUND: The present study was designed to investigate the expression of activation markers on polymorphonuclear cells (PMN) in peripheral blood and dialyser eluates, comparing three different membranes. METHODS: Eight patients were studied during HD with cellulose triacetate (CTA), cuprammonium (CU), and polysulphone (PS) dialysers in a randomized crossover design. In addition to total cell count and microscopic leukocyte differentiation, the expression of degranulation (CD63, CD66b) and adhesion (CD62L) markers on PMN was analysed in peripheral blood over time, and in dialyser eluates at the end of HD. RESULTS: In peripheral blood a significant drop in PMN was noted only during CU HD (P < 0.001), whereas none of the membranes induced any substantial change in the expression of the activation markers mentioned. In dialyser eluates the mean number of cells was 53 x 10(6), CTA yielding a significantly higher number as compared with CU (P = 0.05). The proportion of PMN was 81-91% (P < 0.05 versus peripheral blood). The expression of CD63, and especially CD66b, in dialyser eluates of all membranes was significantly higher in comparison with peripheral blood, whereas the expression of CD62L in dialyser eluates was considerably lower. CONCLUSIONS: Dialyser eluates of all three dialysers consisted mainly of PMN. Based on the relatively modest cell numbers and the expression of the activation markers described, our results suggest primarily degranulation within the dialyser. Apart from differences in cell numbers, CTA yielding the highest cell counts, no differences between CTA, CU, and PS could be demonstrated in dialyser eluates.

Adult↗

PubMed1994

Methodology-dependent variations in reticulocyte counts using a manual and two different flow cytometric procedures.

This paper describes a comparison between the microscopic brilliant cresyl blue and the flow cytometric thiazol orange (FACScan) and auramine O (Sysmex) methods for enumeration of reticulocytes. The mean intra-assay coefficients of variation for the microscopic, FACScan and Sysmex methods were established to be 33.9 and 5% respectively. A rather poor correlation was observed between the microscopic count and both flow cytometric methods (FACScan r = 0.61; Sysmex r = 0.57). However, the correlation between the flow cytometric methods was satisfactory (r = 0.79). Reference ranges for the reticulocyte count, corresponding with the 2.5th and 97.5th percentile, were determined for the microscopic (8-30/1000), FACScan (11-27/1000) and Sysmex (8-18/1000) methods. Sysmex R-3000 methodology definitely revealed the lowest and narrowest reference range. In conclusion, because of higher reproducibility, flow cytometric analysis of reticulocytes is an attractive alternative procedure for the microscopic enumeration method.

Flow Cytometry↗