Eosinopenia and increased markers of endothelial damage are characteristic of COVID-19 infection at time of hospital admission.

In December 2019, a new virus has been discovered, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), leading to coronavirus disease 2019 (COVID-19). COVID-19 has been defined as an evolving disease with different phases. It starts with a mild or asymptomatic phase in which there is minimal disease. Thereafter, most patients recover, however, in 20% of the cases the infection worsens. It is hypothesized that eosinopenia, endothelial injury and the presence of smooth muscle autoantibodies are associated with the severity of the COVID-19. In a subset of 75 blood samples of patients with a SARS-CoV-2 infection at time of hospitalization and 30 healthy control samples concentrations of eosinophils, VEGF, VCAM, endothelin and smooth muscle autoantibodies were determined with hemocytometry, ELISA and immunofluorescence assays. In the group of patients with COVID-19 eosinophils (IQR = 0.0-0.01*109/L) were significantly decreased (p < .001), whereas markers of endothelial damage VCAM (IQR = 740-1120 ng/mL) and endothelin (IQR = 2.0-3.4 pg/mL) were significantly increased (p < .001) compared to the group of healthy controls (eosinophils IQR = 0.09-0.19*109/L, VCAM IQR = 362-561 ng/mL, endothelin IQR = 0.5-1.0 pg/mL). From the multivariate analysis, it is concluded that at time of hospitalization a combination of eosinopenia and increased markers of endothelial damage VCAM and endothelin are characteristic of COVID-19.

CRP-guided antibiotic treatment in acute exacerbations of COPD in hospital admissions.

The role of antibiotics in acute exacerbations of chronic obstructive pulmonary disease (COPD) is controversial and a biomarker identifying patients who benefit from antibiotics is mandatory. We performed a randomised, controlled trial in patients with acute exacerbations of COPD, comparing C-reactive protein (CRP)-guided antibiotic treatment to patient reported symptoms in accordance with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy, in order to show a reduction in antibiotic prescription.Patients hospitalised with acute exacerbations of COPD were randomised to receive antibiotics based either on the GOLD strategy or according to the CRP strategy (CRP ≥50 mg·L-1).In total, 101 patients were randomised to the CRP group and 119 to the GOLD group. Fewer patients in the CRP group were treated with antibiotics compared to the GOLD group (31.7% versus 46.2%, p=0.028; adjusted odds ratio (OR) 0.178, 95% CI 0.077-0.411, p=0.029). The 30-day treatment failure rate was nearly equal (44.5% in the CRP group versus 45.5% in the GOLD-group, p=0.881; adjusted OR 1.146, 95% CI 0.649-1.187, p=0.630), as was the time to next exacerbation (32 days in the CRP group versus 28 days in the GOLD group, p=0.713; adjusted hazard ratio 0.878, 95% CI 0.649-1.187, p=0.398). Length of stay was similar in both groups (7 days in the CRP group versus 6 days in the GOLD group, p=0.206). On day-30, no difference in symptom score, quality of life or serious adverse events was detected.Use of CRP as a biomarker to guide antibiotic treatment in severe acute exacerbations of COPD leads to a significant reduction in antibiotic treatment. In the present study, no differences in adverse events between both groups were found. Further research is needed for the generalisability of these findings.

Transient impairment of reticulocyte hemoglobin content and hepcidin-25 induction in patients with community-acquired pneumonia.

INTRODUCTION: Patients with community-acquired pneumonia (CAP) often exhibit a declining hemoglobin (Hb) concentration. During inflammation pro-inflammatory cytokines and cells of the reticuloendothelial system induce disturbances in iron homeostasis. In this study inflammation markers and hepcidin-25 concentrations were monitored together with short-term alterations in reticulocyte hemoglobinization (RET-He). METHODS: A total of 25 patients with CAP participated in the study. The assay for serum hepcidin-25 is based on a combination of weak cation exchange chromatography and time-of-flight mass spectrometry. RESULTS: At hospital admission serum hepcidin-25 concentrations (14.6 ± 6.9 nMol/L, mean ± SD) were established in the upper level of the reference range (0.5-13.9 nMol/L). Results for C-reactive protein (CRP) and Interleukin-6 (IL-6) were obviously increased compared to the reference ranges. From admission until day 14 hepcidin-25, CRP and IL-6 steadily decreased towards the reference ranges. Hb concentrations declined from admission until day 4 from 8.1 ± 1.0 mMol/L to 7.4 ± 0.9 mMol/L. At admission Ret-He results were within the lower region of the reference range (1900-2300aMol) and results demonstrated a decline during admission from 1931 ± 241 aMol until 1845 ± 199 aMol (NS) at day 4. From a minimum Ret-He value at day 4 results increased towards 2129 ± 136 aMol at day14. CONCLUSION: A transient increase of cytokine-stimulated serum hepcidin-25 in combination with a temporary decrease of Hb and Ret-He is demonstrated in patients with CAP. Our results support the hypothesis that hepcidin-25 induces transient impairment of reticulocyte hemoglobin content (Ret-He).

Coagulation activation, depletion of platelet granules and endothelial integrity in case of uraemia and haemodialysis treatment.

BACKGROUND: During haemodialysis (HD) treatment, increase of platelet (PLT) activation and induction of procoagulant activity is demonstrated. Although the role of the endothelium and its direct interaction with coagulation and homeostasis is known, it is not elucidated how PLT activation markers and activation of coagulation coincide with markers of endothelial integrity during HD treatment. In the present study uraemia and HD induced changes, with particular emphasis on PLT granules depletion, activation of coagulation and endothelial integrity were investigated. METHODS: To detect depletion of PLT granules, peripheral blood slide smears were screened by light microscopy for qualitative evaluation of PLT granule containing cytoplasm, as indicated by its granules staining density. Activation of coagulation was investigated by establishement of thrombin-antithrombin (TAT) and fibrinogen concentrations. To evaluate endothelial integrity proendothelin (proET-1) plasma concentrations were established. RESULTS: Results of our study demonstrate that proET-1 plasma concentrations were obviously increased in the subjects' group with end-stage chronic kidney disease (CKD) and renal failure if compared with a group of apparently healthy subjects. The amount of depleted PLT granules was obviously increased in the subjects' group with end-stage CKD if compared with the group with renal failure. Mean plasma concentrations of TAT and fibrinogen revealed results within the reference range. CONCLUSIONS: It is demonstrated that uraemia is associated with endothelial damage and aberrations in PLT granules morphology in subjects with HD treatment. We hypothesize that increased proET-1 concentrations reflect ongoing stress on endothelial cells amongst others due to uraemia. Biomarkers like proET-1 and aberrations in PLT granules morphology assist in the early detection of procoagulant activity of the endothelium.

Effects of iron supplementation on microcytic and hypochromic red blood cells during the third trimester of pregnancy.

INTRODUCTION: Mild anaemia often occurs in the third trimester of pregnancy. Particularly in the Hb range between 101-110 g/L it is difficult to determine whether the decreased haemoglobin concentration is physiological or pathological and whether supplementation is required. The aim of this study was to gain insight into the added value of measuring the percentages of microcytic RBCs (%MicroR) and hypochromic RBCs (%Hypo-He) for monitoring effects of iron supplementation in case of suspected iron-deficient erythropoiesis (IDE) in the third trimester of pregnancy. METHODS: After assessing haematological parameters and zinc protoporphyrin/heme ratio as marker for IDE, subjects were classified into a group with symptoms of IDE (n = 39) or without IDE (n = 106). The subjects with IDE (n = 39) were treated with iron supplementation. After 4 weeks effects of treatment were evaluated. RESULTS: In the group of pregnant women with IDE results of %MicroR and %Hypo-He were increased (p = <.001), compared to the group without haematological symptoms of IDE, whereas RET-He, RBC-He and delta-He were decreased (p = <.001). A significant positive correlation to increased values of %MicroR (r = .75, p = <.001) and %Hypo-He (r = .77, p = <.001) with ZPP was established. However, in the ZPP interval 75-100 µmol/mol heme a slight overlap was demonstrated between subjects with and without symptoms of IDE. After iron supplementation, %Hypo-He decreased (p = .002) while %MicroR remained stable. RET-He, delta-He and RDW-SD increased (p = <.001). CONCLUSION: The added value of %MicroR and %Hypo-He as a single marker for IDE is poor. However, combined interpretation of %MicroR, %Hypo-He, Ret-He and delta-He has added value in monitoring erythropoiesis during pregnancy.

Relationship between biomarkers and findings on low-dose computed tomography in hospitalised patients with acute exacerbation of COPD.

Background: Acute exacerbations of COPD (AECOPD) and community acquired pneumonia (CAP) often coexist. Although chest radiographs may differentiate between these diagnoses, chest radiography is known to underestimate the incidence of CAP in AECOPD. In this exploratory study, we prospectively investigated the incidence of infiltrative changes using low-dose computed tomography (LDCT). Additionally, we investigated whether clinical biomarkers of CAP differed between patients with and without infiltrative changes. Methods: Patients with AECOPD in which pneumonia was excluded using chest radiography underwent additional LDCT-thorax. The images were read independently by two radiologists; a third radiologist was consulted as adjudicator. C-reactive protein (CRP), procalcitonin (PCT), and serum amyloid A (SAA) at admission were assessed. Results: Out of the 100 patients included, 24 had one or more radiographic abnormalities suggestive of pneumonia. The interobserver agreement between two readers (Cohen's κ) was 0.562 (95% CI 0.371-0.752; p<0.001). Biomarkers were elevated in the group with radiological abnormalities compared to the group without abnormalities. Median (interquartile range (IQR)) CRP was 76 (21.5-148.0) mg·L-1 compared to 20.5 (8.8-81.5) mg·L -1 (p=0.018); median (IQR) PCT was 0.09 (0.06-0.15) µg·L-1 compared to 0.06 (0.04-0.08) µg·L-1 (p=0.007); median (IQR) SAA was 95 (7-160) µg·mL-1 compared to 16 (3-89) µg·mL-1 (p=0.019). Sensitivity and specificity for all three biomarkers were moderate for detecting radiographic abnormalities by LDCT in this population. The area under the receiver operating characteristic curve was 0.66 (95% CI 0.52-0.80) for CRP, 0.66 (95% CI 0.53-0.80) for PCT and 0.69 (95% CI 0.57-0.81) for SAA. Conclusion: LDCT can detect additional radiological abnormalities that may indicate acute-phase lung involvement in patients with AECOPD without infiltrate(s) on the chest radiograph. Despite CRP, PCT and SAA being significantly higher in the group with radiological abnormalities on LDCT, they proved unable to reliably detect or exclude CAP. Further research is warranted.

Evaluation of a new procalcitonin assay for the Siemens ADVIA Centaur with the established method on the B.R.A.H.M.S Kryptor.

BACKGROUND: In this study, we compared the B.R.A.H.M.S Kryptor procalcitonin (PCT) assay with the newly developed ADVIA Centaur B.R.A.H.M-S PCT assay. Furthermore, the long-term stability of PCT at - 20 degrees C was assessed. METHODS: Samples from 97 patients with lower respiratory tract infections were retested on both systems and compared with Passing-Bablok regression over two clinically relevant cutoff ranges for PCT, 0 - 2.0 microg/L and > 2.0 microg/L. RESULTS: After storage for 2.5 to 4 years, PCT levels in patient sera declined only 3.7%. Passing-Bablok regression analysis of the total sample range (n = 97) showed that both methods correlated well (r = 0.9944), although with a deviation from the line of identity (y = 0.880x - 0.025 microg/L). Comparison of both methods within the clinically important interval of 0 - 2.0 microg/L showed acceptable correlation (y = 0.943x + 0.010 microg/L). CONCLUSIONS: The ADVIA Centaur B.R.A.H.M.S PCT assay showed good correlation with the established Kryptor method. Therefore, this new technique can be used in clinical routine with the same clinical interpretation.

Platelet depletion, platelet activation and coagulation during treatment with hemodialysis.

Bioincompatibility is the total of side effects during hemodialysis (HD) including, amongst others, changes in platelet (PLT) level. Deviations in PLT count, immature PLT count, PLT morphology, CD62p expression, Platelet Factor 4 (PF4), ß-Thromboglobulin (ß-TG), serotonin, Thrombin-Antithrombin III (TAT) and Prothrombin Fragment 1+2 (F1+2) are monitored before and during treatment with HD in order to elucidate the interaction between modifications in PLT morphology, PLT activation and markers concerning activation of coagulation. Different patterns with time indicate that there is no correlation between an increased amount of depleted PLTs and increased amounts of PLT activation markers such as CD62p, PF4, ß-TG and serotonin. A statistically significant correlation between increased PLT activation markers and markers for increased activation of coagulation such as TAT and F1+2 has not been established. Only a weak correlation is demonstrated between the increase of markers for activation of coagulation and the decrease in PLT counts, immature PLT counts and depleted PLTs during HD treatment. The change in the extracorporeal circuit during HD is probably a more critical factor in the mechanism leading to activation of the coagulation pathway than the modifications in PLT morphology.

Erythrocyte deformability and aggregability in patients undergoing colon cancer surgery and effects of two infusions with omega-3 fatty acids.

BACKGROUND: An adequate erythrocyte function is vital for tissue oxygenation and wound healing. The erythrocyte membrane phospholipid composition plays an important role in erythrocyte function and administration of omega-3 fatty acids may provide a means to improve it. OBJECTIVE: To investigate peri-operative erythrocyte function and effects of omega-3 fatty acidsMETHODS:Forty-four patients undergoing elective laparoscopic colon resection for non-metastasized cancer were randomized between intravenous omega-3 poly-unsaturated fatty acids (n-3 PUFAs) or placebo (saline). Peri-operative blood samples were analyzed with a Lorrca MaxSIS Ektacytometer and erythrocyte membrane phospholipids were determined with gas chromatography. RESULTS: Patient and operation characteristics were equal between groups. There was a significant increase in erythrocyte membrane eicosapentaenoic acid (EPA) but not docosahexaenoic acid (DHA) in the n-PUFA group. There were no significant differences in erythrocyte deformability but the aggregation index (AI) was significantly lower and the aggregation half time (T½) was significantly higher in the n-3 PUFA group. CONCLUSION: This study confirms rapid changes in erythrocyte membrane phospholipid composition after administration of intravenous n-3 PUFAs. Erythrocyte deformability parameters were not affected but erythrocyte aggregability was decreased in the n-3 PUFA group. Further investigation is necessary to gain more insights in the effects of n-3 PUFA and the postoperative inflammatory response on erythrocyte function.

Erythrocyte deformability and aggregation in morbidly obese women undergoing laparoscopic gastric bypass surgery and effects of oral omega-3 fatty acid supplementation.

BACKGROUND: An adequate erythrocyte function is vital for tissue oxygenation and wound healing. The erythrocyte membrane phospholipid composition plays an important role in erythrocyte function and administration of omega-3 fatty acids may provide a means to improve it. OBJECTIVE: To investigate peri-operative erythrocyte function and effects of oral omega-3 fatty acids in morbidly obese women undergoing gastric bypass surgeryMETHODS:Fifty-six morbidly obese women undergoing laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery were randomized between a low calorie diet (LCD) during 2 weeks or oral omega-3 poly-unsaturated fatty acids (n-3 PUFAs) and a normal diet during 4 weeks. Peri-operative blood samples were analyzed with the Lorrca MaxSIS Ektacytometer for erythrocyte deformability and aggregability. RESULTS: There were no significant differences in erythrocyte function between the groups at any time point. Only erythrocyte aggregability parameters were affected by surgery. At six month follow-up, aggregation index (AI) and cholesterol, glucose and insulin were significantly improved. CONCLUSIONS: In this study, oral Omega-3 supplementation did not affect erythrocyte function compared to a LCD. Six months after surgery a significant improvement in AI and metabolic parameters was observed in both groups, contributing to a reduction in the risk at thromboembolic and cardiovascular complications.

Post-dilution haemodiafiltration and low-flux haemodialysis have dissimilar effects on platelets: a side study of CONTRAST.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death in patients with end-stage renal disease (ESRD). Platelet (PLT) dysfunction, which is a well-known phenomenon in advanced chronic renal failure, corresponds positively with CVD in these patients. The accumulation of retained uraemic toxins might play an important role in this respect. During haemodialysis (HD), both an increase in the expression of the platelet (PLT) cell surface molecule P-selectin (CD62p) and the release of intra-granular substances, such as platelet factor 4 (PF4) and ss-thromboglobulin (BTG), have been described. As the removal of uraemic toxins is superior during haemodiafiltration (HDF), this form of treatment may have quite another impact on PLTs than HD. METHODS: Nineteen chronic HD patients who were treated with low-flux HD for at least 2 months were included in the Dutch CONvective TRAnsport STudy (CONTRAST). After randomization, 10 patients continued low-flux HD and 9 patients switched to post-dilution HDF. The present study describes various parameters of PLT activation and degranulation at baseline (during HD) and after 3 months (during HDF) in the latter group of patients. At both time points, multiple blood samples were drawn. During the first 30 min of treatment, differences over the extracorporeal circuit (ECC) were calculated by taking samples from both afferent (arterial) and efferent (venous) lines. Correlations between various parameters were calculated in the total group of patients after 3 months. RESULTS: Immediately after the start of HD, PLT counts dropped over the ECC. During HDF, PLT counts decreased even more and reached a nadir at t30. CD62p expression increased early during HD and returned to baseline thereafter. During HDF, these changes were more pronounced and more protracted. With respect to degranulation, rather dissimilar results were obtained. During HD, both PF4 and BTG increased over time, whereas during HDF, PF4 increased but BTG did not change. Haemoconcentration and transmembrane pressure (TMP) within the dialyser were, respectively, approximately 10 and 3x higher during HDF than during HD. There was a striking correlation between the changes in haemoconcentration and the changes in both PLT counts and CD62p over the ECC. SUMMARY AND CONCLUSIONS: PLT activation, as measured by the expression of CD62p, was more pronounced and more protracted during HDF than during HD. During HDF, PLTs were trapped abundantly within the ECC, not only after first passage, but also thereafter. The degranulation product BTG increased during HD, but did not change during HDF. These observations may well be explained by the greater haemoconcentration and/or higher TMP during HDF on the one hand, and superior convective transport at the other. Whether the potential harmful effects of enhanced PLT activation are counterbalanced by the beneficial effects of an increased convective transport of degranulation products remains to be established.

Markers of infection in inpatients and outpatients with acute Q-fever.

BACKGROUND: Query-fever (Q-fever) is a zoonotic infection caused by the intracellular Gram-negative coccobacillus Coxiella burnetii. A large ongoing outbreak of Q-fever has been reported in the Netherlands. We studied various markers of infection in inpatients (hospitalised) and outpatients (treated by a general physician) with acute Q-fever in relation to disease severity. METHODS: Leukocyte counts, C-reactive protein (CRP) and procalcitonin (PCT) concentrations were measured in 25 inpatients and 40 outpatients upon presentation with acute Q-fever. Chest X-rays, if available, were analysed and confusion, urea, respiratory rate, blood pressure-age 65 (CURB-65) scores, indicating severity of pneumonia, were calculated. RESULTS: CRP was the only marker that significantly differentiated between inpatients and outpatients. It was increased in all patients from both groups. Leukocyte counts and PCT concentrations did not differ between inpatients and outpatients. Overall, only 13/65 patients had an increased leukocyte count and only 11/65 patients presented with PCT concentrations indicative of possible bacterial respiratory tract infection. Infiltrative changes on the chest X-ray were observed in the majority of patients. CURB-65 score was 0+/-1 (mean+/-SD). CONCLUSIONS: Acute Q-fever, a relatively mild pneumonia with low CURB-65 scores, specifically induces a response in CRP, while PCT concentrations and leukocytes are within the normal range or increased only marginally.

The role of the extracorporeal circuit in the trapping and degranulation of platelets.

BACKGROUND: Although platelet (PLT) activation and degranulation are well-known phenomena during hemodialysis (HD), controversies still exist about their nature and origin. METHODS: PLT characteristics [PLT numbers, mean PLT volume (MPV), PLT distribution width (PDW), PLT large cell ratio (p-LCR), immature PLT fraction] and activation status [CD62p expression, platelet factor 4 (PF4) and beta-thromboglobulin (BTG) plasma levels] were estimated in 19 patients before and during HD. Blood was sampled from both the afferent and efferent lines. Additionally, the influence of low-molecular-weight heparin (LMWH) on PF4 and BTG concentrations was analyzed. RESULTS: CD62p expression increased in the extracorporeal circuit (ECC) in the first 30 min. Simultaneously, PLT numbers dropped markedly within the ECC. MPV, PDW and p-LCR decreased over time. Like CD62p expression, BTG reached peak values at t30, was exclusively released within the ECC and was not influenced by the application of LMWH. In contrast, PF4 was significantly released outside the ECC in response to LMWH. CONCLUSIONS: PLTs are predominantly activated within the ECC and not on a remote distance. PLTs stick to the ECC, particularly after first passage. BTG is an appropriate marker for HD-induced PLT degranulation, whereas PF4 originates from both activated PLTs and LMWH-induced detachment from the endothelium. PLTs are not exhausted due to the repetitive stimulation of clinical HD. Hence, dialysis modalities with longer duration or greater frequency may be associated with a less beneficial PLT activation profile, which may counteract their clinical benefits.

Platelet activation in clinical haemodialysis: LMWH as a major contributor to bio-incompatibility?

BACKGROUND: The sum of undesirable side effects, occurring during haemodialysis (HD), is called bio-incompatibility. Concerning platelets, both an increase in the expression of the cell surface marker P-selectin (CD62p) and release of the intracellular granule product platelet factor 4 (PF4) have been described. However, as PF4 is also abundantly present on endothelium-bound proteoglycans, it is questionable whether the HD-induced increase is exclusively attributable to release from platelets. With respect to the cause of HD-induced bio-incompatibility, interest has been focused mainly on the extracorporeal circuit (ECC), especially the dialyser, whereas only little attention has been paid to other parts of the ECC and the mode of anticoagulation applied. To address the cause and origin of platelet activation and PF4 release during clinical HD, two complementary clinical studies were performed. MATERIALS AND METHODS: In study I, the relative influence of the various parts of the ECC was evaluated by measuring the expression of CD62p, platelet aggregation and levels of PF4 and serotonin at various sampling points. In study II, low-molecular-weight heparin (LMWH) was administered 10 min before the actual start of HD, in order to separate the effects from LMWH and the ECC on platelet activation. RESULTS: In study I, CD62p expression increased across the entire length of the ECC, including the roller pump and dialyser (median at t(5) from 26% to 43%, P = 0.008; median at t(30) from 28% to 48%, P = 0.007). Increments in PF4 and aggregation of platelets were relatively modest. Platelet serotonin content, which was below reference values in healthy controls, and plasma serotonin concentration, which was above reference values, did not change. In study II, PF4 levels increased markedly after the injection of LMWH (from 12 IU/ml at t(-10) to 75 IU/ml at t(0), P = 0.018), whereas CD62p expression remained stable until the start of HD. CONCLUSIONS: Platelet activation, as measured by the up-regulation of CD62p, is an early process, occurring not only within the dialyser, but across the entire length of the ECC. As CD62p remained unaltered after the administration of LMWH 10 min before the actual start of HD, this kind of activation is independent of LMWH. Considering PF4 however, a sharp increment was observed after the administration of LMWH and before the start of HD. This finding suggests that the PF4 release observed early in clinical HD is largely independent from the ECC, and is probably the result of LMWH-induced detachment from the endothelium. As the platelet serotonin content was relatively reduced and the plasma serotonin levels were elevated, platelets from chronic HD patients might be depleted due to chronic repetitive activation. Based on these data, it appears first, that PF4 is an inferior marker of platelet activation in clinical HD and second, that LMWH is a major contributor to HD-induced bio-incompatibility.

Reduction in platelet activation by citrate anticoagulation does not prevent intradialytic hemodynamic instability.

BACKGROUND: The etiology of intradialytic hemodynamic instability is multifactorial. Of the various factors involved, a rise in core temperature seems to be crucial. In this respect, the bioincompatibility of hemodialysis (HD) treatment might play an important role. The application of cool dialysate reduces the number of periods of intradialytic hypotension (IDH) considerably. In rats, roller pump perfusion caused hypotension by shear stress induced platelet aggregation and subsequent serotonin release. During clinical HD, citrate anticoagulation abolished platelet activation almost completely. Hence, citrate anticoagulation might reduce IDH, whereas the beneficial effect of cool dialysate might be partly explained by reduced platelet activation. METHODS: In the present study, blood pressure, IDH episodes, platelet activation, platelet aggregation, and serotonin release were studied crossover in 10 patients during HD with dalteparin anticoagulation at normal and low dialysate temperatures and during HD with citrate. RESULTS: Citrate strongly reduced platelet activation, but did not improve IDH. The blood pressure was best preserved during cool-temperature HD, despite manifest platelet activation. Platelet activation was not accompanied by a rise in the plasma serotonin concentration. CONCLUSIONS: Three major conclusions can be drawn: (1) it is unlikely that platelet activation and subsequent serotonin release underlie IDH in the clinical situation; (2) the protective effects of cool dialysate on IDH appear to be independent of HD-induced platelet activation, and (3) extrapolating results from rat experiments to the human situation requires uppermost prudence.

Hemoglobinization and functional availability of iron for erythropoiesis in case of thalassemia and iron deficiency anemia.

Microcytic erythropoiesis in case of anemia is frequently due to iron deficiency or may be due to alpha- and beta- thalassemia trait as a result of increased activity of erythropoiesis. The aim of the present study was to evaluate alterations with regard to the degree of hemoglobinization in reticulocytes in comparison with mature erythrocytes. Iron availability in subjects with anemia resulting from iron deficiency and alpha- or beta- thalassemia was studied by application of conventional as well hemocytometric parameters that have recently become available. Participants of the study were reference subjects (n=75), subjects with iron deficiency anemia (IDA, n=52) and alpha- (n=26) or beta-thalassemia trait (n=24). If compared with the reference group obviously increased RBC counts together with decreased values for RDW-sd and MCHC were established in case of alpha- and beta- thalassemia subjects. Deviations were demonstrated to be more pronounced in case of beta- thalassemia. Accelerated erythropoiesis in the case of subjects with IDA and beta-thalassemia is manifested by detection of increased results for immature reticulocyte counts. In particular in case of beta- thalassemia, elevated reticulocyte counts combined with slightly increased values for ZPP/heme ratio reflect increased activity of erythropoiesis. In the case of subjects with beta-thalassemia serum transferrin concentrations revealed slightly decreased results, whereas serum ferritin and iron concentrations demonstrated a tendency towards higher values if compared with the group of reference subjects. At a definitive MCV level, the hemoglobin content of reticulocytes is decreased in the case of IDA if compared with the alpha- or beta- thalassemia trait. For the ratio of hemoglobin content of reticulocytes and erythrocytes, obviously decreased results are demonstrated in the case of subjects with iron deficiency anemia (1.02 +/- 0.08, mean +/- SD) and in the case of beta-thalassemia (1.06 +/- 0.04) if compared with the group of reference subjects (1.11 +/- 0.02) and a-thalassemia (1.11 +/- 0.07). Evaluation of the hemoglobinization state should be performed by means of pattern recognition in concordance with characteristic profiles for parameters reflecting the actual iron state. In case of therapy the result of intervention can be appropriately monitored by longitudinal follow-up.

Erythropoiesis activity, iron availability and reticulocyte hemoglobinization during treatment with hemodialysis and in subjects with uremia.

In hemodialysis subjects correction of anemia is facilitated by combined supplementation of intravenous iron and recombinant human erythropoietin. Reticulocyte hemoglobin content (RET-He) is considered to be an actual indicator reflecting functional iron availability for erythropoiesis. In the present study, interdependence between biochemical analytes reflecting iron status and hemocytometric parameters indicating the degree of hemoglobinization of reticulocytes and red blood cells, respectively, is established. Participants of the study were reference subjects (n=75), subjects with iron deficiency anemia (n=52), subjects with uremia (n=19) and subjects undergoing hemodialysis treatment (n=43). If compared with the reference subjects the results for RBC counts and MCHC are statistically significantly decreased in case of subjects with hemodialysis and uremia, whereas increased results are established with regard to RDW-sd values. Significantly increased results for absolute reticulocyte counts and immature reticulocyte fractions (IRF) are also observed in case of subjects with hemodialysis and uremia. Slightly increased values for the ZPP/heme ratio in combination with elevated reticulocyte count reflect increased activity of erythropoiesis. At a definite MCV value, decreased levels for the hemoglobin content of reticulocytes (RET-He) and hemoglobin content of red blood cells (RBC-He) are observed in case of subjects treated with hemodialysis and in subjects with uremia if compared with identical MCV values of the group of reference subjects. For the ratio of RET-He and RBC-He obviously decreased results are demonstrated in case of subjects with iron deficiency anemia (1.02 +/- 0.08, mean +/- SD), hemodialysis (1.05 +/- 0.05) and uremia (1.02 +/- 0.10) if compared with the group of reference subjects (1.11 +/- 0.02). From the combined interpretation of the MCV values within the reference range and decreased values for RET-He and RET-He/RBC-He ratios, respectively, a decreased degree of hemoglobinization is concluded in the case of subjects with hemodialysis or uremia. The conclusion implicating the presumption of reduced functional availability of iron for hemoglobin synthesis is supported by the detection of increased results for sTfR concentrations and ZPP/heme ratios.

Application of Innovative Hemocytometric Parameters and Algorithms for Improvement of Microcytic Anemia Discrimination.

Hemocytometric parameters like red blood cell (RBC) count, mean red blood cell volume (MCV), reticulocyte count, red blood cell distribution width (RDW-SD) and zinc protoporphyrin (ZPP) are frequently established for discrimination between iron-deficiency anemia and thalassemia in subjects with microcytic erythropoiesis. However, no single marker or combination of tests is optimal for discrimination between iron-deficiency anemia and thalassemia. This is the reason why many algorithms have been introduced. However, application of conventional algorithms, only resulted in appropriate classification of 30-40% of subjects. In this mini-review the efficacy of innovative hematological parameters for detection of alterations in RBCs has been considered. It refers to parameters concerning hemoglobinization of RBCs and reticulocytes and the percentages microcytic and hypochromic RBCs, for discrimination between subjects with iron-deficiency anemia (IDA) or thalassemia as well as a combination of both. A new discriminating tool including the above mentioned parameters was developed, based on two precondition steps and discriminating algorithms. The percentage microcytic RBCs is considered in the first precondition step. MCV, RDW-SD and RBC count are applied in the second precondition step. Subsequently, new algorithms, including conventional as well as innovative hematological parameters, were assessed for subgroups with microcytic erythropoiesis. The new algorithms for IDA discrimination yielded results for sensitivity of 79%, specificity of 97%, positive and negative predictive values of 74% and 98% respectively. The algorithms for ß-thalassemia discrimination revealed similar results (74%, 98%, 75% and 99% respectively). We advocate that innovative algorithms, including parameters reflecting hemoglobinization of RBCs and reticulocytes, are integrated in an easily accessible software program linked to the hematology equipment to improve the discrimination between IDA and thalassemia.

Persistent activation of coagulation and fibrinolysis after treatment of active ulcerative colitis.

OBJECTIVE: Haemostatic changes may be involved in the pathogenesis and progression of ulcerative colitis. We studied longitudinally inflammatory and haemostatic parameters in patients treated for severe ulcerative colitis. DESIGN AND SETTING: We carried out a descriptive study of longitudinal blood measurements in patients with severe ulcerative colitis from one large regional hospital. METHODS: Nineteen patients with severe ulcerative colitis were assessed by an endoscopic score and a patient score at baseline. Patients were assessed by patient scores during treatment at scheduled intervals. At each visit, inflammatory and haemostatic parameters were determined. RESULTS: At baseline, the erythrocyte sedimentation rate, C-reactive protein, leucocyte and granulocyte count, thrombin-antithrombin complexes, prothrombin fragment 1+2, fibrinogen and degradation products of fibrinogen and fibrin were increased in patients when compared with controls, whereas albumin concentration and factor XIII activity were significantly lower. Antithrombin activity was normal. During treatment, the median patient score diminished significantly from 12 to 4.5 points after 2 weeks, decreased further to 4 points after 4 weeks and remained below 4 points throughout the remaining study period. Inflammation parameters returned to within the reference range in two patients after 4 weeks, whereas the coagulation markers prothrombin fragment 1+2 and thrombin-antithrombin complexes returned to normal values after 8 weeks and 24 weeks, respectively. In contrast with markers of inflammation, slightly increased concentrations of the degradation products of both fibrinogen and fibrin were found for almost 1 year, which indicated low-grade activation of coagulation and fibrinolysis. CONCLUSIONS: These results are compatible with a condition of persistent hypercoagulation in patients with ulcerative colitis who are in clinical remission. Persistent hypercoagulation may contribute to the clinical course of ulcerative colitis.