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.

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.

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.

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.

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.

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.

New fluorescent method (PLT-F) on Sysmex XN2000 hematology analyzer achieved higher accuracy in low platelet counting.

OBJECTIVES: In thrombocytopenia, high accuracy and precision of low platelet count is essential for appropriate decisions. The recently introduced Sysmex XN2000 analyzer (Sysmex, Kobe, Japan) offers 3 methods for platelet counting: impedance (PLT-I), optical (PLT-O), and a new fluorescence method (PLT-F). The precision of the PLT-F method in blood samples with platelet counts less than 50 × 10(3)/µL (50 × 10(9)/L) was investigated and compared with the ICSH CD61-ImmunoPLT reference method. For comparison, PLT-I and PLT-O were determined on the Sysmex XN2000 and Sysmex XE2100 analyzer. METHODS: Blood samples with platelet counts less than 50 × 10(3)/µL (50 × 10(9)/L) (n = 37) were analyzed on the Sysmex XN2000 and XE2100 analyzers. The CD61-ImmunoPLT method was performed on a Beckman Coulter FC-500 flow cytometer (Miami, FL). RESULTS: At a platelet count of 20 × 10(3)/µL (20 × 10(9)/L), reproducibility for PLT-I, PLT-O, and PLT-F on the XN2000 demonstrated coefficients of variation of 9.3%, 8.5%, and 3.0%, respectively. Correlation between PLT-O on the XN2000 and XE2100 yielded an r value of more than 0.977. Linear regression analysis between the PLT-F and CD61-ImmunoPLT methods resulted in a PLT-F of 0.71*CD61 - 0.8 (r = 0.988). Linear regression between PLT-F and PLT-O on the XN2000 resulted in a PLT-F of 1.05*PLT-O - 2 (r = 0.975), and using the transfusion threshold of 20 × 10(9)/L platelets resulted in a PLT-F of 0.90*PLT-O - 0.4 (r = 0.956). CONCLUSIONS: The new PLT-F method demonstrated excellent results for reproducibility in samples with platelet counts less than 50 × 10(9)/L. PLT-F could be helpful in making better decisions for platelet transfusions.

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.

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).

Aspects of platelet disturbances in haemodialysis patients.

Patients with mild-to-chronic kidney disease (CKD) exhibit a variety of haemostatic disorders, ranging from an increased clotting tendency and reductions in the levels of natural inhibitors of coagulation to defective fibrinolysis. In addition, platelet (PLT) abnormalities are common. In this minireview, we report on aspects of haemodialysis (HD)-induced PLT activation. It is demonstrated that PLTs from HD patients are exhausted due to repeated stimulation of HD treatment and recurrent release of PLT degranulation products. During HD, additional aberrations of the haemostatic process occur. Besides deviations of coagulation and fibrinolysis, PLT activation and a reduction in their granule content have been observed during HD treatment. As HD treatment is carried out three times per week, month after month, chronic HD patients may suffer persistently from coagulation defects and PLT disorders on top of the alterations induced by the uraemic state itself. PLT activation occurs together with thrombin and fibrin generation. However, macro fibrin depositions in clot devices are not demonstrated, microaggregates occur not only in the extracorporeal circuit (ECC) but are also present in the blood circulation. As vascular access thrombosis is a frequent complication in patients with HD treatment, it is believed that hypercoagulability could result from vascular changes combined with PLTs and activation of coagulation factors.

Efficacy of advanced discriminating algorithms for screening on iron-deficiency anemia and ß-thalassemia trait: a multicenter evaluation.

For many years, application of RBC indices has been recommended for discriminating between subjects with iron deficiency from those with thalassemia. However, application of the algorithms resulted in only 30% to 40% of subjects being appropriately classified. The aim of the study was to establish the efficacy of algorithms for anemia screening including new hematologic parameters such as percentage of hypochromic and microcytic RBCs and hemoglobin content of reticulocytes. Subjects with iron deficiency anemia (IDA) (n = 142) and subjects with ß-thalassemia (n = 34) were enrolled in a European multicenter study. Apparently healthy subjects were used as a reference group (n = 309). Hemocytometric investigations were performed on a Sysmex XE5000 hematology analyzer. The algorithms for IDA discrimination yielded results for area under the curve, sensitivity, specificity, and positive and negative predictive values of 0.88, 79%, 97%, 74%, and 98%, respectively. The algorithms for ß-thalassemia discrimination revealed similar results (0.86, 74%, 98%, 75%, and 99%, respectively). We conclude that the advanced algorithms, derived from extended RBC parameters provided by the Sysmex XE5000 analyzer, are useful as laboratory anemia screening devices.

D-dimer levels in assessing severity and clinical outcome in patients with community-acquired pneumonia. A secondary analysis of a randomised clinical trial.

BACKGROUND: D-dimer levels are in several studies elevated in patients with CAP. In this study we assess the use of D-dimer levels and its association with severity assessment and clinical outcome in patients hospitalised with community-acquired pneumonia. METHODS: In a subset of randomised trial patients with community-acquired pneumonia serial D-dimer levels was analysed. CURB-65 scores were calculated at admission. RESULTS: A total of 147 patients were included. D-dimer levels at admission were higher in patients with severe CAP (2166 ± 1258 versus 1630 ± 1197 µg/l, p=0.03), with clinical failure at day 30 (2228 ± 1512 versus 1594 ± 1078 µg/l, p=0.02) and with early failure (2499 ± 1817 µg/l versus 1669 ± 1121 µg/l, p=0.01). Non-survivors had higher D-dimer levels (3025 ± 2105 versus 1680 ± 1128 µg/l, p=0.05). None of the 16 patients with D-dimer levels<500 µg/l died. In multivariate analysis D-dimer levels were not associated with clinical outcome. D-dimer levels have poor accuracy for predicting clinical outcome at day 30 (AUC 0.62, 95% CI 0.51-0.73) or 30 day mortality (AUC 0.71 (95% CI 0.51-0.91)). Addition of D-dimer levels to CURB-65 did not increase accuracy. No differences were observed in serial D-dimer levels between patients with clinical success or failure at day 30. CONCLUSION: D-dimer levels are elevated in patients with CAP. Significantly higher D-dimer levels are found in patients with clinical failure and with severe CAP. D-dimer levels as single biomarker or as addition to the CURB-65 have no added value for predicting clinical outcome or mortality. D-dimer levels<500 µg/l may identify candidates at low risk for complications.

Effects of iron supplementation on red blood cell hemoglobin content in pregnancy.

Although a mild degree of anemia is common in the third trimester of pregnancy, it remains a challenge to establish whether a decrease in hemoglobin (Hb) concentration is physiological or pathological. The World Health Organization suggested a Hb concentration of 110 g/L to discriminate anemia. Several European investigators recommended Hb cut-off values of between 101-110 g/L. The aim of this study was to establish short-term effects of iron supplementation on the hemoglobin content of reticulocytes (Ret-He) and red blood cells (RBC-He) in case of suspected iron deficient erythropoiesis (IDE) in the third trimester of pregnancy. Twenty-five subjects with suspected IDE during pregnancy (Hb ≤110g/L, Ret-He <29.6 pg, zinc protoporphyrin >75 mol/mol hem) participated in the study. After iron supplementation, reticulocyte counts increased from 0.061±0.015×10(12)/L to 0.079±0.026×10(12)/L and Ret-He increased from 23.6±2.8 pg to 28.3±2.6 pg (P=<0.001). RBC-He increased from 26.9±1.9 pg to 27.4±1.8 pg (not significant, NS) and Ret-He/RBC-He ratio increased from 0.97±0.06 towards 1.07±0.05 (P=<0.001). Hb concentrations demonstrated an obvious increase from 105±6 g/L towards 115±5 g/L (P≤0.001) after supplementation. An obvious increase in RBC distribution width was observed from 45.0±3.6 fL towards 52.3±7.0 fL (P≤0.001). We recommend that Ret-He and Ret-He/RBC-He ratio be integrated into the protocols for anemia screening and for monitoring effects of iron supplementation during pregnancy. In particular, the parameters should be considered in subjects with Hb results in the controversial range of 101-108 g/L.

Electron microscopic observation in case of platelet activation in a chronic haemodialysis subject.

During haemodialysis (HD), platelets (PLTs) are activated and release granule contents. As HD treatment occurs three times a week, it has been demonstrated that PLTs are exhausted due to the repetitive character of the treatment. To identify PLT depletion morphologically, PLT evaluation was performed by light microscopy and electron microscopy (EM) in a chronic HD subject and a healthy reference subject. Blood samples were taken before the start of HD treatment for measurement of PLT count, PLT volume and size parameters. Blood smears were screened by light microscopy for qualitative evaluation of PLT granule containing cytoplasm, as indicated by its staining density. Morphological PLT parameters of surface area and size of dense bodies were assessed by EM. Data were compared with results of a group of 20 chronic HD subjects and a group of 20 healthy reference subjects. With respect to the percentage of PLTs with appropriate staining density (>75%), light microscopic evaluation showed that this value (9%) was within the range of a group of chronic HD subjects, but considerably below the reference range (70%). EM evaluation revealed an average PLT surface area and dense bodies area of respectively 42% and 31%, if the healthy reference subject was set on 100%. PLTs from a chronic HD subject are considerably smaller and substantially less granular than PLTs from a healthy reference subject. These findings support the hypothesis of PLT depletion in chronic HD subjects due to frequent PLT activation and/or increased urea concentrations.

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.

Procalcitonin vs C-reactive protein as predictive markers of response to antibiotic therapy in acute exacerbations of COPD.

BACKGROUND: Rational prescription of antibiotics in acute exacerbations of COPD (AECOPD) requires predictive markers. We aimed to analyze whether markers of systemic inflammation can predict response to antibiotics in AECOPD. METHODS: We used data from 243 exacerbations out of 205 patients from a placebo-controlled trial on doxycycline in addition to systemic corticosteroids for AECOPD. Clinical and microbiologic response, serum C-reactive protein (CRP) level (cutoffs 5 and 50 mg/L), and serum procalcitonin level (PCT) (cutoffs 0.1 and 0.25 µg) were assessed. RESULTS: Potential bacterial pathogens were identified in the majority of exacerbations (58%). We found a modest positive correlation between PCT and CRP (r = 0.46, P < .001). The majority of patients (75%) had low PCT levels, with mostly elevated CRP levels. Although CRP levels were higher in the presence of bacteria (median, 33.0 mg/L [interquartile range, 9.75-88.25] vs 17 mg/L [interquartile range, 5.0-61.0] [P = .004]), PCT levels were similar. PCT and CRP performed similarly as markers of clinical success, and we found a clinical success rate of 90% in patients with CRP ≤ 5 mg/L. A significant effect of doxycycline was observed in patients with a PCT level < .1 µg/L (treatment effect, 18.4%; P = .003). A gradually increasing treatment effect of antibiotics (6%, 10%, and 18%), although not significant, was found for patients with CRP values of ≤ 5, 6-50, and > 50 mg/L, respectively. CONCLUSIONS: Contrary to the current literature, this study suggests that patients with low PCT values do benefit from antibiotics. CRP might be a more valuable marker in these patients.

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.