Reference intervals for Sysmex XN hematological parameters as assessed in the Dutch Lifelines cohort.

OBJECTIVES: Our aim was to derive reference intervals for all Sysmex XN hematology analyzer parameters. The rationale behind the study was the lack of reference intervals for the XN analyzer cell population data (CPD) and functional parameters. METHODS: Fresh fasting blood samples from 18,484 participants in the Dutch Lifelines study were analyzed using two automated XN analyzers. Structured health questionnaire data were used to select a subgroup of 15,803 apparently healthy individuals for inclusion in the reference population. The Latent Abnormal Values Exclusion (LAVE) approach was used to reduce the influence of latent diseases in the reference population on the resulting reference intervals. We applied analysis of variance to judge the need for partitioning of the reference intervals by sex or age. RESULTS: We report reference intervals for 105 XN analyzer hematological parameters with and without applying LAVE. Sex-related partitioning was required for red blood cells, (RBC, RBC-O), hemoglobin (HGB, HGB-O), hematocrit (HCT), mean corpuscular hemoglobin concentration (MCHC), reticulocyte production index (RPI), and side scattered light intensity of the red blood cell population in the RET channel (RBC-Z). Partitioning for age was not warranted. Body mass index (BMI) and smoking had moderate influence on a minority of the parameters. CONCLUSIONS: We provide reference intervals for all Sysmex XN analyzer routine, CPD and functional parameters, using a direct approach in a large cohort in the Netherlands.

The intensive care infection score - a novel marker for the prediction of infection and its severity.

BACKGROUND: The prediction of infection and its severity remains difficult in the critically ill. A novel, simple biomarker derived from five blood-cell derived parameters that characterize the innate immune response in routine blood samples, the intensive care infection score (ICIS), could be helpful in this respect. We therefore compared the predictive value of the ICIS with that of the white blood cell count (WBC), C-reactive protein (CRP) and procalcitonin (PCT) for infection and its severity in critically ill patients. METHODS: We performed a multicenter, cluster-randomized, crossover study in critically ill patients between January 2013 and September 2014. Patients with a suspected infection for which blood cultures were taken by the attending intensivist were included. Blood was taken at the same time for WBC, ICIS, CRP and PCT measurements in the control study periods. Results of imaging and cultures were collected. Patients were divided into groups of increasing likelihood of infection and invasiveness: group 1 without infection or with possible infection irrespective of cultures, group 2 with probable or microbiologically proven local infection without blood stream infection (BSI) and group 3 with BSI irrespective of local infection. Septic shock was assessed. RESULTS: In total, 301 patients were enrolled. CRP, PCT and ICIS were higher in groups 2 and 3 than group 1. The area under the receiver operating characteristic curve (AUROC) for the prediction of infection was 0.70 for CRP, 0.71 for PCT and 0.73 for ICIS (P < 0.001). For the prediction of septic shock the AUROC was 0.73 for CRP, 0.85 for PCT and 0.76 for ICIS. These AUROC did not differ from each other. CONCLUSION: The data suggest that the ICIS is potentially useful for the prediction of infection and its severity in critically ill patients, non-inferiorly to CRP and PCT. In contrast to CRP and PCT, the ICIS can be determined routinely without extra blood sampling and lower costs, yielding results within 15 minutes. TRIAL REGISTRATION: ClinicalTrials.gov identifier: ID NCT01847079 . Registered on 24 April 2013.

Detection and quantification of hypo- and hypergranulated neutrophils on the new Sysmex XN hematology analyzer: establishment of an adapted reference interval for the neutrophil-granularity-intensity compared to XE-technology in adult patients.

BACKGROUND: Since the recent introduction of Sysmex hematology analyzers of the XN-series it can be expected that the values of individual hematological parameters might differ between the new XN and the well-established XE platform. One such parameter is called Neutrophil-Granularity-Intensity or NEUT-GI on the XN-series and NEUT-X on the XE-series. Both parameters are used by clinicians to calculate the Granularity-Index (GI-Index), an important tool to detect hypo- or hypergranulated neutrophils occurring during myelodysplasia or inflammation. The aims of this study were to determine if previously reported reference intervals for NEUT-X can be used for NEUT-GI as well and if the GI-Indices on both analyzer platforms correlate with each other. METHODS: NEUT-GI and NEUT-X were assessed in a set of 789 blood samples (n = 543 samples from adult intensive care units and n = 246 samples from adult "blood-healthy" control patients) and the corresponding Granularity-Indices were calculated for all samples using data obtained from XE-5000 and XN-1000 hematology analyzers. RESULTS: NEUT-GI and NEUT-X correlated significantly with each other (r2: 0.6512; p < 0.0001) with statistically significant higher values for NEUT-GI compared to NEUT-X in the control group (p < 0.0001) as well as in the ICU patients (p < 0.0001). This indicated that previously established reference intervals for NEUT-X cannot be used for NEUT-GI. In contrast, the GI-Indices showed no statistically significant difference between the analyzers in both groups. The GI-Indices were higher in the ICU patients compared to the control group on both analyzer platforms (p < 0.0001), as would be expected. CONCLUSIONS: Our study revealed the emphatic need for a new reference interval for NEUT-GI on the XN platform. The resulting 95% reference intervals were 140.91 - 160.46 channels for NEUT-GI and 129.20 - 142.33 channels for NEUT-X. The GI-Indices showed no significant statistical difference between the XN- and XE-series in both cohorts.

"Aged sample" software on automated routine hematology analyzer enables differentiation between pathological and non-pathological WBC flagging in aging samples.

BACKGROUND: Storing K(x)EDTA-conjugated blood samples at room temperature or under insufficient cooling conditions results in various morphological changes such as swelling of the blood cells. These changes are reproducible and have already been described well. However, they can lead to incorrect flagging when using automated hematology analyzers for complete blood counts and white blood cell differentials. The aim of this study was to determine if those changes can be detected automatically and used to prevent false positive flagging. METHODS: 150 blood samples were aged under controlled conditions and the impact on the "Aged sample" software was checked retrospectively. The results were verified in a second retrospective study including 6288 routine samples. RESULTS: When tested in a routine laboratory, the "Aged sample" software was able to reduce overall flagging by 23% without increasing false negative flagging. CONCLUSIONS: The "Aged sample" software of XN-Series analyzers does not only detect and flag samples that are aging or were stored under suboptimal conditions but also prevents false positive flagging.

Revisiting the white blood cell count: immature granulocytes count as a diagnostic marker to discriminate between SIRS and sepsis--a prospective, observational study.

BACKGROUND: Sepsis is a serious disease condition and a major cause of intensive care unit (ICU) admission. Its diagnosis in critically ill patients is complicated. To diagnose an infection rapidly, and to accurately differentiate systemic inflammatory response syndrome (SIRS) from sepsis, is challenging yet early diagnosis is vital for early induction of an appropriate therapy. The aim of this study was to evaluate whether the immature granulocyte (IG) count is a useful early diagnostic marker of sepsis compared to other markers. Therefore, a total of 70 consecutive surgical intensive care patients were assessed. IGs were measured from whole blood samples using an automated analyzer. C-reactive protein (CRP), lipopolysaccharide binding protein (LBP) and interleukin-6 (IL-6) concentrations were also determined. The observation period was a maximum of 21 days and ended with the patients' discharge from ICU or death. Receiver operating characteristic (ROC) analyses were conducted and area under the curve (AUC) was calculated to determine sensitivities and specificities for the parameters. RESULTS: We found that the IG count significantly discriminates between infected and non-infected patients (P < 0.0001) with a sensitivity of 89.2% and a specificity of 76.4%, particularly within the first 48 hours after SIRS onset. Regarding the discriminative power for infection, the IG count was more indicative than other clinical parameters such as CRP, LBP and IL-6, which had a sensitivity of less than 68%. Additionally, the highest diagnostic odds ratio (DOR) with 26.7 was calculated for the IG count within the first 48 hours. During the course of the disease ROC curve analyses showed a superior positive predictive value of the IG count compared to the other measured parameters during the first five days following the fulfillment of SIRS criteria. However, the number of IGs was not correlated with ICU mortality. CONCLUSIONS: The total number of IG in peripheral blood from ICU patients is a good marker to discriminate infected and non-infected patients very early during SIRS. However, the IG count is not suitable as a prognostic marker for mortality. Routine and serial measurement of IGs may provide new possibilities for rapid screening of SIRS patients on ICU with suspected infections.

Use of a weighted, automated analysis of the differential blood count to differentiate sepsis from non-infectious systemic inflammation: the intensive care infection score (ICIS).

INTRODUCTION: Rapid and accurate diagnosis and immediate treatment of sepsis are of crucial importance. However, differentiating sepsis from Systemic Inflammatory Response Syndrome (SIRS) is a difficult challenge. Many diagnostic approaches based on clinical chemistry surrogate markers have not improved the situation. MATERIAL AND METHODS: The ICIS score was established in a cohort of 70 consecutive patients with SIRS. The score includes five parameters involved in the early innate immune response: mature neutrophils count, immature neutrophils count, antibody-secreting cells count, detection of neutrophils and monocytes/macrophages activation. The score can be provided in real-time without sample preparation and is independent from inter-observer variability. RESULTS: Each ICIS score parameter itself is highly correlated with the occurrence of infection. A mean ICIS value of < 5 (lower cut-off level) indicated the absence of infection whereas the score did not fall below a value of 6 in infected patients throughout the observation time. The area under curve to detect infection for ICIS was found to be highest compared to CRP, LBP, EPO, IL-6 and TNF-α (AUC=0.851, P < 0.0001). CONCLUSION: Cut-off values for ICIS as a marker of infection were defined by this pilot study. The superior discriminative power of ICIS compared to CRP, LBP, EPO, IL-6 and TNF-α is underlined by its high positive and negative predictive value, particularly within the first 48 hours (PPV=79.7%, NPV=74.5%). The ICIS score provides promising potential for reliably and swiftly discriminating sepsis from SIRS in the first critical hours.

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.

Reticulocyte hemoglobin measurement--comparison of two methods in the diagnosis of iron-restricted erythropoiesis.

The aims of this study were to diagnose iron-restricted erythropoiesis (functional iron deficiency) in patients with classic iron deficiency (ID), anemia of chronic disease (ACD) and the combined state of ID/ACD with the use of two hematological methods for the measurement of reticulocyte hemoglobinization. In comparison, the biochemical markers of iron status were determined. We studied 474 anemic patients admitted to hospital with a broad spectrum of diseases. We measured indicators of reticulocyte hemoglobinization. CHr was determined on an Advia 120 hematology analyzer. A Sysmex XE-2100 hematology analyzer was used to determine RET-Y, the forward scatter of fluorescence-labeled reticulocytes, which can also be expressed as the reticulocyte hemoglobin equivalent (RET-H(e)), as well as RBC-Y, the forward scatter of fluorescence-labeled erythrocytes, which can be expressed as the erythrocyte hemoglobin equivalent. Ferritin, soluble transferrin receptor (sTfR) and the sTfR/log ferritin ratio (sTfR-F index) were used as biochemical markers. The comparison of RET-Y with CHr demonstrated an excellent curvilinear relationship between the two parameters. The normal reference range for Ret-Y was 1630-1860 arbitrary units (AU); mathematical transformation to RET-H(e) gave a range of 28.2-35.7 pg. Correlations of biochemical iron markers with RET-H(e) were as weak as with CHr in patients with ACD and acute phase response. In a diagnostic plot to identify iron status, RET-H(e) could replace CHr without any loss of sensitivity or specificity. Patient mismatch analysis between RET-H(e) and CHr in the diagnostic plot demonstrated agreement for 449 of 474 patients (94.4%). Patient specific anemia mismatches were 2.9-6.2%. According to our results, the indicators of reticulocyte hemoglobinization, RET-H(e) and CHr, measure the same phenomenon. RET-H(e) is as valuable as CHr for the diagnosis of iron-restricted erythropoiesis. The combination of RET-H(e) and the sTfR-F index in a diagnostic plot offers an attractive tool for the evaluation of iron status and identification of the progression of ID.