Multicenter verification of the Sysmex XN-Series

Evaluation of immature granulocyte parameters in myeloid neoplasms assayed by Sysmex XN hematology analyzer

Immature granulocytes (IGs) have significance for the diagnosis of myeloid neoplasms (MNs). The current study aims to use a hematology analyzer to evaluate the accuracy of IG parameters in MNs. Blood specimens from 388 patients with MN, 524 with non-hematological neoplasms (non-HNs), including 109 patients with inflammation and 68 undergoing G-CSF administration, and 500 healthy control subjects were analyzed. IG parameters was assayed by Sysmex XN-9000 (XN) and compared with manual assessments. A high level of agreement between IG% derived from XN and manual measurements for MN patients (r = 0.828, p < 0.0001) was revealed but only a moderate correlation for acute myeloid leukemia patients (AML; r = 0.597; p < 0.0001). Bland-Altman bias analysis was conducted, and the results showed that differences in IG% from XN and manual analysis for MN patients were considered clinically insignificant. ROC analysis demonstrated a good performance of IG# (AUC = 0.842) and IG% (AUC = 0.885) assessed by XN for MN patients with cut-off values of 0.200 × 109/L and 1.95%, respectively. IG parameters from Sysmex XN analyzer are helpful for screening of MNs even though granulocyte morphological abnormalities may interfere with IG parameter accuracy.

Interchangeability of multiple Sysmex XN10 and XN20 modules for six types of leukocytes

INTRODUCTION

Differential counts of leukocytes are frequent, and often several automated blood cell counters are needed in contemporary laboratories. However, these modules are often individually quality assured. Our aim was therefore to validate the interchangeability of five hematology modules in a large modern laboratory and to compare them with our gold standard (GS) manual white blood cell differential count.

METHODS

At Copenhagen University Hospital, we compared five Sysmex XN-modules for neutrophils, lymphocytes, monocytes, eosinophils, basophils, and immature granulocytes (IG). We analyzed control samples in three levels to evaluate intra- and intermodular precision. Bias between modules was evaluated by analyzing 93 random patient samples within reference intervals. XN-modules' mean counts were compared with GS.

RESULTS

We found acceptable intramodular CV% (0.92%-8.76%), only neutrophils and eosinophils exceeded state-of-the-art imprecision or desirable specifications for medium control levels. Intermodular CV% showed significance difference for only monocytes (ANOVA, P < .0001). For patient samples, there were significant differences between XN-modules regarding four WBC types (ANOVA); however, proportional bias ranged from 1.7% to 3.8%, being within desirable specifications except basophils and IG (bias = 13.3% and 24.9%, respectively). Comparisons with GS, XN-modules exceeded desirable bias for basophils (lower than GS); monocytes and IG (higher than GS).

CONCLUSION

This multimodule comparison shows acceptable intermodular imprecision and bias for clinical purposes, which is important for patient safety. Similar multimodule study should be performed with samples out of reference range in large-scale laboratories to confirm the interchangeability.

Neutrophil-lymphocyte ratio as a link between complex pedal ulcers and poor clinical results after infrainguinal surgical revascularization

BACKGROUND

Our aim was to evaluate the influence of preoperative neutrophil-lymphocyte ratio (NLR) on patency and clinical results after infrainguinal surgical revascularization for chronic limb ischemia.

METHODS

Retrospective analysis of 150 infrainguinal autologous bypasses performed to infragenicular popliteal artery or tibial vessels in 140 (93%) patients with chronic limb-threatening ischemia (CLTI) and in 10 (7%) with disabling claudication. NLR was calculated using blood samples obtained 24 hours preoperatively. The cohort was stratified into 2 groups according to interquartile ranges of NLR: "ELEVATED-NLR" (Quartile 4 N.=37) and "LOW-NLR" (Quartile 1-2-3 N.=113). Reperfused ulcers were described using the WIfI classification. Patency, freedom from MALE and amputation-free survival at 24 months were calculated using the Kaplan-Meier method. Univariate comparisons between NLR groups were performed using the Log-Rank test. Statistical differences on univariate analysis were adjusted in a multivariate model (Cox regression).

RESULTS

NLR values were similar between CLTI and claudication. Ischemic ulcers were more frequent, (83.4% vs. 59.3% P<0.01), more severe (W2-3: 37.8% vs. 22.1% P=0.01) and pedal infection was deeper (fI 2-3: 40.5% vs. 18.6% P=0.003) in "ELEVATED-NLR" group. Severe ischemia (I3) was similar between groups. High NLR values were independent predictors of patency loss (HR: 1.77 CI95% [1.01-3.10] P=0.04), MALE (HR: 2.04 CI95% [1.03-4.04] P=0.04) and worse amputation-free survival (HR:2.10 CI95% [1.06-4.14] P=0.03) rates at 24 months.

CONCLUSIONS

High preoperative NLR values are associated with severe and deep infected ulcers and predicts primary patency loss, higher major adverse limb events and worse amputation-free survival rates on long-term follow-up after infrainguinal surgical revascularization.

Basophil counting in hematology analyzers: time to discontinue?

Basophils (basophilic granulocytes) are the least abundant cells in blood. Nowadays, basophils are included in the complete blood count performed by hematology analyzers and therefore reported in practically all patients in whom hematologic investigations are requested. However, hematology analyzers are not reliable enough to report clinically useful results. This is due to a combination of very high analytical imprecision and poor specificity, because the chemical and physical methods used for basophil counting in hematology analyzers are ill-defined and thus basophils are not well recognized by the analyzers. As a result, false basophil counts are quite common. In view of increasing analytical performance demands, hematology laboratories should stop reporting basophil counts produced by hematology analyzers. Suggestions for alternative pathways are presented for those situations where basophils are of clinical relevance.

The HemoScreen hematology point-of-care device is suitable for rapid evaluation of acute leukemia patients

BACKGROUND

Hematological patients, receiving intensive chemotherapy (predominantly acute leukemia patients), have repeated postchemotherapy periods with severe bone marrow suppression. As a result, these patients require regular monitoring of the complete blood counts (CBC) for optimal patient care. To reduce the strain on the patient, there is a need for a point-of-care (POC) hematology device that provides rapid and reliable results both in general and in cytopenic samples and is suitable for outpatient clinics. We evaluated the HemoScreen device for the most used CBC parameter both overall and at the lower range.

METHODS

The HemoScreen was compared with the Sysmex XN-9000 in 206 routine venous samples and 79 capillary bedside samples focusing on white blood cells (WBC), absolute neutrophil count (ANC), red blood cells (RBC), PLT and HGB.

RESULTS

The HemoScreen was less precise compared to the acceptance criteria set for larger and more advanced hematology instrument with a CV% 3.0-3.7 for WBCs, 3.6-8.4 for ANCs, 1.1-1.5 for RBCs, 2.5-4.4 for PLTs, and 1.7-2.3 for HGB. Correlation coefficient for all five parameters for the entire range was r >.95 and r >.90 at lower range for venous and capillary samples. Bias limits were within the CTCAE acceptance limits.

CONCLUSIONS

The HemoScreen provides rapid and accurate test results, for evaluation of WBC, PLT, and HGB, as well as at low concentrations for guiding transfusions and postchemotherapy treatment. The device is easy to operate and can measure both venous and capillary samples. Therefore, the HemoScreen is well suited for smaller outpatient clinics and potentially home use.

Impact of blood cell counts and volumes on glucose concentration in uncentrifuged serum and lithium-heparin blood tubes

BACKGROUND

Although it is known that glucose concentration exhibits a time-dependent decay in uncentrifuged serum and lithium-heparin blood tubes, no evidence exists on how this variation may depend on blood cell counts (CBC) and volumes.

METHODS

Venous blood was drawn from 30 non fasting healthy volunteers into three serum and three lithium-heparin tubes. One serum and lithium-heparin tubes were centrifuged within 15 min after collection and glucose was measured with a hexokinase assay. The second and third serum and lithium-heparin tubes were maintained at room temperature for 1 and 2 h after the first tubes were centrifuged. These other tubes were then centrifuged and glucose was measured. CBC was performed in the first lithium-heparin tube, before centrifugation.

RESULTS

The mean decrease of glucose was higher in lithium-heparin plasma than in serum (0.33 vs. 0.24 mmol/L/h; p<0.001). Glucose concentration decreased by 7% and 5% per hour in lithium-heparin plasma and serum, respectively. In univariate analysis, the absolute decrease of glucose concentration was associated with sex (higher in men than in women), red blood cell (RBC) count, hematocrit, white blood cell (WBC) count, neutrophils and monocytes in both lithium-heparin plasma and serum. In multivariate analysis, the decrease of glucose concentration remained independently associated with RBC, WBC, neutrophils and monocytes in both sample matrices. No significant association was found with platelet number and erythrocyte or platelet volume.

CONCLUSIONS

Glucose concentration decrease in uncentrifuged lithium-heparin and serum tubes depends on the baseline number of RBC, WBC, neutrophils and monocytes within the tubes.

Short preheating at 41°C leads to a red blood cells count comparable to that in RET channel of Sysmex analysers in samples showing cold agglutination

AIMS

The presence of cold agglutinin in blood samples can cause a spontaneous agglutination of red blood cells (RBCs) when low temperature occurs. This phenomenon causes a spurious lowering of RBC count on the automated haematological analysers that are detected by incongruous values (≥370 g/L) of the mean cellular haemoglobi concentration (MCHC). A preheating at 37°C can remove the RBC agglutination generally resulting in a reliable count. It has been reported that the same result can be reached by using the optical reticulocyte (RET) channel of Sysmex analysers where the RBC count is not influenced by the presence of cold agglutinin. This study aims to evaluate these data in a larger population, with regard to environmental conditions on Sysmex analysers. We have also evaluated the influence of different thermal pretreatments on the RBC count.

METHODS

This study was performed on 96 remnants of peripheral blood samples (48 with MCHC in normal range and 48 with MCHC>370 g/L) which have been analysed in different preanalytical conditions on the Sysmex analysers.

RESULTS

A preheating of samples at 41°C for 1 min leads to a reversibility of the cold agglutination comparable to the one observed in the RET channel and yields better results compared with 37°C for 2 hours.

CONCLUSIONS

None of described procedures assure the complete cold agglutination reversibility in every case. Consequently, since the haematological analysers not yet provide reliable parameters to confirm the complete resolution of agglutination, further verification of RBC count accuracy needs to be performed.