Performance evaluation of the new hematology analyzer UniCel DxH 900.

INTRODUCTION: UniCel DxH900 (Beckman Coulter, Miami, Florida, USA) is a quantitative, multi-parameter, automated hematology analyzer for in vitro diagnostic use in clinical laboratories. The aim of this study was to evaluate the analytical performance of the new DxH900 analyzer to verify its diagnostic and clinical utility in the hematology laboratory of a tertiary care hospital in Spain. The most important and novel feature offered by DxH900 analyzer is providing MDW (monocyte distribution width), a new hematologic parameter which is being clinically validated as an early sepsis indicator with promising results. METHODS: We evaluated imprecision (including MDW), linearity, and carryover of DxH900. Method comparison for cell blood count (CBC) was performed in relation to DxH800 with 100 samples. We compared leukocyte differential (DIFF) from DxH900 with manual 400-cell differential. 390 samples were assessed for flag performance. RESULTS: Results obtained for between days and within-run imprecision were good. DxH900 showed excellent linearity (R = 1.00) over analytical range for white blood cells, red blood cells, hemoglobin, platelets, and reticulocyte count (RET) (R = 0.96) and no significant carryover effect. CBC and RET on the DxH900 correlated well with DxH800 (R ≥ 0.99). Comparison with manual differential showed excellent correlation (R ≥ 0.88), except for basophils. Flagging performance exhibited sensitivity over 90% for majority of alarm messages and very high negative predictive value (over 95%). CONCLUSION: UniCel DxH900 Coulter analyzer provides reliable results and fully comparable to DxH800. DxH900 is an accurate, highly precise analyzer with good analytical performances to be used effectively in high-volume laboratories.

Lung Ultrasound for Heart Failure Diagnosis in Primary Care.

BACKGROUND: Lung ultrasound (LUS) is useful for diagnosing pulmonary congestion, but its value in primary care remains unclear. We investigated whether LUS improved diagnostic accuracy in outpatients with heart failure (HF) suspicion. METHODS AND RESULTS: LUS was performed on 2 anterior (A), 2 lateral (L), and 2 posterior (P) areas per hemithorax. An area was positive when ≥3 B-lines were observed. Two diagnostic criteria were used: for LUS-C1, 2 positive areas of 4 (A-L) on each hemithorax; and for LUS-C2, 2 positive areas of 6 (A-L-P) on each hemithorax. A cardiologist blinded to LUS validated HF diagnosis. 162 patients were included (age 75.6 ± 9.4 years, 70.4% women). Both LUS criteria, alone and combined with other HF diagnostic criteria, were accurate for identifying HF. LUS-C2 outperformed LUS-C1, showing remarkable specificity (0.99) and positive predictive value (0.92). LUS-C2, together with Framingham criteria, N-terminal pro-B-type natriuretic peptide, and electrocardiogram, added diagnostic value (area under the receiver operating characteristic curves 0.90 with LUS-C2 vs 0.84 without; P = .006). In the absence of N-terminal pro-B-type natriuretic peptide, LUS-C2 significantly reclassified one-third of patients above Framingham criteria and electrocardiogram (net reclassification improvement 0.65, 95% confidence interval 0.04-1.1). CONCLUSIONS: LUS was accurate enough to rule-in HF in a primary care setting. The accuracy of diagnostic workup for HF in primary care is enhanced by incorporating LUS, irrespective NT-proBNP availability.

Spanish society of laboratory medicine external quality assurance programmes: evolution of the analytical performance of clinical laboratories over 30 years and comparison with other programmes.

The purpose of this study is to understand the evolution of the analytical performance of the laboratories participating in the Spanish society of laboratory medicine (SEQCML) external quality assurance (EQA) programmes during its 30 years of operation and to compare it with the performance of other EQA programmes to establish whether the results are similar. The results obtained during this period are evaluated by applying the biological variability (BV) and state of the art-derived quality specifications. In addition, the results are compared with those obtained by other EQA programme organisations. It is noted that the laboratories participating in the EQA-SEQCML programmes have improved their performance over 30 years of experience and that the specifications derived from biological variation are achievable. It is difficult to compare EQA programmes, due to lack of accessibility and the differences in the design of these programmes (control materials, calculations used and analytical specifications established). The data from this study show that for some biological magnitudes the results obtained by the programmes are not yet harmonised, although efforts are being made to achieve this. Organisers of EQA programmes should also join the harmonisation effort by providing information on their results to enable comparison.

Lung ultrasound and biomarkers in primary care: Partners for a better management of patients with heart failure?

INTRODUCTION: The association of pulmonary congestion assessed by lung ultrasound (LUS) and biomarkers-other than N-terminal pro-brain natriuretic peptide (NT-proBNP)-is uncertain. METHODS: We investigated the relationship between total B-line count by LUS and several biomarkers in outpatients with suspicion of heart failure (HF). Primary care patients with suspected new-onset nonacute HF were evaluated both with a 12-scan LUS protocol (8 anterolateral areas plus 4 lower posterior thoracic areas) and 11 inflammatory and cardiovascular biomarkers. A cardiologist blinded to LUS and biomarkers except NT-proBNP confirmed HF diagnosis. After log-transformation of biomarkers' concentrations, unadjusted and adjusted correlations were performed. RESULTS: A total of 170 patients were included (age 76 ± 10 years, 67.6% women). HF diagnosis was confirmed in 38 (22.4%) patients. After adjustment by age, sex, body mass index, and renal function, total B-line sum significantly correlated with NT-proBNP (R = 0.29, p < 0.001), growth/differentiation factor-15 (GDF-15; R = 0.23, p = 0.003), high-sensitive Troponin T (hsTnT; R = 0.36, p < 0.001), soluble interleukin-1 receptor-like 1 (sST2; R = 0.29, p < 0.001), cancer antigen 125 (CA-125; R = 0.17, p = 0.03), high-sensitivity C-reactive protein (hsCRP; R = 0.20, p = 0.009), and interleukin (IL)-6 (R = 0.23, p = 0.003). In contrast, IL-33 (R = -0.01, p = 0.93), IL-1ß (R = -0.10, p = 0.20), soluble neprilysin (sNEP; R = 0.09, p = 0.24), tumor necrosis factor-alpha (TNF-α; R = 0.07, p = 0.39), and TNF-α receptor superfamily member 1A (TNFRSF1A; R = 0.14, p = 0.07) did not. CONCLUSIONS: Total B-line sum correlated significantly, although moderately, with congestion and several inflammation biomarkers. Unexpectedly, the highest correlation found was with hsTnT.