Six-Year, Real-World Use of Prophylaxis with Recombinant Factor IX-Albumin Fusion Protein (rIX-FP) in Persons with Hemophilia B: A Single-Center Retrospective-Prospective Study.

Background: Extended half-life (EHL) factor IX (FIX) concentrates allow for prophylaxis with prolonged dosing intervals and high bleeding protection in persons with hemophilia B. Long-term real-world studies are lacking. Methods: In a retrospective-prospective study, the six-year use of prophylaxis with the EHL recombinant FIX-albumin fusion protein (rIX-FP) was analyzed, comparing outcomes with previous standard half-life (SHL) FIX in patients already on prophylaxis. Results: Prophylaxis with rIX-FP was prescribed in 15 patients (10 severe, 5 moderate; follow-up: 57 ± 17 months). Based on a pharmacokinetic assessment and clinical needs, the first regimen was 47 ± 7 IU/Kg every 9 ± 2 days. All but one patient remained on rIX-FP prophylaxis, adjusting infusion frequency and/or dose; the last prescribed frequency was ≥10 days in 10/13 patients, being reduced in seven and increased in four vs. the first regimen. The weekly FIX dose was unchanged; FIX trough levels were >5% in all patients. The annual infusion number and FIX IU/Kg significantly decreased (~60%) in eight patients previously on SHL FIX prophylaxis, with similar concentrate costs. Very low bleeding rates (most traumatic bleeds and the last quartile of the infusion interval), improved orthopedic and pain scores, unchanged HEAD-US scores and problem joints, and high treatment adherence (>90%) and satisfaction were registered. Conclusions: Personalized, carefully adjusted rIX-FP regimens contribute to the diffusion and optimization of prophylaxis in persons with severe and moderate hemophilia B, with long-term favorable bleeding, joint, and patient-reported outcomes.

Multicentric evaluation of analytical performances digital morphology with respect to the reference methods by manual optical microscopy.

AIMS: Optical microscopic (OM) evaluation of peripheral blood (PB) cells is still a crucial step of the laboratory haematological workflow. The morphological cell analysis is time-consuming and expensive and it requires skilled operator. To address these challenges, automated image-processing systems, as digital morphology (DM), were developed in the last few years. The aim of this multicentre study, performed according to international guidelines, is to verify the analytical performance of DM compared with manual OM, the reference method. METHODS: Four hundred and ninety PB samples were evaluated. For each sample, two May Grunwald-stained and Giemsa-stained smears were performed and the morphological evaluation of cells was analysed with both DM and OM. In addition, the assessment times of both methods were recorded. RESULTS: Comparison of DM versus OM methods was assessed with Passing-Bablok and Deming fit regression analysis: slopes ranged between 0.17 for atypical, reactive lymphocytes and plasma cells (LY(AT)) and 1.24 for basophils, and the intercepts ranged between -0.09 for blasts and 0.40 for LY(AT). The Bland-Altman bias ranged between -6.5% for eosinophils and 21.8% for meta-myemielocytes. The diagnostic agreement between the two methods was 0.98. The mean of assessment times were 150 s and 250 s for DM and OM, respectively. CONCLUSION: DM shows excellent performance. Approximately only 1.6% of PB smears need the OM revision, giving advantages in terms of efficiency, standardisation and assessment time of morphological analysis of the cells. The findings of this study may provide useful information regarding the use of DM to improve the haematological workflow.

Multicenter evaluation of analytical performances of platelet counts and platelet parameters: Carryover, precision, and stability.

INTRODUCTION: The correctness of the results of automated platelet analysis is still highly debated. The aim of this multicenter study, conducted according to international guidelines, was to verify the analytical performance of nine different types of hematology analyzers (HAs) in the automated platelet analysis. METHODS: Four hundred eighty-six peripheral blood samples (PB), collected in K3 EDTA tubes, were analyzed by ABX Pentra, ADVIA2120i, BC-6800, BC-6800 Plus, Cell-DYN Sapphire, DxH800, XE-2100, XE-5000, XN-20 with PLT-F App. Within-run imprecision and between-run imprecision were carried out using PB and material control, respectively. The carryover, low limit of quantification (LoQ), and the PB stability were evaluated. RESULTS: The carryover was absent for all HAs. The LoQ of PLT ranged between 2.0 (Cell-Dyn Sapphire) and 25.0 × 109 /L (ADVIA 2120i), while immature platelet fraction (IPF) ranged between 1.0 (XN-20) and 12.0 × 109 /L (XE-5000). The imprecision (%CV) increases as the platelet count decreases. No HAs showed desirable CVAPS for PLT counts less than 50.0 × 109 /L, with the exception of Cell-DYN Sapphire (CV 3.0% with PLT-O mean value of 26.7 × 109 /L), XN-20 (CV 2.4% with PLT-F mean value of 21.5 × 109 /L), and BC-6800 Plus (CV 1.9% with PLT-O mean value of 26.5 × 109 /L). The sample stability ranged between under two hours for MPV by ADVIA2120i and 8 hours for other PLT parameters and HAs. CONCLUSION: The findings of this study may provide useful information regarding carryover, precision, and stability of platelet counts and parameters, especially in thrombocytopenic samples. Moreover, the stability of sample for platelet analysis is conditioned by the HA and by temperature and storage time.

Optimising prophylaxis outcomes and costs in haemophilia patients switching to recombinant FVIII-Fc: a single-centre real-world experience.

BACKGROUND: The recombinant factor VIII (rFVIII)-IgG1 Fc fusion protein (rFVIII-Fc) was the first available extended half-life rFVIII, shown to prolong dosing intervals of individualised prophylaxis in patients with severe haemophilia A, maintaining low bleeding rates and unchanged or lower FVIII dose versus standard half-life (SHL) rFVIII. Few data are available about real-world experience with rFVIII-Fc, including criteria for patient switching from SHL products, follow up and prophylaxis optimisation. MATERIALS AND METHODS: A single-centre retrospective study was designed to review patients switched to rFVIII-Fc, based on individual needs, after pharmacokinetic (PK) assessment, according to routine clinical practice. In patients with adequate post-switch follow up, data about rFVIII-Fc prophylaxis were compared with those from the last 18-months SHL rFVIII prophylaxis. RESULTS: Of 25 candidates, 18 patients (15 severe, 3 moderate; aged 9-62 years; 3 with inhibitor history) started rFVIII-Fc regimens, with comparable FVIII weekly dose and reduced infusion frequency (mean -30%) in all 17 patients previously on SHL rFVIII prophylaxis thrice weekly or every other day. Over a mean 18-month follow up in 13 patients, compared with SHL products, further reduced infusion frequency (mean -40%; p<0.001; interval ≥4 days in 9 patients), improved treatment satisfaction (Hemo-sat questionnaires), significantly lower FVIII weekly dose and annual consumption (mean -12%; p=0.019), comparable bleeding rates and FVIII trough levels, and improved management of breakthrough bleeding were observed. von Willebrand Factor Antigen (VWF:Ag) correlated to PK variables and both had relationships with rFVIII-Fc weekly dose, increasing statistical significance over the follow-up period. No inhibitors or drug-related adverse events were recorded. DISCUSSION: In this real-world series of patients, a switch to rFVIII-Fc, based on careful assessment of clinical needs, PK testing and treatment monitoring, was able to optimise individual convenience, efficacy and costs of prophylaxis.

Evaluation of nucleated red blood cell count by Sysmex XE-2100 in patients with thalassaemia or sickle cell anaemia and in neonates.

BACKGROUND: Current haematology analysers have variable sensitivity and accuracy for counting nucleated red blood cells in samples with low values and in all those conditions characterised by altered sensitivity of red blood cells to the lysing process, such as in beta-thalassaemia or sickle-cell diseases and in neonates. The aim of our study was to evaluate the performance of the automated analyser XE-2100 at counting nucleated red blood cells in the above-mentioned three categories of subjects with potentially altered red blood cell lysis sensitivity and yet a need for accurate nucleated red blood cell counts. MATERIALS AND METHODS: We measured nucleated red blood cell count by XE-2100 in peripheral blood samples of 187 subjects comprising 55 patients with beta-thalassaemia (40 major and 15 traits), 26 sickle-cell patients, 56 neonates and 50 normal subject. Results were compared with those obtained by optical microscopy. Agreement between average values of the two methods was estimated by means of Pearson's correlation and bias analysis, whereas diagnostic accuracy was estimated by analysis of receiver operating characteristic curves. RESULTS: The comparison between the two methods showed a Pearson's correlation of 0.99 (95% CI; 0.98-0.99; p<0.001) and bias of -0.61 (95% CI, -1.5-0.3). The area under the curve of the nucleated red blood cell count in all samples was 0.98 (95% CI, 0.96-1.00; p<0.001). Sub-analysis revealed an area under curve of 0.99 (95% CI, 0.98-1.00; p<0.001) for patients with thalassaemia, 0.94 (95% CI, 0.85-1.00; p<0.001) for patients with sickle cell anaemia, and 1.00 (95% CI, 1.0-1.0) for neonates. DISCUSSION: XE-2100 has excellent performance for nucleated red blood cell counting, especially in critical populations such as patients with haemoglobinopathies and neonates.

What do hemolyzed whole-blood specimens look like? Analysis with a CellaVision DM96 automated image analysis system.

We planned an original study to investigate the morphological changes caused by spurious hemolysis of whole-blood samples, analyzed using an automated image analysis system. Seven whole-blood specimens anticoagulated with EDTA were pooled and divided in two aliquots. The former was left untreated, whereas the latter was subjected to mechanical hemolysis by forced aspiration with an insulin syringe. The complete blood cell count was performed on a Sysmex XE-2100, and the aliquots were then processed with CellaVision DM96. In spuriously hemolyzed samples, the main findings included a rarefaction of erythrocytes, the presence of a remarkable number of cellular debris, a greater degree of microcytosis and anisocytosis, the appearance of band neutrophils, a shift of values between lymphocytes and monocytes, and an increase in smudge cells, artifacts, and large platelets. The results of this study demonstrate for the first time that blood cell morphology may be consistently biased in spuriously hemolyzed whole blood and that the use of an automated image analysis system such as the CellaVision DM96 may be a suitable approach to identify spurious hemolysis in whole-blood specimens.

Evaluation of the fully automated hematological analyzer Sysmex XE-5000 for flow cytometric analysis of peritoneal fluid.

Although microscopy still represents the gold standard for cytometric analysis of peritoneal fluids, automated flow cytometry may improve throughput and accuracy. We evaluated the performance of total nucleated cell (TNC), white blood cell (WBC), polymorphonuclear cell (PMN), and mononuclear cell (MONO) counts of Sysmex XE-5000 on peritoneal fluids. The imprecision was excellent, being always lower than 11%, whereas linearity studies yielded correlation coefficients of 1.00 for all parameters. The carryover was always lower than 0.2%. The comparison between XE-5000 and microscopic analysis of 117 ascitic fluids yielded correlation coefficients always greater than 0.96, with mean biases <11/µL. The diagnostic accuracy versus manual microscopy was greater than that of XE-2100, especially at thresholds for septic ascites (100 versus 98% for ≥500 WBC/µL; 98 versus 93% for ≥250 PMN/µL). The correlation with manual microscopy for macrophages and mesothelial cell count was also higher for XE-5000 than for XE-2100 (0.63 versus 0.55). The results of this evaluation show optimal performance of XE-5000 for routine analysis of ascitic fluids, which are combined with the advantages of automated analysis such as high throughout, shortened turnaround time, no need of sample preparation and trained staff, reduced sample volume, and less likelihood of transcriptional errors.

Evaluation of white blood cell count in peritoneal fluid with five different hemocytometers.

OBJECTIVES: Evaluation of automated flow cytometric analysis of white blood cell (WBC) count in peritoneal fluids. METHODS: One hundred peritoneal fluids were analyzed with manual microscopy, Sysmex XE-2100 and XE-5000, Siemens Advia 2120, Mindray BC-6800, Abbott Sapphire. RESULTS: High correlations (0.978 to 0.999) and modes biases (-132 to 80 WBC/mm(3)) were found. Agreement at septic peritonitis cutoff ranged between 96% and 99%. CONCLUSIONS: These hemocytometers display acceptable performance for WBC screening in peritoneal fluids.