Urine particle evaluation: a comparison between the UF-1000i and quantitative microscopy.

BACKGROUND: The study of urine particles plays a key role in the diagnosis of kidney diseases. In this study, the authors evaluated the correlation between the UF-1000i and quantitative manual microscopy. METHODS: A total of 214 untreated urine samples were studied using the Sysmex UF-1000i and compared with results obtained from quantitative manual microscopy using the Fuchs-Rosenthal counting chamber. RESULTS: Using Pearson statistics, we observed satisfactory correlation between the UF-1000i and quantitative microscopy: for red blood cells (RBCs) r was 0.98, for white blood cells (WBCs) r was 1.00, for epithelial cells (EC) r was 0.96, and for casts r was 0.69. Using linear regression statistics, we also observed satisfactory correlation between the UF-1000i and quantitative microscopy: for RBCs R(2) was 0.95, for WBCs R(2) was 0.99, for EC R(2) was 0.92, and for casts R(2) was 0.48. CONCLUSIONS: In our experience, automated urine particle analysis performed using the Sysmex UF-1000i analyzer is sufficiently precise and improves the workflow in a routine laboratory. Precision was satisfactory and concordance with the reference method is good for RBC, WBC and EC; for casts microscopic observation is required for flagged samples to discriminate hyaline from pathologic casts.

A new turbidimetric standard to improve the quality assurance of the erythrocyte sedimentation rate measurement.

OBJECTIVES: The erythrocyte sedimentation rate (ESR) determined using manual or semi-automated methods has usually been judged a simple procedure that could be performed without any form of Quality Control. According to this point of view, the ESR would seem a semi-quantitative test instead of a real hematological test with any clinical importance. The new millennium has consolidated ESR automation and a QC plan cannot be postponed. DESIGN AND METHODS: Using Test1, an automated ESR analyzer, a new latex control material was evaluated and compared with fresh whole blood for quality control purposes. RESULTS: The new latex control showed satisfactory reproducibility, precision, and "commutability" in comparison to quality control procedures that use fresh whole blood samples. CONCLUSIONS: The new standard represents another advance in ESR testing improving the accuracy of automated TEST1 measurements.

The new reticulocyte parameter (RET-Y) of the Sysmex XE 2100: its use in the diagnosis and monitoring of posttreatment sideropenic anemia.

To verify their clinical usefulness in diagnosis and early response to therapy of sideropenic anemia, we compared the behavior of the reticulocyte parameter (RET-Y), a raw measure dependent on size and content of the cell, generated by the Sysmex XE 2100, with the mean reticulocyte volume (MCVr) and mean reticulocyte hemoglobin content (CHr) from the Bayer ADVIA 120 in healthy subjects and patients with iron deficiency anemia. Correlations were high (r = 0.88 and r = 0.94, respectively). All parameters varied significantly as early as 48 hours after the start of intravenous iron therapy (mean differences of 17.4% [RET-Y], 4.5% [MCVr], and 9.5% [CHr]). Sudden decreases in those parameters at interruption of therapy indicate the reappearance of sideropenic erythropoiesis. The receiver operating characteristic curve demonstrated a high degree of efficiency in differentiating moderate or severe iron deficiency anemia from the healthy state. The best association between sensitivity and specificity was at a cutoff of channel 1,624 for RET-Y and 104.5 fL for MCVr (negative and positive predictive values, respectively, of 99.6% and 96.5% for RET-Y and 98.7% and 93.3% for MCVr). RET-Y is correlated closely with CHr and is useful for diagnosis and early monitoring after the administration of intravenous iron.

Five fully automated methods for performing immature reticulocyte fraction: comparison in diagnosis of bone marrow aplasia.

We performed a parallel evaluation of 5 automated reticulocyte counters to produce the immature reticulocyte fraction (IRF). We analyzed 225 samples from healthy control subjects, 115 from patients with various diseases, 38 with advanced aplasia, and 22 in early erythropoietic recovery after chemotherapy or bone marrow transplantation. The reference intervals were different for each instrument (ADVIA 120, 0.04-0.25; CELL DYN 4000, 0.15-0.35; GEN-S, 0.20-0.37; SE 9500 RET 0.05-0.21; VEGA RETIC: 0.06-0.23). The imprecision, obtained by 1-way analysis of variance on duplicates, was satisfactory for clinical use for all methods (coefficient of variation, 7.6%-20.5% in healthy subjects), although it was higher than the analytic goal based on biologic variability within subjects. The comparison of different methods shows that agreement is good only between SE 9500 RET CELL DYN 4000, and VEGA RETIC (r2 = 0.72-0.78). The study of diagnostic performance in distinguishing aplasia from early bone marrow recovery shows slightly different results (area under the curve from 0.70 for ADVIA 120 to 0.96 for SE 9500 RET). Even with slight differences, the fluorescence-based methods seem to be more robust than other methods for IRF measurement.