Continuous ambulatory peritoneal dialysis, ascitic and pleural body fluids evaluation with the Mindray BC-6800 hematology analyzer.

BACKGROUND: Accurate evaluation of hematology analyzers is recommended before these devices can be broadly introduced for the routine testing of continuous ambulatory peritoneal dialysis (CAPD), ascitic, and pleural fluids. METHODS: We evaluated the performance of Mindray BC-6800 for white blood cell (WBC) and differential cell count in 50 CAPD, 60 ascitic and 40 pleural compared with manual microscopy. Within-run precision, limit of blank (LoB), limit of detection (LoD), limit of quantitation (LoQ), and carryover were assessed. RESULTS: The Passing-Bablok regression in all fluids showed the following equations: yWBC =1.05x+3.31 (95%CI slope 0.95 to 1.12; intercept -0.25 to 5.52); yMN =0.85x+15.63 (95%CI slope 0.72 to 1.05; intercept -24.18 to 84.47); and yPMN =1.21x+13.37 (95%CI slope 1.03 to 1.35; intercept 4.00 to 32.47) with bias 78 cells/µL. The AUC for clinical PMN cut-off was 0.88 (95%CI: 0.77 to 0.98). In ascitic, pleural, and CAPD fluids the AUC for clinical PMN cut-off were 0.88 (95%CI: 0.63 to 1.00), 0.83 (95%CI: 0.68 to 0.99), and 1.00 (95%CI: 1.00 to 1.00) respectively. CV ranged from 3%-34%. LoB of 3 cell/µL was verified. LoD and LoQ reported the same result (8 cells/µL). Carry over never exceeded 0.05%. CONCLUSION: The effectiveness of BC-6800 to categorize cells from different body fluids was not compromised by the slight positive bias observed. This conclusion is supported by the high AUC and agreement between the automated method and the reference method. The results show that BC-6800 offers rapid, accurate, and reproducible results for clinical management of CAPD, ascitic, and pleural fluids.

Erythrocyte deformability and psoriasis.

Psoriasis, a systemic immunomediated disorder, is associated with increased cardiovascular risk, although the contribution of rheological alteration to this risk has been seldom analyzed. We have determined erythrocyte deformability in 91 patients with psoriasis and in 101 sex- and age-matched control subjects by means of the Rheodyn SSD, along with hematological, biochemical and inflammatory parameters. Although psoriatic patients showed higher BMI, waist, triglyceride, C-reactive protein levels, neutrophils count and lower HDL-cholesterol (P < 0.001), no differences in the elongation index and in any of the shear stresses tested (12, 30, 60 Pa) were observed (P > 0.05). The results of the present study indicate that patients with psoriasis do not present impaired erythrocyte deformability. Therefore this rheological parameter does not seem to be involved in the higher cardiovascular risk characterizing these patients.

Psoriasis and hemorheology. Influence of the metabolic syndrome.

Psoriasis is a systemic inflammatory disorder with increased cardiovascular risk which has been partly attributed to the increased prevalence of the metabolic syndrome (MS). However, the contribution of rheological alterations to cardiovascular risk has been scarcely investigated. In 91 psoriasis patients and in 101 healthy volunteers, we determined the rheological profile (fibrinogen, blood viscosity and erythrocyte aggregation), along with lipidic and inflammatory parameters. Patients showed statistically higher BMI, waist, triglycerides, insulin, c-reactive protein (CRP), neutrophils, lower HDL-cholesterol and a higher MS prevalence (p<0.05). When subjects with MS were excluded from the study, patients with psoriasis still showed a worse inflammatory, lipidic and rheological profile in the above-mentioned variables compared with controls without MS (p<0.05). The logistic regression analysis revealed that abdominal obesity and fibrinogen>384 mg/dL were independent predictors of psoriasis (OR 3.75 95% CI 1.77-7.94, p<0.001; OR 2.95 95% CI 1.14-7.64, p=0.025), respectively. Patients on biologics, showed less inflammation and a better rheological profile than those not on biological treatment. In conclusion, patients with psoriasis show an altered rheological profile, which may contribute to increased cardiovascular risk. Although the presence of MS worsens this profile, psoriasis per se shows rheological alterations due to both inflammation and altered metabolic parameters. Anti TNF-α treatment markedly improves the rheological profile by mostly decreasing inflammation.