Biomedical subjects

Luisa Barea

Publications and source records attributed to Luisa Barea.

4 recordsLinked to original sources

PubMed2006

Acute hepatitis B virus window-period blood donations detected by individual-donation nucleic acid testing: a report on the first two cases found and interdicted in Spain.

BACKGROUND: Mathematical models predict that, in Spain, a significant number of blood units will be obtained during the window period of the hepatitis B virus (HBV) infection. Routine nucleic acid testing (NAT) on individual blood units may provide experimental data to evaluate such a theoretical risk. STUDY DESIGN AND METHODS: Between February and July 2005, a total of 34,631 individual units were screened for HBV DNA by a multiplex transcription-mediated amplification (TMA) test. Units that repeatedly reacted in the test, but did not react for HBV surface antigen (HBsAg), were submitted to additional testing by both molecular and conventional assays, and the donors were recalled for follow-up studies and the collection of clinical and epidemiologic data. RESULTS: Confirmatory testing and follow-up studies identified 2 blood units donated during the HBV infection window period (1/17,316 units studied). Sequencing of amplification products obtained by nested polymerase chain reaction (n-PCR) revealed two HBV strains from genotypes D/ayw3 and F/adw4q-, but did not identify HBsAg mutants. The HBV DNA concentration in the index donations was estimated to be below the n-PCR detection level (180 IU/mL), in both cases. One donor developed acute hepatitis 2 months after donating blood, but the other remained asymptomatic and displayed normal alanine aminotransferase levels at follow-up. CONCLUSIONS: The HBV infection window period is a real issue in the setting of Spanish blood transfusions. NAT of individual units by TMA would make a significant contribution to improving the safety of the blood supply in Spain. Additional studies involving a larger number of units and longer periods of time are required, however, to ascertain the true incidence of the problem in this country.

Acute Disease↗

PubMed2006

Hematomas in multicomponent apheresis: searching for related factors.

BACKGROUND: The objective of this study was to identify donation variables that could be related to the development of hematoma during multicomponent apheresis collections (MACs). STUDY DESIGN AND METHODS: This is an observational retrospective study where 1375 donors donated 5177 MACs during a 2-year period with two different machines (Amicus Crescendo [AC], Baxter Healthcare Corp.; and Trima Accel [TA], Gambro BCT). Variable data were recorded prospectively. In the multiple logistic regression analysis, generalized estimating equations were used with an exchangeable correlation matrix to take into account the nonindependence of several measurements from the same donor. RESULTS: During the study period, 170 procedures failed due to hematoma (3.3%). Several variables were related to hematoma development in the adjusted model: operator experience (less than 500 procedures supervised vs. more; odds ratio [OR], 1.66; 95% confidence interval [CI], 1.19-2.31), previous apheresis donations (first time vs. more than 16 donations; OR, 2.87; 95% CI, 1.52-5.45), vein canalized (basilic vs. intermediate antebrachial or cephalic; OR, 1.42; 95% CI, 1.04-1.94), diastolic blood pressure (units divided by 10 mmHg; OR, 0.79; 95% CI, 0.66-0.94), and type of machine used (TA high return limit configuration [RLC] setting configuration vs. AC; OR, 1.94; 95% CI, 1.27-2.96; TA low RLC setting configuration vs. AC; OR, 1.24; 95% CI, 0.83-1.84). CONCLUSIONS: Our study suggests that hematoma in MAC is not a random event. Appropriate machine configuration in the TA could reduce the hematoma rate to a level comparable with that of the AC. Operator training and donor blood pressure are also interesting variables for study because these could be modified to reduce the hematoma rate.

Adolescent↗

PubMed2005

A randomized crossover trial comparing three plateletpheresis machines.

BACKGROUND: The aim of the study was to compare three different apheresis machines with the same donors regarding the processing time required to obtain a 3.5 x 10(11) platelet (PLT) dose and acceptance by donors. STUDY DESIGN AND METHODS: A randomized crossover trial was performed to evaluate the differences between the Amicus Crescendo (Baxter Biotech Corp.), the MCS Plus (Haemonetics Corp.), and the Trima Accel (Gambro BCT). Donations from 51 donors were compared for time adjusted to obtain a standard 3.5 x 10(11) PLT dose (TSD3.5), efficiency, adverse reactions, yield, leukodepletion, machine accuracy, and donor preferences. Processing times were measured by chronometer. The same vein access was used during all three processes in each donor. In the statistical analysis, to take into account the nonindependence of several measurements from the same donor, generalized estimating equations were used with an autoregressive correlation matrix. RESULTS: The Accel produced a TSD3.5 (mean +/- SEM) of 47.9 +/- 1.0 min; the Amicus, 60.3 +/- 1.0 min; and the MCS Plus, 66.7 +/- 1.0 (p < 0.0001). The Amicus presented the greatest efficiency (87.5%; p < 0.0028). The MCS Plus demonstrated the highest capacity for leukodepletion (p < 0.0002) despite one process presenting more than 1 x 10(6) white blood cells per unit. The MCS Plus also measured the processing time with the greatest accuracy. No severe adverse effects were observed. The donors preferred the Accel (61%) followed by the Amicus (35%) and the MCS Plus (4%; p < 0.0001) and the processing speed was the most highly valued measure (55%). CONCLUSIONS: The Accel is the fastest and, because of this advantage, the machine preferred by donors. The Amicus was the most efficient and the MCS Plus was the only one not to underestimate the processing time.

Cross-Over Studies↗

PubMed2004

A comparison of PLT collections from two apheresis devices.

BACKGROUND: The aim of this study was to compare two apheresis devices (COBE Trima and COBE Spectra, Gambro BCT). STUDY DESIGN AND METHODS: The study compares 103 Trima procedures with 61 Spectra procedures. The comparison of single-donor PLTs (SDPs) separation parameters and anticoagulant infusion to the donors were the primary targets. Yield and residual amounts of WBCs of SDPs were secondary targets. Residual amounts of WBCs were measured with the Nageotte method. RESULTS: Trima and Spectra groups were comparable before apheresis. Two procedures were terminated before completion in the Trima group owing to vein damage. Trima infused more anticoagulant--352 +/- 104 mL versus 297 +/- 75 mL (p < 0.01)--and was quicker than Spectra. The time to obtain 3.5 x 10(11) was (median) 55.8 minutes for the Trima machine and 80.3 minutes for Spectra machine (p < 0.001). Regarding leukoreduction, all the SDPs had fewer than 1 x 10(6) WBCs per unit except for one in product obtained by the Trima machine. CONCLUSIONS: The Trima machine is faster and more efficient than the Spectra machine, and both machines allow standard leukoreduced SDPs to be obtained. Although donors receive a higher anticoagulant infusion with the Trima machine, their tolerance is acceptable.

Anticoagulants↗