Analysis of the costs for the laboratory of flow cytometry screening of urine samples before culture.

Urine culture samples comprise a large proportion of the workload in clinical microbiology laboratories, and most of the urine samples show no growth or insignificant growth. A flow cytometry-based analyzer (Sysmex Corporation, Japan) has been used to screen out negative urine samples prior to culture in the Päijät-Häme district. We applied decision analytic modelling to analyze, from a laboratory perspective, the economic feasibility of the screening method as compared to culture only (conventional method) for diagnosis of urinary tract infection. Our model suggests that the least costly analytical strategy is the conventional method. The incremental cost of screening is €0.29/sample. Although laboratory costs are higher, considerable savings on workload can be achieved. Furthermore, screening has numerous benefits on the treatment process of a patient that well warrant the use of the screening method. We conclude that the incremental cost of screening the samples is worth the expense.

Screening of urine samples by flow cytometry reduces the need for culture.

Urine samples constitute a large proportion of samples tested in clinical microbiology laboratories. Culturing of the samples is fairly time- and labor-consuming, and most of the samples will yield no growth or insignificant growth. We analyzed the feasibility of the flow cytometry-based UF-500i instrument (Sysmex, Japan) to screen out urine samples with no growth or insignificant growth and reduce the number of samples to be cultured. A total of 1,094 urine specimens sent to our laboratory for culture during 4 months in the spring of 2009 in Lahti, Finland, were included in the study. After culture, all samples were analyzed with the Sysmex UF-500i for bacterial and leukocyte (white blood cell [WBC]) counts. Youden index and closest (0,1) methods were used to determine the cutoff values for bacterial and WBC counts in culture-positive and -negative groups. By flow cytometry, samples considered positive for UTI in culture had bacterial and WBC values that were significantly higher than those for samples considered negative. The flow cytometric screening worked best when both bacterial counts and WBC counts were used with age- and gender-specific cutoff values for all patient groups, excluding patients with urological disease or anomaly. By use of these cutoff values, 5/167 (3.0%) of culture-positive samples were missed by UF-500i and the percentage of samples that did not need to be cultured was 64.5%. Use of the UF-500i instrument is a reliable method for screening out a major part of the UTI-negative samples, significantly diminishing the amount of work required in the microbiology laboratory.

CTLA-4 polymorphism 49A-G is associated with placental abruption and preeclampsia in Finnish women.

BACKGROUND: Our aim was to study genetic variability in the gene encoding cytotoxic T-lymphocyte antigen (CTLA-4) and individual susceptibility to the development of preeclampsia or placental abruption. METHODS: A total of 361 women (132 with preeclampsia, 117 with placental abruption and 112 healthy controls) were genotyped for 49A-G polymorphism (dbSNP: rs231775) in the CTLA-4 gene. RESULTS: The frequency of the G alleles was significantly higher in women with preeclampsia than in controls (51.1% vs. 42.0%; OR 1.44, 95% CI 1.01-3.48, p<0.043). Women with placental abruption had decreased frequency of AA genotype (22.2% vs. 35.7%) and significantly more AG or GG genotypes compared with controls (OR 1.94, 95% CI 1.09-2.07, p<0.024). No significant differences were detected in the frequencies of genotype GG (29.5%, 21.4% and 19.6%, respectively) between the three groups. CONCLUSIONS: Our data suggest that the 49A-G polymorphism in the CTLA-4 gene is associated with the development of placental abruption and preeclampsia, with women having the G allele being at risk.