Use of artificial intelligence for tailored routine urine analyses.

OBJECTIVES: Urine is the most common material tested in clinical microbiology laboratories. Automated analysis is already performed, permitting quicker results and decreasing the laboratory technologist's (LT) workload. These automatic systems have introduced digital imaging concepts. PhenoMATRIX (PHM) is an artificial intelligence software that merges picture algorithms and user rules to provide presumptive results. This study aimed at designing a tailored workflow using PHM, performing its validation and checking its performance in routine practice. METHODS: Two data collections including 96 and 135 urine samples from nephrostomy/ureterostomy and artificial bladder (US), 948 and 1257 urine samples from catheter (UC) and 3251 and 2027 midstream urine (MSU) were used to compare LT results with those obtained using two versions of PHM. Another 19 US, 102 UC and 508 MSU were used to monitor performance level 3 months after routine implementation. RESULTS: Before and after revisions, agreement between the first version of PHM and LT results were 83% (95% confidence interval [CI], 74.3-90.2) and 83% (95% CI, 75.3-90.9) (US), 66.7% (95% CI, 63.5-69.5) and 71.7% (95% CI, 68.8-74.4) (UC) and 65.4% (95% CI, 63.8-67.1) and 76% (95% CI, 74.1-77.1) (MSU). The second version improved results, demonstrating 96.2% (95% CI, 91.6-98.8) and 97% (95% CI, 92.6-99.2) (US), 87.5% (95% CI, 85.5-89.2) and 88.9% (95% CI, 87.0-90.5) (UC) and 91% (95% CI, 89.7-92.1) and 92% (95% CI, 91.1-93.4) (MSU) of agreement with LT results before and after revisions. The reliability of PHM results was confirmed by a routine study demonstrating 92% (95% CI, 90.0-94.2) overall agreement. CONCLUSIONS: PHM showed high performance, with >90% of results in agreement with LT. PHM could help standardize and secure results, prioritize positive plates during analytical workflow and likely save LT time.

Overview of the in vitro stability of commonly measured vitamins and carotenoids in whole blood.

BACKGROUND: The pre-analytical stabilities of vitamins A, E, K, B1, B2, B6, B12, C, carotenoids and folates in whole blood were studied. The aim of this work was to provide clear and workable pre-analytical procedures specifying optimal delay before freezing for laboratories which perform themselves such analyses or which receive and transfer such specimens to referral laboratories. METHODS: The stability of vitamins was studied in whole blood at room temperature after light exposure up to 24 h (vitamin C), 48 h (vitamins A, E, B1, B2, B6 and carotenoids) and 72 h (vitamins K, B12, red blood cell (RBC) and serum folates). Vitamin C stability after baseline acidification was analysed up to 48 h. Changes observed were compared to a clinical cut-off defined as total change limit based on a combination of analytical performance and within-subject variation. RESULTS: Clinically and statistically significant changes occurred only in vitamins C (-22.5%), B6 (+9.9%) and serum folates (-16.8%) concentrations after 6, 24 and 48 h, respectively. Vitamins A, E, K, B1, B2, B12, RBC folates and carotenoids showed good stability up to 48 or 72 h. Vitamin C in acidified serum conserved at room temperature appeared unstable. The optimal condition for acidified vitamin C conservation was at less than -20℃. CONCLUSION: The majority of vitamins remain stable for up to 48 h. Vitamin C quantification requires serum acidification followed by freezing as soon as possible. Freezing, respectively, within 12 h and 24 h for determination of plasma vitamin B6 and serum folates concentrations is recommended.

Assays for the quantification of melphalan and its hydrolysis products in human plasma by liquid chromatography-tandem mass spectrometry.

Two high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) assays are described for the quantification of melphalan in human plasma. N-phenyldiethanolamine was tested as internal standard. The first assay consisted of a protein precipitation by cold methanol and a reversed-phase HPLC whereas the second one was based on a solid phase extraction and a hydrophilic interaction chromatography. Both provided a very satisfactory mean extraction yield with a small volume of sample. The first method was simple, rapid and used as a routine assay. The second one was developed in order to determine melphalan hydrolysis products and to avoid scarce cases when interferences from biological matrix alter the quantification of melphalan using the first method. The two assays were linear and sensitive in the range of 1-500ng/mL for the first one and in a range of 25-2000ng/mL for the second one. Concentrations out of the range fixed with the first method were also validated. The procedure was reliable with precision and accuracy below 10%. All compounds were detected after positive mode electrospray ionization in selected reaction monitoring mode. These new analytical procedures were developed for melphalan pharmacokinetic studies or therapeutic drug monitoring.

Rapid quantification of miglustat in human plasma and cerebrospinal fluid by liquid chromatography coupled with tandem mass spectrometry.

Miglustat (OGT 918) is an iminosugar recently introduced in therapeutic as potential alternative therapy in disorders found in several diseases such as Tay-Sachs, Gaucher or Niemann-Pick diseases. A highly sensitive liquid-chromatography-electrospray tandem mass spectrometry (LC-MS/MS) assay was developed for the quantification of miglustat in human plasma and cerebrospinal fluid (CSF). The sample preparation consists in a simple protein precipitation with a mixture of acetonitrile/methanol (75/25) which yields 100% recovery. The isocratic separation utilizes an Atlantis Hilic (3 microm, 150 mm x 2.1 mm) column, with a mobile phase of acetonitrile/water/ammonium acetate buffer (75/10/15, v/v/v) delivered at 230 microl/min. Selected reaction monitoring (SRM) mode was used with the transitions m/z 220-->158 for the miglustat and m/z 208-->m/z 146 for the miglitol (internal standard). Good linearity was observed in a range from 125 to 2500 ng/ml and from 50 to 1000 ng/ml, for plasma and CSF, respectively. The within-run precision of the assay was less than 6%, and the between-run run precision was less than 6.5%, for six replicates at each of three concentrations and evaluated on three separated days for both plasma and CSF mediums. Assay accuracy was in the range of 98-106.5%. Stability of miglustat was reported under a variety of storage conditions. The miglustat concentrations in two children are presented to demonstrate the clinical interest of this new method.