LabMed

Measurement of vitamin E levels is used to evaluate the health status in humans. For routine analytics in clinical laboratories, an accurate, quick, and simple determination method is required. An option for the quantification of vitamin E (α-tocopherol) in human blood samples is the use of high-performance liquid chromatography (HPLC) in combination with a UV detector. Several sample preparation methods for this purpose have been reported in the literature. Our aim was to generate an overview and comparison of the different methods. The online database PubMed was searched for published HPLC methods. Of 77 reports screened, 16 methods were selected and summarized in tables. These present the parameters of the sample preparation procedure, HPLC settings, and some validation criteria (limit of detection (LOD), limit of quantification (LOQ), and intra- and inter-assay values, recovery rates) of the reported methods. In the frame of our methodological review, we could find some extraction approaches. The liquid–liquid extraction with hexane or the double extraction with hexane were often used. Another possibility is the single extraction approach. This systematic review highlights the similarities and differences in methods, and it can therefore be used to develop and establish methods in a laboratory.

Plasma cell disorders often have urinary excretion of monoclonal immunoglobulins and renal injury that are evaluated using total protein assays and electrophoresis. Proteinuria was evaluated for 100 patients with plasma cell disorders and 24 h collections. A turbidimetric method on the Abbott Alinity quantified protein. Electrophoresis used agarose gels. Most specimens (66%) had protein concentrations below the manufacturer’s limit of quantitation (LOQ), 6.8 mg/dL (68 mg/L). After validating an LOQ of 3 mg/dL (30 mg/L), 34% of urine specimens still were below the LOQ. After excluding 40 patients with other causes of increased protein excretion (decreased estimated glomerular filtration rate (eGFR), diabetes mellitus, or overflow proteinuria), almost all patients had protein excretion below an upper reference limit of 150 mg/d. Median total protein excretion for these 60 patients was 75 mg/d; only one patient excreted >132 mg/d. However, 32% of these patients without increased total protein excretion had albumin excretion ≥ 30 mg/d, suggestive of kidney injury. Electrophoretic patterns included glomerular, tubular, and overflow proteinuria; 32 specimens contained monoclonal immunoglobulins. Protein concentrations of urine are often below LOQs of total protein assays, raising questions about whether LOQs should be improved. Urine albumin measurements and electrophoretic patterns may serve as more sensitive indicators of kidney injury in patients with plasma cell disorder than measurements of total protein excretion or increased serum creatinine.

Source plasma centers sustain hematology therapeutics by safeguarding testing, traceability, and cold-chain integrity before fractionation. Despite regulatory requirements (21 CFR 606/640; EU Directive 2005/62/EC), published pre-operational validation frameworks demonstrating deviation-readiness before first collections remain sparse. We conducted a simulation-based pre-operational validation of an electronic quality management system (eQMS) with an Incident → Deviation → Corrective Action and Preventive Action (CAPA) pathway at a new source plasma center, performing 20 chairside mock runs, 3 freezer-alarm drills, and a document-control stress test. Primary endpoints were anomaly rate, alarm-response time relative to a 15 min service-level agreement (SLA), and deviation-closure SLA compliance. Analyses were descriptive and designed to demonstrate system functionality, not long-term process stability. Minor anomalies occurred in 6/20 mock runs (30.0%; 95% CI 11.9–54.3); no major/critical events were observed (0/20; 95% CI 0–16.8). Deviation-closure SLAs were met in 6/6 tests (100%; 95% CI 54.1–100). Alarm-response times averaged 7.0 min (SD 1.0; range 6–8 min; 95% CI 4.5–9.5), and all drills met the 15 min vendor SLA, illustrating a preliminary readiness margin (Cpu ≈ 2.7) rather than a statistically stable capability estimate. Simulation-based pre-operational validation produced inspection-ready documentation and quantitative acceptance criteria aligned to U.S./EU expectations, supporting reproducible multi-site deployment. By protecting cold-chain integrity and traceability before first collections, the validated QMS helps preserve supply reliability for plasma-derived therapeutics central to hematology care and establishes the measurement infrastructure for post-operational performance validation.