Band 47, Heft 2

Objectives Reference intervals of total cholesterol concentrations in plasma and of their fractions low-density lipoprotein (LDL)-, high-density lipoprotein (HDL)-and non-HDL concentrations are seldom studied with respect to the relevance of age and sex. Therefore, the effect of age and sex on the reference intervals was reinvestigated with 2 indirect procedures. Methods As an indirect approach, the truncated minimum chi-square method was applied. All analyses were performed by computer programs available. The script published on the homepage of the German Society of Clinical Chemistry and Laboratory Medicine (DGKL) allows to derive a continuous age dependency of reference intervals together with their confidence and equivalence limits. The results of this approach were compared with those obtained by an indirect method developed more recently, the refineR algorithm. Results In the present study, the upper reference limits of total cholesterol varied from 5.1 to 7.8 mmol/L (197–302 mg/dL) depending on various biological variables (as age, sex, inpatients versus outpatients). These upper limits increased with age. Differences between sexes can be neglected except for the age above 80 years. The pattern of reference limits of LDL cholesterol and non-HDL cholesterol paralleled those of total cholesterol. The reference limits of HDL cholesterol were higher in women than in men but were independent of age. Conclusions Reference limits for the concentrations of total cholesterol and their fractions LDL-, HDL-and non-HDL concentrations should be stratified for age and sex.

Objectives Automated sample delivery and laboratory acceptance systems (PTAS) may influence the hemolysis rate of blood samples due to g-forces, abrupt acceleration, and rapid deceleration. However, quantitative data regarding the rate of hemolysis in PTAS is limited. To fill this void, the effect of a pneumatic tube in combination with an acceptance system (PTAS) on the hemolysis rate was investigated in this study. Methods Lithium heparin plasma tubes were transported from different clinical departments to the hospital’s laboratory (a) by employees or (b) with an automated PTAS and analyzed for the presence of hemolysis based on a hemolysis index (HI) of >25. Hemolysis indices of 68.513 samples were retrieved from the laboratory information system before and after installation of the PTAS and were subjected to statistical analysis. Results A total of 32.614 samples were transported by employees, of which 3.815 samples (11.70%) were hemolytic, and 9.441 out of 35.899 samples delivered by PTAS (26.30%) were hemolytic. After the implementation of the PTAS, hemolysis rates increased in all departments. Conclusions Automated PTAS are associated with increased hemolysis rates. This has implications for routine patient management and should be considered for the transportation of samples used for the determination of hemolysis-sensitive laboratory parameters.

Objectives Biobanked samples are becoming increasingly important for research outcomes. Most of the biobanking processes (from preparation to storage) are affected by temperature in a time-dependent manner and have a high impact on sample quality. We aimed to validate time and temperature sensitive processes such as sample preparation, transport, sorting, and storage, which have a high impact on sample quality. Methods Temperature was measured using internal or external temperature data loggers. We analysed the temperature and present real data from our sample transport on dry ice and with the CryoPod, from our ultra-low temperature freezers (UTFs) of different manufacturers and cryostores. We also tested sample sorting on dry ice and in a cryogenic workbench. Results In the UTFs, we identified temperature zones with a temperature difference from 4.7 °C up to 20.8 °C across the whole UTF. For sample transport within approximately 30 min we observed temperatures of −80.2 °C ± 4.0 °C and −173.9 °C ± 16.9 °C for dry ice boxes and the CryoPod, respectively. Sorting on dry ice was best in a polystyrene box half-filled with dry ice pellets, although the temperature increased by 7.5 °C within the first 5 min, whereas the temperature in the cryogenic workbench remained stable below −100 °C for hours. Conclusions Time and temperature play a crucial role in the entire biobanking process, with sometimes immense temperature fluctuations in some equipment. We recommend the validation or verification of all equipment and processes used to avoid pre-analytical errors in accordance with DIN EN ISO 20387.

Objectives Routine blood examination, one of the most commonly performed tests in clinical laboratories, directly reflects the overall state of the body such as inflammation, anemia, and thrombocytopenia. The accuracy of these indicators by tests may be perturbed by various factors including anticoagulants, antibodies, and temperatures. Pseudoleukopenia caused by leukoagglutination was rarely described in the literature. Case presentation We report a rare and unusual pseudo-leukopenia case of a 75-year-old female with a stroke. Blood samples from the patient were collected using different anticoagulants and determined the hematologic parameters and blood smears. We observed the extent of leukocyte aggregation at different anticoagulants or temperatures. The intensity of leukoagglutination was attenuated after incubating at 37 °C for 30 min. After anti-infection treatment and symptomatic treatment, the leukoagglutination of the patient gradually weakened. Conclusions We have found the reason for the pseudo-leukopenia and the leukocyte aggregation phenomenon may vary with disease progression.