Preanalysis in Serum Hepcidin Measurement.

BACKGROUND: Hepcidin is a 25-amino peptide hormone that regulates iron homeostasis. Its serum quantification helps to provide the right therapeutic choice in iron-deficiency anemia and anemia in chronic diseases. Diurnal levels of serum iron might affect hepcidin secretion during the day. Blood collection time is an important part of the preanalytical phase of its quantification. METHODS: During the period 2013 - 2014, we collected blood samples for serum hepcidin quantification in 100 healthy controls. The samples were collected in vacuettes with serum separator gel at three different times during the day: 07:30 - 08:30, 12:00 - 13:00, and 16:00 - 17:00 hours. Hepcidin levels were measured with an ELISA method. RESULTS: We found a significant difference in serum hepcidin levels during the chosen three blood taking times. The normal range for Bulgarian population is 3.05 µg/L - 37.75 µg/L. The measured levels were: at 07:30 - 08:30 hours 12.2 µg/L (5.5 µg/L - 23.6 µg/L), 12:00 - 13:00 hours 14.1 µg/L (7.1 µg/L - 27.2 µg/L), and 16:00 - 17:00 hours 16.5 µtg/L (9.9 µg/L - 29.6 µpg/L) 10.7 < r < 1.0; p < 0.5 between 07:30 - 08:30 and 12:00 - 13:00 hours and p < 0.05 between 07:30 - 08:30 hours and 16:00 - 17:00 hours and 12:00 - 13:00 hours and 16:00 - 17:00 hours]. No significant differences were found for transferrin saturation between measured groups [0.1 < r < 0.3; p > 0.5]. CONCLUSIONS: In order to obtain the most correct results for serum hepcidin quantification (especially in border to referent range levels) in the preanalytical phase, it is important to consider the time of blood sampling.

Quantitative expediency assessment of the zeta sedimentation ratio and the plasma viscosity in arterial hypertension research.

Accepted methods of the ESR methodology (the Westergren mode and ZSR mode) and its alternative the plasma viscosity were tested for diagnostic utility in pregnancy induced hypertension and pre-eclampsia. The receiver-operating characteristic curve (ROC) analysis approved moderate diagnostic accuracy for the ESR methodology and supplied support for its preliminary estimated cutoff values but failed to indicate cogent discernment of pathology by values of plasma viscosity. Likely pathological whole blood alterations boost the erythrocyte aggregation while the concomitant depletion of macromolecules degrades plasma viscosity values.

Serum cystatin C in renal transplant patients.

Assessment of renal function in clinical medicine is of great importance especially in patients with renal transplants. Cystatin C has the characteristics of an ideal marker to assess renal glomerular filtration rate. Forty patients with renal transplants under steady-state post-transplant conditions were included in the study. Steady-state was defined as lack of acute rejection periods during the last 6 months and stable cyclosporin A medication during the past 4 weeks. Gender was balanced with 20 male and 20 female patients, the mean age was 51+/-14 years, time since transplantation was 5+/-3.5 years. Fifteen percent of the patients suffered from diabetes mellitus. Immunosuppression consisted of cyclosporin A, imuran, and prednisolon. To assess renal function cystatin C, creatinine clearance, serum creatinine, and serum beta2-microglobulin were tested. Creatinine was analysed in serum and urine to calculate the creatinine clearance related to 1.73 m(2) body surface. Cystatin C and beta2-microglobulin were determined by using a particle-enhanced turbidimetric assay. Cystatin C correlated best with creatinine clearance (r=0.66), beta2-microglobulin (0.57), and serum creatinine (0.56). The diagnostic accuracy of cystatin C was significantly better than serum creatinine (p<0.05), but did not differ significantly from creatinine clearance (p=0.73), and beta2-microglobulin (p=0.46). Our data show that patients with renal transplants, cystatin C has a similar diagnostic value as creatinine clearance. However, it is superior to serum determination of creatinine and beta2-microglobulin. Cystatin C allows for rapid and accurate assessment of renal function in patients with renal transplants and is clearly superior to the commonly used serum creatinine.

[A new approach to evaluating the results of interlaboratory quality control in Bulgaria]. / Nov podkhod pri otsenkata na rezultatite ot mezhdulaboratorniia kachestven kontrol v Bulgariia.

The results of examinations carried out in 37 clinical laboratories in Bulgaria which participated in the interlaboratory quality assurance check are discussed. The check included 202 laboratories from 5 countries members of the Council of Mutual Economic Aid and covers the examinations of chlorine, sodium, potassium, calcium, urea, creatinine, total protein, cholesterol, glucose, inorganic phosphorus. The results are assessed by the "normative standard deviation" which differs from the "absolute quality index" used in the national external laboratory quality assurance check. The results of the Bulgarian laboratories are better in the examinations of glucose, urea, cholesterol and inorganic phosphorus. The analytical variations in protein, sodium and chlorine equal those of the other participants while the results of calcium, potassium and creatinine show greater variations. The interlaboratory variations of the results obtained by the different analytical methods are discussed. The results of the examinations of calcium and potassium are least acceptable.

[Intralaboratory quality control over random and systematic errors using the combined Shewart-cusum check card]. / Vutrelaboratoren kachestven kontrol na sluchainite i sistemnite greshki s pomoshta na komibirana Shewart-cusum kontrolna karta.

The method of the within-the-laboratory quality assurance check of the casual and systematic mistakes in the analytical process is presented. The results of the control serums are evaluated by the combined Shewart-cusum check card which is suitable for both casual and systematic mistakes while the classical check card controls the casual mistakes only. The method was used for evaluation of the analytical quality of the results determined by the automatic analyzer "RA 1000 Technicon". The general assessment of the combined method is that the systematic mistakes found are very often of no medical importance but in any case they are an "useful" information for the laboratory specialists in their efforts to provide a reliable laboratory information.