Comparison of reference systems in the assessment of age-related serum immunoglobulin levels in pediatric patients

Background/aim

Ig level assessment is frequently used in the diagnosis and follow-up of immunodeficiency, as well as in studies investigating the prevalence of low serum Ig level in specific diseases.Material and methods: Patients who underwent Ig testing in the inpatient and outpatient clinics of our hospital in the years 2010–2016 were included. The Ig levels of the patients were assessed separately according to two reference systems commonly used in Turkey and another reference system used in the USA.

Results

A total of 20,138 patients (57.6% male) were included in the study. The median age of the patients was 55.7 months (interquartile range: 23.1–96.7). According to the reference intervals determined by Tezcan et al., 30.6% of the patients were deficient in one or more Ig values. This rate was 4 times higher than those based on the reference intervals determined by Aksu et al. (7.7%) and those in the Nelson Textbook of Pediatrics (6.8%). We also determined that the frequency of low Ig levels with three reference systems.Conclusion: In this study, we found that the rates of low Ig level in a group of pediatric patients differed significantly when evaluated using three different reference systems for age-related serum Ig levels

Standardization of clinical enzyme analysis using frozen human serum pools with values assigned by the International Federation of Clinical Chemistry and Laboratory Medicine reference measurement procedures

Variation in clinical enzyme analysis, particularly across different measuring systems and laboratories, represents a critical but long-lasting problem in diagnosis. Calibrators with traceability and commutability are imminently needed to harmonize analysis in laboratory medicine. Fresh frozen human serum pools were assigned values for alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), creatine kinase (CK) and lactate dehydrogenase (LDH) by six laboratories with established International Federation of Clinical Chemistry and Laboratory Medicine reference measurement procedures. These serum pools were then used across 76 laboratories as a calibrator in the analysis of five enzymes. Bias and imprecision in the measurement of the five enzymes tested were significantly reduced by using the value-assigned serum in analytical systems with open and single-point calibration. The median (interquartile range) of the relative biases of ALT, AST, GGT, CK and LDH were 2.0% (0.6-3.4%), 0.8% (-0.8-2.3%), 1.0% (-0.5-2.0%), 0.2% (-0.3-1.0%) and 0.2% (-0.9-1.1%), respectively. Before calibration, the interlaboratory coefficients of variation (CVs) in the analysis of patient serum samples were 8.0-8.2%, 7.3-8.5%, 8.1-8.7%, 5.1-5.9% and 5.8-6.4% for ALT, AST, GGT, CK and LDH, respectively; after calibration, the CVs decreased to 2.7-3.3%, 3.0-3.6%, 1.6-2.1%, 1.8-1.9% and 3.3-3.5%, respectively. The results suggest that the use of fresh frozen serum pools significantly improved the comparability of test results in analytical systems with open and single-point calibration.

[Problem of the referral-for-referral system of obstetrical emergencies and the community involvement in the Bamako district]

AIMS

This study aims to evaluate the difficulties of the referral-for-referral system in the V municipality sanitary district of Bamako.

PATIENTS AND METHOD

A descriptive cross-sectional study was carried out from 5th September to 5th November 2011 in the sanitary district of the V municipality in Bamako. Included in the study were patients referred or evacuated for obstetrical care in the health center during the period of study. Not included were the patients referred or evacuated from other sanitary districts and patients referred or evacuated or self-referred for no obstetrical reasons. Data was recorded on the Excel 8.0 software and analyzed on the software packages Epi info 3.5.3 and STATA.

RESULTS

During the period of study we recorded 1824 deliveries among which 180 fit the inclusion criteria. During our study 92.2% of references were adequate; 78.3% were justified and 72.2% were opportune. Only the sanitary district of the V Municipality had paid its quotation due at the time of the study.

CONCLUSION

Our study showed that inadequate logistics and the lack of involvement of communities hamper the proper functioning of the referral system.

Adsorption from a one-dimensional lattice gas and the Brunauer-Emmett-Teller equation

An exact treatment of adsorption from a one-dimensional lattice gas is used to eliminate and correct a well-known inconsistency in the Brunauer-Emmett-Teller (B.E.T.) equation-namely, Gibbs excess adsorption is not taken into account and the Gibbs integral diverges at the transition point. However, neither model should be considered realistic for experimental adsorption systems.