During a normal menstrual cycle, serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and progesterone can vary widely between cycles for the same woman, as well as between different woman. Reliable reference values based on the local population are important for correct interpretation of laboratory results. The purpose of our study was to determine detailed reference values for these hormones throughout the menstrual cycle using the Abbott ARCHITECT system. From 20 volunteers (age 20–36years) with normal cycles and no use of oral contraceptives, samples were taken every day during their cycle. Volunteers received three vaginal ultrasound examinations (days 10 and 13, and 1 or 2days after ovulation) to measure follicular and corpus luteum development. Hormone levels were measured using the corresponding ARCHITECT assay and were synchronized to the LH peak. Median, and 5th and 95th percentile values were determined for each day of the cycle, as well as for early follicular (days −15 to −6), late follicular (days −5 to −1), LH peak (day 0), early luteal (+1 to +4), mid-luteal (days +5 to +9), and late luteal (days +10 to +14) phases of the cycle. Based on our data, we were able to establish detailed reference values for LH, FSH, estradiol, and progesterone, which should aid in the interpretation of results for these reproductive hormones in a variety of circumstances.
, Riyadh and Hassa all used the same Abbott (Architect) analyzers. Methods, instruments and reagents In this second part of the Saudi multicenter RI study, we targeted 20 commonly tested analytes that were all measured using an Abbott, Architect i2000 analyzer. The analytes were five tumor markers (α-fetoprotein [AFP], carcinoembryonic antigen [CEA], carbohydrate antigen 125 [CA125], prostate specific antigen [PSA], ferritin), six reproductive hormones (estradiol, progesterone, testosterone, luteinizing hormone [LH], follicle-stimulating hormone [FSH], prolactin [PRL
Background: Human milk and occasional serum samples contain high concentrations of unsaturated haptocorrin, which influence accurate measurement of cobalamins.
Methods: Cobalamins in serum samples spiked with increasing amounts of unsaturated haptocorrin were measured employing the Centaur, Cobas and Architect analysers. Cobinamide-coated EAH sepharose was employed for pretreatment of the samples. Human milk samples were collected from 24 healthy mothers. Haptocorrin was measured by ELISA.
Results: The measured concentration of cobalamins either increased (Centaur analyser) or decreased (Architect, Cobas analysers) significantly for haptocorrin >10 nM, and was 220%, 52% or 45% of the expected values in a serum sample containing 50 nM haptocorrin. Following pretreatment with cobinamide-sepharose, the expected cobalamin concentration was obtained (Centaur). The milk samples contained 4.5–180 nM haptocorrin. In samples containing >10 nM haptocorrin (n=19), the median concentration of cobalamins decreased from 1.3 nM to 0.67 nM after pretreatment with cobinamide-sepharose.
Conclusions: Haptocorrin in concentrations above 10 nM influences measurement of cobalamins giving rise to falsely elevated or decreased results. Removal of unsaturated haptocorrin by pretreatment with cobinamide-sepharose solves the problem.
This study is a part of the IFCC-global study to derive reference intervals (RIs) for 28 chemistry analytes in Saudis.
Healthy individuals (n=826) aged ≥18 years were recruited using the global study protocol. All specimens were measured using an Architect analyzer. RIs were derived by both parametric and non-parametric methods for comparative purpose. The need for secondary exclusion of reference values based on latent abnormal values exclusion (LAVE) method was examined. The magnitude of variation attributable to gender, ages and regions was calculated by the standard deviation ratio (SDR). Sources of variations: age, BMI, physical exercise and smoking levels were investigated by using the multiple regression analysis.
SDRs for gender, age and regional differences were significant for 14, 8 and 2 analytes, respectively. BMI-related changes in test results were noted conspicuously for CRP. For some metabolic related parameters the ranges of RIs by non-parametric method were wider than by the parametric method and RIs derived using the LAVE method were significantly different than those without it. RIs were derived with and without gender partition (BMI, drugs and supplements were considered).
RIs applicable to Saudis were established for the majority of chemistry analytes, whereas gender, regional and age RI partitioning was required for some analytes. The elevated upper limits of metabolic analytes reflects the existence of high prevalence of metabolic syndrome in Saudi population.
Monoclonal immunoglobulins can cause interference in many laboratory analyses. During a 4 month period we observed seven patients with monoclonal disease and falsely extremely elevated 25-hydroxyvitamin D (25(OH)D) results above 160 ng/mL (>400 nmol/L) measured using an immunoassay from Abbott Diagnostics. Based on these findings, we studied the occurrence of falsely elevated 25(OH)D in samples with paraproteins and investigated possible mechanisms of the observed interference.
25(OH)D was analyzed using the Architect i2000 platform from Abbott Diagnostics and a higher order method, liquid chromatography-mass spectrometry (LC-MS/MS), in serum samples from 50 patients with known monoclonal disease. Patients with falsely elevated 25(OH)D were included in further studies to elucidate the cause of interference. Spuriously elevated results were in addition analyzed on two alternative platforms (Siemens and Roche).
Falsely elevated 25(OH)D levels were present in eight patients on the Abbott analyzer and one on the Siemens platform. Results from Roche were comparable with LC-MS/MS. Additional investigations excluded elevated concentrations of rheumatoid factor and heterophilic antibodies as the cause of interference in the Abbott assay.
Laboratories should be aware of the risk of falsely elevated 25(OH)D in samples run on the Architect analyzer from patients with monoclonal disease. Highly elevated vitamin D results should be diluted and if the dilution is non-linear, rerun by a different method, preferably LC-MS/MS. In patients with spuriously elevated 25(OH)D without known monoclonal disease, the laboratory should consider requesting protein electrophoresis to exclude paraprotein interference.
need for laboratories to confirm that
the reference ranges they use are appropriate for the
population they serve.
*Corresponding author: Manuel González Sagrado, Unidad
de Apoyo a la Investigación, Hospital ‘‘Del Rı́o Hortega’’,
Avda. Cardenal Torquemada s/n, 47010 Valladolid, Spain
Phone: q34-983-420400 (ext. 20740),
Keywords: ARCHITECTanalyzer; reference values;
According to the National Committee for Clinical Lab-
oratory Standardization (NCCLS) guideline C28-A2,
‘‘for a decision making process to occur
strategies of its protagonists – from Walter
Gropius and Le Corbusier to Mies van der Rohe
– against all comers.
The enemy, though, is not one of the architectsanalysed by Sancho Pou, nor is it the “seller”
of strategies; the true enemy is the architect
who keeps going round in circles by himself
and who never innovates.
This brings to mind Walter Benjamin’s “Ange-
lus Novus”, who, with his eyes turned to the
smouldering ruins of the past, is relentlessly
driven by a storm into the future. Benjamin’s
storm stands for progress. Sancho Pou’s mod-
ern Angelus Novus