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Biomedical subjects

M Zaninotto

Publications and source records attributed to M Zaninotto.

At least 19 recordsLinked to original sources
PubMed2004

Quality specifications for biochemical markers of myocardial injury.

BACKGROUND: The current approach to the diagnosis and monitoring of myocardial damage, recognizes to biochemical markers, and in particular to troponins, a key role being well demonstrated that all elevated values were associated with a worsened prognosis. In 2001, the IFCC Committee on Standardization of Markers of Cardiac Damage published guidelines addressing the quality specifications for troponin assays in order to guarantee an analytical performance satisfying medical requirements and to standardize the quality of commercial methods. We describe how the application of quality specifications may be useful in daily practice, in order to provide advice to clinicians in the investigations of complex clinical cases of patients suffering from myocardial damage. MATERIALS AND METHODS: The samples from three patients (cases 1-3) admitted to the hospital with symptoms suggestive of cardiac disease, showing high troponin I (cTnI) values not correlated with clinical condition, were investigated in order to verify the accuracy of the laboratory data. The standard of quality specifications related to assay specificity, imprecision and interferences were evaluated using different platforms for cTnI assays, carrying out imprecision profile and specific studies on more common interferents in immunoassays. RESULTS: The obtained results allow us to demonstrate two cases of false-positive cTnI values attributable to a macrocomplex between a modified "in vivo" cTnI and immunoglobulin G (case 1) and to a presence of heterophilic antibodies affecting the RxL Dimension procedure (case 3). Instead, the accuracy of data obtained in case 2 was evidenced by the imprecision profile obtained in our laboratory and by the comparison of results between different laboratories using same platform. CONCLUSIONS: The lack of standardization as well as the wide differences in the development of each assay give rise to major concerns regarding cTnI determinations. The laboratory must therefore check the compliance between the analytical characteristics of the method utilised against recommended quality specifications for a reliable understanding of the frequency of false-positive results as well as other serious analytical errors.

Adult↗
PubMed2003

Cardiac troponin I, cardiac troponin T and creatine kinase MB concentrations in umbilical cord blood of healthy term neonates.

AIMS: To measure and compare cardiac troponin I, cardiac troponin T and creatine kinase MB concentrations in the umbilical cord blood of healthy term infants and to investigate the relationship between maternal and neonatal troponin values at birth. METHODS: Troponin I, troponin T and creatine kinase MB concentrations were measured from the umbilical cord samples of 85 healthy term neonates and in the blood samples of their respective mothers at birth. RESULTS: Median (interquartile range) umbilical cord concentrations were 0 microg/L (0-0) for troponin I, 0 microg/L (0-0.019) for troponin T and 4.90 microg/L (3.90-6.61) for creatine kinase MB. Troponin I and T concentrations were higher than the detection limit for the assay in 2 (2.3%) and 41 (48.2%) neonates, respectively. Two mothers (2.3%) had cTnT levels above the detection limit; none of them had increased levels of cTnI. CONCLUSION: Probably owing to differences in expression and assay detection limits, cord blood troponin T concentrations are frequently over the detection limit at birth, while troponin I is mostly undetectable and comparable with that in healthy pregnant women. These cardiac regulatory proteins are of neonatal origin and are not influenced by maternal levels.

Creatine Kinase↗
PubMed2003

Serum human cartilage glycoprotein 39 as a marker of arthritis associated with inflammatory bowel disease.

BACKGROUND: Common blood markers of arthritis are difficult to interpret in arthritis associated with inflammatory bowel disease (IBD) owing to the coexistence of two inflammatory events. No specific serological disease marker is available for IBD. OBJECTIVE: To determine a value of serum human cartilage glycoprotein 39 (HC gp39) as a marker of arthritis associated with IBD. METHODS: Serum levels of HC gp39 and ultrasensitive C reactive protein (CRP) were determined in 121 patients with IBD: 58 without arthritis (IBD-nonA) and 63 with arthritis (IBD-A), and in 20 healthy controls. IBD was classified as active (aIBD) and non-active (naIBD), and patients with IBD-A were classified as type I, II, and III arthritis by clinical activity indices. RESULTS: HC gp39 was higher in IBD-A than in IBD-nonA (p<0.001) and controls (p<0.01), while no difference was found between IBD-nonA and controls. CRP was increased in both IBD-A and IBD-nonA compared with the controls (p<0.01 and <0.05, respectively) and in aIBD-nonA v naIBD-nonA (p<0.05), but no difference in CRP was found between aIBD-A and naIBD-A. Finally, a correlation was found between the number of affected joints (NAJ) and HC gp39 (r = 0.6, p<0.001). DISCUSSION: Increased serum levels of HC gp39, which were higher in IBD-A than in IBD-nonA, suggest that this substance might be a marker of arthropathy in IBD. HC gp39, because of its relationship with NAJ in IBD-A, may also be proposed as a disease activity marker in arthritis associated with IBD.

Adipokines↗
PubMed2001

Point-of-care testing of cardiac markers: results from an experience in an Emergency Department.

AIM: An experimental approach to the use of point-of-care testing for cardiac markers in the Emergency Department (ED) of our Institution has been carried out using two devices (SCS, Dade Behring and Triage Cardiac Panel, Biosite Diagnostics) for the measurement of cardiac markers. RESULTS: (1) From the analytical point of view, a fundamental tool for an efficient management of patients was the agreement between results from point-of-care testing and from the instruments located in STAT lab and/or central laboratory: in about 5% of patients, a lack of comparability of data, resulted in an inappropriate admission of patients (medical vs. intensive care unit). (2) The actual total turnaround time (TAT) in the management of samples sent to STAT lab was estimated to be equal to 82.5 min (50th percentile). (3) In the same organizational setting, the use of a point-of-care device produced a turnaround time equal to 17 min (50th percentile). (4) The reduction in turnaround time resulted in a faster discharge for five patients who had normal ECG findings and cardiac marker values, the Delta time (POCT-STAT lab) ranging from -10 to -70 min. CONCLUSIONS: The point-of-care option evaluated also in relation to personnel issues for staff working in the ED, brought some interesting questions about the characteristics of POCT devices (easy to use 100%, safety for operator 91%) and the obtained results (quantitative and correlated to STAT lab, 91%), as well as the need of other options such as the implementation of rapid tube sample delivery.

Attitude of Health Personnel↗
PubMed2001

Alendronate prevents further bone loss in renal transplant recipients.

The aim of this study was to investigate the effects of alendronate, calcitriol, and calcium in bone loss after kidney transplantation. We enrolled 40 patients (27 men and 13 women, aged 44.2 +/- 11.6 years) who had received renal allograft at least 6 months before (time since transplant, 61.2 +/- 44.6 months). At baseline, parathyroid hormone (PTH) was elevated in 53% of the patients and the Z scores for bone alkaline phosphatase (b-ALP) and urinary type I collagen cross-linked N-telopeptide (u-NTX) were higher than expected (p < 0.001). T scores for the lumbar spine (-2.4 +/- 1.0), total femur (-2.0 +/- 0.7), and femoral neck (-2.2 +/- 0.6) were reduced (p < 0.001). After the first observation, patients were advised to adhere to a diet containing 980 mg of calcium daily and their clinical, biochemical, and densitometric parameters were reassessed 1 year later. During this period, bone density decreased at the spine (-2.6 +/- 5.7%;p < 0.01), total femur (-1.4 +/- 4.2%; p < 0.05), and femoral neck (-2.0 +/- 3.0%; p < 0.001). Then, the patients were randomized into two groups: (1) group A-10 mg/day of alendronate, 0.50 microg/day of calcitriol, and 500 mg/day of calcium carbonate; and (2) group B-0.50 microg/day of calcitriol and 500 mg/day of calcium carbonate. A further metabolic and densitometric reevaluation was performed after the 12-month treatment period. At the randomization time, group A and group B patients did not differ as to the main demographic and clinical variables. After treatment, bone turnover markers showed a nonsignificant fall in group B patients, while both b-ALP and u-NTX decreased significantly in alendronate-treated patients. Bone density of the spine (+5.0 +/- 4.4%), femoral neck (+4.5 +/- 4.9%), and total femur (+3.9 +/- 2.8%) increased significantly only in the alendronate-treated patients. However, no trend toward further bone loss was noticed in calcitriol and calcium only treated subjects. No drug-related major adverse effect was recorded in the two groups. We conclude that renal transplanted patients continue to loose bone even in the long-term after the graft. Alendronate normalizes bone turnover and increases bone density. The association of calcitriol to this therapy seems to be advantageous for better controlling the complex abnormalities of skeletal metabolism encountered in these subjects.

Adult↗
PubMed2001

Persistently increased bone turnover and low bone density in long-term survivors to kidney transplantation.

AIMS: There are few data on the long-term outcome of bone health in renal transplant recipients. We wanted to evaluate the prevalence of osteoporosis and related clinical fractures in long-term survivals to kidney transplantation. METHODS: We carried out a cross-sectional study of 80 males and 44 females, aged 45 +/- 1 years, who had undergone kidney transplantation (KTx) 55.6 +/- 4.6 months earlier. Patients were treated according to standard immunosuppressive protocols. RESULTS: High parathyroid hormone levels were observed in 55 out of the 124 patients (44.6%) and the prevalence of secondary hyperparathyroidism (SHPT) remained similar even when subjects were grouped according to the time elapsed since transplant. The Z scores for bone alkaline phosphatase, osteocalcin, urinary N telopeptide and galactosyl-hydroxylysine were increased as compared to normal controls, both in males and females (p < 0.05). Bone formation markers normalized, while bone resorption markers remained elevated in these patients even ten years after transplant. Vertebral and femoral osteoporosis were present in 37% and 56% of the patients, respectively, and no tendency toward a recovery in bone mass was seen even in those patients who had survived the longest time since KTx. Clinical fracture rate was 0.006 and 0.031 patient years, before and after KTx, respectively. The number of fractures was lower in patients taking lower mean daily doses of corticosteroids (p < 0.025). PTH levels positively correlated with bone alkaline phosphatase, osteocalcin and N telopeptide. CONCLUSION: In conclusion, bone density is decreased and bone turnover increased even many years after KTx, with persistent SHPT and corticosteroid use being the main pathogenetic factors.

Adult↗
PubMed2000

Effect of patent ductus arteriosus and indomethacin treatment on serum cardiac troponin T levels in preterm infants with respiratory distress syndrome.

UNLABELLED: Cardiac troponin T (cTnT) represents a sensitive and specific marker of ischemic myocardial damage in adult and neonatal populations. The aim of this study was to detect the potential ischemic effect of persistent patent ductus arteriosus (PDA) and indomethacin treatment on the coronary vascular bed by measuring cTnT concentrations. cTnT levels were measured in 23 preterm infants (<32 weeks of gestational age) with respiratory distress syndrome (RDS), 11 with PDA and 12 without, at 2, 4, and 7 days after birth. cTnT concentrations (mean +/- SEM) significantly decreased (P<0.05) from the 2nd (0.63+/-0.09 microg/l) and the 4th (0.77+/-0.13 microg/l) to the 7th postnatal day (0.28+/-0.04 microg/l). At day 2 after birth, cTnT levels in preterm infants with RDS were significantly higher (P<0.05) than our reference values for healthy preterm neonates (0.63+/-0.09 microg/l vs. 0.18+/-0.04 microg/l). No differences were found between RDS infants with and without PDA at 2 (0.65+/-0.13 vs. 0.61+/-0.14 microg/l), 4 (0.71+/-0.21 vs. 0.87+/-0.16 microg/l), and 7 (0.26+/-0.05 vs. 0.29+/-0.07 microg/l) days of life. In infants with PDA, cTnT levels did not differ before the first dose of indomethacin was given (0.65+/-0.14 microg/l) or 2 h (0.65+/-0.15 microg/l) and 48 h (0.71+/-0.21 microg/l) afterwards. CONCLUSION: In preterm infants with RDS the occurrence of PDA and indomethacin treatment are not associated with ischemic cardiac damage as detected by cTnT measurements.

Cardiovascular Agents↗
PubMed2000

Biological variability in assessing the clinical value of biochemical markers of bone turnover.

Analytical and biological variability of three bone markers, deoxypyridinoline (DPD), CrossLaps (CTx) and galactosylhydroxylysine (GHYL) were compared. From 14 healthy subjects (six women, eight men; age 29-44 years) recruited from our laboratory staff, two sets of samples of early morning urine were obtained - four samples taken weekly for 4 weeks (all subjects) and three samples taken monthly for 3 months from five subjects. Data were expressed as the ratio to creatinine concentration. All the methods met the analytical goals (CV(A)< or =1/2CV(I(within-subject))) DPD 0.06, CTx 0.05 and GHYL 0.07 with CV(I(within-subject)) being 0.22, 0.19 and 0.38, respectively. The reference values were of limited usefulness particularly for CTx and GHYL, the index of individuality (II) being 0.50 and 0.48 respectively. As the index of heterogeneity (IH) was not significant, being 0.23 for CTx, 0.28 for DPD and 0.46 for GHYL, which are all <1.71 (1+2S.D.), within-subject variances can be used to calculate the reference change value (RCV): 0.58 for DPD, 0.54 for CTx and 1. 08 for GHYL. Moreover, we found constant variations in DPD and CTx, week to week and month to month. Our findings suggest that DPD and CTx provide more reliable results than GHYL, showing a lower within-subject variation, a lower and time-constant RCV allowing reliable monitoring without regard for timing.

Adult↗
PubMed2000

Plasma phospholipid arachidonic acid content and calcium metabolism in idiopathic calcium nephrolithiasis.

BACKGROUND: Reports of an increase in plasma and erythrocyte phospholipid arachidonic acid content and in urinary prostaglandin E2 (PGE2) excretion in patients with idiopathic calcium nephrolithiasis suggested their crucial role in the pathogenesis of hypercalciuria, a well-known risk factor for lithogenesis. METHODS: To confirm this hypothesis, 15 healthy subjects and 20 nephrolithiasis patients were evaluated for plasma phospholipid polyunsaturated fatty acid content and PGE2 concentration, serum parathyroid hormone, 25 hydroxyvitamin D3, 1, 25-dihydroxyvitamin D3, and bone-specific alkaline phosphatase levels, as well as urinary excretion of calcium, biochemical markers of bone resorption (hydroxyproline and crossLaps), and intestinal calcium absorption. Furthermore, the effect of a 30-day fish-oil diet supplementation on the previously mentioned parameters was investigated in the patients. RESULTS: At baseline, patients compared with controls showed higher levels of plasma phospholipid arachidonic acid content (P = 0.002), PGE2 (P = 0.0004), serum 25-vitamin D3 (P = 0.001), and 1,25-vitamin D3 (P = 0.001), urinary excretion of calcium (P = 0.001), hydroxyproline (P = 0.007), and crossLaps (P = 0.019), as well as intestinal calcium absorption (P = 0.03 at 60 min). Fish oil supplementation induced a reduction in the plasma phospholipid arachidonic acid level (P < 0.0001), and except for serum concentrations of 25-vitamin D3, normalized baseline blood and urinary parameters, including intestinal calcium absorption. A close correlation between plasma PGE2 and serum 1,25-vitamin D3 (P = 0.004) and between phospholipid arachidonic acid and intestinal calcium absorption (P = 0.0002) and calciuria (P = 0.007) was observed, as well as between urine excretion of crossLaps and hydroxyproline (P < 0.0001), crossLaps and calcium (P < 0.0001), and hydroxyproline and calcium (P < 0.0001). CONCLUSIONS: These findings indicate that the phospholipid arachidonic acid content anomaly could represent the primary event responsible for the mosaic of metabolic and clinical alterations that are distinctive features of renal stone formers, and suggest that a common pathogenetic mechanism might account for the several forms of hypercalciuria detected in idiopathic calcium nephrolithiasis.

Adult↗
PubMed2000

High serum cardiac troponin T concentrations in preterm infants with respiratory distress syndrome.

UNLABELLED: In preterm infants with respiratory distress syndrome (RDS), cardiac function is negatively influenced by the severity of the lung disease. On day 2 of life, cardiac troponin T (cTnT), biochemical marker of myocardial injury, was measured in 46 preterm infants (gestational age < or =32 wk), 26 with RDS and 20 without: median (range) 0.38 (0.02-1.57) microg/L vs 0.13 (0.02-0.85) microg/L, respectively. CONCLUSION: High cTnT concentrations in preterm infants with RDS suggest the presence of myocardial damage in this group of high-risk patients.

Female↗
PubMed2000

Parathyroid hormone and bone metabolism in kidney-transplanted patients.

BACKGROUND: Decreases in bone mass and increased susceptibility to fractures are well-recognized complications in organ transplants. SUBJECTS AND METHODS: We performed a cross-sectional study on 60 patients (40 males, 20 females, mean age 43.2 +/- 1.06, SE range 22 - 70) who underwent kidney transplantation (KTX) 55.6 +/- 4.5 months before. Blood and 24-hour urine samples were analyzed for the main parameters of mineral metabolism, and also for osteocalcin (BGP), bone alkaline phosphatase (b-ALP, urine N-telopeptid (u-NTx) and urine galactosyl-hydroxylysine (u-Ghyl). DEXA scan of the lumbar spine (LS) and proximal femur (PF) and ultrasound determination of the heel (stiffness) was also performed. RESULTS: T-score values for bone density (BD) were 2.14 +/- 0.11 SD's for LS, -2.56 +/- 0.09 for PF and 2.49 +/- 0.15 for stiffness. There were 29 peripheral fractures in 16 patients. The rate of fractures before KTX were 0.0011 per patient/year and 0.0005 after transplantation (p < 0.02). When expressed as number of SD's with respect to normal controls, BGP (1.48 +/- 0.23), b-ALP (0.95 +/- 0.19), u-NTx excretion correlated negatively with BD at the femoral neck (p < 0.02) and trochanter (p < 0.03). Cumulative steroids intake were negatively correlated with b-ALP positively (p < 0.05). Current CsA was positively correlated with b-ALP (p < 0.001). Both cumulative steroid (p < 0.02) and CSA (p < 0.01) intakes were negatively correlated with BD at Wards triangle. CONCLUSIONS: Our data demonstrate an important bone depletion at each stage KTX. PTH plays a major role in the observed increase in bone turnover, exacerbating the negative effects on the bone on immunosuppressive treatment. Glucocorticosteroid therapy is an important risk factor for osteoporosis in this setting also.

Adult↗
PubMed2000

[The role of biochemical markers of myocardial damage in clinical practice: the diagnosis of infarct and risk stratification. The Intersociety Interdisciplinary Study Group of the ANMCO-SIBioC-SIMeL, Markers of Muocardial Lesions. L'Associazione Nazionale Medici Cardiologi Ospedalieri-Società Italiana di Biochimica Clinica-Società Italiana di Medicina di Laboratorio].

For many years creatine kinase (CK) and CK-MB isoenzymes were used together with the ECG to confirm the presence of myocardial infarction. During the last decade newer cardiac markers have been introduced and immunological test systems developed for their quantification. Among these new markers, a prominent role has emerged for cardiac troponins (T or I). These technological advanced assays have shown greater sensitivity compared to "conventional cardiac enzymes;, thereby identifying patients with small--at times, microscopic--infarcts who would not have met defining criteria for myocardial infarction in an earlier era. Another major advantage shown by both cardiac troponins with respect to "conventional cardiac enzymes" is their ability to predict clinical outcome over a short- or long-term follow-up in patients with acute coronary syndromes, and this appears to be particularly relevant in patients with micronecrosis, who constitute a high-risk subgroup of unstable angina patients. Recently, myoglobin has also been widely applied as a marker. Although lacking in myocardial specificity, it is the earliest marker to show an increase after coronary occlusion. Thus, the combined use of myoglobin and a cardiospecific structural protein such as troponin T or I may prove an attractive strategy for biochemical testing in chest pain patients. With the routine use of these novel cardiac markers, fascinating opportunities are now open in the field of diagnostic classification (making the World Health Organization definition of myocardial infarction obsolete) and risk stratification in chest pain patients; opportunities that were unforeseen in the era of cardiac enzymes. However, the use of these markers has also posed some important questions on: a) the best and most cost-effective diagnostic strategy in chest pain patients; b) the remaining role of cardiac enzymes; c) the therapeutic consequences of a positive test result.

Biochemical Phenomena↗
PubMed2000

Multicenter evaluation of five assays for myoglobin determination.

BACKGROUND: Lacking assay standardization, different myoglobin methods may produce results that differ significantly. METHODS: A multicenter study was carried out to compare the analytical performance of five commercially available assays for myoglobin measurement. Linearity, imprecision, interferences, and method comparison were studied according to NCCLS guidelines, whereas reference values were determined following IFCC recommendations. RESULTS: The BNA and Opus showed relatively high imprecision (all but one total CV >7.4%). Other assays showed lower CVs, but they varied among laboratories, particularly at a normal myoglobin concentration (Access, 6.0-11%; Hitachi, 3.8-5.8%; Stratus, 3.4-6.5%). Results were lower in anticoagulated samples on the Access, in heparin and citrate samples on the Stratus, and in citrate samples on the BNA and Opus, and increased in heparin and EDTA samples on the Hitachi. Use of separator gel produced results significantly lower (P <0.001) on the Hitachi and higher (P = 0.016) on the Opus. Bilirubin, turbidity, and hemoglobin had no effect on evaluated methods, but rheumatoid factor affected the Access. In method comparisons, high correlation coefficients (>/=0.98) were obtained. The Stratus gave higher results; however, the Access and BNA gave the lowest. The following upper reference limits (microgram/L) for men and women, respectively, were obtained: Access, 70 and 52; BNA, 51 and 49; Hitachi, 67 and 58; Opus, 80 and 50; and Stratus, 86 and 63. CONCLUSION: The possibility of high imprecision and marked disagreement among commercial myoglobin assays should be carefully considered in clinical practice.

Humans↗
PubMed1999

Cardiac markers: present and future.

In the early twentieth century, acute myocardial infarction secondary to acute thrombotic coronary occlusion was considered a rare, fatal condition. Acute myocardial infarction is now one of the most-commmon serious illnesses in the industrialized world. Laboratory medicine now plays a crucial role in identifying risk factors, early events, and conditions triggering plaque rupture in coronary ischemic disease. However, the greatest progress in laboratory research has resulted from the discovery of new and more-promising biochemical markers of myocardial damage. The discovery of cardiac troponins, in particular, has heralded a new age in the diagnosis and treatment or management of a broad spectrum of diseases, grouped together under the heading of acute coronary syndrome, and including stable and unstable angina, and non-Q wave infarction to Q-wave infarction. Cardiac troponins, which are selectively released by damaged myocardiocytes, have a specificity that has not only allowed an improvement in the diagnosis of acute cardiac ischemic disorders, but has also enabled us to make a more-reliable stratification of risk and prediction of outcome. It is generally agreed that two biochemical markers should be used: an early marker (and we recommed myoglobin for this) and a definitive marker, which is cardiac troponin (I or T). Future research is likely to include the standardization of methods for measuring current markers, troponin I in particular, the assessment of rapid bedside tests, and the investigation of the relationship between cardiac markers and emerging immunological and coagulation parameters. Thrombogenesis is now recognized as important in the final process of coronary atherosclerosis, and new markers of thrombogenesis should be used to evaluate the risk of plaque rupture and to monitor the outcome of thrombolytic therapy. Moreover, recent vascular biology studies have provided information on the developmental stages of atherosclerosis and emphasized the importance of the endothelium as a modulator of vascular reactivity, atherogenesis, and plaque stability. The different types of laboratory test (biochemical, immunological, and coagulative) now available, should soon allow improvement in the diagnosis and therapy of ischemic coronary diseases.

Arteriosclerosis↗
PubMed1999

Strategies for the early diagnosis of acute myocardial infarction using biochemical markers.

We evaluated different diagnostic strategies for the early diagnosis of acute myocardial infarction, combining sensitivity and specificity of different markers evaluated singly and using combination testing in parallel and serial modes. Myoglobin, cardiac troponin I (TnI), creatine kinase (CK), and CK-MB mass were tested in blood samples from 26 patients with acute myocardial infarction collected at admission (T0; mean = 3.3 hours from the onset of chest pain) and 3 and 6 hours later. The comparison group was made up of 70 patients with renal failure, skeletal muscle diseases, stable angina, unstable angina, and chest pain of nonischemic origin. Single tests showed different sensitivities in relation to the different release kinetics; myoglobin was the most sensitive (69% at T0) although less specific (46%), and TnI showed the highest specificity (90%) and a sensitivity of 54%. Combination testing in a parallel mode using myoglobin and TnI or CK-MB had the same sensitivity and specificity as myoglobin tested singly. The best combination in a serial mode is myoglobin and TnI (at T0 sensitivity, 54%; specificity, 98%), as confirmed by the analysis of the positive predictive value, the negative predictive value, and the accuracy evaluated as a function of different disease prevalences.

Aged↗
PubMed1999

Assessment of package inserts for diagnostic kits.

To assure the quality of service in laboratory medicine, it is necessary to implement a quality system which comprises the entire testing process. The use of quality reagents is an important aspect of the process. Despite the fact that it is the responsibility of the laboratory to ensure the quality of the analytical system (including reagents) and since it is impossible to evaluate all commercial diagnostic kits, the laboratory often depends on statements issued by the manufacturer to select the most appropriate diagnostics for a particular laboratory. In this study we report the results of the analysis of information provided in 887 package inserts enclosed in the more widely used commercial diagnostic kits, following the Standard for the labelling of clinical laboratory materials of the European Committee for Clinical Laboratory Standards (ECCLS). Only a third of these were in agreement with the guidelines of ECCLS Standard, reporting complete and correct information. We believe that it is necessary to implement a constructive cooperation between manufacturers of diagnostic materials and clinical laboratories to produce a more uniform approach to improvements in laboratory quality assurance.

Product Labeling↗
PubMed1999

Immunoturbidimetric assay of glycated hemoglobin.

We investigated the performances of HbA1c determination by a latex enhanced turbidimetric immunoassay using the specific monoclonal antibodies (Unimate, Roche) against the beta-N-terminal fragments. The coefficients of variation ranges from 1.7 to 3.8% within assay (n = 30) and from 3.9 to 4.9% between assay (n = 20). The assay was linear from 2.5 to 14.9% of HbA1c. No interferences was found from fetal, carbamylated, or variant (S) hemoglobins and from labile Schiff adduct with glucose. The following relationship was derived from fresh sample comparison between HPLC (Diamat-BioRad) (x) and immunoassay (y) method: y = 0.971 x + 0.87%, r=0.98, n = 115. The immunoassay provides a highly precise and specific method for HbA1c.

Antibodies, Monoclonal↗