Application of a combined protocol for rational request and utilization of antibody assays improves clinical diagnostic efficacy in autoimmune rheumatic disease.

CONTEXT: Because of a marked increase in the number of requests for antinuclear antibodies, anti-extractable nuclear antigen antibodies, and anti-double-stranded DNA antibodies for the diagnosis of autoimmune rheumatic disease, guidelines have been proposed for their appropriate use. OBJECTIVE: To evaluate in terms of clinical efficacy and cost-benefit ratio the outcome of applying a protocol for the diagnosis of autoimmune rheumatic disease. DESIGN: A diagnostic protocol for the rational utilization of second-level tests (anti-extractable nuclear antigen antibodies and anti-double-stranded DNA antibodies) was applied at Hospital Polyclinic beginning January 2004. The appropriateness of 685 consecutive requests received at the clinical pathology laboratory from January to June 2004 was assessed. Patients who underwent these laboratory tests were followed up for 12 months after blood sample drawing. RESULTS: Introduction of the protocol led to a significant reduction in the number of second-level tests prescribed (27.9% vs 49.5% for anti-extractable nuclear antigen antibodies; 27.5% vs 56.6% for anti-double-stranded DNA antibodies). After the period of observation, none of the 163 patients who had negative results on the first-level test and were asymptomatic, for whom second-level tests had not therefore been performed, were found to have autoimmune rheumatic disease. In 90.5% (77/85) of patients positive for the second-level tests, clinical confirmation of autoimmune rheumatic disease was obtained. CONCLUSIONS: Not only did application of the diagnostic protocol reduce the number of second-level tests performed but it also increased their specificity. Our data thus indicate that the use of shared guidelines by clinical and laboratory specialists yields satisfactory results.

Integration between the tele-cardiology unit and the central laboratory: methodological and clinical evaluation of point-of-care testing cardiac marker in the ambulance.

The aim of this study was to identify patients with myocardial necrosis in pre-hospital phase during transport by ambulance, without ST-segment elevation (NSTE) on the ambulance ECG. The analytical performance of the i-STAT troponin I (cTnI) method was assessed. A total of 53 NSTE ambulance ECG patients admitted to hospital were followed. The ambulance had experimental software able to receive data from the i-STAT device and transmit it to a protected address and server. cTnI mean values from 2.0 to 34 microg/L showed a total CV of 3.0-5.6%. The detection limit was 0.016 microg/L. A mean cTnI concentration of 0.09 microg/L was associated with a CV of 8.0% (decision limit). The i-STAT cTnI method was linear for concentrations from 0 to 35 microg/L. There was no effect (p<0.05) of interfering substances. For point-of-care testing (POCT), cTnI was >0.09 microg/L in 20 AMI patients (91%). The median ambulance turnaround time (TAT) was 12 min and median hospital TAT was 40 min, a difference of 28 min. The high sensitivity of the i-STAT cTnI method integrated with tele-medicine procedures could play an important role in the management of acute coronary syndrome patients related to the pre-hospital phase (early diagnosis and treatment in the ambulance). These approaches may allow improvements in patient outcomes and continuous monitoring of the POCT network in the central laboratory, thus meeting quality requirements.

Prognostic value of brain natriuretic peptide in the management of patients receiving cardiac resynchronization therapy.

OBJECTIVE: To evaluate the role of brain natriuretic peptide (BNP) in predicting the progression of heart failure (HF) after cardiac resynchronization therapy (CRT). BACKGROUND: It has been shown that BNP predicts the prognosis and can guide the treatment of HF. METHODS: We studied 50 consecutive patients (61+/-10 years, 23 male) with HF (8 with ischaemic cardiomyopathy), NYHA class III, left bundle branch block, left ventricular ejection fraction (LVEF) 91.5 pg/ml had 89% sensitivity, 59% specificity, and negative and positive predictive values of 96% and 33%, respectively, for HF progression after 12 months. CONCLUSIONS: HF patients with high BNP values after 1 month of CRT have worse prognosis during follow-up. Therefore, in these patients other therapeutic options should be considered.

Laboratory network of excellence: enhancing patient safety and service effectiveness.

Clinical laboratories have undergone major changes due to technological progress and economic pressure. While costs of laboratory testing continue to be the dominant issue within the healthcare service worldwide, quality, effectiveness and impact on outcomes are also emerging as critical value-added features. Five Italian laboratories are therefore promoting a network of excellence by investigating markers of effectiveness of laboratory services and sharing their experience of using them in clinical practice. In the present study we report preliminary data on indicators of quality in all phases of the so-called total testing process, the key to evaluating all phases of the total testing process, including the appropriateness of test requests and data interpretation. Initial findings in evaluating pre-analytical causes of specimen rejection in three different laboratories and the effects of introducing three laboratory clinical guidelines are reported. These data should stimulate debate in the scientific community and encourage more clinical laboratories to use the same indicators to improve clinical effectiveness and clinical outcomes within the healthcare service.

Analytical evaluation of the Dade Behring Dimension RxL automated N-Terminal proBNP (NT-proBNP) method and comparison with the Roche Elecsys 2010.

Methods to quantify B-type natriuretic peptide (BNP) and N-terminal-propeptide (NT-proBNP) in plasma or serum samples are well established. We assessed the analytical performance of the Dimension RxL NT-proBNP method (Dade-Behring). Evaluation of different sample types was carried out. Controls and heparin plasma pools were used to determine the detection limit, precision, and linearity. Sample stability and the effect of interfering substances on the NT-proBNP concentrations were evaluated. Agreement between Dimension RxL and Elecsys 2010 (Roche Diagnostics) NT-proBNP methods was assessed. The influence of age and sex on NT-proBNP concentrations was evaluated in healthy subjects. Heparin plasma should be the matrix of choice. The detection limit was 2.0 ng/L. The total imprecision was 2.6-3.6% for concentrations from 231 to 9471 ng/L; mean NT-proBNP concentrations of 21 and 15 ng/L were associated with coefficients of variation of 9.9% and 14.7%, respectively. The method was linear up to 32,650 ng/L. There was no effect of temperature, freeze-thaw cycles and interfering substances. A bias was detected when Dimension RxL and Elecsys 2010 NT-proBNP methods were compared. Age and sex were significantly and independently related to NT-proBNP concentrations. The Dimension RxL NT-proBNP method, like the Elecsys 2010, is suitable for routine use in the diagnosis of heart failure.

Monitoring of cardiac function on the basis of serum troponin I levels in patients with acute leukemia treated with anthracyclines.

Anthracyclines are used extensively in the therapy of hematologic malignancies. However, their use has been limited by acute and chronic cardiotoxicity. Cardiac troponins have emerged as sensitive and specific markers of even minor myocardial damage. In this study we prospectively evaluated serial measurements of serum cardiac markers and echocardiography in patients with de novo acute myeloid and lymphoid leukemias (AML and ALL, respectively) treated with anthracyclines. We examined and subdivided 79 patients into 3 groups: group 1 (37 patients with AML, all < 60 years), group 2 (25 with AML, all 260 years), group 3 (17 with ALL). Serum specimens were collected before treatment and during and after therapy and were analyzed for troponin I (Tnl), myoglobin, creatine phosphokinase-muscle myocardium isoenzyme B, and lactate dehydrogenase concentrations. In group 1, 4 of the 37 patients (11%) had increased levels of Tnl on the 14th day of induction therapy, but by the 28th day the Tnl level had returned to normal in 3 of these 4 patients. In group 2, 3 of the 25 patients (12%) demonstrated increased Tnl concentrations on the 7th day of induction therapy, but by the 14th day these levels had normalized in 2 of the 3. In group 3, we detected no increased Tnl concentrations. Echographic study did show a significant correlation with the Tnl levels (P < .001), involving a reversible decrease in left ventricular ejection fraction among patients with increased Tnl levels (> 0.15 ng/mL) on day 14 in group 1 and on day 7 in group 2. These results may aid the clinician in the treatment of patients by identifying high-risk patients who may benefit from closer observation or supportive cardiac therapy.

Proteomic approach to the diagnosis of acute coronary syndrome: preliminary results.

BACKGROUND: Cardiac multimarker strategy is recommended by the IFCC, ESC and the ACC for an early risk stratification in non-ST-segment elevation (NSTE) ECG patients with chest pain. A new approach, based on protein biochip array technology, performs simultaneously: cTnI, CK-MB, myoglobin, CAIII, GFBB and FABP using a single chip. METHODS: We evaluated the analytical performance of the Randox-Evidence Investigator -biochip cardiac panel according to IFCC recommendations and NCCLS guidelines; a preliminary clinical evaluation was carried out on chest pain NSTE ECG patients, to evaluate the accuracy of the multimarker approach in an early diagnosis of AMI, related to the final diagnosis (ACC/ESC criteria). RESULTS: Troponin, CK-MB and FABP methods provide reproducible within-run and between-day results (total % CVs from 5.9% to 9.7%), and myoglobin and CAIII methods showed the total % CVs from 16.4% to 25.8%. Our preliminary clinical data suggests that FABP had a better diagnostic performance (sensibility = 100%) than myoglobin (sensibility = 75%) to detect AMI in the first hours after the onset of the chest pain and myoglobin/CAIII ratio (specificity = 92.9%) improved the myoglobin specificity. CONCLUSIONS: Cardiac markers have different diagnostic roles and, in this contest, biochip technology could be an interesting approach supporting clinical expectations.

Integration between point-of-care cardiac markers in an emergency/cardiology department and the central laboratory: methodological and preliminary clinical evaluation.

To achieve rapid assessment of chest pain in emergency/cardiology departments, a short turnaround time for cardiac marker testing is necessary. Nevertheless, Total Quality Management principles must be incorporated into the management of point-of-care testing (POCT); in this setting we implemented the Stratus CS assay as POCT for cardiac markers in our emergency/cardiology department. The analytical performance of the troponin I method was evaluated; information connectivity between the Stratus CS data management system and the laboratory information system was implemented and practical training of testing personnel was carried out at the POCT site. A total of 41 non-ST-segment elevation patients admitted to the hospital were followed to evaluate the appropriateness of hospital admission, formulated on the basis of the cardiac troponin-I level measured at the POCT site by clinical staff. Our preliminary clinical data suggest that the high sensitivity of the Stratus CS troponin method could play an important role in the early identification of patients with acute myocardial infarction in a low to intermediate-risk population for acute coronary syndrome. Our POCT model suggests that the central laboratory could ensure that the POCT program remains in compliance with quality requirements. Nevertheless, our comparison studies suggest that the implementation of POCT requires a high level of integration between cardiologists and pathologists to guarantee appropriate interpretation of the monitoring results for suspected ACS patients.

Anti-cyclic citrullinated peptide autoantibodies measured by an automated enzyme immunoassay: analytical performance and clinical correlations.

BACKGROUND: Autoantibodies against cyclic citrullinated peptide (anti-CCP) are considered to be a sensitive and specific marker for rheumatoid arthritis (RA). This study evaluated the analytical performance and clinical correlation of an automated enzyme immunoassay (DSX, DINEX Technologies), for the detection of anti-CCP autoantibodies (DIASTAT anti-CCP, Axis-Shield, DUNDEE UK). METHODS: Commercial controls and serum pools were used to determine its precision, analytical sensitivity, functional sensitivity and linearity. Sera from 83 patients with established RA and from 140 controls, including patients with various autoimmune diseases, viral infections and cancer, as well as sex- and age-matched healthy subjects, were studied. The rheumatoid factor (RF) was also assayed in each sample, and the results were compared to the anti-CCP findings. RESULTS: The total imprecision (CV%) was 4.7-7.2% for concentrations ranging between 1.98 and 71.81 U/mL. The lower detection limit was 0.038 U/mL. At a cut-off of 5 U/mL, the sensitivity and specificity for RA were 67.5% and 99.3%, respectively. The RF had a sensitivity of 66.3% and a lower specificity 82.1% than anti-CCP. When the two antibodies were used together, the specificity was 99.1%. CONCLUSIONS: The anti-CCP assay we examined on a fully automated system showed a good analytical performance (analytical and functional sensitivity, linearity) and good clinical correlation. We conclude that this system can provide rapid, useful data.

Kinetics of the circulating levels of bone alkaline phosphatase in a case of hungry bone disease following total parathyroidectomy.

We present the case of a 55-year-old patient who underwent total parathyroidectomy for severe hyperparathyroidism unresponsive to medical therapy, 4 years after having started hemodialysis treatment. It was decided to perform total parathyroidectomy because at macroscopic evaluation the parathyroid glands appeared completely compromised. After surgery, the patient developed hungry bone disease, characterized by severe hypocalcemia and hypophosphatemia. After parathyroidectomy, serial measurements were made for the long-term monitoring of the calcemia, phosphatemia and the serum levels of intact parathormone and bone alkaline phosphatase, a marker of bone turnover that mainly expresses bone formation. There was initially a slight decrease in the circulating levels of bone alkaline phosphatase as the calcemia dropped dramatically, then a new increase that anticipated the subsequent calcemia increase and finally, 6 months later, a decrease to very low values. We believe that the calcemia and blood bone alkaline phosphatase could be useful for the laboratory monitoring of the hungry bone state, providing information which may be useful to avoid excessive calcium administration and the dangerous consequences such as soft-tissue calcification.

Analytical evaluation of an automated immunoassay for cardiac troponin I: the Vidas Troponin I assay.

Cardiac troponin I (cTnI) is a sensitive and specific biochemical marker of myocardial damage. We assessed the analytical performance of the Vidas Troponin I assay (Biomerieux). Controls and serum pools were used to determine the precision, analytical sensitivity and linearity; 97.5 and 99.5 percentiles concentrations were determined from the reference population. Fifty corresponding samples of serum and plasma (lithium-heparin) were tested and the results compared. The in vitro stability of serum and plasma samples was assessed at 20 degrees C, 4 degrees C and -20 degrees C, respectively. Samples of serum were used to assess the agreement between the Vidas Troponin I method and the revised Dimension RxL cTnI method (Dade-Behring). The total imprecision (CVs) was 13.1-5.2% for concentrations ranging between 0.25 and 19.8 microg/l cTnI. The lower detection limit was <0.1 microg/l. The upper reference limit (97.5 and 99.5 percentiles) was 0.11 microg/l and 0.12 microg/l, respectively (CV > 10%). The assay was linear up to 21 microg/l. The concentrations in lithium-heparin plasma were higher compared to those of the matched serum samples. The study of the agreement between the Vidas and Dimension RxL cTnI assays showed a total concordance of 96% with a bias value of -0.042. The Vidas Troponin I test is a fast, precise and sensitive method for the determination of cTnI.

Appropriateness of point-of-care testing (POCT) in an emergency department.

BACKGROUND: Acute coronary syndrome is a major cause of death, morbidity and access in emergency departments (ED). METHODS: We evaluated a point-of-care testing (POCT) for the determinations of cardiac markers in an emergency department (ED), defining the clinical efficiency (management of patient with chest pain) and economic effectiveness (rationalization of preanalytical phase) related to data of Core Lab. RESULTS: The results of analytical performances showed a good correlation (cTnI r(2)=0.89, myoglobin r(2)=0.84, CK-MB r(2)=0.9) between POCT and Core Lab and a significant decrease of the turn around time (TAT): difference of medians=-54 min, 95% CI from -48 to -60 min. CONCLUSIONS: Our data confirmed that the accurate utilization of POCT in the ED assumes an effective triage of patient with chest pain and the improvement of preanalytical phase out of the laboratory (delivery of specimens) and within the laboratory reception, centrifugation. However, efficiency must be linked to methodological and quality control of the Core Lab, mainly through connectivity.

Comparison of hysteroscopic and hysterectomy findings for assessing the diagnostic accuracy of office hysteroscopy.

OBJECTIVE: To assess the diagnostic accuracy of office hysteroscopy by comparing the hysteroscopic findings with the histologic findings on the hysterectomy specimens. DESIGN: Retrospective clinical study. SETTING: University-affiliated hospital. PATIENT(S): Review of the hospital records of 443 patients who underwent office hysteroscopy and, within 2 months, hysterectomy. INTERVENTION(S): We compared the hysteroscopic findings (including targeted biopsies) with the histologic findings that were obtained after hysterectomy. The results of this study were then compared with those of a previous study in which we examined the diagnostic accuracy of dilatation and curettage (D&C). MAIN OUTCOME MEASURE(S): We evaluated the diagnostic accuracy of office hysteroscopy. RESULT(S): When compared with the histologic diagnosis of the uterus, the hysteroscopic findings showed a diagnostic sensitivity of 98%, a specificity of 95%, a positive predictive value (PPV) of 96%, and a negative predictive value (NPV) of 98%. Hysteroscopy was found to have a greater diagnostic accuracy than D&C: the sensitivity and the NPV of the two diagnostic procedures were statistically different. CONCLUSION(S): Office hysteroscopy is confirmed as a powerful diagnostic tool, but targeted biopsies, performed with a small diameter operative hysteroscope, must be performed in cases of suspect endometrium to confirm the image-based diagnosis.

The national health system: future possibilities for the clinical laboratory.

BACKGROUND: The heavy burden of the costs of medical care has brought changes in the public health policy. The changes are partly related to the health management factors, but several cultural, social and environmental factors have also had a significant impact on healthcare. The role of the laboratory is now considered amidst changes that have occurred in the American health model (free-trader) and in the European-Canadian model (universalistic). Moreover, costs and clinical decision-making in laboratories in Italy have also changed in response to the new focus on the pre- and post-analytical phases of the testing process. METHODS: In the present study, we used the Laboratory Information System (LIS) to evaluate whether the time involved in stages in the turnaround time (TAT) (admission, performance of tests, validation and decision-making for treatment) were reduced following improvements made to the laboratory organization and management of the pre-analytical and post-analytical phases. In particular, an analysis was made of laboratory testing for myocardial markers in patients with acute coronary syndrome. RESULTS: TAT for myocardial markers in an emergency setting was reduced by 30% following changes made in the laboratory organization and in the management of the pre-analytical and post-analytical phases of the testing process. CONCLUSIONS: Thanks to changes in healthcare service/system in Italy, laboratory services will now play a crucial role in cultural and socioeconomic changes, particularly where testing processes and techniques are concerned.