Appropriateness of diagnostics tests

The evolution of the concept of 'appropriateness', in the three past decades, from 'no harm' and 'no waste' to 'medical decision-making' and 'determining outcomes' highlights two main points: its foundation is evidence-based medicine, and it is a quality of every phase of the total testing process, not only for the selection of tests. Nevertheless, appropriateness in Laboratory Hematology, as well as in Laboratory Medicine, is an elusive concept: 'Appropriateness' interplays with 'patient's safety', 'healthcare costs', 'clinical decision-making', and 'effectiveness', and the criteria for appropriateness, mainly adherence to clinical guidelines, are often not evidence-based and not always consensus-based. Moreover, practising appropriateness is a complex issue because of the ambiguity of the criteria and targets, the never-ending work of implementing guidelines and their audit, and the uniqueness of the clinical situation of the individual patient. Authors agree on some practical rules: establishing a multidisciplinary and multiprofessional team, choosing carefully clinical targets, finding or building evidences, sharing guidelines with clinicians, choosing adequate tools for changing, working hard on implementation, identifying the 'right' laboratory methods and processes, checking progress indefinitely, providing information, interpretations, and consultations, and promoting feedback and audits. The success depends on the 'right' combination of educational, operative, and reinforcing interventions. Competences in organization, in implementation science, and in interpersonal relationship management are essential as well as knowledge and experience in Hematology, not only in Laboratory Hematology.

Evaluation of Aution Max AX-4280 automated urine test-strip analyser

Aution Max AX-4280, an automated urine test-strip analyser, was evaluated in three centres. Method comparison, imprecision, carry-over, linearity, detection limit and drift studies were performed for glucose, protein, blood and leukocytes using Uriflet S 9UB strips. These strips enable measurement of pH, glucose, protein, blood, leukocytes, ketones, bilirubin, urobilinogen and nitrite. Specific gravity is determined by the refractive index method. Within-run and between-day imprecision, assessed using pooled urines and quality control materials, were good. No drift over 24 h or sample carry-over was observed. Method comparison with quantitative methods for glucose, protein and specific gravity yielded good correlations. Ascorbate negatively interfered with haemoglobin, glucose and nitrite measurements. Acetylsalicylic acid lowered pH, the effect being greatest when protein was absent. During the assessment period no malfunction or breakdown was reported. The Aution Max is easy to use and needs minimal maintenance.

DNA vaccination with full-length or truncated neu induces protective immunity against the development of spontaneous mammary tumors in HER-2/neu transgenic mice

Genetic immunization against tumor antigens is an effective way to induce an immune response able to oppose cancer progression. Overexpression of HER-2/neu can lead to neoplastic transformation and has been found in many human primary breast cancers. We constructed DNA expression vectors encoding the full-length neu oncogene of rat cDNA (pCMV-NeuNT), the neu extracellular domain (pCMV-ECD), or the neu extracellular and transmembrane domains (pCMV-ECD-TM). We evaluated whether i.m. injection of these plasmids induces protection against the development of mammary tumors occurring spontaneously in FVB/N neu-transgenic mice. We found that pCMV-ECD-TM induced the best protection, whereas both pCMV-ECD and pCMV-NeuNT were less effective. The coinjection with a bicistronic vector for murine IL-12 increased the efficacy of pCMV-ECD and pCMV-NeuNT plasmids, and led to the same protection obtained with pCMV-ECD-TM alone. Anti-neuECD antibodies were detected in pCMV-ECD-TM vaccinated mice and, after coinjection with pCMV-IL12 plasmids, they appeared also in animals immunized with pCMV-ECD. Our data demonstrate the effectiveness of DNA vaccination using truncated Neu plasmids in inducing antitumor protection in a spontaneous mammary tumor model.

[Is a more efficient operative strategy feasible for the emergency management of the patient with acute chest pain?]

Patients with acute chest pain are a common problem and a difficult challenge for clinicians. In the United States more than 5 million patients are examined in the emergency department on a yearly basis, at a cost of 6 billion dollars. In the CHEPER registry the prevalence of patients with chest pain in the Emergency Department was 5.3%. Similarly, in 1997 at our institution the prevalence was 4.8%. Only 50% of the patients are subsequently found to have cardiac ischemia as the cause of their symptoms and 50-60% of them showed a non-diagnostic electrocardiogram (ECG). Twenty-five-50% of chest pain patients are not appropriately admitted to the hospital and despite this conservative approach, acute myocardial infarction is misdiagnosed up to 8% of patients with acute chest pain who are released from the emergency department without further evaluation, accounting for approximately 20% of emergency department malpractice in the United States. Important diagnostic information is covered by the patient's medical history, physical examination, and ECG, but often this approach is inadequate for a definitive diagnosis. Creatine kinase (CK) and CK isoenzyme--cardiac muscle subunit (CK-MB)--are traditionally obtained in the emergency department in patients admitted for suspected acute coronary syndrome. Mass measurements of CK-MB have improved sensitivity and specificity, and to date this is the gold standard test for diagnosis of acute myocardial infarction. CK-MB, however, is not a perfect marker because it is not totally cardiac specific and does not identify patients with unstable angina and minimal myocardial damage. There are no controlled clinical impact trials showing that these tests are effective in deciding whether to discharge or to appropriately admit the patient with suspected acute coronary syndrome. Relevant investigative interest has recently been focused on new markers for myocardial injury, including myoglobin, cardiac troponins T and I. Myoglobin, a sensitive but not specific marker for cardiac damage, increases earlier than CK-MB and cardiac troponins. It should be used early after symptom onset and in conjunction with a more specific marker of myocardial damage. Cardiac troponins T and I are highly specific markers for cardiac damage, rise parallel to CK-MB and remain elevated longer, up to 5 to 9 days. They are useful for detection of less severe degrees of myocardial injury, which may occur in several patients with unstable angina who are at higher risk of cardiac events. Recent studies suggest that cardiac troponins have good diagnostic performance and prognostic value in the heterogeneous population of patients seen in the Emergency Department with acute chest pain. Despite these promising data, several analytical and interpretative problems in the routine use of cardiac troponins must be solved. Incremental value of echocardiography in acute chest pain patients is still uncertain. Echocardiography can be recommended as an adjunctive test if readily available during acute chest pain or prolonged pain, especially in patients without previous myocardial infarction. Rest myocardial radionuclide imaging has been studied in the emergency department setting and although the overall diagnostic performance and prognostic value of sestamibi has been found to be promising, it is not suitable, in our country, for extensive clinical use. ECG exercise stress test in the emergency department population has been shown to be safe and it has a good negative predictive value for cardiac events. It should be recommended that any institution identify specific and shared protocol and strategies for management of patients with chest pain. These should include basal clinical evaluation, serial ECG and the use of specific and sensitive myocardial markers. Adjunctive tests, such as echocardiography, nuclear studies and stress tests should be employed when indicated taking into account local facilities.

External Quality Assessment of stat test intralaboratory turnaround times. Pilot study from the Members of the Working Group for the Standardization and Promotion of Turnaround Time Control under the Auspices of the Comitato Italiano per la Standardizzazione dei Metodi Ematologici e di Laboratorio

We describe procedures, results and prospects of a pilot program in External Quality Assessment (EQA) of the stat test intralaboratory turnaround times. Our goals are to promote quality by systematic monitoring and comparison of performances by laboratories, continuous investigation into the state of the art of the processes from receipt of sample to transmission of results and creation of a data base for standardization of measures and definition of consensus values for turnaround time. Of 30 laboratories invited to participate, 25 took part, agreeing to record times of arrival and transmission for all determinations of three analytes (blood hemoglobin, serum/plasma potassium and plasma prothrombin time) for seven consecutive days and to continue for one or more further periods of seven days as necessary if there were less than 300 determinations for each analyte. Within a preset time limit, data were sent by e-mail on an Excel file and we sent back two reports per analyte, showing: i) the graph for time vs. percentage of tests completed and several measures of turnaround time; ii) results of all laboratories in graph form, allowing each laboratory to identify only its own data. The high proportion of participating laboratories among those invited (83%) encourages us to implement the EQA program systematically, on a half-yearly basis, extending it to all laboratories wishing to participate in Italy or elsewhere in Europe.

Evaluation of most frequent errors in daily compilation and use of a radiation treatment chart

Between 1 March and 30 April (1994) we recorded the errors detected by the physician, the radiographer or the physicist during prescription, preparation and execution phases of 227 treatment plans. The radiation treatment modalities used were the following: (i) single or opposed fields, moulded or not; and (ii) multiple fields or kinetic techniques. The total number of sessions performed is 1613 with the cobalt unit and 2131 with the linear accelerator (total, 3744). The total number of wrong data is 155, consisting of 24/227 (10.5%) in compilation, 22/3744 (0.58%) in execution and 109/3744 (2.9%) in registration phases. The number of missing data is 140, consisting of 10/227 (4.4%) in compilation, 9/3744 (0.2%) in execution and 121/3744 (3.2%) in registration phases. Wrong data of compilation, even if in high rate (10.5%), were all found during the same compilation phase or at the first treatment, so that they did not alter the exactness of the treatment plan. Wrong and missing data, found in the registration phase (2.9% and 3.2%, respectively), depend on the repetition of daily treatment and on the registration of data on the chart after having digitized them on the display.

Multicentre evaluation of the Bayer DAX system

The analytical performance of the DAX, a high-throughput random access analyser, was studied according to ECCLS guidelines (ECCLS Document Vol. 3, No. 2, Beuth Verlag, Berlin, 1986) in a multicentre evaluation involving four laboratories. The trial took about 4 months. Determinations of 12 analytes produced more than 60,000 data. The imprecision study on 3 control sera for all analytes gave a within-run CV (median of 4 laboratories) which never exceeded 3% and was below 2% in 94% of the results. The median between-day CV was less than 3% in 92% of the results, with a highest value of 5.0%. No significant drift was detected during the 5-hour work period. No relevant sample- and cuvette-related carry-over was found. The manufacturer's claims concerning linearity were fulfilled or exceeded. The recovery of the assigned values for the control sera (median of 4 laboratories) ranged from 94 to 106%. In the method comparison on patients' samples, deviations were statistically significant in some cases, due to differences either in the methods used or in the calibration of the systems used for comparison; the regression lines, as inspected visually, and the coefficients of correlation were, however, generally acceptable. Imprecision and inaccuracy were within the acceptability limits as recommended by the Société Française de Biologie Clinique (SFBC) (Biochim. Clin. 12 (1988) 284-327) and the Deutsche Gesellschaft für Klinische Chemie (DGKC) (Dt. Arztebl. 85 (11) (1988) A697-A712). The limits of acceptance, proposed more recently by Fraser et al. (Eur. J. Clin. Chem. Clin. Biochem. 30 (1992) 311-317), were met in thirty-three of thirty-six cases. The alpha-amylase assay was significantly affected by bilirubin and haemolysis; interferences for the remaining analytes were predictable and well-known from the literature. The rate of sample throughput was found to be in agreement with that claimed by the manufacturer. The software did not present problems and was readily accepted by the operators. The practicability of the instrument was rated very good. Since the DAX is the primary chemistry analyzer in all four participating laboratories, the present experiments were necessarily intermixed with a large routine workload. Therefore, the system performance was assessed under definitely "usual" conditions. Because of its high productivity and reliability, the DAX is highly suitable for routine use in medium to large sized hospitals.

Eosinophilic peroxidase deficiency. Cytochemical and ultrastructural characterization of 21 new cases

Morphologic, instrumental (flow cytometric), cytochemical, ultrastructural, and chromosomal studies were performed in 21 cases of eosinophilic peroxidase deficiency that were observed in an area of northeastern Italy in the last 5 years. It was found that eosinophilic peroxidase deficiency occurred with a frequency of 1 case in 14,000 complete blood counts yearly, and thus is less rare than previously thought. Eosinophils appeared morphologically normal when examined using the light microscope, but ultrastructural study disclosed several aspecific granule alterations. In the first family studied, members with partial and total deficit were identified; in all the other cases, the enzyme deficit was total (negative cytochemical reactions and absence of dimethylaminoazobenzene-positive specific granules at the electron microscope), isolated (a single affected member in each family examined), and stable (persistent at long-term follow-up). Eosinophilic peroxidase deficiency was not correlatable with any particular disease, although a nonsignificant association with allergic-type conditions was observed. Studies are in progress to examine the modality of the defect's genetic transmission, as well as problems related to possible functional alterations and correlated clinical consequences.

Time-related shape control modifications during erythrocyte storage with additive solutions

To obtain more detailed information on the reversibility of shape alterations in blood bank stored erythrocytes, we have studied shape recovery after chemical crenation and rheological properties in 8 PAGGS-sorbitol preserved erythrocyte concentrates during a five week storage period under blood bank conditions. Our results show that red cell capability to regain a normal discoid shape after chemical crenation decreases during storage but is not lost over a five week period. Moreover there is a significant but weak correlation between red cell ATP content and both shape recovery capability and viscosity. Our results confirm suspicious that red cell shape perturbations following blood bank storage are widely reversible. Two different mechanisms may be involved in reducing shape recovery capability during storage, namely an ATP-dependent mechanism and an energy-independent one. The energy dependent mechanism may be preserved by the previous addition of solutions which maintain higher energy levels during storage.

Mean platelet volumes: facts or artifacts?

Blood samples collected after venipuncture and skin-puncture from a series of ten healthy volunteers were used to determine platelet counts, mean platelet volumes (MPVs), and platelet distribution width (PDW). Measurements were performed on untreated venous whole blood and on whole or diluted samples, with or without anticoagulants. In this study, platelet indices were significantly different in untreated venous whole blood in comparison with blood from skin puncture and whole blood with anticoagulant.

Effects of posture on plasma and serum viscosity

This study demonstrates the importance of defining normal reference population ranges for P- and S-viscosity with respect to posture. The normal ranges determined for P-viscosity are not acceptable as a reference range for a hospitalized population that is predominantly in a supine position. Mean percentage changes of P- and S-viscosity in the recumbent posture as compared to the same population in the upright posture were 7.51 and 5.88, respectively.

Alpha-naphthyl butyrate esterase (a selective cytochemical monocyte marker)

This paper describes a cytochemical technique for alpha-naphthyl butyrate esterase demonstration in monocytes obtained from peripheral blood of normal subjects, of a patient with reactive monocytosis and of a patient with myelomonocytic leukemia. It utilizes pH 6.1 alpha-naphthyl butyrate as substrate. At this pH value, alpha-naphthyl butyrate is a specific monocyte marker. The cytochemical procedure proposed is simple, rapid and standardized, as it utilizes stable and easily available reagents.

Clinical chemical indexes and severity of coronary atherosclerosis

The present study measured triglycerides (TG), total cholesterol (TC), HDL-cholesterol (HDL-C), LDL and LDL/HDL-C, TC/HDL-C and HDL-C/TC. 100 ratios in 261 men and women undergoing coronary arteriography. The results show that TG, TC, HDL-C and LDL levels are not related to the severity of coronary artery disease (CAD). The LDL/HDL-C, TC/HDL-C and HDL/TC.100 ratios are statistically related to the severity of CAD. The LDL/HDL-C ratio appeared to be the most sensitive index for reflecting CAD of mild severity with a predictive value of 83.3% at 76.6% specificity and at 77.7% sensitivity (cut-off: 3.20). Average values of LDL and HDL-C alone are not reliable indices of mild severity CAD.

[Serum viscosity and chronic hepatopathies]

In 26 patients with chronic liver disease, the serum viscosity was studied. In 42% of subjects, the serum viscosity was found increased, almost always associated with clinical findings of central nervous system involvement. The remission of central nervous system symptoms occurs with fall into normal range of serum viscosity levels. Therefore, the serum hyperviscosity should be included among various causes of cirrhosis encephalopathy. When serum viscosity is increased, relates rather to immunoglobulins (IgG, IgA, IgM) increases then to increased amounts of total globulins.