The risks of defensive (emergency) medicine. The laboratory perspective

Diagnostic testing is a crucial aspect of the clinical decision making, especially in emergency settings where timely and accurate diagnoses are essential for appropriate patient management. Reliable statistics attest that the vast majority of clinical decisions for diagnosis, treatment and follow-up of both acute and chronic diseases are influenced by results of laboratory analyses. As specifically concerns the emergency department, many unnecessary laboratory tests are also ordered in this healthcare setting, with unfavorable consequences on laboratory and healthcare organization. As far as the laboratory environment is concerned, defensive (emergency medicine) may be associated with incremental costs, derangement of laboratory organization, enhanced complexity of data management process, diagnostic delay attributable to performance of unnecessary testing, and litigation. Educative or even regulatory interventions are hence urgently needed to addresses problems of the current liability system, in order to decrease the detrimental effects of defensive (emergency) medicine in the laboratory

Human epididymis protein 4 (HE4) in benign and malignant diseases

Background: Human epididymis protein 4 (HE4) is described as a useful new biomarker in ovarian cancer. As HE4 is neither tumor nor organ specific, we intensively investigated the occurrence of this protein in female and male patients with various benign and malignant diseases in order to avoid misinterpretation and to identify potential additional clinical relevance. Methods: We retrospectively investigated HE4 (ARCHITECT (R), Abbott Diagnostics, US) in the sera of 205 healthy individuals, 654 patients with benign disorders and 720 patients with cancer before initial treatment. Results: The lowest concentrations of HE4 were observed in healthy men (median 26.2 pmol/L) followed by healthy women (median 40.4 pmol/L). In benign diseases, highest HE4 concentrations were seen in both women and men with renal failure (women, median 1041 pmol/L; men, median 1368 pmol/L). In women, the highest HE4 levels in malignant diseases were observed in ovarian cancer (median 242 pmol/l), whereas the highest HE4 concentrations in men occurred in lung cancer (median 89.2 pmol/L). The area under the curve (AUC) of HE4 in women was highest in ovarian cancer and borderline tumors as compared to benign gynecological disorders (88.9%), with a sensitivity of 67.4% at 95% specificity. Also, significantly elevated concentrations of HE4 with reference to the respective group of benign diseases were observed in uterus corpus and breast cancer as well as in lung cancer for men and women. Conclusions: HE4 has the highest relevance in ovarian cancer but can be elevated in a variety of benign and malignant diseases

Ruderal Plants Providing Bees Diversity on Rural Properties

Many  are  the  anthropogenic  drivers  of  pollinator  decline,  but  the  loss  of  suitable  habitats, among other effects caused by agricultural intensification, deserves special attention.  Reduction  in  the  availability  of  floral  resources  negatively  affects  bee communities, compromising bee species composition, foraging behavior, corporal size, and fitness. Our study aims to understand whether the presence of herbaceous plants, acting as foraging sites, next to crops contributes to bee species richness in smallholder rural properties. Bee sampling was performed on smallholder rural properties in the municipality of Guapiara, southern São Paulo state. Individuals who visited the flowers of ruderal plants and crops were collected, using an entomological net, for ten months. A total of 61 bee species were identified, with the highest species richness being sampled in ruderal plant flowers in the three properties studied. Only in one property, ruderal plants hosted a more diverse bee assemblage (Shannon-Weiner and taxonomic diversity indices), but species composition differed from that sampled in crop plants (Jaccard index) in all properties. Thirty-two species were sampled exclusively in ruderal plants, versus 9 only in crops and 20 species in both types of plants. Pollen analysis showed that of the 22 species of bees that were sampled only on flowers of ruderal plants, 9 species carried pollen of tomato and one species of bee carried pollen of kabocha squash. Ruderal plants can provide an alternative food resource for pollinators, enabling these insects to remain in or be attracted to crop areas, where, in addition to visiting such plants, they also visit the cultivated plant flowers. Allowing coexistence between crops and ruderal plants, provided that the issues of plant health are observed, is a simple and low-cost measure for farmers and will provide both economic and environmental benefits

Relationship between ABO blood group and von Willebrand factor levels: from biology to clinical implications

Although a number of studies have demonstrated the influence of ABO blood group on plasma levels of von Willebrand factor (VWF), the nature of this association and its clinical importance is still largely unknown

Comparison of platelet function between sedentary individuals and competitive athletes at rest

BACKGROUND: There are controversial evidences on the effect of different types and workloads of physical exercise on primary hemostasis. In particular, little is known on the chronic influence of a strenuous and regular aerobic training regimen on platelet function. METHODS: The aim of this investigation was to compare platelet function between sedentary controls and trained athletes at rest and to evaluate whether a greater amount of exercise performed in professional cyclists may contribute to increased platelet chronic responsiveness compared to both elite cyclists and sedentary individuals. Platelet's ability to adhere and aggregate was assayed following a 12–24 h resting period in 49 active professional male road cyclists, 40 elite male cyclists and 43 matched sedentary healthy male volunteers, by the platelet function analyzer 100 (PFA-100). RESULTS AND DISCUSSION: Mean values of the collagen-epinephrine test did not differ between controls and athletes (sedentary controls: 111 ± 33 s; elite athletes: 113 ± 26 s, p = 0.93; professional athletes: 120 ± 33 s; p = 0.33), whereas mean values of the collagen-ADP test displayed a slightly but significant trend towards decreased values when comparing sedentary controls (83 ± 21 s) with either elite (77 ± 11 s, p < 0.01) or professional (75 ± 16 s, p < 0.01) athletes. CONCLUSION: The trend towards slightly lower collagen-ADP values are suggestive for a modest but significant chronic activation of primary hemostasis, highlighting the need to set appropriate reference ranges for the PFA-100 when evaluating primary hemostasis in physically active subjects

Plasma D-dimer concentration in patients with systemic sclerosis

BACKGROUND: Systemic sclerosis (SSc) is an autoimmune disorder of the connective tissue characterized by widespread vascular lesions and fibrosis. Little is known so far on the activation of the hemostatic and fibrinolytic systems in SSc, and most preliminary evidences are discordant. METHODS: To verify whether SSc patients might display a prothrombotic condition, plasma D-dimer was assessed in 28 consecutive SSc patients and in 33 control subjects, matched for age, sex and environmental habit. RESULTS AND DISCUSSION: When compared to healthy controls, geometric mean and 95% confidence interval (IC95%) of plasma D-dimer were significantly increased in SSc patients (362 ng/mL, IC 95%: 361–363 ng/mL vs 229 ng/mL, IC95%: 228–231 ng/mL, p = 0.005). After stratifying SSc patients according to disease subset, no significant differences were observed between those with limited cutaneous pattern and controls, whereas patients with diffuse cutaneous pattern displayed substantially increased values. No correlation was found between plasma D-dimer concentration and age, sex, autoantibody pattern, serum creatinine, erythrosedimentation rate, nailfold videocapillaroscopic pattern and pulmonary involvement. CONCLUSION: We demonstrated that SSc patients with diffuse subset are characterized by increased plasma D-dimer values, reflecting a potential activation of both the hemostatic and fibrinolytic cascades, which might finally predispose these patients to thrombotic complications

Non-commutability of results of highly sensitive troponin I and T immunoassays

Introduction: The measurement of cardiospecific troponins is pivotal in the diagnostic and prognostic approach of patients with suspected acute myocardial infarction (AMI). However, no information is available on the commutability of results between the novel highly-sensitive (HS) troponin T (TnT) and I (TnI) immunoassays. Materials and methods: The study population consisted in 47 consecutive patients presenting at the emergency department (ED) of the Academic Hospital of Parma with suspected AMI. TnI was measu-red with the novel prototype Beckman Coulter HS-AccuTnI immunoassay on Access 2, whereas TnT was measured with the Roche HS-TnT immunoassay on Cobas. Results: Eight out of the 47 patients (17%) were finally diagnosed as having an AMI. The overall cor-relation between TnT and TnI for total patient group was acceptable (r = 0.944; P < 0.01). Neverthe-less, when the analysis of data was carried out in separate groups according to the final diagnosis of AMI, two different equation results were obtained, i.e., HS-TnT = HS-AccuTnI x 0.349 + 20 (r = 0.823; P < 0.01) in non-AMI patients, and HS-TnT = HS-AccuTnI x 0.134 + 67 (r = 0.972; P < 0.01) in those with AMI. Conclusions: This study suggests the existence of two biological relationships between TnI and TnT in plasma, depending on the source of release from the myocardium. Moreover, the non-commutability of data between HS-TnT and HS-AccuTnI jeopardizes the clinical decision making, makes it impossible to calculate the delta or reference change value using the two biomarkers and to finally establish a reliable kinetics of troponin release from the injured myocardium

The effective reduction of tourniquet application time after minor modification of the CLSI H03-A6 blood collection procedure

Introduction: The phlebotomists’ procedures are a still source of laboratory variability. The aim of this study was to verify the efficacy of minor modification in procedure for collection of diagnostic blood specimens by venipuncture from CLSI H03-A6 document is able to reduce the tourniquet application time. Materials and methods: Thirty phlebotomists were invited to participate. Each phlebotomist was trained individually to perform the new venipuncture procedure that shortens the time of tourniquet release and removal. The phlebotomy training program was delivered over 8h. After training, all phlebotomists were monitored for 20 working days, to guarantee the adoption of the correct new procedures for collection of diagnostic blood specimens. After this time frame the phlebotomists were evaluated to verify whether the new procedure for blood collection derived from CLSI H03-A6 document was effective to improve the quality process by decrease in tourniquet application time. We compared the tourniquet application time and qualitative difference of phlebotomy procedures between laboratories before and after phlebotomy training. Results: The overall mean ± SD tourniquet application time before and after this intervention were 118 ± 1 s and 30 ± 1 s respectively. Minor modifications in procedure for blood collection were able to reduce significantly the tourniquet application time (-88 s, P < 0.001). Conclusions: The minor modifications in procedure for collection of diagnostic blood specimens by venipuncture from CLSI H03-A6 document were able to reduce the tourniquet application time. Now the proposed new procedure for collection of diagnostic blood specimens by venipuncture could be considered usefulness and should be put into practice by all quality laboratory managers and/or phlebotomy coordinators to avoid preanalytical errors regard venous stasis and guarantee patient safety

Effectiveness of citrate buffer-fluoride mixture in Terumo tubes as an inhibitor of in vitro glycolysis

Introduction: Glycolysis affects glucose determination in vitro. The placement of sample tubes in ice-water slurry with plasma separation within 30 minutes is recommended, or alternatively the use of a glycolysis inhibitor. The aim of our two-steps study was to evaluate which Terumo tube is best for glucose determination in routine clinical setting. Materials and methods: In the first study, blood from 100 volunteers was collected into lithium heparin (LH), NaF/Na heparin (FH) and NaF/citrate buffer/Na2EDTA (FC-Mixture) tubes. LH sample was treated as recommended and considered as reference, while FH and FC-Mixture samples were aliquoted, maintained at room temperature (RT) for 1, 2 and 4 hours; centrifuged and plasma analysed in triplicate. In the second study, samples from 375 volunteers were collected in LH, FH and FC-Mixture tubes and held at RT before centrifugation from 10 to 340 minutes, depending on each laboratory practice. Samples were analysed in one analytical run. Results: In the first study, FH glucose concentrations were 5.15 ± 0.66 mmol/L, 5.05 ± 0.65 mmol/L and 5.00 ± 0.65 mmol/L (P < 0.001) in tubes stored at RT for 1, 2 and 4 hours, respectively. Mean biases in all time points exceeded the analytical goal for desirable bias based on biological variation criteria. FC-Mixture glucose concentrations were 5.48 ± 0.65 mmol/L, 5.46 ± 0.6 mmol/L and 5.46 ± 0.64 mmol/L in tubes stored at RT for 1, 2 and 4 hours, respectively. Mean biases for FC-Mixture glucose in all time points reached optimal analytical goals. In the second study, the biases for LH and FH glucose compared to reference FC-Mixture glucose exceeded the preset analytical goals, regardless of the blood collection to centrifugation time interval. Conclusions: FC-mixture tubes glucose concentrations were preserved up to 4h storage at RT. We confirmed that NaF alone does not allow immediate glycolysis inhibition in real life pre-centrifugation storage conditions (up to 340 minutes). FC-Mixture should be used exclusively for glucose determination in laboratories unable to implement the recommended blood samples’ treatment