Point-of-care testing: state-of-the art and perspectives.

Point-of-care testing (POCT) is becoming an increasingly popular way to perform laboratory tests closer to the patient. This option has several recognized advantages, such as accessibility, portability, speed, convenience, ease of use, ever-growing test panels, lower cumulative healthcare costs when used within appropriate clinical pathways, better patient empowerment and engagement, and reduction of certain pre-analytical errors, especially those related to specimen transportation. On the other hand, POCT also poses some limitations and risks, namely the risk of lower accuracy and reliability compared to traditional laboratory tests, quality control and connectivity issues, high dependence on operators (with varying levels of expertise or training), challenges related to patient data management, higher costs per individual test, regulatory and compliance issues such as the need for appropriate validation prior to clinical use (especially for rapid diagnostic tests; RDTs), as well as additional preanalytical sources of error that may remain undetected in this type of testing, which is usually based on whole blood samples (i.e., presence of interfering substances, clotting, hemolysis, etc.). There is no doubt that POCT is a breakthrough innovation in laboratory medicine, but the discussion on its appropriate use requires further debate and initiatives. This collective opinion paper, composed of abstracts of the lectures presented at the two-day expert meeting "Point-Of-Care-Testing: State of the Art and Perspective" (Venice, April 4-5, 2024), aims to provide a thoughtful overview of the state-of-the-art in POCT, its current applications, advantages and potential limitations, as well as some interesting reflections on the future perspectives of this particular field of laboratory medicine.

Combined use of the multidimensional prognostic index (MPI) and procalcitonin serum levels in predicting 1-month mortality risk in older patients hospitalized with community-acquired pneumonia (CAP): a prospective study.

BACKGROUND: Several scores and biomarkers, i.e., procalcitonin (PCT), were proposed to stratify the mortality risk in community-acquired pneumonia (CAP). AIM: Evaluating prognostic accuracy of PCT and Multidimensional Prognostic Index (MPI) for 1-month mortality risk in older patients with CAP. METHODS: At hospital admission and at discharge, patients were evaluated by a Comprehensive Geriatric Assessment to calculate MPI. Serum PCT was measured at admission and 1, 3, and 5 days after hospital admission. RESULTS: 49 patients were enrolled. The overall 1-month mortality was 44.5 for 100-persons year. Mortality rates were higher with the increasing of MPI. In survived patients, MPI at discharge showed higher predictive accuracy than MPI at admission. Adding PCT levels to admission MPI prognostic accuracy for 1-month mortality significantly increased. CONCLUSION: In older patients with CAP, MPI significantly predicted 1 month mortality. PCT levels significantly improved the accuracy of MPI at admission in predicting 1-month mortality.

Abnormalities in the 24-hour rhythm of skin temperature in cirrhosis: Sleep-wake and general clinical implications.

BACKGROUND & AIMS: Sleep preparation/onset are associated with peripheral vasodilatation and a decrease in body temperature. The hyperdynamic syndrome exhibited by patients with cirrhosis may impinge on sleep preparation, thus contributing to their difficulties falling asleep. The aim of this study was the assessment of skin temperature, in relation to sleep-wake patterns, in patients with cirrhosis. METHODS: Fifty-three subjects were initially recruited, and 46 completed the study. Of the final 46, 12 were outpatients with cirrhosis, 13 inpatients with cirrhosis, 11 inpatients without cirrhosis and 10 healthy volunteers. All underwent baseline sleep-wake evaluation and blood sampling for inflammatory markers and morning melatonin levels. Distal/proximal skin temperature and their gradient (DPG) were recorded for 24 hours by a wireless device. Over this period subjects kept a sleep-wake diary. RESULTS: Inpatients with cirrhosis slept significantly less well than the other groups. Inpatients and outpatients with cirrhosis had higher proximal temperature and blunted rhythmicity compared to the other groups. Inpatients with/without cirrhosis had higher distal temperature values and blunted rhythmicity compared to the other groups. Inpatients and outpatients with cirrhosis had significantly lower DPG values compared to the other groups, and DPG reached near-zero values several hours later. Significant correlations were observed between temperature and sleep-wake variables and inflammatory markers. CONCLUSIONS: Alterations of distal/proximal skin temperature, their gradient and their time-course were observed in patients with cirrhosis, which may contribute to their sleep disturbances.

An international study of how laboratories handle and evaluate patient samples after detecting an unexpected APTT prolongation.

BACKGROUND: An unexpectedly detected prolonged activated partial thromboplastin time (APTT) can be a harmless laboratory finding, but can also reflect a thrombotic tendency or a bleeding disorder. The assistance of laboratory professionals in the interpretation of an unexpectedly detected prolonged APTT (uAPTT) is often required. The way in which uAPTTs are evaluated in laboratories was assessed in this international study with the aim of determining whether laboratory professionals are able to fulfill this need. METHODS: Postanalytical practices after uAPTT were investigated and the mixing study methodology (if used) was studied by circulating a case report with a questionnaire to staff in the invited laboratories. In addition, the interpretations of those staff regarding the presence or absence of inhibitors in three APTT mixing study scenarios were examined. RESULTS: Large within- and between-country variations were detected in both postanalytical practices and mixing study methodologies among the 990 responding laboratories, 90% of which were in 13 countries. Shortcomings regarding the investigation of uAPTTs leading to potentially incorrect or delayed clinical diagnoses were found in 88% of the laboratories. Of the laboratories to which the interpretative questions were sent, 49% interpreted all mixing study scenarios correctly. uAPTTs were investigated appropriately and all mixing study scenarios interpreted correctly in parallel in only 9.6% of the participating laboratories. CONCLUSIONS: The clinical requirement for the assistance of laboratory professionals in the interpretation of uAPTTs cannot be met at most of the participating laboratories. Laboratory professionals should be trained in the evaluation of ordinary laboratory tests, such as that for uAPTTs.

Complete blood count at the ED: preanalytic variables for hemoglobin and leukocytes.

OBJECTIVE: The objective of this study is to determine the ways in which preanalytic factors related to physiologic status can affect the complete blood cell count (CBC) in patients referring to an emergency department (ED). METHODS: Over a 1-year period, the results of hemoglobin (Hb) level and white blood cell (WBC) counts of the first CBC tests undertaken in consecutive patients (n = 11487) referring to the ED were compared with those obtained in the same patients at a second test undertaken within 24 hours of admission. A prospective evaluation of the same differences was made in another group (group 2) of 1025 consecutive ED patients, several clinical characteristics being taken into consideration. RESULTS: Mean Hb concentrations were higher in the first (range, 8.0-15.9 g/dL) than in the second test results (median overestimation, 0.4-0.8 g/dL; P < .0001). At multivariate analysis of results in group 2 patients, fluid administration (>0.5 L) and the presence of edema played a significant role in the initial overestimation of Hb level (P = .001 and P = .045, respectively). The comparison between leukocyte counts (WBC) showed that values from the first were higher than those in the second test (median overestimation ranging from 0.42 to 3.63 × 10(9)/L cells, in the range counts from 4.0 to 30.0 × 10(9)/L). None of the clinical factors studied appeared to have affected this overestimation. CONCLUSIONS: On interpreting CBC results in patients admitted to the ED, physicians must consider the effect of physiologic variables on Hb level (mainly hydration status) and WBC count (mental and physical stress).

Urgent Thyroid-Stimulating Hormone Testing in Emergency Medicine: A Useful Tool?

BACKGROUND: Thyroid-stimulating hormone (TSH) has recently been introduced among the tests available to the Emergency Department (ED) of our hospital. OBJECTIVE: To evaluate the prevalence of TSH-level-dependent thyroid dysfunction and to assess the usefulness of urgent TSH testing in a series of emergency patients. METHODS: We planned a single-center observational cross-sectional clinical study. We divided patients in groups according to their thyroid status using defined TSH decision levels. Previously diagnosed history of thyroid dysfunction and newly diagnosed thyroid dysfunctions were differentiated. Further, we analyzed the subset of emergency patients affected by atrial fibrillation (AF) due to the role of hyperthyroidism in AF pathogenesis. For each TSH request, we made a retrospective chart review to assess the usefulness of the test based on clinical efficacy and management efficiency indicators. RESULTS: The present study showed that, although the overall thyroid dysfunction rate was higher than in the general population, only a few newly diagnosed thyroid dysfunctions were found with limited clinical utility. We categorized urgent TSH requests as useful and not useful, by retrospective evaluation, and we identified and compared the main TSH testing clinical indications in the two groups. CONCLUSION: We found a positive impact of urgent TSH determination in emergency decision-making. Nevertheless, a stronger clinical impact could be achieved by improving request appropriateness and by targeting TSH testing to some clinical indications identified by the study. The work was considered a quality-improvement project by the Hospital Committee for Quality Management.

Exploring the initial steps of the testing process: frequency and nature of pre-preanalytic errors.

BACKGROUND: Few data are available on the nature of errors in the so-called pre-preanalytic phase, the initial steps of the testing process. We therefore sought to evaluate pre-preanalytic errors using a study design that enabled us to observe the initial procedures performed in the ward, from the physician's test request to the delivery of specimens in the clinical laboratory. METHODS: After a 1-week direct observational phase designed to identify the operating procedures followed in 3 clinical wards, we recorded all nonconformities and errors occurring over a 6-month period. Overall, the study considered 8547 test requests, for which 15 917 blood sample tubes were collected and 52 982 tests undertaken. RESULTS: No significant differences in error rates were found between the observational phase and the overall study period, but underfilling of coagulation tubes was found to occur more frequently in the direct observational phase (P = 0.043). In the overall study period, the frequency of errors was found to be particularly high regarding order transmission [29 916 parts per million (ppm)] and hemolysed samples (2537 ppm). The frequency of patient misidentification was 352 ppm, and the most frequent nonconformities were test requests recorded in the diary without the patient's name and failure to check the patient's identity at the time of blood draw. CONCLUSION: The data collected in our study confirm the relative frequency of pre-preanalytic errors and underline the need to consensually prepare and adopt effective standard operating procedures in the initial steps of laboratory testing and to monitor compliance with these procedures over time.

Different biochemical correlates for different neuropsychiatric abnormalities in patients with cirrhosis.

UNLABELLED: The diagnosis of hepatic encephalopathy (HE) relies on clinical, neurophysiological, psychometric and laboratory variables. The relationships between such tests remain debated. The aim of this study was to determine the laboratory correlates/prognostic value of neurophysiological/psychometric abnormalities in patients with cirrhosis. Seventy-two patients and 14 healthy volunteers underwent EEG and paper-and-pencil psychometry (PHES). Blood was obtained for C reactive protein (CRP), interleukin 6 (IL6), tumor necrosis factor (TNF)α, ammonia and indole/oxindole. Patients were followed prospectively for a median of 22 months in relation to the occurrence of death, transplantation and HE-related hospitalizations. Thirty-three patients had normal PHES and EEG, 6 had abnormal PHES, 18 abnormal EEG and 13 abnormal PHES and EEG. Patients with abnormal PHES had higher CRP (17 ± 22 vs 7 ± 6, P < 0.01), IL6 (32 ± 54 vs 12 ± 13, P < 0.05) and TNFα (17 ± 8 vs 11 ± 7, P < 0.001) levels than those with normal PHES. Patients with abnormal EEG had higher indole (430 ± 270 vs 258 ± 255, P < 0.01) and ammonia (66 ± 35 vs 45 ± 27, P < 0.05) levels than those with normal EEG. Psychometric test scores showed significant correlations with CRP, TNFα and IL6; EEG indices with ammonia and IL6. CRP and TNFα concentrations were independent predictors of abnormal PHES, ammonia and indole of abnormal EEG on multivariate analysis. Seven patients were lost to follow-up; of the remaining 65, 20 died and 14 underwent transplantation; 15 developed HE requiring hospitalization. PHES and EEG performance were independent predictors of HE and death (P < 0.05). CONCLUSION: PHES and EEG abnormalities in patients with cirrhosis have partially different biochemical correlates and independently predict outcome.

Monitoring quality indicators in laboratory medicine does not automatically result in quality improvement.

BACKGROUND: Data on quality indicators (QIs) should be collected over time in order to identify and continuously monitor clinical laboratory performance and to improve patient safety by identifying and implementing effective interventions. The aim of the present study was to ascertain whether the utilization of a set of quality indicators over a 3-year period resulted in an improvement in the efficiency and effectiveness of an individual laboratory. METHODS: Over a 3-year time interval (2009-2011), a series of 38 QIs covering all stages of the total testing process (21 in the pre-analytic, nine in the analytic and eight in the post-analytic phase) was monitored. RESULTS: On the basis of their patterns, QIs have been grouped into the following categories: [1] seven QIs of the pre-analytical phase and three of the intra-analytical phase with a significant trend and a significant linearity demonstrating an improvement over time; [2] 10 QIs of the pre-analytical and two of the intra-analytical phase with a significant trend and a non-significant linearity demonstrating that changes were not constant; [3] two QIs of the pre-analytical and one of the intra-analytical phase with a non-significant trend and significant linearity showing neither improvement nor worsening; and [4] two QIs of the pre-analytical and three of the intra-analytical phase with a non-significant trend and non-significant linearity. CONCLUSIONS: Data on a set of QIs collected over a 3-year time-frame demonstrate that processes and indicators under the control of the clinical laboratory had improved much more than processes requiring close co-operation between the laboratory and care teams.

Two SARS-CoV-2 IgG immunoassays comparison and time-course profile of antibodies response.

INTRODUCTION: The persistence of circulating antibodies to SARS-CoV-2 infection is not yet well known. We compare the results of 2 automated systems for the determination of IgG against SARS CoV-2 and assess the time-course of the IgG response. METHODS: IgG were measured in 103 specimens of 55 patients with COVID-19 (time from the symptoms' onset: 3-187 days) using the automated tests "Abbott SARS-COV-2 IgG" and "MAGLUMI 2019-nCoV IgG". RESULTS: The 2 methods had a concordance of 90.3%, but the quantitative correlation, although significant, showed dispersed results. All the specimens resulted positive after 17 days. However, the median concentrations of IgG rapidly increased up to 20 days and decreased for Maglumi IgG while Abbott IgG showed a constant trend up to 85 days, and then slowly declined. CONCLUSIONS: The titer of IgG against SARS-CoV-2 may significantly and rapidly decrease, but with a very different time-course depending on the method used for the determination.

Antibodies against SARS-CoV-2 Time Course in Patients and Vaccinated Subjects: An Evaluation of the Harmonization of Two Different Methods.

The time course of antibodies against SARS-CoV-2 is not yet well elucidated, especially in people who underwent a vaccination campaign. In this study, we measured the antibodies anti-S1 and anti-RBD with two different methods, both in patients and in vaccinated subjects. One hundred and eight specimens from 48 patients with COVID-19 (time from the onset of symptoms from 3 to 368 days) and 60 specimens from 20 vaccinated subjects (collected after 14 days from the first dose, 14 days and 3 months after a second dose of Comirnaty) were evaluated. We used an ELISA method that measured IgG against anti-Spike 1, and a chemiluminescence immunoassay that measured IgG anti-RBD. In the patients, the antibodies concentrations tended to decline after a few months, with both the methods, but they persisted relatively high up to nearly a year after the symptoms. In the vaccinated subjects, the antibodies were already detectable after the first dose, but after the booster, they showed a significant increase. However, the decrease was rapid, given that 3 months after the second vaccination, they were reduced to less than a quarter. The conversion of the results into BAU units improves the relationship between the two methods. However, in the vaccinated subjects, there was no evidence of proportional error after the conversion, while in the patients, the difference between the two methods remained significant.

Corneal transplantation during the COVID-19 pandemic: An operational guide.

PURPOSE: To provide an operational guide for corneal transplantation during the COVID-19 pandemic aimed to maintain surgery and avoid spreading of SARS-CoV-2. METHODS: Prospective observational case series study in patients requiring corneal graft manage toward separate free and restricted pathways for those COVID-19 negative or positive, respectively. RESULTS: During the national lockdown, 30 consecutive patients underwent endothelial (n = 16), penetrating (n = 9), and anterior lamellar keratoplasty (n = 5). Two patients followed the COVID-19 restricted pathway, as they were considered positive while waiting for test results. Nine patients were hospitalized one night in the hospital. On admission to the hospital before surgery, at surgery, the day after surgery and at 7 and 30 days all patients and health-care personnel showed no symptoms and resulted negative at risks factors/exposure to the SARS-CoV-2 infection and occurrence of COVID-19. Nucleic acid testing resulted not detectable in all patients and SARS-CoV-2 antibodies quantification showed IgG and IgM below the positive predicted value in 29 patients. One patient showed IgM above the cut-off of significance (1.21 and 1.03 preoperative and 1-month postoperative, respectively) that were considered irrelevant because of the absence of symptoms and exposure risks. CONCLUSIONS: The concept of donor emergency (i.e. short-term availability of transplant tissues), makes corneal transplantation an always-urgent activity because it is related to the availability of the corneal tissue from a donor. Modest adjustments to ophthalmic clinic and eye surgery organization are required to maintain surgery and care of eye patients in a safe environment.

Multidimensional Prognostic Index and pro-adrenomedullin plasma levels as mortality risk predictors in older patients hospitalized with community-acquired pneumonia: a prospective study.

BACKGROUND: To evaluate the prognostic accuracy of proadrenomedullin (proADM) in comparison with and in addition to the Multidimensional Prognostic Index (MPI), a validated predictive tool for mortality derived from a comprehensive geriatric assessment (CGA) to predict one-month mortality risk in older patients hospitalized with community-acquired pneumonia (CAP). METHODS: All patients aged 65 years and older, consecutively admitted to an acute geriatric ward with a diagnosis of CAP from February to July 2012. At admission and at discharge they were submitted to a standard CGA in order to calculate MPI. Moreover, plasma samples were taken at baseline and after one, three and five days of hospitalization for the analysis of pro-ADM. RESULTS: Fifty patients (mean age 86.2±7.5 years), with 31 at high risk of mortality (MPI-3) were enrolled. ProADM and MPI, both at admission and at discharge, were significant predictor of mortality. As expected, MPI at admission showed lower predictive accuracy than MPI at discharge (survival C-statistic 0.667 vs. 0.851). The addition of proADM to the MPI at admission significantly increased accuracy in predicting one-month mortality (C-statistics from 0.667 to 0.731, P=0.018 at baseline; from 0.667 to 0.733, P=0.008 at 1 day; from 0.633 to 0.724; P=0.019 at 3 days; from 0.667 to 0.828; P=0.003 at 5 days). Conversely, adding pro-ADM to the MPI at discharge did not significantly improve the model's prognostic accuracy. CONCLUSIONS: ProADM may significantly improve the prognostic accuracy of the MPI at admission in hospitalized elderly patients with CAP.

Metabolic activity of rat hepatocytes cultured on homologous acellular matrix and transplanted into Gunn rats.

The metabolic activity of hepatocytes cultured on homologous acellular matrix (HAM) and transplanted into rats genetically incapable of bilirubin conjugation (Gunn rats) has been investigated. Hepatocytes from Wistar male rats were seeded on HAM and cultured for 9 days, and the proliferation rate and albumin mRNA expression were assayed daily. HAM alone or HAM plus hepatocytes (cultured for 3 days) were implanted in a subcutaneous pocket of the dorsal region of Gunn rats. No immunosuppression therapy was used. Blood samples were collected weekly and rats were sacrificed 10 weeks after surgery. Hepatocytes cultured on HAM displayed a higher proliferation rate than those cultured on plastic, and albumin mRNA expression was detected in hepatocytes seeded on HAM, but not on plastic. Serum bilirubin concentrations did not differ from baseline values in both the sham-operated control and HAM transplanted rats. On the contrary, in rats transplanted with HAM plus hepatocytes, circulating bilirubin levels decreased from week 4-7, and then plateaued until week 10. Histology did not evidence signs of rejection, but only a mild degree of inflammation around the implanted patches. It is concluded that hepatocytes seeded on HAM and transplanted into Gunn rats are able to metabolize bilirubin for at least two months, without signs of rejection even in the absence of immunosuppressive therapy.

Is D-dimer used according to clinical algorithms in the diagnostic work-up of patients with suspicion of venous thromboembolism? A study in six European countries.

INTRODUCTION: Clinical algorithms consisting of pre-test probability estimation and D-dimer testing are recommended in diagnostic work-up for suspected venous thromboembolism (VTE). The aim of this study was to explore how physicians working in emergency departments investigated patients suspected to have VTE. MATERIALS AND METHODS: A questionnaire with two case histories related to the diagnosis of suspected pulmonary embolism (PE) (Case A) and deep venous thrombosis (DVT) (Case B) were sent to physicians in six European countries. The physicians were asked to estimate pre-test probability of VTE, and indicate their clinical actions. RESULTS: In total, 487 physicians were included. Sixty percent assessed pre-test probability of PE to be high in Case A, but 7% would still request only D-dimer and 11% would exclude PE if D-dimer was negative, which could be hazardous. Besides imaging, a D-dimer test was requested by 41%, which is a "waste of resources" (extra costs and efforts, no clinical benefit). For Case B, 92% assessed pre-test probability of DVT to be low. Correctly, only D-dimer was requested by 66% of the physicians, while 26% requested imaging, alone or in addition to D-dimer, which is a "waste of resources". CONCLUSIONS: These results should encourage scientific societies to improve the dissemination and knowledge of the current recommendations for the diagnosis of VTE.