Diagnostic utility of FGF-23 in mineral bone disorder during chronic kidney disease

Our data confirm that intact fibroblast growth factor 23 (iFGF-23) concentration is increased in patients with chronic kidney disease (CKD) and that it increases with disease progression (stages I-V). Therefore, iFGF-23 could be considered an early biomarker in the course of chronic kidney disease-mineral bone disorder (CKD-MBD), which has several aspects that make it potentially useful in clinical practice. The availability of an automated method for iFGF-23 assay may represent an added value in the management of the patient with CKD-MBD already from the early stages of the disease, before the increase of the routinely used laboratory parameters, 1-84 parathyroid hormone (PTH) and 25-OH-vitamin D (25-OH-vitD), which occur in more advanced stages of the disease.

Pharmacokinetics of the disialoganglioside, GD2, a circulating tumor biomarker for neuroblastoma, in nonhuman primates

Background: The ganglioside GD2 is a potential circulating tumor biomarker for the childhood cancer, neuroblastoma. Interpreting the levels of a circulating tumor biomarker depends in part on a knowledge of the biomarker’s clinical pharmacology. Background: The ganglioside GD2 is a potential circulating tumor biomarker for the childhood cancer neuroblastoma. Interpreting the levels of a circulating tumor biomarker depends in part on a knowledge of the biomarker’s clinical pharmacology. Methods: We studied the plasma and cerebrospinal fluid (CSF) pharmacokinetics of the C18 lipoform of GD2 in two nonhuman primates with indwelling subcutaneous CSF lateral ventricular reservoir systems. GD2 was quantified with a validated high-performance liquid chromatography (HPLC)/tandem mass spectrometry assay. GD2 was administered as a short intravenous infusion and frequent plasma and CSF samples were drawn over 72 hours. Results: GD2 plasma concentration declined monoexponentially with a half-life of 16 hours. Clearance was 0.0136 and 0.0131 L/h and volume of distribution (Vd) was 0.035 and 0.038 L/kg in the two animals. Vd was equivalent to plasma volume. Greater than 98% of GD2 in plasma is in a bound form consistent with its known association with lipoproteins and accounting for its limited volume of distribution. GD2 did not cross over from plasma into the CSF. Conclusions: The pharmacokinetic profile of GD2 is favorable for a circulating tumor biomarker. This study demonstrates the value of characterizing the clinical pharmacology of circulating biomarkers to better understand their clinical behavior.

Serum IL-33 as a biomarker in different diseases: useful parameter or much need for clarification?

Interleukin-33 (IL-33), a member of the IL-1 family, is critically involved in the modulation of the activity of a diverse range of immunocompetent cells. Essential roles have been implicated in cardioprotection, in both innate and adaptive immune responses in mucosal organs, and in the maintenance of adipose tissue cells. Over the past 10 years, several studies evaluated the usability of IL-33 as a biomarker in diseases of inflammatory and noninflammatory origin. Our group is currently evaluating the predictive role of serum IL-33 in acute kidney injury (AKI). The aim of the article is to discuss selected studies on IL-33 in different diseases and its potential role as a biomarker molecule.

Circulating erythroblast abnormality associated with systemic pathologies may indicate bone marrow damage

Background: The circulating rare cell population is diverse and rich in diagnostic information. Its characterization and clinical exploitation by cell-based liquid biopsy is an ongoing research task. Bone marrow is one of the major contributors to the peripheral blood rare cell population and, consequently, determines individual rare cell profiles thus depending on bone marrow health status. Bone marrow damage has been associated with aggressive or late-stage systemic diseases and egress of various bone marrow cells into the blood circulation. The association of quantity and heterogeneity of circulating erythroblast with bone marrow damage is of particular interest. Methods: Circulating CD71high/CD45-/Hoechsthigh blast cells from healthy, noncancer- and cancer-afflicted donors were enriched by CD45 depletion and analyzed by immunofluorescence microscopy. Results: A new finding of aberrant and mitotic circulating erythroid-like cells that appear similar across blood donors afflicted with various systemic pathologies is reported. Further presented is a classification of said erythroblast-like cells in nine subcategories according to morphological differences between phenotypically similar cells. Conclusion: Aberrant and mitotic bone marrow-derived rare circulating erythroid-like cells can be detected in the blood of afflicted individuals but not in healthy donors, suggesting the cause of bone marrow damage.

Circulating progastrin-releasing peptide in the diagnosis of Small Cell Lung Cancer (SCLC) and in therapeutic monitoring

Introduction: Progastrin-releasing peptide (proGRP), a precursor of GRP, has been recently reported as a putative circulating biomarker for differential diagnosis between non–small cell lung cancer (NSCLC) and SCLC. We evaluated the diagnostic effectiveness of proGRP to differentiate patients with NSCLC and SCLC and the usefulness of combined measurement of proGRP and neuron-specific enolase (NSE) for diagnosing SCLC. Methods: Serum proGRP, NSE, cytokeratin 19 fragment 21-1 (CYFRA 21.1), squamous cell carcinoma antigen (SCC Ag) and carcinoembryonic antigen (CEA) were prospectively collected and measured in patients with a new diagnosis of lung cancer. Serum proGRP was also measured in healthy subjects. The serum proGRP, NSE, CYFRA 21.1 and CEA concentrations were determined by an electrochemiluminescence immunoassay and the serum SCC Ag concentration was determined by an automated immunofluorescence assay. Differences between proGRP and NSE in patients with SCLC and NSCLC were evaluated and compared using Mann-Whitney test. Results: A total of 77 patients affected by SCLC (n = 17) and NSCLC (n = 60) were enrolled in the present study. Moreover, 50 cases of healthy subjects were analyzed for proGRP. SCLC patients showed a significantly higher proGRP (1,484 pg/mL; range 168-3,777) levels compared to NSCLC patients (45 pg/mL; range 31.7-60.6), p<0.0001. In healthy subjects the median proGRP level was 36.1 (28.8-43.5) pg/mL, significantly lower than SCLC patients. ProGRP showed a higher specificity when compared to NSE, with a difference in proportion of 47.5% (95% confidence interval 32.5% to 62.5%, p<0.001). Serial measurements of proGRP in SCLC patients showed a decrease in responsive chemotherapy patients.

Value of clinical laboratory test for early prediction of mortality in patients with COVID-19: the BGM score

Background: COVID-19 causes high mortality and long hospitalization periods. The aim of this study was to search for new early prognostic strategies accessible to most health care centers. Methods: Laboratory results, demographic and clinical data from 500 patients with positive SARS-CoV-2 infection were included in our study. The data set was split into training and test set prior to generating different multivariate models considering the occurrence of death as the response variable. A final computational method called the BGM score was obtained by combining the previous models and is available as an interactive web application. Results: The logistic regression model comprising age, creatinine (CREA), D-dimer (DD), C-reactive protein (CRP), platelet count (PLT), and troponin I (TNI) showed a sensitivity of 47.3%, a specificity of 98.7%, a kappa of 0.56, and a balanced accuracy of 0.73. The CART classification tree yielded TNI, age, DD, and CRP as the most potent early predictors of mortality (sensitivity = 68.4%, specificity = 92.5%, kappa = 0.61, and balanced accuracy = 0.80). The artificial neural network including age, CREA, DD, CRP, PLT, and TNI yielded a sensitivity of 66.7%, a specificity of 92.3%, a kappa of 0.54, and a balanced accuracy of 0.79. Finally, the BGM score surpassed the prediction accuracy performance of the independent multivariate models, yielding a sensitivity of 73.7%, a specificity of 96.5%, a kappa of 0.74, and a balanced accuracy of 0.85. Conclusions: The BGM score may support clinicians in managing COVID-19 patients and providing focused interventions to those with an increased risk of mortality.

Development of an immunofluorescent AR-V7 circulating tumor cell assay – A blood-based test for men with metastatic prostate cancer

Introduction: Here we describe the development of a protein immunofluorescent assay for the detection of nuclear-localized androgen receptor variant 7 (AR-V7) protein within circulating tumor cells (CTCs) identified in patient blood samples. Used in the clinic, the test result serves as a validated biomarker of futility for patients with progressing metastatic castration-resistant prostate cancer (mCRPC) who are treated with androgen receptor targeted therapies (AATT) in whom nuclear-localized AR-V7 CTCs are identified and have received level 2A evidence in the 2019 National Cancer Center Network (NCCN) guidelines (v1.0). Methods: Assay development was completed on the Epic Sciences rare cell detection platform using control cell lines of known AR-V7 status and clinical testing of mCRPC patient samples obtained at the decision point in management. Results and conclusions: Using these samples, all assay parameters, scoring criteria, and clinical cutoffs for positivity were prospectively selected and locked. After assay lock, blinded clinical validation testing was initiated on multiple, independent, clinical cohorts as reported by Scher et al (JAMA Oncol. 2016;2:1441-1449; JAMA Oncol. 2018;4:1179-1186) and Armstrong et al (J Clin Oncol. 2019;37:1120-1129).

Lung ultrasound and biomarkers in primary care: Partners for a better management of patients with heart failure?

Introduction: The association of pulmonary congestion assessed by lung ultrasound (LUS) and biomarkers—other than N-terminal pro-brain natriuretic peptide (NT-proBNP)—is uncertain. Methods: We investigated the relationship between total B-line count by LUS and several biomarkers in outpatients with suspicion of heart failure (HF). Primary care patients with suspected new-onset nonacute HF were evaluated both with a 12-scan LUS protocol (8 anterolateral areas plus 4 lower posterior thoracic areas) and 11 inflammatory and cardiovascular biomarkers. A cardiologist blinded to LUS and biomarkers except NT-proBNP confirmed HF diagnosis. After log-transformation of biomarkers’ concentrations, unadjusted and adjusted correlations were performed. Results: A total of 170 patients were included (age 76 ± 10 years, 67.6% women). HF diagnosis was confirmed in 38 (22.4%) patients. After adjustment by age, sex, body mass index, and renal function, total B-line sum significantly correlated with NT-proBNP (R = 0.29, p < 0.001), growth/differentiation factor-15 (GDF-15; R = 0.23, p = 0.003), high-sensitive Troponin T (hsTnT; R = 0.36, p < 0.001), soluble interleukin-1 receptor-like 1 (sST2; R = 0.29, p < 0.001), cancer antigen 125 (CA-125; R = 0.17, p = 0.03), high-sensitivity C-reactive protein (hsCRP; R = 0.20, p = 0.009), and interleukin (IL)-6 (R = 0.23, p = 0.003). In contrast, IL-33 (R = −0.01, p = 0.93), IL-1β (R = −0.10, p = 0.20), soluble neprilysin (sNEP; R = 0.09, p = 0.24), tumor necrosis factor-alpha (TNF-α; R = 0.07, p = 0.39), and TNF-α receptor superfamily member 1A (TNFRSF1A; R = 0.14, p = 0.07) did not. Conclusions: Total B-line sum correlated significantly, although moderately, with congestion and several inflammation biomarkers. Unexpectedly, the highest correlation found was with hsTnT.

Exploring adipogenic and myogenic circulatory biomarkers of recurrent pressure injury risk for persons with spinal cord injury

Purpose: To investigate linkages between circulatory adipogenic and myogenic biomarkers, gluteal intramuscular adipose tissue (IMAT), and pressure injury (PrI) history following spinal cord injury (SCI). Methods: This is an observational repeated-measures study of 30 individuals with SCI. Whole blood was collected regularly over 2-3 years. Circulatory adipogenic and myogenic gene expression was determined. IMAT was defined as above/below 15% (IMATd) or percentage (IMAT%). PrI history was defined as recurrent PrI (RPrI) or PrI number (nPrI). Model development used R packages (version 3.5.1). Univariate analysis screened for discriminating genes for downstream multivariate and combined models of averaged and longitudinal data for binary (RPrI/IMATd) and finer scales (nPrI/IMAT%). Results: For adipogenesis, Krüppel-like factor 4 was the top RPrI predictor together with resistin and cyclin D1, and sirtuin 2 was the top IMAT predictor. For myogenesis, the top RPrI predictor was dysferlin 2B, and pyruvate dehydrogenase kinase-4 was the top IMAT predictor together with dystrophin. Conclusion: Circulatory adipogenic and myogenic biomarkers have statistically significant relationships with PrI history and IMAT for persons with SCI. Biomarkers of interest may act synergistically or additively. Variable importance rankings can reveal nonlinear correlations among the predictors. Biomarkers of interest may act synergistically or additively, thus multiple genes may need to be included for prediction with finer distinction.

Plasma vitronectin is reduced in patients with myasthenia gravis: Diagnostic and pathophysiological potential

Myasthenia gravis (MG) is an autoimmune disease leading to varying degrees of skeletal muscle weakness. It is caused by specific antibodies directed against definite components in the postsynaptic membrane at the neuromuscular junction (NMJ), such as the acetylcholine receptor (AChR) and the muscle-specific kinase (MUSK) receptor. In clinical practice, MG patients may be classified into three main subgroups based on the occurrence of serum autoantibodies directed against AChR or MUSK receptor or antibody-negative. As the MG subgroups differ in terms of clinical characteristics, disease pathogenesis, prognosis, and response to therapies, they could benefit from targeted treatment as well as the detection of other possible disease biomarkers. We performed proteomics on plasma fractions enriched in low-abundance proteins to identify potential biomarkers according to different autoimmune responses. By this approach, we evidenced a significant reduction of vitronectin in MG patients compared to healthy controls, irrespective of the autoantibodies NMJ target. The obtained results were validated by mono- and two-dimensional Western blotting analysis. Vitronectin is a multifunctional glycoprotein involved in the regulation of several pathophysiological processes, including complement-dependent immune response, coagulation, fibrinolysis, pericellular proteolysis, cell attachment, and spreading. The pathophysiological significance of the reduction of plasma vitronectin in MG patients has yet to be fully elucidated. It could be related either to a possible deposition of vitronectin at NMJ to counteract the complement-mediated muscle damage at this level or to a parallel variation of this glycoprotein in the muscle extracellular matrix with secondary induced alteration in clustering of AChRs at NMJ, as it occurs with variation in concentrations of agrin, another extracellular matrix component. The clinical value of measuring plasma vitronectin has yet to be defined. According to present findings, significantly lower plasma values of this glycoprotein might be indicative of an impaired complement-dependent immune response.