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On the nomenclature for V-region serological markers.

A recent article in Immunology Today raised significant questions concerning the appropriate use of the terms 'idiotype' and 'V-region isotype'. An alternative approach to the usage of these terms, which emphasizes their functional aspects, is presented here by Alfred Nisonoff.

Animals↗

Applications of population approaches in toxicology.

Many experimental or observational studies in toxicology are best analysed in a population framework. Recent examples include investigations of the extent and origin of intra-individual variability in toxicity studies, incorporation of genotypic information to address intra-individual variability, optimal design of experiments, and extension of toxicokinetic modelling to the analysis of biomarker studies. Bayesian statistics provide powerful numerical methods for fitting population models, particularly when complex mechanistic models are involved. Challenges and limitations to the use of population models, in terms of basic structure, computational burden, ease of implementation and data accessibility, are identified and discussed.

Animals↗

Prognostic usage of V(H) gene mutation status and its surrogate markers and the role of antigen selection in chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease with many patients surviving for decades with minimal or no treatment, whereas others succumb rapidly to their disease despite therapy. In recent years, new molecular prognostic factors have emerged in CLL that have significantly improved the subgrouping of the disease. One of the most important molecular predictors, the immunoglobulin V(H) gene mutation status, divides CLL into two prognostic groups, depending on the presence or absence of somatic hypermutation, where unmutated V(H) genes are associated with considerably worse prognosis than mutated V(H) genes. An exception to this appears to be CLL patients utilizing the V(H)3-21 gene as they have poor outcome irrespective of mutation status. Surrogate markers for the VH gene mutation status have been suggested, such as CD38 and ZAP-70 expression. However, the CD38 level was later shown to display poor correlation to the mutation status, although it may still serve as an independent prognostic factor. More promising is the expression levels of ZAP-70, which appears to be both a strong surrogate marker for V(H) gene mutation status, although discrepancies have been reported, as well as an independent prognostic marker. Immunoglobulin gene analysis has also indicated the possibility of antigen selection in CLL considering the significant bias in V(H) gene usage. Intriguingly, the V(H)3-21+ group and several other CLL subsets using certain V(H) genes was recently reported to display strikingly restricted immunoglobulin gene features, in both their heavy and light chain gene rearrangements, thus further high-lighting the possible role of antigen involvement in CLL development.

Antigens, Neoplasm↗

Coordinate expression of apoptosis-associated proteins in human breast cancer before and during chemotherapy.

PURPOSE: Induction of apoptosis is a key factor in the response of tumors to chemotherapy. Laboratory studies have established many of the factors that regulate and execute apoptosis, but the significance of these in human tumors is poorly understood. Therefore, the relationship between key components of this machinery was examined in primary human breast carcinomas before and 24 h after the initiation of chemotherapy. EXPERIMENTAL DESIGN: Apoptosis was measured using the terminal deoxynucleotidyl transferase-mediated nick end labeling assay, and proliferation was assessed using the anti-Ki67 antibody MIB-1. Monospecific polyclonal antibodies were used for immunohistochemical detection of Bcl-2, Bax, XIAP, activated (cleaved) caspase 3 and 6, and cleaved DNA Fragmentation Factor-40 (DFF40) using paraffin-embedded tissues. RESULTS: Before treatment, a significant correlation was found between apoptosis and proliferation (r = 0.64, P < 0.0001), between caspases 3 and 6 (r = 0.49, P = 0.004) and between cleaved DFF40 and active caspases 3 (r = 0.66, P < 0.0001) or 6 (r = 0.47, P = 0.006). Before treatment, expression of inhibitor of apoptosis protein, XIAP, also correlated positively with cleaved caspase 3 (r = 0.64, P < 0.0001), caspase 6 (r = 0.36, P = 0.04), and DFF40 (r = 0.61, P = 0.0001). At 24 h after chemotherapy, significant increases in apoptosis and decreases in proliferation were observed, with the degree of increase in apoptosis inversely associated with decrease in proliferation. Chemotherapy-induced increases in Bax were correlated with increases in cleaved DFF40 (r = 0.54, P = 0.0008), but no other variables showed significant change at 24 h after initiation of chemotherapy. CONCLUSION: The pretreatment biomarker relationships suggest parallel cleavage and activation of these executioner proteins in breast cancer and that XIAP may maintain cell survival in the face of caspase activation. The findings provide in vivo evidence in human breast cancer that chemotherapy induces an apoptotic program characterized by up-regulation of Bax and cleavage of caspase substrate DFF40.

Adult↗

Molecular markers for animal biotechnology: sea bass (Dicentrarchus labrax, L.) HMG-CoA reductase mRNA.

Modern technologies may improve fish production and quality and, at the same time, reduce environmental impact with benefits on the public perception of the industry. To be economically profitable, these modern technologies request an increase of rearing density that, however, could affect fish welfare. With the aim to search for molecular biomarkers to describe fish welfare, we have recently compared gene expression of sea bass farmed at different population densities by differential display obtaining six bands differentially expressed. In this paper, we have cloned the mRNA corresponding to one of those differentially expressed bands obtaining a 3860-bp sequence with an ORF of 2664 bp. Its virtual translation originated a 887-aa polypeptide that, by comparison with the other sequences available in the public data bases, resulted to be the 3-hydroxil-3-methyl-glutaryl coenzyme A reductase (HMGCR). In sea bass, as for the other species, the N- and C-terminus portions are the most conserved and are linked by an hydrophilic region that appears to be quite variable. Due to its role in the synthesis of cholesterol, HMGCR mRNA could be a good biomarker for detecting fish welfare. For this reason, we also followed, by real-time PCR, its expression after crowding stress comparing it with mRNA levels of HSP 70 and 90: HMGCR mRNA resulted highly expressed in the fishes farmed at 100 kg/m(3).

Animals↗

Mass spectrometric identification of human prostate cancer-derived proteins in serum of xenograft-bearing mice.

Lack of sensitivity and specificity of current tumor markers has intensified research efforts to find new biomarkers. The identification of potential tumor markers in human body fluids is hampered by large variability and complexity of both control and patient samples, laborious biochemical analyses, and the fact that the identified proteins are unlikely produced by the diseased cells but are due to secondary body defense mechanisms. In a new approach presented here, we eliminate these problems by performing proteomic analysis in a prostate cancer xenograft model in which human prostate cancer cells form a tumor in an immune-incompetent nude mouse. Using this concept, proteins present in mouse serum that can be identified as human will, by definition, originate from the human prostate cancer xenograft and might have potential diagnostic and prognostic value. Using one-dimensional gel electrophoresis, liquid chromatography, and mass spectrometry, we identified tumor-derived human nm23/nucleoside-diphosphate kinase (NME) in the serum of a nude mouse bearing the androgen-independent human prostate cancer xenograft PC339. NME is known to be involved in the metastatic potential of several tumor cells, including prostate cancer cells. Furthermore we identified six human enzymes involved in glycolysis (fructose-bisphosphate aldolase A, triose-phosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase, alpha enolase, and lactate dehydrogenases A and B) in the serum of the tumor-bearing mice. The presence of human NME and glyceraldehyde-3-phosphate dehydrogenase in the serum of PC339-bearing mice was confirmed by Western blotting. Although the putative usefulness of these proteins in predicting prognosis of prostate cancer remains to be determined, the present data illustrate that our approach is a promising tool for the focused discovery of new prostate cancer biomarkers.

Amino Acid Sequence↗

Serum neopterin, beta2-microglobulin, soluble interleukin-2 receptors, and immunoglobulin levels in healthy adolescents.

Serum biomarkers, such as neopterin, beta2-microglobulin (B2M), and soluble interleukin-2 receptors (sIL-2R), are elevated in viral infections, including HIV-1 infection, and in inflammatory conditions, autoimmune disease, and malignancies. For many of these conditions, serum levels correlate with disease activity. Application of these biomarkers in adolescents is limited by a lack of information on the range and determinants of variability (age, sex, race) for serum levels of these important molecules in this age group. To address this question, we analyzed serum samples from a well-characterized heterogeneous population of 111 healthy adolescents. White children had significantly higher serum levels of sIL-2R and IgM and lower levels of IgG (P </= 0.001) than black children. Boys had higher sIL-2R and B2M levels (P < 0.005) and lower IgM levels (P < 0.05) than girls. No significant age effect on B2M or neopterin level was observed over the age range of 12-19 years included in this analysis. However, stratification by race showed that serum sIL-2R level was significantly associated with age among whites, but not among blacks. Values of these biomarkers in this population are compared with age-stratified values in the previously analyzed 20- to 69-year-old population from whose households the adolescent subjects were recruited.

Adolescent↗

Responses of Hexaplex (Murex) trunculus to selected pollutants.

Cadmium, copper and zinc concentrations (in whole soft body and in tissues) were measured in Hexaplex trunculus collected from the Bizerta lagoon in Tunisia. An evaluation of the biological effects of the most toxic metals (cadmium and copper) and of two organics (carbofuran and lindane), present in the sediments of the Bizerta lagoon, was attempted by measuring biomarkers (acetylcholinesterase: AChE, catalase: CAT and glutathione S-transferase: GST activities) in animals experimentally exposed for 48 or 72 h. The concentration ranges as follows: Zn>Cu>Cd. Copper concentrations are highly variable (8.0 to 235 microg g(-1) d.w.) whereas cadmium (range 1.35-4.86 microg g(-1)) and zinc (range 360-1320 microg g(-1)) concentrations are less variable. The digestive gland and the gill take up more metal than the muscle. AChE activity in H. trunculus is decreased by exposure to carbofuran or the mixture carbofuran and cadmium, in the digestive gland and muscle and by copper and by lindane in the digestive gland. AChE is generally inhibited by carbamates but some other compounds may also decrease this activity as observed in this paper. An increase in CAT activity associated with a decrease in GST activity is noted in the muscle of H. trunculus exposed to cadmium, to carbofuran and to the mixture of cadmium and carbofuran, and in the digestive gland of animals exposed to lindane. These pollutants may act upon glutathione and decrease the GST activity that cannot detoxify them and CAT activity has a protective effect. On the contrary, copper increases CAT and GST activities in the digestive gland of exposed gastropods; these enzymes seem to cooperate and play together their rôle of anti-oxidant enzymes. If H. trunculus is not a bioindicator species for metal concentrations, due to a high variability in metal concentrations, nevertheless the biochemical responses to pollutants (cadmium, copper, carbofuran and lindane) represented by AChE, CAT and GST activities may act as biomarkers of exposure in this species.

Acetylcholinesterase↗

CS Ratio is an immune-related prognostic biomarker for cervical cancer.

BACKGROUND: The tumor microenvironment (TME) plays a crucial role in cancer progression but its complex structure significant variability among patients present considerable challenges for research. Recent studies have demonstrated that macrophage polarization states defined by the expression levels of CXCL9 SPP1 (CS Ratio) are more prognostically relevant than traditional M1/M2 markers. The CS polarization state reflects a highly coordinated network of pro-tumor anti-tumor variables offering a simplified yet effective immune response indicator for the complex TME. The CS Ratio has been shown to correlate with the abundance of anti-tumor immune cells the gene expression programs of tumor-infiltrating cells responses to immunotherapy. Cervical cancer, one of the most common gynecological malignancies, still faces limited therapeutic options. CXCL9, a member of the CXC chemokine family, plays a critical role in immune regulation, inflammation, tumor growth, angiogenesis, and metastasis. Similarly, SPP1, a cytokine, influences immune-related pathways by regulating molecules such as interferon-&#x3b3; and interleukin-12. However, no studies have systematically investigated the role of the CS Ratio in cervical cancer or its relationship with immunotherapy characteristics. Research in this area could provide critical insights into the role and clinical potential of the CS Ratio in cervical cancer and related tumors. METHODS: The expression ratio of CXCL9 to SPP1 was analyzed in cervical cancer patients using data from the Gene Expression Omnibus (GEO) database, which revealed significant differences. Data for cervical cancer patients were obtained from The Cancer Genome Atlas (TCGA) database. The optimal cutoff value for the CS Ratio was determined using the maxstat package in R, and Kaplan-Meier (KM) survival curves were constructed. Patients were categorized into High and Low groups based on the median CS Ratio. Immune scores were analyzed, and immune cell infiltration was assessed using CIBERSORT. Differences in the CS Ratio were evaluated across patients with varying pathological T stages and FIGO stages. Additionally, receiver operating characteristic (ROC) analysis was performed using the pROC package in R to calculate the area under the curve (AUC). Univariate and multivariate Cox regression analyses were performed to evaluate the potential of the CS Ratio as an independent prognostic factor in cervical cancer. A Cox regression-based nomogram integrating four key features was subsequently developed for the TCGA-CESC cohort. Nomogram performance was assessed using calibration curves and ROC analysis. RESULTS: The CS Ratio was significantly lower in cervical cancer patients compared to normal controls (P < 0.05). KM survival curves indicated that patients in the CS High group exhibited better prognoses. Immune score analysis revealed significantly higher immune scores (P < 0.05) and lower tumor purity (P < 0.05)in the CS High group compared to the Low group. CIBERSORT analysis revealed significantly higher proportions of CD8+ T cells (P < 0.05) and M1 macrophages (P < 0.05), and a significantly lower proportion of M2 macrophages (P < 0.05), in the CS High group compared to the Low group. The CS Ratio significantly decreased with advancing FIGO stage (P < 0.05). Both univariate (P < 0.05) and multivariate Cox regression analyses (P < 0.05) confirmed the CS Ratio as an independent prognostic factor. ROC analysis demonstrated that the CS Ratio had higher AUC values for predicting 1-year (AUC=0.69), 3-year (AUC=0.66), and 5-year OS (AUC=0.68) than CXCL9 or SPP1 alone. The Cox regression-based nomogram integrating four key features demonstrated predictive capability for 1-, 3-, and 5-year OS in CESC patients (Concordance Index = 0.751; 95% CI: 0.678-0.824; p = 1.50&#xcd;10-11). Significant survival differences were observed between the high-risk and low-risk groups based on the nomogram score. ROC analysis yielded high AUC values for survival prediction: 0.85 (95% CI: 0.94-0.75) at 1-year, 0.74 (95% CI:0.84-0.64) at 3-year, and 0.72 (95% CI:0.84-0.61) at 5-year. CONCLUSION: The CS Ratio may serve as a more effective prognostic biomarker for cervical cancer patients.

CXCL9↗

The determinants of pulmonary diffusing capacity in a national sample of U.S. adults.

Racial and gender differences in single-breath pulmonary diffusing capacity for carbon monoxide (DLCO) have previously received little attention. Between 1971 and 1975, the first National Health and Nutrition Examination Survey determined DLCO for 4,439 adults ages 25 to 74 residing in the United States, including 2,345 women and 438 blacks. The large sample permitted an evaluation of interactions and nonlinear relationships with DLCO, and its association with biomarkers of inflammation. In a model with separate race, sex, and smoking status intercepts, positive associations with FVC, height, weight, hemoglobin concentration, and negative associations with age and neutrophil count explained 59% of the variation in DLCO. In women, the decline in DLCO with age was much less than in men, but after age 47 the decline with age approached that seen in men. Blacks had lower DLCO levels (-1.96 ml/min/mm Hg, 95% confidence interval [CI] -0.77 to -3.14) with or without adjustment for FVC, but the changes in DLCO with age and height were similar in both races. Former smokers had lower DLCO (-1.13 ml/min/mm Hg, 95% CI -1.57 to -0.69), but this reduction was fully explained by the number of pack-years smoked. In current smokers, cigarettes per day and pack-years were predictive of DLCO even after control for FVC and controlling for these variables fully explained the difference in DLCO between never and current smokers. Peripheral neutrophil count, a biomarker of inflammation, was associated with reduced DLCO. Thus, substantial sex and race differences exist for DLCO within the general United States population.

Adult↗

Intercorrelations and sources of variability in three mutagenicity assays: a population-based study.

The purpose of this study was to evaluate the intercorrelation between three genetic assays in 112 subjects. The group was pooled from two originally separate but homogeneous subgroups of 56 persons each. Procedures included assays for hprt mutant frequencies, micronuclei in human lymphocytes, and mutations at the glycophorin A (gpa) loci. We found no statistically significant or biologically important intercorrelations among the three biomarkers. We did, however, observe significant correlations between log(e) hprt mutant frequency and cloning efficiency (inverse correlation for these 2 variables), age and log(e) hprt mutant frequency, an inverse relationship between cloning efficiency and age, and an important differential sex effect favoring a greater micronuclei frequency in females than males. No significant correlations between the covariates of interest and glycophorin A variant frequencies NN or NO were observed. Using multivariable linear regression, age was found to account for the majority of the variability in hprt mutant frequency (greater than sex and/or smoking); for micronuclei data, only sex contributed a statistically significant and biologically important proportion to the total variation. We conclude that despite observing no significant intercorrelations between the three assays performed simultaneously from the same individuals in a large population database, a significant correlation between age and hprt mutant frequency and an inverse association between cloning efficiency and hprt do exist; furthermore, we verified the strong differential sex-specific effect on micronucleus frequencies.

Age Factors↗

Organochlorine-associated immunosuppression in prefledgling Caspian terns and herring gulls from the Great Lakes: an ecoepidemiological study.

The objectives of study were to determine whether contaminant-associated immunosuppression occurs in prefledgling herring gulls and Caspian terns from the Great Lakes and to evaluate immunological biomarkers for monitoring health effects in wild birds. During 1992 to 1994, immunological responses and related variables were measured in prefledgling chicks at colonies distributed across a broad gradient of organochlorine contamination (primarily polychlorinated biphenyls), which was measured in eggs. The phytohemagglutinin skin test was used to assess T-lymphocyte function. In both species, there was a strong exposure-response relationship between organochlorines and suppressed T-cell-mediated immunity. Suppression was most severe (30-45%) in colonies in Lake Ontario (1992) and Saginaw Bay (1992-1994) for both species and in western Lake Erie (1992) for herring gulls. Both species exhibited biologically significant differences among sites in anti-sheep red blood cells antibody titers, but consistent exposure-response relationships with organochlorines were not observed. In Caspian terns and, to a lesser degree, in herring gulls, there was an exposure-response relationship between organochlorines and reduced plasma retinol (vitamin A). In 1992, altered White blood cell numbers were associated with elevated organochlorine concentrations in Caspian terns but not herring gulls. The immunological and hematological biomarkers used in this study revealed contaminant-associated health effects in wild birds. An epidemiological analysis strongly supported the hypothesis that suppression of T-cell-mediated immunity was associated with high perinatal exposure to persistent organochlorine contaminants.

Animals↗

Hsp70 instability and induction by a pesticide in Folsomia candida.

The heat shock protein Hsp70 has been shown to be a promising biomarker in aquatic and terrestrial organisms. However, its analysis in the soil insect Folsomia candida (Collembola) poses many problems as the protein is particularly unstable in this species. Western blotting has shown that the principal degradation fragment has a size of 48 kDa. We have developed a Western blot method that avoids the degradation of Hsp70 and was successful in detecting the protein in the springtail F. candida after a heat shock (12, 18 and 24 h at 32 degrees C). In the second part of the study the organisms were exposed to artificial compressed soil contaminated with the dinitrophenol dinoseb (10, 15 and 20 micrograms g-1 dry weight [DW]). Hsp70 was analysed in pooled samples (40 to 150 collembola according to age) after 1, 2, 3, 4, 5, 6, 7, 11 and 14 days. The only significant induction was observed after 5 days at 20 micrograms g-1 DW of dinoseb. The induction patterns over time were dissimilar for the different concentrations and a relatively high variability between the replicates was observed. Our results show that we must be cautious when interpreting biomarker results, especially those for Hsp70.

2,4-Dinitrophenol↗

Detection of CYP1A1 mRNA levels and CYP1A1 Msp polymorphisms as possible biomarkers of exposure and susceptibility in smokers and non-smokers.

It is important to determine sensitive biomarkers for both exposure and susceptibility since differences in individual susceptibility to potentially hazardous chemicals may represent a major variable in the assessment of risk. Induction of cytochrome P450IA1 (CYP1A1) may be a measure of environmental exposure to aromatic hydrocarbons in cigarette smoke. This study investigated the use of reverse transcriptase-polymerase chain reaction (RT-PCR) to detect constitutive levels of CYP1A1 mRNA in the peripheral lymphocytes of a population of smokers and non-smokers as a potential marker of exposure. In addition, the presence of an Msp 1 restriction fragment length polymorphism was analyzed using a simple PCR method as a biomarker for susceptibility. DNA and RNA were isolated from the peripheral lymphocytes of 20 smokers and a matched group of non-smokers. RT-PCR was used to detect the endogenous levels of CYP1A1 mRNA with glyceraldehyde-3-phosphate dehydrogenase as a control gene. The 3'-region of CYP1A1 gene was amplified by PCR and underwent restriction digestion with Msp 1 to detect the polymorphism. The endogenous CYP1A1 expression as detected by RT-PCR was very low and variable and there was a slight but not significant increase in the smokers by comparison with non-smokers. Thirty-two of the volunteers were homozygous for the normal allele while 8 were heterozygous for the uncommon Msp 1 allele and none was homozygous for the polymorphism. The allele frequency (0.1) was found to be in Hardy-Weinberg equilibrium. Since only a slight increase was seen in endogenous CYP1A1 mRNA levels in the peripheral lymphocytes of smokers by comparison with non-smokers, the effect may have been diluted by variation in sensitivity to dose, a threshold of exposure effect, or the return of mRNA to baseline between exposures. The wide variation in mRNA levels may reflect the influence and exposure of different environmental factors. The sensitivity of PCR-based methods suggests that they may have an important role in future overall biomonitoring of exposure and susceptibility to environmental chemicals.

Biomarkers↗

Effect of different environmental variables on the synthesis of Hsp70 in Raphidocelis subcapitata.

Heat-shock proteins (Hsp) or stress proteins are strong candidates for biomarkers of environmental pollution since they are activated very early in the cascade of cellular events that follow toxic exposure and at concentrations below the lethal dose. Included in a test battery comprised of different bioassays, Hsp induction could provide a general purpose tier I indicator of pollution. Still, little is known on the induction of Hsp under different environmental conditions. In the present study we have made use of an Enzyme Linked Immunosorbent Assay (ELISA) to detect the synthesis of Hsp70 in Raphidocelis subcapitata in response to changes in pH, temperature, humic acids, nitrates and phosphates. The results show that algae respond to these changes in the environment by a transient increase in Hsp70 levels, the extend of which is dependent on the actual parameter under investigation. Out of these five parameters studied, only temperature and possibly pH were able to induce acquired tolerance, i.e. algae grown at a pH or at a temperature different from control conditions were shown to have acquired resistance to a subsequent challenge with Zn (10(-5) M). Adjustment of the pH and temperature in two physico-chemically different natural surface waters was demonstrated to be sufficient to obtain similar induction patterns of Hsp70 upon exposure to zinc. These results qualify Hsp70 as a good biomonitor for environmental pollution provided essential environmental parameters such as pH and temperature are kept constant.

Environmental Monitoring↗

Correlation between glutathione peroxidase activity and anthropometrical parameters in adolescents with Down syndrome.

Since we have recently found that regular exercise increased erythrocyte antioxidant enzyme activities such as glutathione peroxidase (GPX) in adolescents with Down syndrome, these programs may be recommended. This study was designed to assess the role of anthropometrical parameters as easy, economic and non-invasive biomarkers of GPX. Thirty-one adolescents with Down syndrome performed a 12-week training program. Three days after its ending, GPX activity and anthropometrical parameters were assessed. Pearson's correlation coefficient showed negative but significant association (r=0.49, p=0.022) between GPX activity and waist circumference (WC). Body mass index (BMI) and waist-to-hip ratio (WHR) were not significant. We may conclude that anthropometrical parameters such as WC are easy to perform but not strongly associated to GPX activity. Further studies concerning other variables are needed.

Adolescent↗

Correlations between estimated and true dietary intakes.

PURPOSE: It is unclear how well questionnaire or so-called reference methods of dietary assessment correlate with true dietary intake. We develop a method to estimate such correlations. METHODS: An error model is described that uses data from a food frequency questionnaire (Q), a reference method (R), and a biological marker (M). The model does not assume the classical error model for either R or M, or that the correlation between errors in the questionnaire and reference data is zero. Credible intervals can be placed about correlations between R, Q, M and true dietary data (T), also about the correlations between errors in reference and questionnaire data. RESULTS: Application of this model to a validation data set mainly found correlations in the range 0.4 to 0.8, and that correlations (R,T) generally exceeded correlations (Q,T), providing evidence that R is more valid than Q. Estimated correlations between errors in R and Q were often far from zero suggesting that regression calibration to imperfect reference data is problematic unless these error correlations can be estimated. CONCLUSION: A biological marker in addition to dietary data, allows calculation of correlations between estimated and true dietary intakes under reasonable assumptions about errors. However, sensitivity analyses are necessary on one variable.

Adult↗

Artificial intelligence-based tumour infiltrating lymphocyte quantification in patients with triple-negative breast cancer: an independent validation study.

BACKGROUND: Tumour-infiltrating lymphocytes (TILs) are a robust prognostic marker in patients with triple-negative breast cancer. Artificial intelligence (AI)-derived computational tools assessing TILs could improve efficiency, but require independent validation against clinical outcomes. We aimed to compare the prognostic performance of AI-derived TIL scores with pathologist-scored TILs in a large, prospectively collected dataset pooled from randomised controlled trials. METHODS: CATALINA was an independent, external validation study using prospectively collected long-term clinical outcome data pooled from seven randomised clinical trials conducted at multiple sites. We independently evaluated two previously validated AI pipelines that generate five computationally assessed tumour-infiltrating lymphocyte (cTIL) scores by masked, independent deployment of locked models. cTIL scores were correlated with the mean of the pathologist-scored stromal TILs (sTILs) in 220 digitised haematoxylin and eosin whole slide images in a cohort of patients with early-stage triple-negative or HER-2 positive breast cancer, previously scored by trained pathologists in a TIL-reproducibility study. Prognostic performance was assessed in a separate cohort of patients with early triple-negative breast cancer pooled from seven prospective, randomised adjuvant trials. Multivariable Cox regression models adjusted for clinicopathological factors and study heterogeneity assessed associations of cTIL score and sTIL score with invasive disease-free survival, distant disease-free survival, and overall survival. 5-year discrimination was estimated using time-dependent area under the receiver operating characteristic curve (AUC). FINDINGS: Individual data were collated from 1759 patients, of whom 1356 had complete clinicopathological data, pathologist sTIL scores, and cTIL scores available. Modest correlation (r 0&#xb7;375-0&#xb7;473) was observed between cTIL scores and the mean pathologist sTIL score. Both sTIL and cTIL were independently associated with 5-year invasive disease-free survival, distant disease-free survival, and overall survival after adjustment for clinicopathological factors (hazard ratio for invasive disease-free survival was 0&#xb7;73 [95% CI 0&#xb7;66-0&#xb7;82]; q<0&#xb7;0001, distant disease-free survival was 0&#xb7;70 [0&#xb7;61-0&#xb7;79]; q<0&#xb7;0001, and overall survival was 0&#xb7;72 [0&#xb7;63-0&#xb7;82]; q<0&#xb7;0001 for sTIL scores and 0&#xb7;80 [0&#xb7;73-0&#xb7;89]; q<0&#xb7;0001, 0&#xb7;77 [0&#xb7;69-0&#xb7;86]; q<0&#xb7;0001, and 0&#xb7;79 [0&#xb7;70-0&#xb7;88]; q=0&#xb7;0002, respectively, for percentage_lymphocyte scores). In models adjusted for clinicopathological variables and sTIL score, cTIL score did not maintain a statistically significant prognostic association. Both sTIL and cTIL scores improved the 5-year AUC over clinicopathological variables alone, while cTIL score did not significantly further improve AUC when combined with clinicopathological variables and sTIL score. INTERPRETATION: Two cTIL models deployed entirely without retraining or modification provided statistically significant prognostic information and improved risk discrimination compared with clinicopathological variables alone in this large, platform-based, independent validation study. Although cTIL score did not incrementally improve prognostication compared with models combining clinicopathological variables with sTIL score, these findings support the application of cTILs as a reproducible prognostic biomarker, particularly in settings where routine or widespread pathologist assessment is unavailable. FUNDING: Breast Cancer Research Foundation (USA).

Humans↗