Journal of Circulating Biomarkers

A novel liquid biopsy assay for detection of ERBB2 (HER2) amplification in circulating tumor cells (CTCs)

Giuseppe Di Caro — 2024-10-04

Purpose: Circulating tumor cell (CTC)-based ERBB2 (HER2) assay is a laboratory test developed by Epic Sciences using single-cell genomics to detect ERBB2 (HER2) amplification in CTCs found in the peripheral blood of metastatic breast cancer (MBC) patients.

Patients and methods: Peripheral blood was collected in Streck tubes and centrifugation was used to remove plasma and red blood cells. The remaining nucleated cells were deposited on glass slides, immunofluorescent-stained with proprietary antibodies, scanned by a high-definition digital scanner, and analyzed by a proprietary algorithm. In addition, single-cell genomics was performed on selected CTC. Analytical validation was performed using white blood cells from healthy donors and breast cancer cell lines with known levels of ERBB2 amplification. Clinical concordance was assessed on MBC patients whose blood was tested by the CTC ERBB2 (HER2) assay and those results are compared to results of matched metastatic tissue biopsy (immunohistochemistry [IHC] 3+ or IHC2+/in situ hybridization [ISH+]).

Results: Epic’s ERBB2 (HER2) assay detected 2-fold ERBB2 amplification with 85% sensitivity and 94% specificity. In the clinical concordance study, among the 50% of the cases that had ERBB2 status results from CTCs found to be chromosomally-unstable, the CTC ERBB2 (HER2) assay showed sensitivity of 69% and specificity of 78% when compared to HER2 status by metastatic tissue biopsy.

Conclusions: The CTC ERBB2 (HER2) assay can consistently detect ERBB2 status in MBC cell lines and in the population of patients with MBC with detectable chromosomally unstable CTCs for whom tissue biopsy is not available or is infeasible.

Comparative evaluation of serum and gingival crevicular fluid levels of interleukin 21 in periodontally diseased and healthy patients

Shabnam Gulfishan — 2024-09-20

Background: Periodontitis is an inflammatory reaction to subgingival pathogenic microorganisms that causes gradual deterioration of the gingiva, periodontal ligament, and alveolar bone. Interleukin (IL)-21 is the most recently found member of type I cytokine family that is upregulated during inflammation. The current study aims to investigate the biological plausibility of IL-21 as a biomarker for chronic periodontitis.

Materials and methods: This cross-sectional clinico-biochemical investigation included 15 systemically healthy, 15 periodontally healthy, 15 chronic gingivitis, and 15 chronic periodontitis subjects aged 25 to 60 years. Following subject enrollment, gingival crevicular fluid (GCF) and blood samples were then taken from each subject. The concentration of IL-21 in all samples was determined using enzyme-linked immunosorbent assay (ELISA) kit. The data was examined using the Kruskal-Wallis test and the Spearman correlation test.

Results: Serum IL-21 levels in chronic periodontitis patients were substantially greater than in periodontally healthy individuals. GCF IL-21 levels were substantially greater in gingivitis and chronic periodontitis patients compared to periodontally healthy individuals. In terms of clinical indicators, serum IL-21 levels correlated significantly with bleeding index (BI) in the chronic periodontitis group. In chronic periodontitis group, disease severity as evaluated by probing pocket depth (PPD) and clinical attachment loss (CAL) did not correlate with serum or GCF IL-21 levels.

Conclusion: According to the current study’s findings, periodontally involved patients had higher IL-21 levels than periodontally healthy patients, suggesting it can be used as biomarker. Further studies with larger sample size can shed more light on the clinical advantage of IL-21 as a possible marker for disease activity and progression.

Relation between interleukin-13 and annexin-V levels and carotid intima-media thickness in nephrotic syndrome

Asmaa Elsehmawy — 2024-06-18

Background and aim: The aim of the current study is to assess the relation between carotid intima-media thickness (CIMT) measurements, renal Doppler resistive index (RI) and serum levels of interleukin-13 (IL-13) and annexin-V (An-V) in children with idiopathic nephrotic syndrome (INS).

Materials and methods: The present case-control study was conducted on 60 children with INS and 60 age- and sex-matched healthy children. All participants were subjected to evaluation of serum levels of IL-13 and An-V and ultrasound Doppler measurement of CIMT and renal RI.

Results: Patients expressed significantly higher An-V (5.9 ± 2.6 vs. 2.1 ± 0.8 ng/mL, p<0.001) and IL-13 (19.2 ± 7.6 vs. 3.4 ± 1.4 ng/L) levels when compared with healthy counterparts. Moreover, it was shown that patients had significantly higher CIMT (0.49 ± 0.06 vs. 0.35 ± 0.03, p<0.001) as compared to controls. No significant differences were noted between the studied groups regarding right or left RIs. Correlation analysis identified significant direct correlation between serum An-V levels and albumin/creatinine ratio (ACR) (r = 0.55), cholesterol (r = 0.48), triglycerides (r = 0.36), IL-13 (r = 0.92) and CIMT (r = 0.53). Similar correlations could be found between serum IL-13 levels and CIMT measurements and the corresponding parameters.

Conclusions: The present study suggests an association between higher early atherosclerosis expressed as elevated CIMT measurements in children with INS and elevated serum levels of An-V and IL-13.

Detection of PSMA expression on circulating tumor cells by blood-based liquid biopsy in prostate cancer

Santosh Gupta — 2024-02-21

Background: For patients with mCRPC, PSMA-targeted radioligand treatment has significantly improved the clinical outcome. A blood-based liquid biopsy assay for recognizing PSMA protein expression on circulating tumor cells may be beneficial for better informing therapeutic decision-making and identifying the patients most likely to benefit from PSMA-targeted radioligand therapy.

Methods: Using high-throughput imaging and digital AI pathology algorithms, a four-color immunofluorescence assay has been developed to find PSMA protein expression on CTCs on a glass slide. Cell line cells (LNCaP/PC3s/22Rv1) spiked into healthy donor blood were used to study the precision, specificity, sensitivity, limit of detection, and overall accuracy of the assay. Clinical validation and low-pass whole-genome sequencing were performed in PSMA-PET-positive patients with high-risk mCRPC (N = 24) utilizing 3 mL of blood.

Results: The PSMA CTC IF assay achieved analytical specificity, sensitivity, and overall accuracy above 99% with high precision. In the clinical validation, 76% (16/21) of the cases were PSMA positive with CTC heterogeneity, and 88% (21/24) of the patients contained at least one conventional CTC per milliliter of blood. Thirty-six low-pass-sequenced CTCs from 11 individuals with mCRPC frequently exhibited copy number increases in AR and MYC and losses in RB1, PTEN, TP53, and BRCA2 locus.

Conclusions: The analytical validation utilizing Epic Sciences’ liquid biopsy CTC platform demonstrated the potential to detect PSMA protein expression in CTCs from patients with mCRPC. This assay is positioned as an effective research tool to evaluate PSMA expression, heterogeneity, and therapeutic response in many ongoing clinical studies to target tumors that express PSMA.

Comments to: Relation between interleukin-13 and annexin-V levels and carotid intima-media thickness in nephrotic syndrome

Christian Saleh — 2024-09-25

Not applicable

Author’s reply to: Comments to: Relation between interleukin-13 and annexin-V levels and carotid intima-media thickness in nephrotic syndrome

Asmaa Elsehmawy — 2024-09-25

Not applicable