Tuesday 23 September 2025

Predicative Biomarker Testing: Current, Evolving & Emerging Applications

David Allen, Cellular Pathology Manager, HSL Advanced Diagnostics

10:30 – 11:00

The presentation will:

• Outline the importance of predictive biomarkers in cancer care
• Review established predictive biomarkers in various cancer types
• Explain challenges and limitations, especially regarding change of use or testing modifications
• Explore emerging biomarkers and changing applications of established markers in clinical practice

Posters

In vitro evaluation of the effect of anticoagulation on thrombin generation in haemophilia A (Poster 7)

Arti Kirit, Specialist Biomedical Scientist, Haemophilia, Royal Free Hospital

Introduction: Advancements in haemophilia treatment have extended the life expectancy of patients with haemophilia A (HA). Consequently, modern care for persons with haemophilia requires consideration of conditions associated with ageing, including thrombotic conditions that often require treatment with anticoagulation. There is limited data from clinical trials regarding the effect of anticoagulant agents in HA patients treated with factor (F)VIII concentrates or other novel therapies (e.g. FVIII bispecific antibody).

Aim: To evaluate the in vitro effect on thrombin generation (TGT) of different anticoagulants in FVIII deficient plasma in the presence of FVIII concentrate or a FVIII bispecific antibody.

Method: FVIII concentrate (Elocta®) at a range of concentrations (0 to 100 IU/dL) or FVIII bispecific antibody (Hemlibra®) at 10 and 50 µg/mL were spiked into FVIII deficient plasma. Different anticoagulants (fondaparinux, apixaban, rivaroxaban, and tinzaparin) were then spiked into these samples at two levels (trough and peak). Each sample was evaluated using TGT, triggered with recombinant(r) human tissue factor (TF) at 5pM and 10pM (tinzaparin and fondaparinux), 5pM (apixaban and rivaroxaban) or rTF at 1pM and 5pM for the FVIII bispecific antibody samples.

Results: The effect of apixaban on Elocta® spiked samples showed: 1. The endogenous thrombin potential (ETP) was higher in the 100IU spiked sample and decreased gradually till the 10IU spiked sample at peak and trough levels (except 10IU trough where there was an 100% reduction). 2. Peak height (PH) was highest in the 100IU and decreased gradually till 10IU at peak and trough levels. 3. Time to peak (tTP) was lowest in the 100IU sample and increased gradually with reduction in the spiked Elocta® levels till 30IU at both peak and trough level. The effect of rivaroxaban on the Elocta® samples: 1. ETP at peak anticoagulant level showed a 100% reduction at 100IU, 30IU and 10U and trough level ETP was highest in the 100IU and decreased gradually till 30IU spiked sample. 2. PH is highest on 100IU and decreases gradually till 30IU at peak and trough level. 3. tTP it is the lowest on 100IU and increases gradually with reduction of Elocta® till 30IU. For the Hemlibra® spiked samples with apixaban and rivaroxaban, both 1pM and 5pM triggers at peak and trough anticoagulant levels, TG was present.  For spiked Elocta® and Hemlibra® samples containing fondaparinux using different TF triggers, no conclusion on the best TF trigger or TGT conditions could be made. The effect of tinzaparin on the Elocta® and Hemlibra® spiked samples suppressed TG at peak and trough levels using both trigger concentrations.  

Conclusion: TGT was discriminatory between different spiked FVIII levels and FVIII bispecific antibody samples and trough and peak levels for apixaban and rivaroxaban with either TF trigger. For fondaparinux and tinzaparin spiked samples, no optimum TGT conditions could be identified.

The role of CYP2C19 genetic testing in Clopidogrel therapy (Poster No.10)

Sabina McCann, Deputy Head of Department, UCLH RRL Haemostasis

Clopidogrel is a P2Y12 inhibitor drug that is administered to ischaemic stroke and transient ischemic attack patients in an inactive form to prevent further strokes. Clopidogrel is converted to its active form via cytochrome P450 enzymes (2C19). The effectiveness of clopidogrel is thought to be dependent on the individual’s CYP2C19 gene status. Currently, the efficacy of clopidogrel and investigation of clopidogrel resistance is assessed through platelet function testing.

Platelet aggregation testing with high dose ADP using a PAP8E profiler and under shear stress using a PFA-200 analyser. Pre-analytical checks for platelet count, platelet clumps and immature platelet fraction (IPF) processed on Sysmex XN-20 and von Willebrand (VWF) antigen analysed on Sysmex CS2500 platform.

The National Institute for Health and Care Excellence guidelines for the use of clopidogrel recommend CYP2C19 genotype testing prior to administration of the drug. This study has compared the CYP2C19 Genedrive point of care testing to laboratory-based genetic testing and evaluated the predicted CYP2C19 phenotype results alongside established platelet function tests for clopidogrel efficacy. The 1-hour turnaround time of the Genedrive CYP2C19 test is advantageous as timely administration of clopidogrel is critical to a positive outcome for the patient. The correlation of CYP2C19 genotyping results between Genedrive and traditional laboratory-based genetics was excellent at 97%. In the intermediate metabolizer predicted phenotype group, 41.6% of subjects had complete inhibition of the P2Y12 receptor confirmed through platelet function assessment. However, current clopidogrel therapy guidelines suggest that for intermediate metabolizers, clopidogrel should be avoided due to the loss of function of one allele. Review of the platelet function tests alongside predicted CYP2C19 has indicated that other factors apart from CYP2C19 genotype effect clopidogrel efficacy.

Caplacizumab Resistance in immune thrombotic thrombocytopenia purpura (TTP)(Poster 11)

Sabina McCann, Deputy Head of Department, UCLH RRL Haemostasis

Caplacizumab has been shown to reduce the time to platelet normalisation, reduce thrombotic thrombocytopenic purpura (TTP) exacerbations and prevent refractory acute disease. We report the first case of caplacizumab ‘resistance’ in a patient with iTTP with a failure of suppression of in vivo von Willebrand factor (VWF) activity by the drug and persistence of VWF-mediated platelet capture in a flow-based in vitro assay. VWF activity results confirmed using Sysmex CS2100 and CS2500 via ristocetin co-factor and VWF:glycoprotein IbM gain of function assay respectively. Genetic analysis revealed a missense variant P1266L in exon 28 of VWF, which affects the A1 domain binding site for GPIb but is associated with normal platelet counts. Failure of caplacizumab therapy resulting in TTP exacerbation or relapse has, to date, been related to premature stopping of therapy in association with severe ADAMTS13 activity. This case presents a hitherto not described phenomenon relating to a variant in VWF affecting the A1 domain and the site of caplacizimab binding, impairing its effect.

Malaria Screening in the Haematology laboratory – QBC or gold standard (Poster 12)

Paulo Leite, HSL Blood Sciences Quality Manager, Royal Free Hospital

Malaria is an infection caused by Plasmodium parasites transmitted by Anopheles mosquitoes; five species are known to infect humans.

The United Kingdom is not currently an endemic area. However, climate change models suggest that there is a low risk of local P. vivax transmission by 2030. Additionally, in 2023 the number of imported malaria cases surpassed 2000, the highest in over twenty years.

Haematology laboratories across the UK may face an increase in the number of malaria screening requests, but need to be able to keep producing fast and accurate results, as studies show that early diagnosis is crucial for positive outcomes.

In the Haematology Laboratory at the Royal Free Hospital, QBC is used instead of the observation of thick films.

In this study, 104 samples were tested to ascertain how the QBC kits (dry haematology and malaria kit) perform when compared with the RDT BinaxNOW, Fields’ stained thick film and Giemsa stained thin film (gold standards) and the Sysmex DI60 digital morphology system.

The QBC kits showed higher sensitivity and specificity than other methods. They are fast and practical, need less training than microscopy, but do not allow for quantification of parasitaemia or speciation.

Thick and Thin films allow speciation and quantification but are slower, need highly skilled staff, and this study found that they were more prone to errors, which resulted in lower sensitivity than QBC methods.

The Sysmex DI-60 was the least sensitive method. It required more sample volume and collection to be made into compatible sample vials (i.e. pierceable caps).

Future studies should consider the advances in PCR technology which could reduce cost and improve turnaround times, and advances in Digital Morphology systems, which could benefit from the use of artificial intelligence to bring significant improvements in their accuracy as malaria screening methods.  

Wednesday 24 September 2025 

Posters

HPV-Associated Cancers: Histopathology Insight (Poster 25)

Emuobo Erhawah, Biomedical Scientist, Cellular Pathology

Introduction: Human Papilloma Virus (HPV) is a prevalent sexually transmitted infection consisting of over 200 associated viruses. Unlike HPV cervical infections which can take a year to naturally clear. HPV associated oropharyngeal and laryngeal squamous cell carcinomas represent clear different clinical pathological entities compared to their HPV-negative counterparts. However these infections do not clear typically. This poster highlights key histological differences, molecular characteristics, and prognostic implications, emphasising the role of histopathology in guiding diagnosis.

Methodology: A systematic literature review was conducted to synthesis our knowledge of SCC morphology and diagnostic criteria.  Databases were searched and our key words were SCC morphology, immunological and histological cellular atypia; inclusion criteria are care review article from 2020-2025.

Summary of interpretations and conclusion: HPV-Positive SCCs morphology are predominantly non-keratinising or basaloid patterns, characterised by sheets of immature basaloid cells with high nuclear to cytoplasmic ratios, minimal keratinisation, and frequent lymphoid stroma infiltration. Hybrid variants may show abrupt keratinisation or comedo-type necrosis within non-maturing tumour islands.  

HPV- Negative SCCs morphology is typically keratinising, with well differentiated squamous pearls, intercellular bridges, and stromal desmoplasia. Variants include verrucous, spindle cell, and adeno-squamous subtypes.  

Histopathological evaluation remains pivotal in distinguishing HPV-driven SCCs, which demand tailored therapeutic approaches. Understanding these differences enhances prognostic accuracy of oropharyngeal and laryngeal cancers.

Reassessment of Her-2 Testing in the Context of Her-2-low (Poster 28)

Renzyl Gillespy, Trainee Biomedical Scientist, HSL Advanced Diagnostics

Background: Her-2 overexpression has traditionally been associated with aggressive forms of tumour and poor prognosis. Her-2 targeted therapies have significantly improved outcomes for Her-2-positive patients. The DESTINY-Breast04 trial has reshaped our understanding of Her-2, introducing a subset of Her-2-negative called “Her-2-low” characterised by IHC scores of 1+ or 2+ with negative FISH. T-Dxd was also shown to be effective in the treatment of individuals with Her-2-low breast cancer.

Aim: This study determined the true prevalence of Her-2-low and inter-observer agreement, as well as the suitability of RNAscope as a potential predictor for Her-2- low when compared to IHC and its reproducibility as a semi-quantitative measure of Her-2-low status. 432 invasive breast cancer cases were reassessed to determine the prevalence of Her-2-low, and the retrospective clinical audit evaluated inter-observer agreement using kappa test.

Method: RNAscope assay was performed on 80 selected cases to detect ErbB2 mRNA and compared with Her-2 IHC, analysed using Kruskal-Wallis test and post hoc analysis.

Findings: Results showed moderate inter-observer agreement (κ=0.564) significantly deviating from chance agreement (p-value= <0.001; 95% CI=0.507-0.624). Rescoring showed a notable increase in cases classified as 1+ (24.1% to 51.9%) and a decrease in original 2+ cases (45.1% to 22.9%). The prevalence of Her-2-low was at 65.51%, comprised of 63.25% 2+/FISH- cases and 36.75% 1+ cases. A statistically significant correlation was observed between Her-2 IHC score and ErbB2 mRNA expression (p<0.001), with all HER-2 IHC subgroups showing significant differences in mRNA score, except for 0 and 1+, and 2+/FISH+ and 3+.

Conclusion: Discordance in IHC scores were attributed to pre analytical, analytical, and post-analytical factors. This study successfully demonstrated the use of RNAscope to assess mRNA expression in archival FFPE material, similar to IHC. However, mRNA threshold levels for identifying Her-2-low cases have not been established, and no significant difference was found between Her-2-low and Her-2-zero mRNA expression.

Clinicopathological correlation of PD-L1 and CD8 expression in a series of 100 DNA mismatch repair protein proficient (pMMR) and deficient (dMMR) colorectal cancers (Poster 33)

Sahar Zagarzadeh, Quality Manager, HSL Advanced Diagnostics

Introduction and aim: This MSc project investigated the clinicopathological correlation of PD-L1 and CD8 expression in 100 colorectal cancer (CRC) cases, focusing on DNA mismatch repair protein proficient (pMMR) and deficient (dMMR) subtypes. Given that dMMR CRC is associated with distinct immune responses and better outcomes with immunotherapy, the study aimed to explore the expression patterns of PD-L1 and CD8 as potential biomarkers and therapeutic targets.

Method: Using immunohistochemistry (IHC) and PCR-based microsatellite instability (MSI) testing, the study analysed 53 dMMR and 47 pMMR CRC cases. Digital image analysis was used to quantify PD-L1 expression using a Combined Positive Score (CPS), while CD8+ T-cell infiltration was also assessed.

Findings: The findings demonstrated a higher prevalence of PD-L1 expression and CD8 infiltration in dMMR cases, supporting the potential of PD-L1 as a therapeutic target in this subgroup. Notably, a subset of pMMR cases also showed high PD-L1 expression, suggesting possible benefit from immune checkpoint inhibitors. These results contribute to the understanding of immune marker expression in CRC and highlight the relevance of molecular subtyping for personalised cancer therapy.

WHO Cervical Cancer Elimination and removing barriers to screening engagement: A primary HPV screening laboratory experience of testing self-collected samples (Poster 37)

Gulseren Akgul, Senior Biomedical Scientist, Cervical Screening

Background: Few diseases reflect global inequities as much as cervical cancer. Worldwide, it is the fourth most common cancer among women. It is vaccine preventable and curable if detected early. In England, approximately 3 in 10 eligible people do not engage with cervical screening. Self- sampling may have the potential to help this cohort attend screening. 

Aim: To share our laboratory experience of testing self-collected samples for HPV based cervical screening.

Methods: Between 2020 and 2023, Cervical Screening London (CSL) supported research into self-sampling, with its participation in both the You Screen and HPValidate studies.
We performed a review of the implementation of laboratory testing of self-collected samples, using the People, Process, Technology framework. In excess of 9,000 self-collected samples processed by the laboratory between 2021 and 2022 were considered in the review.

Findings: Multiorganisational partnership working was identified as an interdependency for People, Process and Technology (PPT) to achieve optimal harmony. Pre-analytical electronic requesting reduced the risk of error. Visual aids enhanced laboratory recognition of the sample type improving the analytical process. Electronic transfer of results improved the post-analytical process.

Conclusion: Laboratories can incorporate testing of self-collected samples for HPV-based cervical screening alongside established healthcare sample taker derived screening samples. 
Partnership working across organisations is critical to establish agreed protocols. 
Self-sampling has the potential to increase screening coverage, particularly in women who may not participate in cervical screening. 

All poster entries will be available to view soon after the event.