Events in 2023

Diphtheria is a potentially fatal disease caused by strains of Corynebacterium diphtheriae, C. ulcerans or C. pseudotubercolosis that express the diphtheria toxin. It can present as a respiratory infection or as non-healing skin wounds. Diphtheria was historically most likely to be caused by C. diphtheriae. It is very rare in England (typically <10 cases per year) due to a successful routine immunisation programme. However, there has been a recent gradual increase in cases over several years, particularly cutaneous infections and those caused by toxigenic C. ulcerans strains (which can be carried by household pets).

In 2022, there was a particulary large increase in diphtheria in England, with 87 cases and 3 deaths. This included 72 toxigenic C. diphtheriae infections in asylum seekers, thought to be aquired during their travel to the UK. Symptoms ranged from severe respiratory diphtheria to cutaneous infections and asymptomatic carriage. Similar increases of C. diphtheriae infections in travelling migrants have been seen in several European countries. Some of these isolates are multidrug resistant, including to macrolides, the default recommendation for treatment, and this will require careful monitoring.

Many of us have diagnosed, treated or researched Clostridiodes difficile infection (CDI) for many years and probably know the organism and the disease it produces very well indeed. But how well do we really know it? In truth, we only know this from our own perspective. What is it really like to suffer from CDI? How well do the pathways and guidance we contribute to function in the experience patients?

This talk will focus on patient experiences of CDI, what they can teach us as clinicians and researchers and why involving patients and the public in designing our research and clinical services can help everyone.

Cell blocks from Diagnostic Cytopathology (DC) samples have always had value in the diagnostic process as a complement to the traditional cytology stains – Papanicolaou and Romanowsky. It has become more important to provide material for Immunocytochemistry to refine malignant diagnosis, and more recently, the use of molecular testing to aid in the choice of tailored chemotherapy regimens. If this information can be obtained from DC samples, which are less invasive than biopsy samples, the patient will benefit.

External Quality Assurance of cell block preparations has up to now been covered by the Tissue Diagnostic scheme. However, this is not entirely appropriate as cytopathology departments use a variety of cell block preparation methods and fixatives. The increase in number of cell block Haematoxylin and Eosin slides submitted to our evaluation service and the queries we receive regarding advice on best preparation methods suggested there was a need for a separate scheme for evaluation of cell blocks. A circulated survey indicated that there is a need for such a scheme. In response to this we performed 2 pilot studies which were well supported and successful, leading to the launch of the live scheme in April 2023.

This presentation covers the development of the scheme and the results of the 2 pilots. As an ongoing process the scheme will be able to garner information about ‘best methods’ and this can be passed on to laboratories experiencing problems and improve standards. UKNEQAS CPT is not just a ‘tick box’ service for UKAS, it is also an advisory service which aims to improve diagnostic practices.

Postpartum haemorrhage is caused by obstetric complications but may be exacerbated by haemostatic impairment. It is a common observation that placental abruption and amniotic fluid embolism are associated with a severe and early coagulopathy characterised by hypofibrinogenaemia and increased fibrinolysis.

In Cardiff, a programme of research has been undertaken investigating the early detection and replacement of fibrinogen based on viscoelastic haemostatic assays. This culminated in the development of a care bundle for postpartum haemorrhage called the Obstetric Bleeding Strategy for Wales (OBS Cymru). Introduction of the OBS Cymru intervention across Wales resulted in fewer women experiencing massive postpartum haemorrhage (defined as >2500 mL) and decreased need for blood transfusion. The intervention is being investigated further in a NIHR supported study.

At term, women have increased levels of procoagulant clotting factors and reduced anticoagulants leading to a prothrombotic state. Our study confirmed these findings and demonstrated significantly raised thrombin generation. We identified two main types of coagulopathy; a dilutional coagulopathy with coagulation factors and platelets falling progressively with bleed size. However, clinically significant reductions in clotting factors were not seen until bleeds of 3000-4000 mL had occurred due to the high starting levels. Despite this, thrombin generation did not decrease due to increased levels of factor VIII during bleeds. Similar dilution-related falls were seen with fibrinogen levels. The exception was factor XIII which falls at term and decreases further with bleed size. The clinical significance of this finding has not been investigated but could suggest a role for cryoprecipitate.

In a subgroup of women we identified an early and severe consumptive coagulopathy caused by hyperfibrinolysis with very high D-dimer and plasmin/antiplasmin complexes which we termed acute obstetric coagulopathy (AOC). In addition, women with AOC had low levels of fibrinogen and evidence of an acquired dysfibrinogenaemia demonstrated by a reduced Clauss/antigenic ratio. The coagulopathy caused depletion of factor V and factor VIII but other clotting factors and thrombin generation was preserved. An increase in activated protein C was observed but no increase in soluble thrombomodulin demonstrating similarities and differences to trauma-induced coagulopathy.

AOC occurred in about 1/1000 deliveries and was associated with a high rate of fetal and neonatal deaths. It was most commonly associated with placental abruption but occurred with all underlying causes of postpartum haemorrhage.

This presentation is based on a case study used for a portfolio of Higher Specialist Diploma awarded by the IBMS. The presentation will look at how blood cultures taken on admission helped with diagnosis and appropriate treatment of a patient. It will also go in to brief detail on the organism isolated, Streptobacillus moniliformis.

Changing and expanding roles in Cellular Pathology

In this presentation, Imran Jabbar, will delve into the crucial topic of measuring human chorionic gonadotrophin (hCG) in gestational trophoblastic disease (GTD). With a focus on trophoblastic tumours, Imran will explore the significance of hCG as a diagnostic and monitoring tool in GTD. The presentation will cover the principles behind hCG measurement techniques, including immunoassays and molecular methods.

Imran will highlight the challenges and advancements in accurately quantifying hCG levels, and discuss their clinical implications. Attendees will gain insights into the role of hCG measurement in early detection, disease monitoring, and prognostic evaluation, ultimately contributing to improved patient outcomes in GTD management.

What is ISO 22367 and how can it help the laboratory comply with the risk requirements of ISO15189

Ovarian Hyperstimulation Syndrome is one of the most dangerous complications associated with assisted conception using invitro fertilisation (IVF). If not managed appropriately it can even lead to death of the women developing ovarian hyperstimulation syndrome. Clinical Biochemistry aids significantly in the diagnosis and management of ovarian hyperstimulation syndrome.

This presentation aims to summarise the role of various biochemical parameters that are used routinely in the diagnosis and management of ovarian hyperstimulation syndrome.

A case study into iron deficiency polycythaemia diagnosis, looking at the pathology and how this relates to the results we see and investigations to confirm diagnosis.