Real-world study of the multimorbidity and health service utilisation among individuals with non-diabetic hyperglycemia and type 2 diabetes mellitus in North West London.

INTRODUCTION: The prevalence of non-diabetic hyperglycemia (NDH) and type 2 diabetes mellitus (T2DM) is increasing. While T2DM is recognised to be associated with multimorbidity and early mortality, people with NDH are frequently thought to be devoid of such complications, potentially exposing individuals with NDH to suboptimal care. We therefore used the Discover London Secure Data Environment (SDE) dataset to appreciate the relationship of NDH/T2DM with multimorbidity, healthcare usage, and clinical outcomes. RESEARCH DESIGN AND METHODS: The dataset was retrospectively analysed between January 1, 2015 and December 31, 2020 to understand the relationship between NDH/T2DM and multimorbidity primary/secondary healthcare usage and clinical outcomes. This was compared with a cohort of individuals with thyroid disease but no NDH/T2DM. RESULTS: The dataset identified 152,384 and 124,190 adults with NDH and T2DM compared with 11,626 individuals with thyroid disease (control group). Individuals with NDH and individuals with T2DM had a high burden of disease, with only 13.1% of individuals with either NDH or T2DM not found to be suffering from at least one of the disease states of interest. The three most common comorbidities experienced by individuals with NDH were hypertension (41.4%), hypercholesterolemia (37.5%), and obesity (29.8%) compared with retinopathy (68.7%), hypertension (59.4%), and obesity (45.8%) in individuals with T2DM. Comparatively, the most common comorbidities in the control group were depression (30.8%), hypercholesterolemia (24.4%), and hypertension (17.1%). 28 (control group), 12 (NDH), and 16 (T2DM) primary care contacts per individual per year were identified, with 27,881, 282,371, and 314,880 inpatient admissions for the control, NDH, and T2DM cohorts, respectively. Prescription of drugs used to treat T2DM in individuals with NDH and T2DM was 27,772 (18.2%) and 109,361 (88.1%), respectively, accounting for approximately one in five individuals with NDH developing T2DM. CONCLUSION: Both NDH and T2DM were associated with significant multimorbidity alongside primary and secondary care utilisation. Given the morbidity highlighted with NDH, we highlight the need for earlier detection of NDH, recognition of multimorbidity associated with both NDH and T2DM, as well as the need for the further implementation of interventions to prevent progression to T2DM/multimorbidity.

Characteristics and outcomes of patients with COVID-19 at high risk of disease progression receiving sotrovimab, oral antivirals or no treatment in England: a retrospective cohort study.

OBJECTIVE: To describe characteristics and acute clinical outcomes for patients with COVID-19 treated with sotrovimab, nirmatrelvir/ritonavir or molnupiravir, or untreated patients at highest risk per National Health Service (NHS) criteria. METHODS: Retrospective study of non-hospitalized patients between 1 December 2021 and 31 May 2022, using data from the Discover-NOW dataset (North-West London). Included patients were aged ≥12 years and treated with sotrovimab, nirmatrelvir/ritonavir or molnupiravir, or untreated but expected to be eligible for early treatment per NHS highest-risk criteria. COVID-19-related and all-cause hospitalizations were reported for 28 days from COVID-19 diagnosis (index). Subgroup analyses were conducted in patients with advanced renal disease, those aged 18-64 and ≥65 years, and by period of Omicron BA.1, BA.2 and BA.5 (post-hoc exploratory) predominance. RESULTS: Overall, 1503 treated and 4044 eligible high-risk untreated patients were included. A high proportion of patients on sotrovimab had advanced renal disease (29.3%), ≥3 high-risk comorbidities (47.6%) and were aged ≥65 years (36.9%). Five of 696 (0.7%) patients on sotrovimab, <5/337 (0.3-1.2%) on nirmatrelvir/ritonavir, 10/470 (2.1%) on molnupiravir and 114/4044 (2.8%) untreated patients were hospitalized with COVID-19. Similar results were observed across all subgroups. The proportion of patients dying within 28 days of the index period was similarly low across all cohorts (<2%). CONCLUSION: Patients receiving sotrovimab appeared to show evidence of multiple high-risk comorbidities. Low hospitalization rates were observed for all treated cohorts across subgroups and periods of predominant variants of concern. These results require confirmation with comparative effectiveness analyses adjusting for differences in underlying patient characteristics.

Comparative effectiveness of sotrovimab versus no treatment in non-hospitalised high-risk COVID-19 patients in north west London: a retrospective cohort study.

BACKGROUND: We assessed the effectiveness of sotrovimab vs no early COVID-19 treatment in highest-risk COVID-19 patients during Omicron predominance. METHODS: Retrospective cohort study using the Discover dataset in North West London. Included patients were non-hospitalised, aged ≥12 years and met ≥1 National Health Service highest-risk criterion for sotrovimab treatment. We used Cox proportional hazards models to compare HRs of 28-day COVID-19-related hospitalisation/death between highest-risk sotrovimab-treated and untreated patients. Age, renal disease and Omicron subvariant subgroup analyses were performed. RESULTS: We included 599 sotrovimab-treated patients and 5191 untreated patients. Compared with untreated patients, the risk of COVID-19 hospitalisation/death (HR 0.50, 95% CI 0.24, 1.06; p=0.07) and the risk of COVID-19 hospitalisation (HR 0.43, 95% CI 0.18, 1.00; p=0.051) were both lower in the sotrovimab-treated group; however, statistical significance was not reached. In the ≥65 years and renal disease subgroups, sotrovimab was associated with a significantly reduced risk of COVID-19 hospitalisation, by 89% (HR 0.11, 95% CI 0.02, 0.82; p=0.03) and 82% (HR 0.18, 95% CI 0.05, 0.62; p=0.007), respectively. CONCLUSIONS: Risk of COVID-19 hospitalisation in sotrovimab-treated patients aged ≥65 years and with renal disease was significantly lower compared with untreated patients. Overall, risk of hospitalisation was also lower for sotrovimab-treated patients, but statistical significance was not reached.

Association and progression of multi-morbidity with Chronic Kidney Disease stage 3a secondary to Type 2 Diabetes Mellitus, grouped by albuminuria status in the multi-ethnic population of Northwest London: A real-world study.

INTRODUCTION: The prevalence of Diabetic Kidney Disease (DKD) secondary to Type 2 Diabetes Mellitus (T2DM) is rising worldwide. However, real-world data linking glomerular function and albuminuria to the degree of multi-morbidity is lacking. We thus utilised the Discover dataset, to determine this association. METHOD: Patients with T2DM diagnosed prior to 1st January 2015 with no available biochemical evidence of CKD were included. Patients subsequently diagnosed and coded for CKD3a in 2015, were grouped by the degree of albuminuria. Baseline and 5-year co-morbidity was determined, as were prescribing practices with regards to prognostically beneficial medication. RESULTS: We identified 56,261 patients with T2DM, of which 1082 had CKD stage 3a diagnosed in 2015 (224-CKD3aA1,154-CKD3aA2,93-CKD3aA1; 611 patients with CKD3a but no uACR available in 2015 were excluded from follow up). No statistically significant difference was observed in the degree of co-morbidities at baseline. A significant difference in the degree of hypertension, retinopathy, ischaemic heart disease and vascular disease from baseline compared to study end point was observed for all 3 study groups. Comparing co-morbidities developed at study end point, highlighted a statistical difference between CKD3aA1 Vs CKD3aA3 for retinopathy alone and for hypertension and heart failure between CKD3aA2 Vs CKD3aA3. 40.8% of patients with CKD3aA2 or A3 were prescribed Renin Angiotensin Aldosterone inhibitors (RAASi) therapy between June-December 2021. Survival analysis showed 15% of patients with CKD3aA3 developed CKD stage 5 within 5 years of diagnosis. DISCUSSION: CKD3a secondary to DKD is associated with significant multimorbidity at baseline and 5 years post diagnosis, with CKD3aA3 most strongly associated with CKD progression to CKD 5, heart failure, hypertension and retinopathy compared to CKD3aA1 or CKD3aA2 at 5 years post diagnosis. The lack of uACR testing upon diagnosis and poor prescribing of RAASi, in those with CKD3aA2/A3, raises significant cause for concern. CONCLUSION: DKD is associated with significant multimorbidity. Significant work is needed to be done to ensure patients undergo testing for uACR, to allow for future risk stratification and ability to be started on prognostically beneficial medication.

Smartphone-Based Remote Monitoring in Heart Failure With Reduced Ejection Fraction: Retrospective Cohort Study of Secondary Care Use and Costs.

BACKGROUND: Despite effective therapies, the economic burden of heart failure with reduced ejection fraction (HFrEF) is driven by frequent hospitalizations. Treatment optimization and admission avoidance rely on frequent symptom reviews and monitoring of vital signs. Remote monitoring (RM) aims to prevent admissions by facilitating early intervention, but the impact of noninvasive, smartphone-based RM of vital signs on secondary health care use and costs in the months after a new diagnosis of HFrEF is unknown. OBJECTIVE: The purpose of this study is to conduct a secondary care health use and health-economic evaluation for patients with HFrEF using smartphone-based noninvasive RM and compare it with matched controls receiving usual care without RM. METHODS: We conducted a retrospective study of 2 cohorts of newly diagnosed HFrEF patients, matched 1:1 for demographics, socioeconomic status, comorbidities, and HFrEF severity. They are (1) the RM group, with patients using the RM platform for >3 months and (2) the control group, with patients referred before RM was available who received usual heart failure care without RM. Emergency department (ED) attendance, hospital admissions, outpatient use, and the associated costs of this secondary care activity were extracted from the Discover data set for a 3-month period after diagnosis. Platform costs were added for the RM group. Secondary health care use and costs were analyzed using Kaplan-Meier event analysis and Cox proportional hazards modeling. RESULTS: A total of 146 patients (mean age 63 years; 42/146, 29% female) were included (73 in each group). The groups were well-matched for all baseline characteristics except hypertension (P=.03). RM was associated with a lower hazard of ED attendance (hazard ratio [HR] 0.43; P=.02) and unplanned admissions (HR 0.26; P=.02). There were no differences in elective admissions (HR 1.03, P=.96) or outpatient use (HR 1.40; P=.18) between the 2 groups. These differences were sustained by a univariate model controlling for hypertension. Over a 3-month period, secondary health care costs were approximately 4-fold lower in the RM group than the control group, despite the additional cost of RM itself (mean cost per patient GBP £465, US $581 vs GBP £1850, US $2313, respectively; P=.04). CONCLUSIONS: This retrospective cohort study shows that smartphone-based RM of vital signs is feasible for HFrEF. This type of RM was associated with an approximately 2-fold reduction in ED attendance and a 4-fold reduction in emergency admissions over just 3 months after a new diagnosis with HFrEF. Costs were significantly lower in the RM group without increasing outpatient demand. This type of RM could be adjunctive to standard care to reduce admissions, enabling other resources to help patients unable to use RM.

Survival and health economic outcomes in heart failure diagnosed at hospital admission versus community settings: a propensity-matched analysis.

BACKGROUND AND AIMS: Most patients with heart failure (HF) are diagnosed following a hospital admission. The clinical and health economic impacts of index HF diagnosis made on admission to hospital versus community settings are not known. METHODS: We used the North West London Discover database to examine 34 208 patients receiving an index diagnosis of HF between January 2015 and December 2020. A propensity score-matched (PSM) cohort was identified to adjust for differences in socioeconomic status, cardiovascular risk and pre-diagnosis health resource utilisation cost. Outcomes were stratified by two pathways to index HF diagnosis: a 'hospital pathway' was defined by diagnosis following hospital admission; and a 'community pathway' by diagnosis via a general practitioner or outpatient services. The primary clinical and health economic endpoints were all-cause mortality and cost-consequence differential, respectively. RESULTS: The diagnosis of HF was via hospital pathway in 68% (23 273) of patients. The PSM cohort included 17 174 patients (8582 per group) and was matched across all selected confounders (p>0.05). The ratio of deaths per person-months at 24 months comparing community versus hospital diagnosis was 0.780 (95% CI 0.722 to 0.841, p<0.0001). By 72 months, the ratio of deaths was 0.960 (0.905 to 1.020, p=0.18). Diagnosis via hospital pathway incurred an overall extra longitudinal cost of £2485 per patient. CONCLUSIONS: Index diagnosis of HF through hospital admission continues to dominate and is associated with a significantly greater short-term risk of mortality and substantially increased long-term costs than if first diagnosed in the community. This study highlights the potential for community diagnosis-early, before symptoms necessitate hospitalisation-to improve both clinical and health economic outcomes.

Clinical characteristics and comorbidities associated with testosterone prescribing in men.

OBJECTIVE: Testosterone replacement therapy (TRT) is recommended for the treatment of symptomatic hypogonadism in men. Data on prescription behaviours are, however, limited and conflicting. The objective of this study was to investigate clinical characteristics associated with the likelihood of being prescribed TRT by general practitioners (GP) in North-West London (NWL). DESIGN: Retrospective cohort study using Discover database of GP-registered patients in NWL between 2015 and 2019. PATIENTS: We identified 20,299 men aged ≥18 years with serum total testosterone measurement (TT) and without prior TRT prescription records. MEASUREMENTS: We determined whether TRT was subsequently commenced, while analysing clinical characteristics related to hypogonadism. RESULTS: Of all men having TT measurement, 19,583 (96.4%) were not commenced on TRT (Group A) and 716 (3.5%) men were commenced on TRT (Group B). Men prescribed TRT (Group B) had higher mean age, body mass index (BMI) and higher risks of hypertension, depression type 2 diabetes and ischaemic heart disease; conversely, men in Group B had lower mean pretreatment TT and were less likely to have prostate cancer. Four-hundred and thirty-six men (24.3%) with TT < 8 nmol/L and symptoms of low libido were not prescribed TRT. CONCLUSIONS: Our study highlights several factors which may influence the decisions made by clinicians when initiating TRT in primary care. Clearer guidance for clinicians may help to improve the consistency of treatment of men with hypogonadism.

Burden and impact of chronic cough in UK primary care: a dataset analysis.

OBJECTIVE: Chronic cough (CC) is a debilitating respiratory symptom, now increasingly recognised as a discrete disease entity. This study evaluated the burden of CC in a primary care setting. DESIGN: Cross-sectional, retrospective cohort study. SETTING: Discover dataset from North West London, which links coded data from primary and secondary care. The index date depicted CC persisting for ≥8 weeks and was taken as a surrogate for date of CC diagnosis. PARTICIPANTS: Data were extracted for individuals aged ≥18 years with a cough persisting ≥8 weeks or cough remedy prescription, between Jan 2015 and Sep 2019. MAIN OUTCOME MEASURES: Demographic characteristics, comorbidities and service utilisation cost, including investigations performed and treatments prescribed were determined. RESULTS: CC was identified in 43 453 patients from a total cohort of 2 109 430 (2%). Median (IQR) age was 64 years (41-87). Among the cohort, 31% had no recorded comorbidities, 26% had been given a diagnosis of asthma, 17% chronic obstructive pulmonary disease, 12% rhinitis and 15% reflux. Prevalence of CC was greater in women (57%) and highest in the 65-74 year age range. There was an increase in the number of all investigations performed in the 12 months before and after the index date of CC diagnosis, and in particular for primary care chest X-ray and spirometry which increased from 6535 to 12 880 and from 5791 to 8720, respectively. This was accompanied by an increase in CC-associated healthcare utilisation costs. CONCLUSION: One-third of individuals had CC in the absence of associated comorbidities, highlighting the importance of recognising CC as a condition in its own right. Overall outpatient costs increased in the year after the CC index date for all comorbidities, but varied significantly with age. Linked primary-care datasets may enable earlier detection of individuals with CC for specialist clinic referral and targeted treatment.

Blood tests in general practice: the use of routine data to characterise venous blood testing in North West London, 2016-2018.

BACKGROUND: Laboratory testing is an integral diagnostic tool, contributing to 70% of diagnoses in the NHS today. Its use has been steadily increasing despite estimates that ≤40% of blood tests ordered are unnecessary. Understanding blood-testing patterns is a fundamental step to tackling overuse. AIM: To characterise the volume, type, and per patient frequency (PPF) of venous blood testing reported in general practice in North West London, 2016-2018. METHOD: Following ethics clearance, aggregate data of blood tests reported in general practice in North West London between 2016 and 2018 were extracted from the Discover database. Non-venous blood test codes and codes not used within the designated time period were excluded. Codes reporting the same analyte were aggregated. Overall volume and PPF were calculated per analyte. RESULTS: Three hundred and thirty-six individual analytes were reported and grouped into 35 recognised panels or groupings. Blood testing increased by 16.5% over the 3-year period. Full blood count, urea and electrolytes, liver function tests, and lipid profile accounted for 80.4% of all venous blood tests. Requests for HbA1c increased by 52.8% and non-HDL cholesterol by 148.7%, whereas glucose decreased by 13.3% and urea by 15.7%. The PPF remained unchanged over the 3-year period at 1.29 blood tests per person per year. The coagulation assay had the highest PPF at 3.0. CONCLUSION: Routine general practice data revealed important trends in blood testing. Trends uncovered can inform innovative and targeted solutions to reduce unnecessary blood testing.

Development of a novel recombinant biotherapeutic with applications in targeted therapy of human arthritis.

OBJECTIVE: To isolate recombinant antibodies with specificity for human arthritic synovium and to develop targeting reagents with joint-specific delivery capacity for therapeutic and/or diagnostic applications. METHODS: In vivo single-chain Fv (scFv) antibody phage display screening using a human synovial xenograft model was used to isolate antibodies specific to the microvasculature of human arthritic synovium. Single-chain Fv antibody tissue-specific reactivity was assessed by immunostaining of synovial tissues from normal controls and from patients with rheumatoid arthritis and osteoarthritis, normal human tissue arrays, and tissues from other patients with inflammatory diseases displaying neovasculogenesis. In vivo scFv antibody tissue-specific targeting capacity was examined in the human synovial xenograft model using both (125)I-labeled and biotinylated antibody. RESULTS: We isolated a novel recombinant human antibody, scFv A7, with specificity for the microvasculature of human arthritic synovium. We showed that in vivo, this antibody could efficiently target human synovial microvasculature in SCID mice transplanted with human arthritic synovial xenografts. Our results demonstrated that scFv A7 antibody had no reactivity with the microvasculature or with other cellular components found in a comprehensive range of normal human tissues including normal human synovium. Further, we showed that the reactivity of the scFv A7 antibody was not a common feature of neovasculogenesis associated with chronic inflammatory conditions. CONCLUSION: Here we report for the first time the identification of an scFv antibody, A7, that specifically recognizes an epitope expressed in the microvasculature of human arthritic synovium and that has the potential to be developed as a joint-specific pharmaceutical.

Transient over-expression of estrogen receptor-α in breast cancer cells promotes cell survival and estrogen-independent growth.

Estrogen receptor-α (ERα) positive breast cancer frequently responds to inhibitors of ERα activity, such as tamoxifen, and/or to aromatase inhibitors that block estrogen biosynthesis. However, many patients become resistant to these agents through mechanisms that remain unclear. Previous studies have shown that expression of ERα in ERα-negative breast cancer cell lines frequently inhibits their growth. In order to determine the consequence of ERα over-expression in ERα-positive breast cancer cells, we over-expressed ERα in the MCF-7 breast cancer cell line using adenovirus gene transduction. ERα over-expression led to ligand-independent expression of the estrogen-regulated genes pS2 and PR and growth in the absence of estrogen. Interestingly, prolonged culturing of these cells in estrogen-free conditions led to the outgrowth of cells capable of growth in cultures from ERα transduced, but not in control cultures. From these cultures a line, MLET5, was established which remained ERα-positive, but grew in an estrogen-independent manner. Moreover, MLET5 cells were inhibited by anti-estrogens showing that ERα remains important for their growth. Gene expression microarray analysis comparing MCF-7 cells with MLET5 highlighted apoptosis as a major functional grouping that is altered in MLET5 cells, such that cell survival would be favoured. This conclusion was further substantiated by the demonstration that MLET5 show resistance to etoposide-induced apoptosis. As the gene expression microarray analysis also shows that the apoptosis gene set differentially expressed in MLET5 is enriched for estrogen-regulated genes, our findings suggest that transient over-expression of ERα could lead to increased cell survival and the development of estrogen-independent growth, thereby contributing to resistance to endocrine therapies in breast cancer patients.

A simple laboratory practical to illustrate RNA mediated gene interference using drosophila cell culture.

RNA mediated gene interference (RNAi) is now a key tool in eukaryotic cell and molecular biology research. This article describes a five session laboratory practical, spread over a seven day period, to introduce and illustrate the technique. During the exercise, students working in small groups purify PCR products that encode in vitro transcription promoters fused to sequences from Drosophila genes of the Rho/Rac GTPase family. These DNA templates are then used to synthesize double stranded RNAs (dsRNA), which are subsequently used to transfect Drosophila Kc embryonic cells. The resulting RNAi produces simple cellular phenotypes that are observed following fluorescent histochemical staining. These phenotypes are ultimately related to gene ontology data that the students generate through a bioinformatic analysis of the sequences transcribed into dsRNA. Taken together, this laboratory exercise provides "hands on" experience of RNAi in a class setting and provides a framework for the in-depth discussion of how this technique can be applied to studies of gene function.

A novel HSV-1 virus, JS1/34.5-/47-, purges contaminating breast cancer cells from bone marrow.

PURPOSE: Oncolytic herpes simplex virus type 1 (HSV-1) vectors show considerable promise as agents for cancer therapy. We have developed a novel recombinant HSV-1 virus (JS1/34.5-/47-) for purging of occult breast cancer cells from bone marrow of patients. Here, we evaluate the therapeutic efficacy of this oncolytic virus. EXPERIMENTAL DESIGN: Electron microscopy was used to determine whether human breast cancer and bone marrow cells are permissive for JS1/34.5-/47- infection. Subsequently, the biological effects of JS1/34.5-/47- infection on human breast cancer cells and bone marrow were established using cell proliferation and colony formation assays, and the efficiency of cell kill was evaluated. Finally, the efficiency of JS1/34.5-/47- purging of breast cancer cells was examined in cocultures of breast cancer cells with bone marrow as well as bone marrow samples from high-risk breast cancer patients. RESULTS: We show effective killing of human breast cancer cell lines with the JS1/34.5-/47- virus. Furthermore, we show that treatment with JS1/34.5-/47- can significantly inhibit the growth of breast cancer cell lines without affecting cocultured mononuclear hematopoietic cells. Finally, we have found that the virus is effective in destroying disseminated tumors cells in bone marrow taken from breast cancer patients, without affecting the hematopoietic contents in these samples. CONCLUSION: Collectively, our data show that the JS1/34.5-/47- virus can selectively target breast cancer cells while sparing hematopoietic cells, suggesting that JS1/34.5-/47- can be used to purge contaminating breast cancer cells from human bone marrow in the setting of autologous hematopoietic cell transplantation.

ZNF366 is an estrogen receptor corepressor that acts through CtBP and histone deacetylases.

The regulation of gene expression by estrogen receptor-alpha (ERalpha) requires the coordinated and temporal recruitment of diverse sets of transcriptional co-regulator complexes, which mediate nucleosome remodelling and histone modification. Using ERalpha as bait in a yeast two-hybrid screen, we have identified a novel ERalpha-interacting protein, ZNF366, which is a potent corepressor of ERalpha activity. The interaction between ZNF366 and ERalpha has been confirmed in vitro and in vivo, and is mediated by the zinc finger domains of the two proteins. Further, we show that ZNF366 acts as a corepressor by interacting with other known ERalpha corepressors, namely RIP140 and CtBP, to inhibit expression of estrogen-responsive genes in vivo. Together, our results indicate that ZNF366 may play an important role in regulating the expression of genes in response to estrogen.

Silencing of androgen-regulated genes using a fusion of AR with the PLZF transcriptional repressor.

The androgen receptor (AR) is a member of the nuclear receptor superfamily of ligand-activated transcription factors and plays a key role in the development and progression of prostate cancer. Current therapies include the use of antiandrogens aimed at inhibiting the transcriptional activation of AR-regulated genes by AR. Here, we explore a strategy aimed at obtaining silencing of AR-regulated genes, based on the properties of the transcriptional repressor promyelocytic leukamia zinc-finger protein (PLZF). In order to do this, we have made a fusion protein between PLZF and AR, named PLZF-AR, and show that PLZF-AR is able to bring about silencing of genomically encoded AR-regulated genes and inhibit the androgen-regulated growth of LNCaP prostate cancer cells. Together, our results show that this strategy is able to bring about potent repression of AR-regulated responses and, therefore, could be of value in the development of new therapies for prostate cancer.

In vitro deregulation of markers characteristic of human prostate epithelial cells.

We have screened primary cultures of human prostate for the expression of markers reported to be characteristic of specific cell lineages in vivo, in order to ascertain whether human prostate cells in vitro maintain and reflect their in vivo differentiated phenotypes and to evaluate the homogeneity of the populations of cells that can be derived from this tissue. Using single and dual stain immunofluorescent microscopy to analyse very early organoid and subsequently derived monolayer stage cultures, we have observed that expression of markers characteristic of human prostate epithelial cells in vivo is deregulated within 48h, indicating that dissociation of human prostate tissue and cultivation of prostate epithelial cells in culture can result in promiscuous expression of cell type specific markers of prostate epithelial cells. These observations have important implications for studies of cell lineage and differentiation of prostate cells in vitro.