Relative Vaccine Effectiveness of Cell- vs Egg-Based Quadrivalent Influenza Vaccine Against Test-Confirmed Influenza Over 3 Seasons Between 2017 and 2020 in the United States.

Background: Influenza vaccine viruses grown in eggs may acquire egg-adaptive mutations that may reduce antigenic similarity between vaccine and circulating influenza viruses and decrease vaccine effectiveness. We compared cell- and egg-based quadrivalent influenza vaccines (QIVc and QIVe, respectively) for preventing test-confirmed influenza over 3 US influenza seasons (2017-2020). Methods: Using a retrospective test-negative design, we estimated the relative vaccine effectiveness (rVE) of QIVc vs QIVe among individuals aged 4 to 64 years who had an acute respiratory or febrile illness and were tested for influenza in routine outpatient care. Exposure, outcome, and covariate data were obtained from electronic health records linked to pharmacy and medical claims. Season-specific rVE was estimated by comparing the odds of testing positive for influenza among QIVc vs QIVe recipients. Models were adjusted for age, sex, geographic region, influenza test date, and additional unbalanced covariates. A doubly robust approach was used combining inverse probability of treatment weights with multivariable regression. Results: The study included 31 824, 33 388, and 34 398 patients in the 2017-2018, 2018-2019, and 2019-2020 seasons, respectively; ∼10% received QIVc and ∼90% received QIVe. QIVc demonstrated superior effectiveness vs QIVe in prevention of test-confirmed influenza: rVEs were 14.8% (95% CI, 7.0%-22.0%) in 2017-2018, 12.5% (95% CI, 4.7%-19.6%) in 2018-2019, and 10.0% (95% CI, 2.7%-16.7%) in 2019-2020. Conclusions: This study demonstrated consistently superior effectiveness of QIVc vs QIVe in preventing test-confirmed influenza over 3 seasons characterized by different circulating viruses and degrees of egg adaptation.

Estimates of Seasonal Influenza Burden That Could Be Averted by Improved Influenza Vaccines in the Australian Population Aged Under 65 Years, 2015-2019.

BACKGROUND: The interpretation of relative vaccine effectiveness (rVE) of improved influenza vaccines is complex. Estimation of burden averted is useful to contextualise their potential impact across different seasons. For the population aged under 65 years in Australia, this study estimated the additional morbidity and mortality that could be averted using improved influenza vaccines. METHODS: We used observed, season-specific (2015-2019) influenza notification and influenza-coded hospitalisation frequencies and published modelled estimates of influenza-associated hospitalisations and deaths that occurred under the prevailing influenza vaccination coverage scenario. After back-calculating to the estimated burden in the population without vaccination, we applied published standard influenza vaccine effectiveness and coverage estimates to calculate the burden potentially averted by standard and improved influenza vaccines. A plausible range of rVE values were used, assuming 50% coverage. RESULTS: The percentage point difference in absolute vaccine effectiveness (VE) of an improved vaccine compared to a standard vaccine is directly proportional to its rVE and inversely proportional to the effectiveness of the standard vaccine. The incremental burden averted by an improved vaccine is a function of both its difference in absolute VE and the severity of the influenza season. Assuming an rVE of 15% with 50% coverage, the improved vaccine was estimated to additionally avert 1517 to 12,641 influenza notifications, 287 to 1311 influenza-coded hospitalisations and 9 to 33 modelled all-cause influenza deaths per year compared to the standard vaccine. CONCLUSIONS: Improved vaccines can have substantial clinical and population impact, particularly when the effectiveness of standard vaccines is low, and burden is high.

SALL4B, not targeted by IMiD, is important for SALL4-mediated tumorigenesis.

Oncofetal transcription factor SALL4 is essential for cancer cell survival. 1-5 Recently, several groups reported that immunomodulatory imide drugs (IMiDs) could degrade SALL4 in a proteasome-dependent manner. 6,7 Intriguingly, we observed that IMiDs had no effect on SALL4-positive cancer cells. Further studies demonstrated that IMiDs could only degrade SALL4A, one of the SALL4 isoforms. This finding raises the possibility that SALL4B, the isoform not affected by IMiDs, may be essential for SALL4-mediated cancer cell survival. SALL4B knockdown led to an increase in apoptosis and inhibition of cancer cell growth. SALL4B gain-of-function alone led to liver tumor formation in mice. Our observation that protein degraders can possess isoform-specific effects exemplifies the importance of delineating drug action and oncogenesis at the isoform level to develop more effective cancer therapeutics.

Targeting an Inducible SALL4-Mediated Cancer Vulnerability with Sequential Therapy.

Oncofetal protein SALL4 is critical for cancer cell survival. Targeting SALL4, however, is only applicable in a fraction of cancer patients who are positive for this gene. To overcome this limitation, we propose to induce a cancer vulnerability by engineering a partial dependency upon SALL4. Following exogenous expression of SALL4, SALL4-negative cancer cells became partially dependent on SALL4. Treatment of SALL4-negative cells with the FDA-approved hypomethylating agent 5-aza-2'-deoxycytidine (DAC) resulted in transient upregulation of SALL4. DAC pretreatment sensitized SALL4-negative cancer cells to entinostat, which negatively affected SALL4 expression through a microRNA, miRNA-205, both in culture and in vivo. Moreover, SALL4 was essential for the efficiency of sequential treatment of DAC and entinostat. Overall, this proof-of-concept study provides a framework whereby the targeting pathways such as SALL4-centered therapy can be expanded, sensitizing cancer cells to treatment by transient target induction and engineering a dependency. SIGNIFICANCE: These findings provide a therapeutic approach for patients harboring no suitable target by induction of a SALL4-mediated vulnerability.

Zinc Finger Protein SALL4 Functions through an AT-Rich Motif to Regulate Gene Expression.

The zinc finger transcription factor SALL4 is highly expressed in embryonic stem cells, downregulated in most adult tissues, but reactivated in many aggressive cancers. This unique expression pattern makes SALL4 an attractive therapeutic target. However, whether SALL4 binds DNA directly to regulate gene expression is unclear, and many of its targets in cancer cells remain elusive. Here, through an unbiased screen of protein binding microarray (PBM) and cleavage under targets and release using nuclease (CUT&RUN) experiments, we identify and validate the DNA binding domain of SALL4 and its consensus binding sequence. Combined with RNA sequencing (RNA-seq) analyses after SALL4 knockdown, we discover hundreds of new SALL4 target genes that it directly regulates in aggressive liver cancer cells, including genes encoding a family of histone 3 lysine 9-specific demethylases (KDMs). Taken together, these results elucidate the mechanism of SALL4 DNA binding and reveal pathways and molecules to target in SALL4-dependent tumors.

Early impact of the Australian national shingles vaccination program with the herpes zoster live attenuated vaccine.

Herpes zoster (shingles) is a painful condition resulting from reactivation of latent varicella zoster virus (VZV). The Australian National Shingles Vaccination Program (commenced November 2016) provides free herpes zoster vaccination for eligible adults aged 70 years, with a 5-year catch-up program (until October 2021) for adults aged 71-79 years. Patterns and impact of the program were evaluated by analysis of vaccine distribution and delivery data and specific antiviral prescription data from the Pharmaceutical Benefits Scheme. During the first 2 years, uptake of funded live attenuated shingles vaccine ZOSTAVAX® (Zoster Virus Vaccine Live; ZVL) was high across the ongoing and catch-up programs. Before program implementation (2006-2016), herpes zoster coded antiviral prescription rates increased by 2.2% per year (95% CI: 1.5, 2.9) in the 70-79 years age group. In the two years since program launch, herpes zoster antiviral prescription rates declined substantially in this age group, by an average of 13.6% per year (95% CI: 1.5, 24.2). These results indicate that the National Shingles Vaccination Program has been highly successful in vaccinating a considerable proportion of Australian adults aged 70-79 years against herpes zoster and suggest that vaccine uptake was associated with decreased incidence of herpes zoster.

New High-Throughput Screening Identifies Compounds That Reduce Viability Specifically in Liver Cancer Cells That Express High Levels of SALL4 by Inhibiting Oxidative Phosphorylation.

BACKGROUND & AIMS: Some oncogenes encode transcription factors, but few drugs have been successfully developed to block their activity specifically in cancer cells. The transcription factor SALL4 is aberrantly expressed in solid tumor and leukemia cells. We developed a screen to identify compounds that reduce the viability of liver cancer cells that express high levels of SALL4, and we investigated their mechanisms. METHODS: We developed a stringent high-throughput screening platform comprising unmodified SNU-387 and SNU-398 liver cancer cell lines and SNU-387 cell lines engineered to express low and high levels of SALL4. We screened 1597 pharmacologically active small molecules and 21,575 natural product extracts from plant, bacteria, and fungal sources for those that selectively reduce the viability of cells with high levels of SALL4 (SALL4hi cells). We compared gene expression patterns of SALL4hi cells vs SALL4-knockdown cells using RNA sequencing and real-time polymerase chain reaction analyses. Xenograft tumors were grown in NOD/SCID gamma mice from SALL4hi SNU-398 or HCC26.1 cells or from SALL4lo patient-derived xenograft (PDX) cells; mice were given injections of identified compounds or sorafenib, and the effects on tumor growth were measured. RESULTS: Our screening identified 1 small molecule (PI-103) and 4 natural compound analogues (oligomycin, efrapeptin, antimycin, and leucinostatin) that selectively reduced viability of SALL4hi cells. We performed validation studies, and 4 of these compounds were found to inhibit oxidative phosphorylation. The adenosine triphosphate (ATP) synthase inhibitor oligomycin reduced the viability of SALL4hi hepatocellular carcinoma and non-small-cell lung cancer cell lines with minimal effects on SALL4lo cells. Oligomycin also reduced the growth of xenograft tumors grown from SALL4hi SNU-398 or HCC26.1 cells to a greater extent than sorafenib, but oligomycin had little effect on tumors grown from SALL4lo PDX cells. Oligomycin was not toxic to mice. Analyses of chromatin immunoprecipitation sequencing data showed that SALL4 binds approximately 50% of mitochondrial genes, including many oxidative phosphorylation genes, to activate their transcription. In comparing SALL4hi and SALL4-knockdown cells, we found SALL4 to increase oxidative phosphorylation, oxygen consumption rate, mitochondrial membrane potential, and use of oxidative phosphorylation-related metabolites to generate ATP. CONCLUSIONS: In a screening for compounds that reduce the viability of cells that express high levels of the transcription factor SALL4, we identified inhibitors of oxidative phosphorylation, which slowed the growth of xenograft tumors from SALL4hi cells in mice. SALL4 activates the transcription of genes that regulate oxidative phosphorylation to increase oxygen consumption, mitochondrial membrane potential, and ATP generation in cancer cells. Inhibitors of oxidative phosphorylation might be used for the treatment of liver tumors with high levels of SALL4.

Increasing trends of herpes zoster in Australia.

BACKGROUND: Increasing trends in incidence of herpes zoster (HZ) have been reported in Australia and internationally. This may reflect the impact of childhood VZV vaccination programs introduced universally in Australia in late 2005. The objective of this study was to evaluate changes in incidence of HZ and PHN in Australia over time, and associated healthcare resource utilisation. METHODS: Australian data on general practice (GP) encounters for HZ, specific antiviral prescribing data from the pharmaceutical benefits scheme, emergency department presentations from the states of NSW and Victoria and national hospitalisation data for HZ were analysed for time trends using regression models. Two time periods (2000-2006 and 2006-2013) were compared which correspond broadly with the pre- and post- universal VZV vaccination period. RESULTS: All data sources showed increasing rates of HZ with age and over time. The GP database showed a significant annual increase in encounters for HZ of 2.5 per 100,000 between 1998 and 2013, and the rates of prescriptions for HZ increased by 4.2% per year between 2002 and 2012. In the 60+ population HZ incidence was estimated to increase from 11.9 to 15.4 per 1,000 persons using GP data or from 12.8 to 14.2 per 1,000 persons using prescription data (p<0.05, between the two periods). Hospitalisation data did not show the same increasing trend over time, except for the age group ≥80 years. Most emergency visits for HZ were not admitted, and showed significant increases over time. DISCUSSION: The burden of HZ in Australia is substantial, and continues to increase over time. This increase is seen both pre- and post-universal VZV vaccination in 2005, and is most prominent in the older population. The substantial burden of HZ, along with ageing of the Australian population and the importance of healthy ageing, warrants consideration of HZ vaccination for the elderly.

Decreased management of genital warts in young women in Australian general practice post introduction of national HPV vaccination program: results from a nationally representative cross-sectional general practice study.

OBJECTIVES: Since the introduction of Australia's human papillomavirus vaccination program, the management rate of genital warts in sexual health clinics and private hospitals has decreased in women of vaccine-eligible age. However, most genital warts in Australia are managed in general practice. This study examines whether a similar decrease occurred in Australian general practice after the introduction of the program. METHODS: Analysis of a nationally representative cross-sectional database of Australian general practice activity (1,175,879 patient encounters with 11,780 general practitioners). Genital warts management rates were estimated for the periods before and after introduction of the program (Pre-program, July 2002-June 2006; Post-program, July 2008-June 2012). Control conditions included genital herpes and gardnerella/bacterial vaginosis in female patients and genital herpes and urethritis in male patients. Trends in management rates by year, pre-vaccine (July 2000-June 2007) and post-vaccine (July 2007-June 2012) were also calculated. RESULTS: Management rate of genital warts among women potentially covered by program (aged 15-27 years) decreased by 61% from 4.33 per 1,000 encounters in the Pre-program period to 1.67 in the Post-program period. Trend analysis of the post-vaccine period showed, among women of vaccine eligible age, a significant year-on-year reduction in the rate of genital warts management (p<0.0001) and a significant increase in the management rate of control conditions per year (p<0.0001). For all other age-sex groups there was no significant change in the management rate of genital warts between the Pre- and Post-program periods. CONCLUSION: The large decrease in general practice management of genital warts in women of vaccine-eligible age highlights the success of the program in the wider community.

Geographical clustering of anal cancer incidence in Australia.

INTRODUCTION: Homosexual men are at an increased risk of anal cancer. We aimed to establish the burden of anal squamous cell carcinoma (SCC) in those parts of Australia where homosexual men are most likely to live. METHODS: Data on the proportion of homosexual male residents were obtained from published estimates. Men were categorised into three postcode groups by prevalence of men reporting homosexual identity. Male population data in age groups were extracted for each postcode group and analyses of cancer incidence were performed by postcode group. The analyses were restricted to 2000-2005. RESULTS: Eight postcodes had populations where more than 10% of males reported homosexual identity (high prevalence) and 4-10% of men reported homosexual activity in a further 19 postcodes (medium prevalence). From 2000 to 2005, the average annual age-standardised incidence rates of anal SCC in males was 7.61 per 100000 (95% confidence interval (CI): 4.68-10.55) and 2.21 per 100000 (95% CI: 1.05-3.37) in high and medium prevalence postcodes, respectively. The corresponding incidence rate ratios compared with low prevalence postcodes (less than 4% of males reported homosexual identity) were 9.6 (95% CI: 6.6-14.1) for the high prevalence and 2.4 (95% CI: 1.4-4.1) for the medium prevalence postcodes. CONCLUSION: A substantial concentration of the burden of anal cancer occurred among areas where large proportions of homosexual men reside. These results should guide the prioritisation of health service investment in anal cancer treatment and prevention to appropriate geographical areas.

Trends in anal cancer in Australia, 1982-2005.

BACKGROUND: Most anal squamous cell carcinomas (SCCs) are caused by high risk types of human papillomavirus (HPV) and are potentially preventable by HPV vaccination. In order to understand the burden of potentially preventable anal cancer in Australia, we examine the incidence and survival from invasive anal SCC 1982-2005. METHODS: We reviewed data on invasive anal cancer cases notified to the National Cancer Statistics Clearing House. Age specific incidence rates of SCC were calculated by year of cancer diagnosis and by birth cohort, and rates of anal adenocarcinoma were included for comparison. Incidence rates were age standardised to the Australian 2001 standard population. Trends in relative survival of SCC were examined. RESULTS: During the study period, a total of 4615 invasive anal cancer cases were diagnosed and most (69.7%) were SCC. Annual incidence of SCC increased almost 50%, from 0.65 to 1.00/100,000. Incidence increased at all ages. The annual rate of increase was almost two-folder higher in men (3.42%, 95% CI 2.49-4.35) than in women (1.88%, 95% CI 1.18-2.58). Five-year relative survival increased by nearly 10% from 58.9% to 68.3% over the last 20 years. Younger patients and women had better survival. For anal adenocarcinoma, increases of borderline significance were seen in men and women. CONCLUSION: There is an increasing burden of anal SCC in Australia. The group with the highest incidence - homosexual men - are not likely to be protected under the current vaccination policy.

Cancers attributable to human papillomavirus infection.

Although the human papillomavirus (HPV) vaccine was introduced primarily as a cervical cancer prevention vaccine, HPV has a causal role in several types of cancer. This article reviews the epidemiological evidence for the role of HPV in human cancer, and describes Australian trends in these cancers. HPV is a necessary cause of cervical cancer. The currently vaccine-preventable subtypes of HPV 16 and 18 are responsible for ~70% of cervical cancer. The introduction of an organised Pap smear program in Australia led to a steep decline in incidence over the past decades. HPV can be detected in ~40% and 70% of vulval and vaginal cancers respectively. Rates of these cancers have been stable over the past 20 years. The prevalence of HPV in penile cancer is ~50% and incidence has not recently changed. For anal cancer, ~85% of cases are HPV positive, and incidence has increased significantly in both men and women over the past 20 years. In the oral cavity, ~35% of oropharyngeal cancers and ~25% of other oral cavity cancers are HPV positive. The incidence of HPV-related oral cavity and oropharyngeal cancers is increasing, whereas incidence at HPV-unrelated sites is decreasing. Overall, 1154 HPV-related cancer cases were potentially preventable by vaccination. If HPV-related cancers at non-cervical sites are prevented by vaccination, then a similar number of cancer cases will be prevented as in the cervix. However, almost one-quarter of the potentially preventable cancer cases are in men, who are not included in the current national immunisation program.

Genital warts incidence and healthcare resource utilisation in Australia.

OBJECTIVES: To estimate for the first time the incidence and healthcare resource utilisation associated with genital warts (GW) in Australia prior to the human papillomavirus vaccination programme. METHOD: The authors analysed data from the nationally representative Bettering the Evaluation of Care and Health general practice cross-sectional programme and from the National Hospital Morbidity Database to estimate age-related incidence and community (non-hospital) and hospital-related costs (in 2009 Australian dollars) associated with medical treatment of GW. RESULTS: The authors estimated an annual incidence of 2.19 cases of GW per 1000 Australians (95% CI 1.88 to 2.49), with peak incidence in women aged 20-24 years at 8.61 cases per 1000 and in men aged 25-29 years at 7.40 cases per 1000. The estimated number of consultations per GW case was 2.9 (95% CI 2.5 to 3.3) for women and 2.8 (95% CI 2.3 to 3.2) for men. Ablative treatments in general practice were more common in men (60% of consultations) than in women (37% of consultations). In contrast, more women (16% vs 8%) were referred to specialists, and 75% of ablative procedures requiring hospitalisation were performed in women. The annual cost of management of GW is over A$14 million, with an estimated cost per treated case of A$251 for men and A$386 for women. CONCLUSIONS: GW impose a large health and cost burden on Australians. The national immunisation programme with the quadrivalent human papillomavirus vaccine has the potential to greatly reduce this burden, and future research measuring its impact is keenly anticipated.

Patterns of treatment of external genital warts in Australian sexual health clinics.

BACKGROUND: External genital warts are a common sexually transmitted viral disease. We describe the patterns of treatment for initial presentations of external genital warts (EGWs) in Australian sexual health centers. METHODS: This was a retrospective audit of 489 case notes from consecutive individuals who presented with a new diagnosis of EGWs to 1 of 5 major sexual health clinics in Australia. Eligibility criteria were consecutive patients aged 18 to 45 years inclusively, presenting with first ever episode of EGWs from January 1, 2004. Exclusion criteria were patients who were immunocompromised, including HIV infection, or enrollment in a treatment study for EGWs. RESULTS: The median age at presentation of women was 23.2 years and of men 26.8 years. One quarter (n = 127) of patients had another sexually transmitted infection diagnosed at presentation. Nearly half of the patients (n = 224) presented only once for treatment. Most often, patients were treated with a monotherapy (n = 382/489; 78%), usually cryotherapy (257; 53%). Staff applied treatment in 361 (74%) cases. There was wide variation across sites, possibly reflecting local policies and budgets. We found no difference in wart resolution (n = 292; 60%) by initial treatment chosen. CONCLUSIONS: The diagnosis and treatment of genital warts constitute a sizable proportion of clinical visits to the audited sexual health services and require a large input of staff time to manage, including the application of topical treatments. Our results help complete the picture of the burden of EGWs on Australian sexual health centers before the introduction of the HPV vaccine.

Herpes zoster burden of illness and health care resource utilisation in the Australian population aged 50 years and older.

Incidence of zoster and post-herpetic neuralgia (PHN) and associated health care resource utilisation were investigated in the Australian population aged > or =50 years, using general practice data from 2000 to 2006, and pharmaceutical prescribing, hospital morbidity and emergency department data from 1998 to 2005. Zoster and PHN incidence rates were estimated as approximately 10/1000 and 1.45/1000 persons, respectively, with antivirals prescribed for 73.5% of zoster cases. Estimated hospitalisation and emergency department visit rates were 0.67/1000 and 0.38/1000 persons, respectively. Management of zoster (including PHN) involved approximately 2.4 general practitioner consultations. Total costs to the health care system were estimated as approximately 32.8 million per year. The substantial burden of zoster and PHN highlights the potential benefit of zoster vaccination.

The contribution of podocytes to chronic allograft nephropathy.

BACKGROUND: Progressive proteinuria and glomerulosclerosis characterize chronic allograft nephropathy. However, the causes are not fully elucidated. Podocytes function to prevent proteinuria; injury to this glomerular cell leads to glomerulosclerosis. The potential role of podocytes in the failing transplanted kidney is unknown. A rat model of kidney transplantation, characterized by proteinuria and glomerulosclerosis, was utilized to examine the potential role of podocytes. METHODS: Archival tissue was examined from allografts (Dark Agouti kidneys transplanted into operationally tolerant Albino Surgery rats), isografts (Dark Agouti) and controls (Dark Agouti: age-matched or after unilateral nephrectomy). The number of podocytes (by WT-1 staining) as well as the podocyte proteins podocin, nephrin and synaptopodin (by immunostaining) were measured at days 0, 2, 6 and at 6 months after transplantation. Changes in these parameters were compared between groups and correlated with urinary protein excretion. RESULTS: At 6 months, podocyte number was reduced in allografted kidneys, accompanied by a decrease in nephrin and synaptopodin, but not podocin staining. Remnant kidneys in the uninephrectomized rats also showed a decreased podocyte number but no change in podocyte protein staining. Podocyte loss in allografts was established on day 6, whereas a decrease in nephrin and synaptopodin was not evident until 6 months. In contrast, podocyte number and protein staining was decreased but not significantly so in remnant and isografted kidneys. CONCLUSION: A decrease in the slit diaphragm proteins, nephrin and synaptopodin, is a component of chronic allograft pathology.

Late onset antibody-mediated rejection and endothelial localization of vascular endothelial growth factor are associated with development of cardiac allograft vasculopathy.

BACKGROUND: Improvements in cardiac transplant practice and immunosuppressive treatment have done much to curb the incidence of acute cellular rejection (ACR); however, antibody-mediated rejection (AMR) and cardiac allograft vasculopathy (CAV) remain prevalent. Recent studies have shown that allograft rejection is governed by both allogeneic and nonallogeneic factors such as inflammation. Initial studies have suggested that vascular endothelial growth factor (VEGF), a leukocyte mitogen produced by activated endothelial cells and leukocytes, may play a specific role in not only leukocyte trafficking, but also in the augmentation of ACR and development of CAV. METHODS: We investigated the localization of VEGF protein using immunohistochemistry in a cohort of 76 heart transplant patients during periods of ACR and AMR and assessed the development of CAV. RESULTS: We showed a significant correlation between lymphocytic localization of VEGF protein and severe ACR (P<0.001). Antibody-mediated rejection positive biopsies taken at 12 months posttransplantation showed significantly greater endothelial localization of VEGF than time-matched AMR negative biopsies (P=0.006). Diffuse endothelial expression of VEGF was also associated with a 2.5-fold increase in the risk of developing CAV (P=0.001). CONCLUSIONS: These results show that localization of VEGF protein to the vascular endothelium during AMR is significantly increased in patients who develop CAV. This study also highlights the potential pathogenic role of the endothelial cell in late onset AMR and the development of CAV.

Increased vascular endothelial growth factor mRNA in endomyocardial biopsies from allografts demonstrating severe acute rejection: a longitudinal study.

Investigation into the contribution of the immune system and inflammatory cascade to acute rejection (AR) and cardiac allograft vasculopathy (CAV) has implicated vascular endothelial growth factor (VEGF). The endomyocardial biopsy (EB) has proved invaluable in the diagnosis of AR, and in providing information concerning the biological processes occurring following transplantation. The association between VEGF and AR and the development of CAV was examined in endomyocardial biopsies (EBs) from a cohort of 76 heart transplant recipients. VEGF mRNA levels were quantified through real time RT-PCR in 712 EBs, obtained at routine intervals during post-operative monitoring. VEGF and leukocyte and endothelial markers were assessed in a subset of biopsies through immunohistochemistry. The results of generalised linear modelling, adjusting for covariates, revealed VEGF mRNA expression was 19% greater during severe AR as compared to no rejection (p=0.007). Immunohistochemical results supported these findings. Mean VEGF mRNA levels were not significant predictors for the development of CAV (p=0.554). However the risk of cardiac related death increased 9-fold for a 1 unit increase in mean VEGF expression (p=0.006). Similarly, a single unit increase in mean AR severity equated to a 10-fold increase in the risk of cardiac related death (p<0.005). Our data suggest that increased VEGF expression is strongly associated with severe AR and cardiac related death.