Serological evidence of exposure of healthy dogs to Leptospira in Sydney, New South Wales, Australia

In 2017, highly fatal canine leptospirosis emerged in Sydney, Australia. Based on results of microscopic agglutination testing (MAT), serovar Copenhageni appeared to be the most common causative serovar. Prior to this, no clinical cases had been reported since 1976. In a serosurvey of healthy dogs in Australian shelters in 2004, 2.4% of 431 New South Wales dogs had serological evidence of exposure to Copenhageni, the most prevalent serovar. The aim of this study was to estimate the current prevalence of Leptospira exposure and associated serovars in healthy Sydney dogs, previously unvaccinated against Leptospira. Serum samples from 411 healthy dogs in leptospirosis hotspots and neighbouring suburbs were collected before vaccination. MAT for 23 serovars was performed at the WHO Leptospirosis Reference Laboratory in Queensland, Australia. The overall seroprevalence was 4.1% (17/411) with low titres (1/50-1/200) detected. Eleven dogs were from known leptospirosis hotspots. Eight dogs were known to hunt rodents. One dog had been in contact with a leptospirosis positive dog 1 year prior. Serovar Topaz was the most prevalent serovar (n = 5) followed by serovars Australis (n = 4), Copenhageni (n = 4), Djasiman (n = 2), Cynopteri (n = 1), Javanica (n = 1), Medanensis (n = 1), and Pomona (n = 1). In conclusion, serological evidence of exposure of dogs in Sydney to Leptospira is low, but apparently has increased since 2004. Positive titres to serovars not previously reported to cause disease in dogs could be due to low virulence of those serovars or cross-reactivity with other serovars.

Low prevalence of antimicrobial resistant organisms (methicillin resistant Staphylococcus aureus, extended beta-lactamase producing Enterobacteriaceae, and vancomycin resistant enterococci) in bulk tank milk in New South Wales, Australia

OBJECTIVE

Estimate the presence of methicillin resistant Staphylococcus aureus (MRSA), extended beta-lactamase (ESBL) producing Enterobacteriaceae, and vancomycin resistant enterococci (VRE) in bulk tank milk in dairy herds in New South Wales (NSW), Australia.

METHODS

Bulk tank milk samples (n = 80) were collected from dairy farms (n = 40, i.e. 2 per farm) in NSW during 2021. Bacteria were cultured using selective chromogenic indicator media with isolate identity confirmed using biochemical testing, Gram stain, and MALDI-TOF mass spectroscopy. Antimicrobial resistance (AMR) was confirmed using antibiotic disk diffusion.

RESULTS

No samples tested positive to the targeted AMR organisms.

CONCLUSION

The prevalence of MRSA, ESBL-producing Enterobacteriaceae, and VRE is low in NSW dairy herds.

A framework for evaluation of on-farm mastitis diagnostics in Australia

Numerous culture-based diagnostics are available on the Australian and international markets for on-farm detection of bacterial pathogens in milk. Use of such diagnostics may provide an opportunity to improve the prudent use of antimicrobials in udder health management. Farms are low-resource settings in terms of diagnostic microbiology capacity. The World Health Organisation has identified criteria for the evaluation of diagnostic tests in low resource settings based on Accuracy, Sensitivity, Specificity, User-friendliness, being Rapid or Robust, Equipment-free and being Deliverable (ASSURED). Here, we review how those criteria can be interpreted in the context of microbiological diagnosis of mastitis pathogens, and how on-farm diagnostics that are currently available in Australia perform relative to ASSURED criteria. This evaluation identifies multiple trade-offs, both with regard to scientific criteria and with regards to convenience criteria. More importantly, the purpose of testing may differ between farms, and test performance should be evaluated relative to its intended use. The ability of on-farm mastitis diagnostics to inform mastitis treatment decision-making in a timely and cost-effective manner depends not just on test characteristics but also on farm-specific pathogen prevalence, and on the farm enterprise's priorities and the farm manager's potential courses of action. With most assay evaluations to date conducted in professional laboratories, there is a surprising dearth of information on how well any of the diagnostic tests perform on-farm and, indeed, of the on-farm decision-making processes that they aim to inform.

A 2-4 keV multilayer mirrored channel for the NIF Dante system

During inertial confinement fusion experiments at the National Ignition Facility (NIF), a capsule filled with deuterium and tritium (DT) gas, surrounded by a DT ice layer and a high-density carbon ablator, is driven to the temperature and densities required to initiate fusion. In the indirect method, 2 MJ of NIF laser light heats the inside of a gold hohlraum to a radiation temperature of 300 eV; thermal x rays from the hohlraum interior couple to the capsule and create a central hotspot at tens of millions degrees Kelvin and a density of 100-200 g/cm³. During the laser interaction with the gold wall, m-band x rays are produced at ∼2.5 keV; these can penetrate into the capsule and preheat the ablator and DT fuel. Preheat can impact instability growth rates in the ablation front and at the fuel-ablator interface. Monitoring the hohlraum x-ray spectrum throughout the implosion is, therefore, critical; for this purpose, a Multilayer Mirror (MLM) with flat response in the 2-4 keV range has been installed in the NIF 37° Dante calorimeter. Precision engineering and x-ray calibration of components mean the channel will report 2-4 keV spectral power with an uncertainty of ±8.7%.

Factors influencing dairy cattle farmer use of antimicrobials on farms in New South Wales, Australia

Antimicrobial use (AMU) in the food chain is a potential driver of antimicrobial resistance. Despite Australia's strong regulation of AMU limited to veterinary prescriptions, a proportion of empirical antimicrobial treatments are administered by dairy farmers to manage common cattle health problems. This cross-sectional survey identified key influences on AMU by dairy cattle farmers within New South Wales, Australia, to detect opportunities for antimicrobial stewardship (AMS) engagement. The study identified existing relationships, resources and attitudes of the dairy farmers that could be optimised for on-farm AMS strategies. Farmers were most highly influenced by veterinary advice and clinical signs of the animal followed by the withholding period and the potential for antimicrobial resistance development. Farmers' high confidence regarding their own knowledge of antimicrobials (>90%), their high regard for veterinary advice (>90%) and high rate of veterinary health care plan use (69%) provides a strong framework to build the profile and practice of AMS on dairy farms. Positive engagement by dairy farmers (survey response of 20%), was achieved by working with the NSW Food Authority. Despite respondents reporting low reliance on formal (government and commercial) organisations for information about AMU, their engagement demonstrates an opportunity for groups with unparalleled access to dairy farmers to drive AMS. An association between frequent use of veterinary advice and respondents keeping ceftiofur on-farm requires further investigation. Quantitative and qualitative analysis of on-farm resources, decision-making, and practices is required to understand how practices relate to veterinary advice and accepted standards of appropriate AMU on dairy farms.

Detection of Brucella spp. during a serosurvey of pig-hunting and regional pet dogs in eastern Australia

Brucellosis is a zoonotic disease with worldwide distribution. Brucella suis serotype 1 is thought to be maintained in the Australian feral pig population, with disease prevalence higher in Queensland (Qld) than New South Wales (NSW). Pig hunting is a popular recreational activity in rural Qld and NSW, with feral pigs in these states thought to carry B. suis. Brucellosis associated with B. suis has been diagnosed in dogs engaged in pig hunting in some of these areas. A total of 431 dogs from northern Qld and north‐west NSW were recruited. Two distinct cohorts of clinically healthy dogs were tested – (1) 96 dogs from central, north and far north Queensland actively engaged in pig‐hunting and (2) 335 dogs from rural and remote north‐west NSW that were primarily companion (non‐pig hunting) animals. Serum samples were tested for antibodies to Brucella spp. using the Rose Bengal test (RBT) test followed by complement fixation testing (CFT) for RBT‐positive samples. A subset of samples was retested using RBT and CFT. Seven dogs were considered seropositive for B. suis from Qld and remote NSW, including 4/96 (4.2%; 95% CI 3.5% to 4.3%) from the pig‐hunting cohort and 3/335 (0.9%) from the regional pet dog cohort. The use of RBT and CFT in dogs to detect anti‐Brucella antibodies requires validation. Veterinarians treating pig‐hunting dogs and physicians treating pig hunters in central, north and far north Qld need to be aware of the zoonotic risk posed by B. suis to these groups.

Feline immunodeficiency virus (FIV) infection in domestic pet cats in Australia and New Zealand: Guidelines for diagnosis, prevention and management

Despite the passage of over 30 years since its discovery, the importance of feline immunodeficiency virus (FIV) on the health and longevity of infected domestic cats is hotly debated amongst feline experts. Notwithstanding the absence of good quality information, Australian and New Zealand (NZ) veterinarians should aim to minimise the exposure of cats to FIV. The most reliable way to achieve this goal is to recommend that all pet cats are kept exclusively indoors, or with secure outdoor access (e.g., cat enclosures, secure gardens), with FIV testing of any in‐contact cats. All animal holding facilities should aim to individually house adult cats to limit the spread of FIV infection in groups of animals that are stressed and do not have established social hierarchies. Point‐of‐care (PoC) FIV antibody tests are available in Australia and NZ that can distinguish FIV‐infected and uninfected FIV‐vaccinated cats (Witness™ and Anigen Rapid™). Although testing of whole blood, serum or plasma remains the gold standard for FIV diagnosis, PoC testing using saliva may offer a welfare‐friendly alternative in the future. PCR testing to detect FIV infection is not recommended as a screening procedure since a negative PCR result does not rule out FIV infection and is only recommended in specific scenarios. Australia and NZ are two of three countries where a dual subtype FIV vaccine (Fel‐O‐Vax® FIV) is available and offers a further avenue for disease prevention. Since FIV vaccination only has a reported field effectiveness of 56% in Australia, and possibly lower in NZ, FIV‐vaccinated cats should undergo annual FIV testing prior to annual FIV re‐vaccination using a suitable PoC kit to check infection has not occurred in the preceding year. With FIV‐infected cats, clinicians should strive to be even more thorough than usual at detecting early signs of disease. The most effective way to enhance the quality of life and life expectancy of FIV‐infected cats is to optimise basic husbandry and to treat any concurrent conditions early in the disease course. Currently, no available drugs are registered for the treatment of FIV infection. Critically, the euthanasia of healthy FIV‐infected cats, and sick FIV‐infected cats without appropriate clinical investigations, should not occur.

Seroprevalence of Coxiella burnetii in pig-hunting dogs from north Queensland, Australia

The causative agent of Q fever, Coxiella burnetii, is endemic to Queensland and is one of the most important notifiable zoonotic diseases in Australia. The reservoir species for C. burnetii are classically ruminants, including sheep, cattle and goats. There is increasing evidence of C. burnetii exposure in dogs across eastern and central Australia. The present study aimed to determine if pig-hunting dogs above the Tropic of Capricorn in Queensland had similar rates of C. burnetii exposure to previous serosurveys of companion dogs in rural north-west New South Wales. A total of 104 pig-hunting dogs had serum IgG antibody titres to phase I and phase 2 C. burnetii determined using an indirect immunofluorescence assay test. Almost one in five dogs (18.3%; 19/104; 95% confidence interval 9.6%-35.5%) were seropositive to C. burnetii, with neutered dogs more likely to test positive compared to entire dogs (P = 0.0497). Seropositivity of the sampled pig-hunting dogs was one of the highest recorded in Australia. Thirty-nine owners of the pig-hunting dogs completed a survey, revealing 12.8% (5/39) had been vaccinated against Q fever and 90% (35/39) were aware that both feral pigs and dogs could potentially be sources of C. burnetii. Our findings indicate that pig hunters should be aware of the risk of exposure to Q fever during hunts and the sentinel role their dogs may play in C. burnetii exposure.

Emerging leptospirosis in urban Sydney dogs: a case series (2017-2020)

Canine leptospirosis has not been reported in the Sydney dog population since 1976. However, between 2017 and 2020, leptospirosis was confirmed in 17 dogs, five of which were known to hunt rodents. Dogs infected between 2017 and 2019 lived within a 3 km radius in the Inner City of Sydney (n = 11). In 2020, cases emerged across a broader area of Sydney; Inner City (n = 1), Inner West (n = 3), Lower North Shore (n = 1) and Upper North Shore (n = 1). The disease was characterised by severe hepatorenal involvement resulting in an unusually high case fatality rate (88%). In conjunction with supportive clinical signs, diagnosis was confirmed by real‐time PCR on whole blood (n = 1), kidney (n = 1), urine (n = 4), whole blood and urine (n = 9) or by seroconversion (n = 3). Antibody titres determined by Microscopic Agglutination Test (MAT) to Leptospira serovars were measured in 12 dogs: seven were positive for serovar Copenhageni, one was positive for serovar Hardjo, three were negative for all serovars, likely due to insufficient time for seroconversion before death and one had a low positive titre (1/50) for serovars Australis and Robinsoni. This sudden emergence of a highly fatal disease in pet dogs in Sydney has led to the introduction of Leptospira vaccination protocols for dogs living in inner Sydney using a monovalent vaccine containing serovar Copenhageni. The success of this vaccination program will require ongoing research to understand the emergence of leptospirosis in this region and the serovars involved.

1267 Utility of Artificial Intelligence in the Cystoscopic Detection of Bladder Cancer: A Systematic Review and Meta-Analysis

Aim

Detection of suspected bladder cancer at diagnostic cystoscopy is challenging and is dependent on clinician skill. Artificial Intelligence (AI) algorithms, specifically, machine learning and deep learning, have shown promise in accurate classification of pathological images in various specialties. However, utility of AI for urothelial cancer diagnosis is unknown. Here, we aimed to systematically review the extant literature in this field and quantitively summarise the role of these algorithms in bladder cancer detection.

Method

The EMBASE, PubMed and CENTRAL databases were searched up to December 22nd 2020 , in accordance with the PRISMA guidelines, for studies that evaluated AI algorithms for cystoscopic diagnosis of bladder cancer. Random-effects meta-analysis was performed to summarise eligible studies. Risk of Bias was assessed using the QUADAS-2 tool.

Results

Five from 6715 studies met criteria for inclusion. Pooled sensitivity and specificity values were 0.93 (95% CI 0.89–0.95) and 0.93 (95% CI 0.80–0.89) respectively. Pooled positive likelihood and negative likelihood ratios were 14 (95% CI 4.3–44) and 0.08 (95% CI: 0.05–0.11), respectively. Pooled diagnostic odds ratio was 182 (95% CI 61–546). Summary AUC curve value was 0.95 (95% CI 0.93–0.97). No significant publication bias was noted.

Conclusions

In summary, AI algorithms performed very well in detection of bladder cancer in this pooled analysis, with high sensitivity and specificity values. However, as with other clinical AI usage, further external validation through deployment in real clinical situations is essential to assess true applicability of this novel technology.

Should we perform systematic biopsies in case of suspicious MRI for prostate cancer in 2020? A review of literature

CONTEXT

Multiparametric magnetic resonance imaging (MRI) is now recommended before performing prostate biopsies, looking for suspicious lesions to perform targeted biopsies (TB). However, the association or exclusive performance of systematic biopsies (SB), criticized for its morbidity and for the detection of insignificant cancers, remains debated.

OBJECTIVE

To perform a literature review to answer three questions: (1) In the presence of a suspicious MRI lesion, should we always perform SB in addition to TB? (2) Can we avoid SB when considering focal treatment? (3) Is there an increase in adverse events when associating SB with TB?

SOURCES

A non-systematic literature review was carried out on Medline in April 2020 using the keywords "MRI", "PROSTATE CANCER", "SYSTEMATIC BIOPSY", "TARGETED BIOPSY", "ADVERSE EVENTS". The references of the selected articles were analyzed for additional articles. Selection of Studies published in the last five years were analyzed and retained if the available data made it possible to answer one of the three questions asked.

RESULTS

In biopsy-naive patients, the added value of SB to TB for detection of significative cancer varied from +5 to+7% and was reduced to +1 to +3% in the case of a previous series of negative biopsies. For patients under active surveillance, this added value was higher, ranging from +8% to +17%. MRI has a negative predictive value of 85 to 95%, but this value drops to 55% for the detection of secondary or tertiary foci. The use of SB is necessary if focal treatment is considered. Serious complications from biopsies requiring hospitalization range from 1.4 to 6.9% and are increased by the number of previous biopsy series performed more than by the number of biopsies per series.

CONCLUSION

In the presence of a suspicious MRI lesion, SB is indicated in addition to TB but can be discussed in patients with previous negative biopsies. They are necessary if focal treatment is considered to aid surgical planning. Severe complications from biopsies do not seem to increase when SB are associated to TB, but rather with the number of biopsy series performed.

What to expect from a non-suspicious prostate MRI? A review

BACKGROUND

Many guidelines now recommend multiparametric MRI (mpMRI) prior to an initial or repeat prostate biopsy. However, clinical decision making for men with a non-suspicious mpMRI (Likert or PIRADS score 1-2) varies.

OBJECTIVES

To review the most recent literature to answer three questions. (1) Should we consider systematic biopsy if mpMRI is not suspicious? (2) Are there additional predictive factors that can help decide which patient should have a biopsy? (3) Can the low visibility of some cancers be explained and what are the implications?

SOURCES

A narrative review was performed in Medline databases using two searches with the terms "MRI" and "prostate cancer" and ("diagnosis" or "biopsy") and ("non-suspicious" or "negative" or "invisible"); "prostate cancer MRI visible". References of the selected articles were screened for additional articles.

STUDY SELECTION

Studies published in the last 5 years in English language were assessed for eligibility and selected if data was available to answer one of the three study questions.

RESULTS

Considering clinically significant cancer as ISUP grade≥2, the negative predictive value (NPV) of mpMRI in various settings and populations ranges from 76% to 99%, depending on cancer prevalence and the type of confirmatory reference test used. NPV is higher among patients with prior negative biopsy (88-96%), and lower for active surveillance patients (85-90%). The PSA density (PSAd) with a threshold of PSAd<0.15ng/ml/ml was the most studied and relevant predictive factor used in combination with mpMRI to rule out clinically significant cancer. Finally, mpMRI-invisible tumours appear to differ from a histopathological and genetic point of view, conferring clinical advantage to invisibility.

LIMITATIONS

Most published data come from expert centres and results may not be reproducible in all settings.

CONCLUSION

mpMRI has high diagnostic accuracy and in cases of negative mpMRI, PSA density can be used to determine which patient should have a biopsy. Growing knowledge of the mechanisms and genetics underlying MRI visibility will help develop more accurate risk calculators and biomarkers.

A history of canine parvovirus in Australia: what can we learn?

Canine parvovirus (CPV) has been reported throughout the world since the late 1970s. Published information was reviewed to draw insights into the epidemiology, pathogenesis, diagnosis, treatment and outcomes of CPV disease in Australia and the role of scientific research on CPV occurrence, with key research discoveries and knowledge gaps identified. Australian researchers contributed substantially to early findings, including the first reported cases of parvoviral myocarditis, investigations into disease aetiopathogenesis, host and environmental risk factors and links between CPV and feline panleukopenia. Two of the world's first CPV serological surveys were conducted in Australia and a 1980 national veterinary survey of Australian and New Zealand dogs revealed 6824 suspected CPV cases and 1058 deaths. In 2010, an Australian national disease surveillance system was launched; 4940 CPV cases were reported between 2009 and 2014, although underreporting was likely. A 2017 study estimated national incidence to be 4.12 cases per 1000 dogs, and an annual case load of 20,110 based on 4219 CPV case reports in a survey of all Australian veterinary clinics, with a 23.5% response rate. CPV disease risk factors identified included socioeconomic disadvantage, geographical location (rural/remote), season (summer) and rainfall (recent rain and longer dry periods both increasing risk). Age <16 weeks was identified as a risk factor for vaccination failure. Important knowledge gaps exist regarding national canine and feline demographic and CPV case data, vaccination coverage and population immunity, CPV transmission between owned dogs and other carnivore populations in Australia and the most effective methods to control epizootics.

Canine parvovirus prevention-What influence do socioeconomics, remoteness, caseload and demographics have on veterinarians' perceptions and behaviors?

Canine parvovirus (CPV) is a cause of severe disease in dogs globally, yet is preventable by vaccination. A range of vaccination protocols are used by veterinary practitioners with evidence suggesting some protocols provide better protection than others in high infection-risk situations. This study investigated associations between veterinarians' vaccination recommendations and hospital remoteness, socioeconomic disadvantage, CPV caseload, and veterinarian perceptions and demographics. A national Australian veterinary survey in 2017 received 569 practitioner responses from 534 unique hospitals (23.6 % response rate). Respondents from major city hospitals had the lowest perceptions of the national CPV caseload (p < 0.0001). Those from hospitals with mild to moderate caseloads (6-40 cases per annum) recommended more frequent puppy revaccination - which is considered more protective - than those with the highest caseload (p = 0.0098), which might increase vaccination failure risk. Respondents from the most socioeconomically disadvantaged regions were over-represented in recommending annual revaccination of adult dogs; those from the least disadvantaged regions were over-represented in recommending triennial revaccination (p < 0.0001). Hospitals with higher CPV caseloads, greater socioeconomic disadvantage or increased remoteness did not favor two puppy vaccination protocols that are considered more protective (younger first vaccination age or older final vaccination age), despite these regions presenting higher CPV caseload risk. Titer testing to determine whether to revaccinate was more likely to be used in major city hospitals (p = 0.0052) and less disadvantaged areas (p = 0.0550). University of graduation was associated with CPV caseload, remoteness and level of socioeconomic disadvantage of the region where the graduate worked. University of graduation was significantly associated with age for final puppy vaccination and titer-testing recommendations. Graduates from one university were over-represented in recommending an earlier (10-week) finish protocol and titer testing, compared to all other universities. Year and university of graduation, and respondent's age were associated with a number of vaccination protocol recommendations suggesting that inherent biases might affect veterinarians' decisions. Emphasis on currently recommended vaccination protocols in undergraduate curricula and more protective vaccination protocol use in higher-risk regions could reduce immunization failure and CPV caseload.

SAT0596 ASSOCIATIONS BETWEEN CIRCULATING LIPID MEDIATORS AND INCIDENT INFLAMMATORY ARTHRITIS IN AN ANTI-CITRULLINATED PROTEIN ANTIBODY POSITIVE POPULATION

Background:

Lipid mediators are endogenously derived from the metabolism of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) and have important roles in promoting and resolving inflammation in the body (1). Epidemiological studies have shown higher omega-3 PUFA status to be associated with a lower risk of both autoimmunity and progression to inflammatory arthritis (IA) (2,3).

Objectives:

To determine the association of lipid mediators with progression from rheumatoid arthritis (RA)-related autoimmunity to inflammatory arthritis (IA).

Methods:

We conducted a prospective cohort study using data from the Studies of the Etiologies of Rheumatoid Arthritis (SERA). SERA enrolled first-degree relatives (FDRs) of individuals with RA (FDR cohort) and individuals who screened positive for RA-related autoantibodies at health fairs (screened cohort). We followed 133 anti-CCP3.1 positive participants, of which 29 developed IA (22 classified as RA by 2010 ACR/EULAR criteria). We quantified lipid mediators from stored plasma samples via liquid chromatography tandem mass spectrometry methods validated against the collection and storage methods used in the study. A priori, we selected 5S-HETE, 15S-HETE and 17S-HDHA because they are precursors to leukotrienes, Lipoxin A4 and Resolvin D series lipid mediators, respectively. We fit Cox proportional hazard models for each lipid mediator as a time-varying covariate. For lipid mediators significantly associated with progression to IA we then examined IL-1β, IL-6, IL-8 and TNF-α (Bio-Plex Pro™ assay) as potential mediators of this relationship.

Results:

Higher plasma 5S-HETE levels were associated with an increased risk of incident IA after adjusting for age at baseline, cohort (FDR or screened), and shared epitope (SE) status (Table 1). The models examining 15S-HETE and 17S-HDHA had the same trend but did not reach statistical significance. We did not find evidence that the association between 5S-HETE and IA risk was mediated by the tested pro-inflammatory cytokines, suggesting a direct role for this lipid mediator in conversion to IA.

Table 1.

Hazard ratios and 95% confidence intervals of lipid mediator concentrations associated with IA, n=29 IA cases

Lipid mediatorCrudeAdjustedb5S-HETE2.10 (1.12, 3.92)2.41 (1.43, 4.07)15S-HETE1.61 (0.88, 2.93)1.52 (0.87, 2.65)17-HDHAa1.59 (0.68, 3.74)1.61 (0.72, 3.56)

adichotomized as <limit of detection (reference) or detected

bAdjusted for SE, age at baseline and cohort

Conclusion:

In a prospective cohort of anti-CCP positive individuals, higher circulating levels of 5S-HETE, an important precursor to pro-inflammatory leukotrienes, was associated with subsequent IA. Our findings highlight the potential pathologic and prognostic significance of these PUFA metabolites in inflammatory processes in pre-RA populations.

References:

[1]Serhan CN. Pro-resolving lipid mediators are leads for resolution physiology. Nature. 2014;510(7503):92-101.

[2]Gan RW, Bemis EA, Demoruelle MK, Striebich CC, Brake S, Feser ML, et al. The association between omega-3 fatty acid biomarkers and inflammatory arthritis in an anti-citrullinated protein antibody positive population. Rheumatology. 2017.

[3]Gan RW, Young KA, Zerbe GO, Demoruelle MK, Weisman MH, Buckner JH, et al. Lower omega-3 fatty acids are associated with the presence of anti-cyclic citrullinated peptide autoantibodies in a population at risk for future rheumatoid arthritis: a nested case-control study. Rheumatology. 2016;55(2):367-76.

Disclosure of Interests:

Kristen Polinski: None declared, Elizabeth Bemis: None declared, Kristen Demoruelle Grant/research support from: Pfizer, Jennifer Seifert: None declared, Tessa Crume: None declared, Fan Yang: None declared, William Robinson: None declared, Michael Clare-Salzler: None declared, Kevin Deane Grant/research support from: Janssen, Consultant of: Inova, ThermoFisher, Janseen, BMS and Microdrop, Michael Holers Shareholder of: AdMIRx, Grant/research support from: AdMIRx, Pfizer, Janssen R&D, Consultant of: AdMIRx, Janssen R&D, Celgene, Bristol-Myers Squibb, Jill Norris Grant/research support from: Janssen R&D, Pfizer, Consultant of: Celgene, BMS

Canine parvovirus prevention and prevalence: Veterinarian perceptions and behaviors

Canine Parvovirus (CPV) causes severe morbidity and mortality in dogs, particularly puppies, worldwide. Although vaccination is highly efficacious in preventing disease, cases continue to occur and vaccination failures are well documented. Maternally derived antibody interference is the leading cause of vaccination failure and age at vaccine administration is a significant risk factor for failure. However, no studies have been performed on practicing veterinarians' usage of and compliance with published vaccination guidelines and label recommendations. Likewise, there are no published studies of veterinarian perceptions on CPV occurrence and mortality and its influence on case outcome. We report a study in which all Australian small companion animal (canine and feline) veterinary hospitals were surveyed, yielding a response rate of 23.5% (534 unique veterinary hospitals). Respondents overall perceived national CPV occurrence ten-times lower (median 2000 cases) than the estimated national caseload (20,000 cases). Respondents from hospitals that did not diagnose CPV perceived national occurrence twenty-times lower (median 1000 cases) than the estimated rate (p < 0.0001). Perceived disease mortality (50%) was 2.74 times higher than that reported (18.2%). In addition, 26.7% of veterinarians reported using serological titer testing to some degree, which some practitioners use in lieu of vaccination if a titer is perceived to reflect sufficient immunity. Based on this study veterinarians appear to be aware of the disease risk in their region but unaware of the burden of CPV disease nationally, and perceive mortality risk higher than it actually is. This might lead to an overestimation of cost to treat, and over-recommendation of euthanasia. Nearly half (48.7%) of respondents recommended final puppy vaccination earlier than guidelines recommend, while 2.8% of respondents recommended a puppy re-vaccination interval longer than supported by vaccine labels and guidelines. Both of these practices may put puppies at risk of CPV infection.

Screening characteristics for enrichment of individuals at higher risk for transitioning to classified SLE

OBJECTIVE

Further prospective study is needed to elucidate the etiology and natural history of systemic lupus erythematosus development. The clinical complexity of this heterogeneous disease makes study design challenging. Our objective was to ascertain useful screening factors for identifying at-risk individuals for follow-up rheumatologic assessment or inclusion in prospective studies.

METHODS

We attempted to re-contact 3823 subjects with a family history of systemic lupus erythematosus, who did not meet American College of Rheumatology systemic lupus erythematosus classification at a baseline study visit; 436 agreed to follow-up participation an average of 6.3 years after baseline. In total, 56 of these individuals had transitioned to classified systemic lupus erythematosus (≥ 4 cumulative American College of Rheumatology criteria, verified by medical record review) by the time of follow up. Generalized estimating equations assessed associations between our dichotomous outcome of transitioning to systemic lupus erythematosus with baseline characteristics, including ANA positivity, Connective Tissue Disease Screening questionnaire systemic lupus erythematosus score, and number of American College of Rheumatology criteria. We analyzed predictive accuracy of characteristics on transitioning.

RESULTS

ANA positivity, Connective Tissue Disease Screening questionnaire systemic lupus erythematosus score categorization of possible or probable systemic lupus erythematosus, and greater number of American College of Rheumatology criteria at baseline were each associated with transitioning to systemic lupus erythematosus classification. Being ANA positive and having confirmed immunologic criteria at baseline had the highest positive predictive value and specificity for transitioning to systemic lupus erythematosus. American College of Rheumatology Connective Tissue Disease Screening questionnaire systemic lupus erythematosus score categorization of possible or probable systemic lupus erythematosus had a better positive predictive value, negative predictive value, sensitivity, and specificity than ANA positivity.

CONCLUSION

Given limited resources, identifying individuals for follow up based on the systemic lupus erythematosus portion of the Connective Tissue Disease Screening questionnaire could be an efficient way to identify family members at highest risk of disease transition.

Less than 7 hours of sleep per night is associated with transitioning to systemic lupus erythematosus

Background The role of sleep in the etiology of systemic lupus erythematosus (SLE) has not been well studied. We examined whether sleep duration was associated with subsequent transitioning to SLE in individuals at risk for SLE. Methods Four hundred and thirty-six relatives of SLE patients who did not have SLE themselves at baseline were evaluated again an average of 6.3 (± 3.9) years later. Fifty-six individuals transitioned to SLE (≥ 4 cumulative American College of Rheumatology (ACR) criteria). Sleep duration, medication use and medical history were assessed by questionnaire; ACR criteria were confirmed by medical record review. Vitamin D was measured by ELISA. Generalized estimating equations, accounting for correlation within families, assessed associations between baseline sleep and the outcome of transitioning to SLE. Results Reporting sleeping less than 7 hours per night at baseline was more common in those who subsequently transitioned than those who did not transition to SLE (55% versus 32%, p = 0.0005; OR: 2.8, 95% CI 1.6-4.9). Those who transitioned to SLE were more likely to sleep less than 7 hours per night than those who did not transition to SLE adjusting for age, sex and race (OR: 2.8, 95% CI 1.6-5.1). This association remained after individual adjustment for conditions and early symptoms that could affect sleep, including prednisone use, vitamin D deficiency and number of ACR criteria (OR: 2.0, 95% CI 1.1-4.2). Conclusion Lack of sleep may be associated with transitioning to SLE, independent of early clinical manifestations of SLE that may influence sleep duration. Further evaluation of sleeping patterns and biomarkers in at-risk individuals is warranted.

Abstract P1-10-08: Development of a first-in-class oral selective ERα covalent antagonist (SERCA) for the treatment of ERαWT and ERαMUT breast cancer

Mutations in estrogen receptor alpha (ERα) are detected in up to 30% of breast cancer patients who have relapsed during endocrine therapy. ERα mutations functionally confer resistance to existing classes of endocrine therapies, likely through gaining constitutive activity. The fact that current ER-directed therapies are only partially effective in the ERα mutant setting, and that a significant proportion of resistant breast cancer metastases continue to remain dependent on ERα signaling for growth/survival, highlights the critical need to develop the next generation of ERα antagonists that can overcome aberrant ERα activity. Using structure-based drug design approaches we have identified a novel class of ERα antagonist referred to as Selective ERα Covalent Antagonist (SERCA) that inactivate both wild-type and mutant ERα by targeting a unique cysteine residue that is not conserved among other steroid hormone receptors. Biophysical, biochemical and cellular analyses confirm the covalent mechanism of action, specific binding to ER and selective inhibition of ERα-dependent transcription of SERCAs. H3B-6545 is a highly selective SERCA that potently antagonizes wild-type and mutant ERα in biochemical and cell based assays demonstrating increased potency over standard of care and other experimental agents. In vivo, H3B-6545 shows superior efficacy to fulvestrant in the MCF-7 xenograft model with once daily oral dosing, achieving maximal antitumor activity at doses &gt;10x below the maximum tolerated dose in mice. In addition, H3B-6545 shows superior antitumor activity to both tamoxifen and fulvestrant in patient derived xenograft models of breast cancer carrying estrogen receptor mutations. In summary, H3B-6545 is a first-in-class, orally available and selective ER covalent antagonist with a compelling pre-clinical profile that is being developed for the treatment of ERα positive breast cancer.

Citation Format: Korpal M, Puyang X, Furman C, Zheng GZ, Banka D, Wu J, Zhang Z, Thomas M, Mackenzie C, Yao H, Rimkunas V, Kumar P, Caleb B, Karr C, Subramanian V, Irwin S, Larsen N, Vaillancourt F, Nguyen T-V, Davis A, Chan B, Hao MH, O'Shea M, Prajapati S, Agoulnik S, Kuznetsov G, Kumar N, Yu Y, Lai G, Hart A, Eckley S, Fekkes P, Bowser T, Joshi JJ, Selvaraj A, Wardell S, Norris J, Smith S, Reynolds D, Mitchell L, Wang J, Yu L, Kim A, Rioux N, Sahmoud T, Warmuth M, Smith PG, Zhu P. Development of a first-in-class oral selective ERα covalent antagonist (SERCA) for the treatment of ERαWT and ERαMUT breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-10-08.

Local Expansion of Donation After Circulatory Death Kidney Transplant Activity Improves Waitlisted Outcomes and Addresses Inequities of Access to Transplantation

In the United Kingdom, donation after circulatory death (DCD) kidney transplant activity has increased rapidly, but marked regional variation persists. We report how increased DCD kidney transplant activity influenced waitlisted outcomes for a single center. Between 2002-2003 and 2011-2012, 430 (54%) DCD and 361 (46%) donation after brain death (DBD) kidney-only transplants were performed at the Cambridge Transplant Centre, with a higher proportion of DCD donors fulfilling expanded criteria status (41% DCD vs. 32% DBD; p = 0.01). Compared with U.K. outcomes, for which the proportion of DCD:DBD kidney transplants performed is lower (25%; p < 0.0001), listed patients at our center waited less time for transplantation (645 vs. 1045 days; p < 0.0001), and our center had higher transplantation rates and lower numbers of waiting list deaths. This was most apparent for older patients (aged >65 years; waiting time 730 vs. 1357 days nationally; p < 0.001), who received predominantly DCD kidneys from older donors (mean donor age 64 years), whereas younger recipients received equal proportions of living donor, DBD and DCD kidney transplants. Death-censored kidney graft survival was nevertheless comparable for younger and older recipients, although transplantation conferred a survival benefit from listing for only younger recipients. Local expansion in DCD kidney transplant activity improves survival outcomes for younger patients and addresses inequity of access to transplantation for older recipients.

Maternal diet quality in pregnancy and neonatal adiposity: the Healthy Start Study

BACKGROUND/OBJECTIVES

Poor maternal diet in pregnancy can influence fetal growth and development. We tested the hypothesis that poor maternal diet quality during pregnancy would increase neonatal adiposity (percent fat mass (%FM)) at birth by increasing the fat mass (FM) component of neonatal body composition.

METHODS

Our analysis was conducted using a prebirth observational cohort of 1079 mother-offspring pairs. Pregnancy diet was assessed via repeated Automated Self-Administered 24-h dietary recalls, from which Healthy Eating Index-2010 (HEI-2010) scores were calculated for each mother. HEI-2010 was dichotomized into scores of ⩽57 and >57, with low scores representing poorer diet quality. Neonatal %FM was assessed within 72 h after birth with air displacement plethysmography. Using univariate and multivariate linear models, we analyzed the relationship between maternal diet quality and neonatal %FM, FM, and fat-free mass (FFM) while adjusting for prepregnancy body mass index (BMI), physical activity, maternal age, smoking, energy intake, preeclampsia, hypertension, infant sex and gestational age.

RESULTS

Total HEI-2010 score ranged between 18.2 and 89.5 (mean: 54.2, s.d.: 13.6). An HEI-2010 score of ⩽57 was significantly associated with higher neonatal %FM (β=0.58, 95% confidence interval (CI) 0.07-1.1, P<0.05) and FM (β=20.74; 95% CI 1.49-40.0; P<0.05) but no difference in FFM.

CONCLUSIONS

Poor diet quality during pregnancy increases neonatal adiposity independent of maternal prepregnancy BMI and total caloric intake. This further implicates maternal diet as a potentially important exposure for fetal adiposity.

Canine superficial bacterial pyoderma: evaluation of skin surface sampling methods and antimicrobial susceptibility of causal Staphylococcus isolates

OBJECTIVE

To evaluate three easily performed methods of skin surface sampling for bacterial culture of Staphylococcus isolates obtained from dogs with superficial bacterial pyoderma (SBP) presenting to two veterinary teaching hospitals in Sydney, Australia, and to determine the antimicrobial susceptibility of isolates.

DESIGN

Prospective study of 27 dogs with SBP. Cytologically confirmed SBP lesions were sampled for bacterial culture using a dry cotton swab, a saline-moistened cotton swab and a skin surface scraping. Isolates were identified by standard discriminatory phenotypic and biochemical analyses, and confirmed using matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI-TOF MS). Susceptibilities to 14 antimicrobials were determined by disk diffusion and by detection of the mecA gene using PCR. Sampling methods were compared according to bacterial yield, antibiograms and bacterial phenotypic analysis. Location of causative bacteria was evaluated via 8-mm punch skin biopsies using haematoxylin and eosin, Gram-Twort and Giemsa staining, and fluorescence in situ hybridisation (FISH).

RESULTS

Staphylococcus sp. were isolated from lesions in all dogs, either S. pseudintermedius (24 dogs) or S. schleiferi (3 dogs). Susceptibility was highest to cephalexin (96%) and amoxycillin clavulanate (96%). Methicillin resistance assessed by mecA real-time PCR and phenotypic oxacillin resistance was found in one dog (4.3%). Routine histology and FISH revealed bacteria within superficial stratum corneum.

CONCLUSION

Staphylococcal isolates from canine SBP demonstrated high susceptibility to common empirical antimicrobials. Histological techniques confirmed presence of bacteria at superficial sites, likely to be accessed by the sampling techniques. The three techniques afforded similar results and may be equally suitable for obtaining samples for culture.

Smoking is not associated with autoantibody production in systemic lupus erythematosus patients, unaffected first-degree relatives, nor healthy controls

OBJECTIVE

The objective of this paper is to examine whether smoking is associated with autoantibody production in systemic lupus erythematosus (SLE) patients, unaffected first-degree relatives (FDR) of individuals with SLE--a group at increased risk of developing SLE--or unaffected, unrelated controls.

METHODS

Detailed demographic, environmental, clinical, and therapeutic information was collected by questionnaire on 1242 SLE patients, 981 FDRs, and 946 controls in the Lupus Family Registry and Repository; a blood sample was obtained. All sera were tested for multiple lupus autoantibodies by immunofluorescence and luminex bead-based assays. Generalized estimating equations, adjusting for age, gender, and ethnicity and accounting for correlation within families, were used to assess smoking status with the dichotomous outcome variables of positivity for SLE status, positivity of ANA by immunofluorescence (≥1:120), positivity for ≥1 autoantibody by the luminex assay, and positivity for each of the 11 autoantibodies.

RESULTS

Current smoking was associated with being positive for ≥1 autoantibody (excluding ANA) (adjusted OR = 1.53, 95% CI 1.04-2.24) in our subjects with SLE. No association was observed in unaffected FDRs or healthy controls. Former smoking was associated with anti-Ro/SS-A60 in our unaffected FDRs. There was an increased association with anti-nRNP A seropositivity, as well as a decreased association with anti-nRNP 68 positivity, in current smokers in SLE subjects.

CONCLUSIONS

No clear association between smoking status and individual autoantibodies was detected in SLE patients, unaffected FDRs, nor healthy controls within this collection. The association of smoking with SLE may therefore manifest its risk through mechanisms outside of autoantibody production, at least for the specificities tested.

Vitamin D in youth with Type 1 diabetes: prevalence of insufficiency and association with insulin resistance in the SEARCH Nutrition Ancillary Study

AIMS

To determine the prevalence of plasma vitamin D (25-dihydroxyvitamin D) insufficiency in individuals with Type 1 diabetes and to determine the cross-sectional and longitudinal associations of plasma vitamin D with insulin resistance.

METHODS

Participants from the SEARCH for Diabetes in Youth Study [n = 1426; mean age 11.2 years (sd 3.9)] had physician-diagnosed Type 1 diabetes [diabetes duration mean 10.2 months (sd 6.5)] with data available at baseline and follow-up (approximately 12 and 24 months after baseline). Insulin resistance was estimated using a validated equation. Cross-sectional and longitudinal multivariate logistic regression models were used to determine the association of plasma vitamin D with insulin resistance, adjusting for potential confounders.

RESULTS

Forty-nine per cent of individuals had plasma vitamin D < 50 nmol/l and 26% were insulin resistant. In cross-sectional multivariate analyses, participants who had higher plasma vitamin D (65 nmol/l) had lower odds of prevalent insulin resistance than participants with lower plasma vitamin D (25 nmol/l) (odds ratio 0.70, 95% CI 0.57-0.85). This association was attenuated after additional adjustment for BMI z-score, which could be a confounder or a mediator (odds ratio 0.81, 95% CI 0.64-1.03). In longitudinal multivariate analyses, individuals with higher plasma vitamin D at baseline had lower odds of incident insulin resistance, but this was not significant (odds ratio 0.85, 95% CI 0.63-1.14).

CONCLUSIONS

Vitamin D insufficiency is common in individuals with Type 1 diabetes and may increase risk for insulin resistance. Additional prospective studies are needed to determine the association between plasma vitamin D and insulin resistance, and to further examine the role of adiposity on this association.

A comparison of facial muscle squeezing versus non-facial muscle squeezing on the efficacy of botulinumtoxin-A injections for the treatment of facial dystonia

BACKGROUND

This study was performed to address whether voluntary muscle squeezing post botulinum toxin-A treatment with increased neuronal activity translates into noticeable patient benefit in practice.

METHODS

This was a prospective, consecutive, double crossover interventional study. Participants were receiving regular (3 monthly) botulinum toxin-A treatment for aberrant facial nerve regeneration (AFNR), benign essential blepharospasm (BEB) or hemifacial spasm (HFS). Twenty-six participants were recruited and these were randomised into two groups (A and B). Group A performed a program of intensive facial exercises for 5 minutes after their first and third treatment whereas after their second treatment, they were asked to rest in a seated position for 5 minutes, and instructed not to talk or perform any voluntary movements of their face. Conversely group B were only asked to perform squeezing exercises after their second treatment. Outcomes were evaluated objectively using video-recordings and subjectively by questionnaire and telephone interview of participants.

RESULTS

Video-recording data was complete for 21 participants. There was a mean 40% reduction in the frequency of facial muscle spasms and a 33% lower severity score (video-recordings graded by 1 masked investigator) where intensive facial exercises were performed post-treatment. These findings did not reach statistical significance (Mann- Whitney two-tailed test; p = 0.367).

CONCLUSION

Although statistical significance was not achievable, this study suggested a possible trend towards an increased efficacy of botulinum toxin-A, with facial muscle squeezing post BTX treatment. Future studies with a larger number and a better defined subset of subjects may lead to statistical significance.

NIMROD: The Near and InterMediate Range Order Diffractometer of the ISIS second target station

NIMROD is the Near and InterMediate Range Order Diffractometer of the ISIS second target station. Its design is optimized for structural studies of disordered materials and liquids on a continuous length scale that extends from the atomic, upward of 30 nm, while maintaining subatomic distance resolution. This capability is achieved by matching a low and wider angle array of high efficiency neutron scintillation detectors to the broad band-pass radiation delivered by a hybrid liquid water and liquid hydrogen neutron moderator assembly. The capabilities of the instrument bridge the gap between conventional small angle neutron scattering and wide angle diffraction through the use of a common calibration procedure for the entire length scale. This allows the instrument to obtain information on nanoscale systems and processes that are quantitatively linked to the local atomic and molecular order of the materials under investigation.

Candidate loci for insulin sensitivity and disposition index from a genome-wide association analysis of Hispanic participants in the Insulin Resistance Atherosclerosis (IRAS) Family Study

AIMS/HYPOTHESIS

The majority of type 2 diabetes genome-wide association studies (GWAS) to date have been performed in European-derived populations and have identified few variants that mediate their effect through insulin resistance. The aim of this study was to evaluate two quantitative, directly assessed measures of insulin resistance, namely insulin sensitivity index (S(I)) and insulin disposition index (DI), in Hispanic-American participants using an agnostic, high-density single nucleotide polymorphism (SNP) scan, and to validate these findings in additional samples.

METHODS

A two-stage GWAS was performed in Hispanic-American samples from the Insulin Resistance Atherosclerosis Family Study. In Stage 1, 317,000 SNPs were assessed using 229 DNA samples. SNPs with evidence of association with glucose homeostasis and adiposity traits were then genotyped on the entire set of Hispanic-American samples (n = 1,190). This report focuses on the glucose homeostasis traits: S(I) and DI.

RESULTS

Although evidence of association did not reach genome-wide significance (p = 5 x 10(-7)), in the combined analysis SNPs had admixture-adjusted p values of p (ADD) = 0.00010-0.0020 with 8 to 41% differences in genotypic means for S(I) and DI.

CONCLUSIONS/INTERPRETATION

Several candidate loci were identified that are nominally associated with S(I) and/or DI in Hispanic-American participants. Replication of these findings in independent cohorts and additional focused analysis of these loci is warranted.

Supervised machine learning and logistic regression identifies novel epistatic risk factors with PTPN22 for rheumatoid arthritis

Investigating genetic interactions (epistasis) has proven difficult despite the recent advances of both laboratory methods and statistical developments. With no 'best' statistical approach available, combining several analytical methods may be optimal for detecting epistatic interactions. Using a multi-stage analysis that incorporated supervised machine learning and methods of association testing, we investigated epistatic interactions with a well-established genetic factor (PTPN22 1858T) in a complex autoimmune disease (rheumatoid arthritis (RA)). Our analysis consisted of four principal stages: Stage I (data reduction)-identifying candidate chromosomal regions in 292 affected sibling pairs, by predicting PTPN22 concordance using multipoint identity-by-descent probabilities and a supervised machine learning algorithm (Random Forests); Stage II (extension analysis)-testing detailed genetic data within candidate chromosomal regions for epistasis with PTPN22 1858T in 677 cases and 750 controls using logistic regression; Stage III (replication analysis)-confirmation of epistatic interactions in 947 cases and 1756 controls; Stage IV (combined analysis)-a pooled analysis including all 1624 RA cases and 2506 control subjects for final estimates of effect size. A total of seven replicating epistatic interactions were identified. SNP variants within CDH13, MYO3A, CEP72 and near WFDC1 showed significant evidence for interaction with PTPN22, affecting susceptibility to RA.

Childhood growth and age at diagnosis with Type 1 diabetes in Colorado young people

OBJECTIVE

Studies have suggested that the age at diagnosis of Type 1 diabetes (T1D) is decreasing over time. The overload hypothesis postulates that risk factors, such as accelerated growth, may be responsible for this decrease. We assessed changes in age, body mass index (BMI), weight and height at diagnosis with T1D in non-Hispanic white (NHW) and Hispanic (HISP) young people from Colorado, using data from the IDDM Registry and SEARCH Study.

METHODS

In three time periods, 656 (1978-1983), 562 (1984-1988) and 712 (2002-2004) young people aged 2-17 years were newly diagnosed with T1D. Age, weight, height and presence of diabetic ketoacidosis (DKA) at diagnosis with T1D were obtained from medical records. Trends over the three time periods were assessed with regression analyses.

RESULTS

Age at diagnosis decreased by 9.6 months over time (P = 0.0002). Mean BMI standard deviation score (SDS), weight SDS and height SDS increased over time (P < 0.0001), while prevalence of DKA decreased (P < 0.0001). Increasing height over time accounted for 15% (P = 0.04) of the decreasing age at diagnosis with T1D.

CONCLUSIONS

Our study provides evidence that increased linear growth, but not increased BMI or weight over time, may account, at least in part, for the younger age at diagnosis of T1D in Colorado children. This finding supports the hypothesis that increasing environmental pressure resulting from changes in potentially preventable risk factors may accelerate the onset of T1D in children.

Height growth velocity, islet autoimmunity and type 1 diabetes development: the Diabetes Autoimmunity Study in the Young

AIMS/HYPOTHESIS

Larger childhood body size and rapid growth have been associated with increased type 1 diabetes risk. We analysed height, weight, BMI and velocities of growth in height, weight and BMI, for association with development of islet autoimmunity (IA) and type 1 diabetes.

METHODS

Since 1993, the Diabetes Autoimmunity Study in the Young (DAISY) has followed children at increased type 1 diabetes risk, based on HLA-DR, -DQ genotype or family history, for the development of IA and type 1 diabetes. IA was defined as the presence of autoantibodies to insulin, GAD or protein tyrosine phosphatase islet antigen 2 twice in succession, or autoantibody-positive on one visit and diabetic at the next consecutive visit within 1 year. Type 1 diabetes was diagnosed by a physician. Height and weight were collected starting at age 2 years. Of 1,714 DAISY children <11.5 years of age, 143 developed IA and 21 progressed to type 1 diabetes. We conducted Cox proportional hazards analysis to explore growth velocities and size measures for association with IA and type 1 diabetes development.

RESULTS

Greater height growth velocity was associated with IA development (HR 1.63, 95% CI 1.31-2.05) and type 1 diabetes development (HR 3.34, 95% CI 1.73-6.42) for a 1 SD difference in velocity.

CONCLUSIONS/INTERPRETATION

Our study suggests that greater height growth velocity may be involved in the progression from genetic susceptibility to autoimmunity and then to type 1 diabetes in pre-pubertal children.

Insulin resistance, beta cell dysfunction and visceral adiposity as predictors of incident diabetes: the Insulin Resistance Atherosclerosis Study (IRAS) Family study

AIMS/HYPOTHESIS

Central obesity, insulin resistance and beta cell dysfunction are independent risk factors for incident type 2 diabetes, although few studies have used detailed measures of these disorders. Our objective was to study the association of directly measured visceral and subcutaneous adipose tissue (VAT, SAT), insulin sensitivity (S (I)) and the acute insulin response (AIR) with incident type 2 diabetes.

METHODS

Participants were 1,230 Hispanic-Americans and African-Americans in the Insulin Resistance Atherosclerosis Study (IRAS) Family Study who were free of type 2 diabetes at baseline (2000-2002). S (I) and AIR were determined from frequently sampled IVGTTs with minimal model analysis. VAT and SAT were determined by computed tomography. Impaired fasting glucose and type 2 diabetes were defined according to American Diabetes Association criteria.

RESULTS

Incident type 2 diabetes was diagnosed in 90 participants after 5 years. After adjustment for age, sex, ethnicity, centre, impaired fasting glucose, triacylglycerol, HDL-cholesterol and systolic BP, both S(I) and AIR were inversely associated with type 2 diabetes (S (I), OR 0.53, 95% CI 0.39-0.73; AIR, OR 0.22, 95% CI 0.14-0.34 per SD; both p < 0.001), while both VAT and SAT were positively associated with type 2 diabetes (VAT, OR 1.68, 95% CI 1.22-2.33; SAT, OR 1.49, 95% CI 1.13-1.99; both p < 0.01). In a model including all four factors, S (I) and AIR (S (I), OR 0.55, 95% CI 0.37-0.80; AIR, OR 0.21, 95% CI 0.13-0.33; both p < 0.01) were significant predictors of type 2 diabetes, although associations with VAT and SAT were no longer significant. A significant sex x VAT interaction indicated a stronger association of VAT with type 2 diabetes in women than in men.

CONCLUSIONS/INTERPRETATION

Insulin resistance, beta cell dysfunction and VAT predicted incident type 2 diabetes, with evidence of a stronger association of VAT with type 2 diabetes among women.

A genome-wide association scan for acute insulin response to glucose in Hispanic-Americans: the Insulin Resistance Atherosclerosis Family Study (IRAS FS)

AIMS/HYPOTHESIS

This study sought to identify genes and regions in the human genome that are associated with the acute insulin response to glucose (AIRg), an important predictor of type 2 diabetes, in Hispanic-American participants from the Insulin Resistance Atherosclerosis Family Study (IRAS FS).

METHODS

A two-stage genome-wide association scan (GWAS) was performed in IRAS FS Hispanic-American samples. In the first stage, 317K single nucleotide polymorphisms (SNPs) were assessed in 229 Hispanic-American DNA samples from 34 families from San Antonio, TX, USA. SNPs with the most significant associations with AIRg were genotyped in the entire set of IRAS FS Hispanic-American samples (n = 1,190). In chromosomal regions with evidence of association, additional SNPs were genotyped to capture variation in genes.

RESULTS

No individual SNP achieved genome-wide levels of significance (p < 5 x 10(-7)); however, two regions (chromosomes 6p21 and 20p11) had multiple highly ranked SNPs that were associated with AIRg. Additional genotyping in these regions supported the initial evidence of variants contributing to variation in AIRg. One region resides in a gene desert between PXT1 and KCTD20 on 6p21, while the region on 20p11 has several viable candidate genes (ENTPD6, PYGB, GINS1 and RP4-691N24.1).

CONCLUSIONS/INTERPRETATION

A GWAS in Hispanic-American samples identified several candidate genes and loci that may be associated with AIRg. These associations explain a small component of variation in AIRg. The genes identified are involved in phosphorylation and ion transport, and provide preliminary evidence that these processes are important in beta cell response.