OP0252 FACTORS ASSOCIATED WITH SEVERE COVID-19 OUTCOMES IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHY: RESULTS FROM THE COVID-19 GLOBAL RHEUMATOLOGY ALLIANCE PHYSICIAN-REPORTED REGISTRY

Background

There is a paucity of data in the literature about the outcome of patients with idiopathic inflammatory myopathy (IIM) who have been infected with SARS-CoV-2.

Objectives

To investigate factors associated with severe COVID-19 outcomes in patients with IIM.

Methods

Data on demographics, number of comorbidities, region, COVID-19 time period, physician-reported disease activity, anti-rheumatic medication exposure at the clinical onset of COVID-19, and COVID-19 outcomes of IIM patients were obtained from the voluntary COVID-19 Global Rheumatology Alliance physician-reported registry of adults with rheumatic disease (from 17 March 2020 to 27 August 2021). An ordinal COVID-19 severity scale was used as primary outcome of interest, with each outcome category being mutually exclusive from the other:a) no hospitalization, b) hospitalization (and no death), or c) death. Odds ratios (OR) were estimated using multivariable ordinal logistic regression. In ordinal logistic regression, the effect size of a categorical predictor can be interpreted as the odds of being one level higher on the ordinal COVID-19 severity scale than the reference category.

Results

Complete hospitalization and death outcome data was available in 348 IIM cases. Mean age was 53 years, and 223 (64.1%) were female. Overall, 167/348 (48.0%) people were not hospitalized, 136/348 (39.1%) were hospitalized (and did not die), and 45/348 (12.9%) died. Older age (OR=1.59 per decade of life, 95%CI 1.32-1.93), male sex (OR=1.63, 95%CI 1.004-2.64; versus female), high disease activity (OR=4.05, 95%CI 1.29-12.76; versus remission), presence of two or more comorbidities (OR=2.39, 95%CI 1.22-4.68; versus none), prednisolone-equivalent dose >7.5 mg/day (OR=2.37, 95%CI 1.27-4.44; versus no glucocorticoid intake), and exposure to rituximab (OR=2.60, 95%CI 1.23-5.47; versus csDMARDs only) were associated with worse COVID-19 outcomes (Table 1).

Table 1.

Multivariable logistic regression analysis of factors associated with the ordinal COVID-19 severity outcomes. AZA, azathioprine; CI, confidence interval; combo, combination; CSA, ciclosporin; CYC, cyclophosphamide; DMARD, disease-modifying anti-rheumatic drug; b/tsDMARD, biologic/targeted synthetic DMARD, csDMARD, conventional synthetic DMARD; HCQ, hydroxychloroquine; IVIg, intravenous immunoglobulin; LEF, leflunomide; MMF, mycophenolate mofetil; mono, monotherapy; MTX, methotrexate; OR, odds ratio; Ref, reference; RTX, rituximab; SSZ, sulfasalazine; TAC, tacrolimus.

VariableOR (95%CI)P-valueVariableOR (95%CI)P-valueAge (per decade)1.59 (1.32-1.93)<0.001ComorbiditiesMale sex1.63 (1.004-2.64)0.048NoneRefNAPrednisolone-equivalent doseOne1.46 (0.79-2.72)0.228NoneRefNATwo or more2.39 (1.22-4.68)0.011>0 to 7.5mg/day1.10 (0.57-2.11)0.779Physician-reported disease activity>7.5mg/day2.37 (1.27-4.44)0.007RemissionRefNAIVIg0.41 (0.15-1.16)0.093Low/moderate1.23 (0.67-2.28)0.504DMARDsHigh4.05 (1.29-12.76)0.018csDMARD only (mono or combi - HCQ, MTX, LEF, SSZ)RefNARegionNo DMARD1.84 (0.90-3.75)0.094EuropeRefNAb/tsDMARD mono or combi (except RTX)1.60 (0.49-5.26)0.435North America0.89 (0.49-1.61)0.694CSA/CYC/TAC mono or combi (except RTX or b/tsDMARDs)1.55 (0.52-4.58)0.429Other4.25 (2.21-8.16)<0.001AZA mono1.70 (0.69-4.19)0.249Time periodMMF mono1.22 (0.53-2.82)0.634Before 15 June 2020RefNAAZA/MMF combi (except RTX or b/tsDMARDs)0.71 (0.25-2.00)0.51716 June - 30 September 20200.58 (0.26-1.27)0.171RTX mono or combi2.60 (1.23-5.47)0.012After 1 October 20200.58 (0.35-0.95)0.032

Conclusion

These are the first global registry data on the impact of COVID-19 on IIM patients. Older age, male gender, higher comorbidity burden, higher disease activity, higher glucocorticoid intake and rituximab exposure were associated with worse outcomes. These findings will inform risk stratification and management decisions for IIM patients.

References

None

Disclosure of Interests

Su-Ann Yeoh: None declared, Milena Gianfrancesco: None declared, Saskia Lawson-Tovey: None declared, Kimme Hyrich Speakers bureau: AbbVie unrelated to this work, Grant/research support from: Pfizer, BMS, both unrelated to this work, Anja Strangfeld Speakers bureau: AbbVie, Celltrion, MSD, Janssen, Lilly, Roche, BMS, Pfizer, all unrelated to this work, Laure Gossec Consultant of: AbbVie, Amgen, BMS, Galapagos, Gilead, GSK, Janssen, Lilly, Novartis, Pfizer, Samsung Bioepis, Sanofi-Aventis, UCB, all unrelated to this work, Grant/research support from: Amgen, Galapagos, Lilly, Pfizer, Sandoz, all unrelated to this work, Loreto Carmona: None declared, Elsa Mateus Consultant of: Boehringer Ingelheim Portugal, not related to this work, Martin Schaefer: None declared, Christophe Richez Speakers bureau: Abbvie, Amgen, Astra Zeneca, Biogen, BMS, Celltrion, Eli Lilly, Galapagos, GSK, MSD, Novartis, and Pfizer, all unrelated to this abstract, Consultant of: Abbvie, Amgen, Astra Zeneca, Biogen, BMS, Celltrion, Eli Lilly, Galapagos, GSK, MSD, Novartis, and Pfizer, all unrelated to this abstract, Eric Hachulla Speakers bureau: Johnson & Johnson, GlaxoSmithKline, Roche-Chugai, all unrelated to this work, Consultant of: Bayer, Boehringer Ingelheim, GlaxoSmithKline, Johnson & Johnson, Roche-Chugai, Sanofi-Genzyme, all unrelated to this work, Grant/research support from: CSL Behring, GlaxoSmithKline, Johnson & Johnson, Roche-Chugai, Sanofi-Genzyme, all unrelated to this work, Marie Holmqvist: None declared, Carlo Alberto Scirè Grant/research support from: AbbVie, Lilly, both unrelated to this work, Rebecca Hasseli: None declared, Arundathi Jayatilleke: None declared, Tiffany Hsu: None declared, Kristin D’Silva: None declared, Victor Pimentel-Quiroz: None declared, Monica Vasquez del Mercado: None declared, Samuel Katsuyuki Shinjo: None declared, Edgard Reis Neto: None declared, Laurindo Rocha Jr: None declared, Ana Carolina de Oliveira e Silva Montandon Speakers bureau: GSK, not related to this work, Paula Jordan: None declared, Emily Sirotich: None declared, Jonathan Hausmann Speakers bureau: Novartis, Biogen, Pfizer, not related to this work, Consultant of: Novartis, Biogen, Pfizer, not related to this work, Jean Liew Grant/research support from: Pfizer research grant, completed in 2021, not related to this work, Lindsay Jacobsohn: None declared, Monique Gore-Massy Speakers bureau: Aurinia Pharmaceuticals, Boehringer Ingelheim, Bristol-Myers Squibb, not related to this work, Consultant of: Aurinia Pharmaceuticals, Boehringer Ingelheim, Bristol-Myers Squibb, not related to this work, Paul Sufka: None declared, Rebecca Grainger Speakers bureau: AbbVie, Janssen, Novartis, Pfizer and Cornerstones, all unrelated to this work, Consultant of: AbbVie, Novartis, both unrelated to this work, Suleman Bhana Shareholder of: Pfizer, Inc, Speakers bureau: AbbVie, Horizon, Novartis, and Pfizer, all unrelated to this work, Consultant of: AbbVie, Horizon, Novartis, and Pfizer, all unrelated to this work, Employee of: Pfizer, Inc, Zachary Wallace: None declared, Philip Robinson Speakers bureau: Abbvie, Janssen, Roche, GSK, Novartis, Lilly, UCB, all unrelated to this work, Paid instructor for: Lilly, unrelated to this work, Consultant of: GSK, Kukdong, Atom Biosciences, UCB, all unrelated to this work, Grant/research support from: Janssen, Pfizer, UCB and Novartis, all unrelated to this work, Jinoos Yazdany Consultant of: Aurinia, Astra Zeneca, Pfizer, all unrelated to this work, Grant/research support from: Astra Zeneca, Gilead, BMS Foundation, all unrelated to this work, Pedro Machado Speakers bureau: Abbvie, BMS, Celgene, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Orphazyme, Pfizer, Roche and UCB, all unrelated to this work., Consultant of: Abbvie, BMS, Celgene, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Orphazyme, Pfizer, Roche and UCB, all unrelated to this work.

OP0160 HLA-DRB1 ASSOCIATIONS WITH AUTOANTIBODY-DEFINED SUBGROUPS IN IDIOPATHIC INFLAMMATORY MYOPATHIES (IIM)

Background

There is a gap between how IIM patients are classified in practice and current validated classification criteria1. Also, different associations with genetic variations in HLA can inform about different T-cell mechanisms involved in disease pathogenesis.

Objectives

We aimed to systematically study associations between HLA-DRB1 alleles, clinical manifestations, and autoantibody-defined IIM subgroups.

Methods

We included 1348 IIM patients from five European countries. An unsupervised cluster analysis was performed using 14 autoantibodies: anti-Jo1, -PL7, -PL12, -EJ, -OJ, -SRP, -U1RNP, -Ro52, -Mi2, -TIF1γ, -MDA5, -PMScl, -SAE1, and -NXP2 to identify patients’ subgroups. Logistic regressions were used to estimate the associations between HLA-DRB1 alleles, clinical manifestations and the identified subgroups.

Results

Eight subgroups were defined by the autoantibody status (Table 1). Three of the subgroups (1, 2 and 6) have overlapping autoantibodies, while four are almost monospecific (3,4,5 and 7), and one (8) has patients negative for tested autoantibodies. Figure 1 represents the significant associations between HLA-DRB1 alleles and the eight subgroups. Heliotrope rash and Gottron’s sign were significantly more frequent in subgroups 3 (OR:2.2 95%CI:[1.1-4.8], OR:2.6 95%CI:[1.3-5.9], respectively), 4 (OR:12 95%CI:[3.6-75], OR:7.8 95%CI:[2.8-33], respectively) and 7 (OR:22 95%CI:[4.5-385], OR:10 95%CI:[3.1-65], respectively), and Raynaud’s phenomenon was significantly more frequent in subgroup 6 (OR:3.3 95%CI:[1.2-11]).

Table 1.

Autoantibody-defined subgroups using an unsupervised cluster analysis.

Subgroups/ MedoidsVariables1 Ro522 U1RNP3 PMScl4 Mi25 Jo16 Jo1/Ro527 TIF18 None*Alln (%)137 (10)183 (14)107 (8)65 (5)119 (9)140 (10)78 (6)519 (39)1348 (100)Female (%)93 (68)116 (63)79 (74)45 (69)76 (64)96 (69)64 (82)313 (60)882 (65)Age at diagnosis, median (IQR)56 (16)51.5 (23)51 (25)57 (22.5)47.5 (23.25)52 (19.5)53.5 (21.75)58 (22)55 (23)AutoantibodiesAnti-Jo106 (3)01 (2)119 (100)140 (100)00266 (20)Anti-PL77 (5)13 (7)00000020 (1.5)Anti-PL125 (4)3 (2)1 (1)01 (1)00010 (0.7)Anti-EJ2 (2)00000002 (0.1)Anti-OJ07 (4)0000007 (0.5)Anti-TIF110 (7)2 (1)2 (2)00078 (100)092 (7)Anti-Mi21 (1)1 (1)1 (1)65 (100)02 (1)0070 (5)Anti-SAE18 (6)23 (13)00000031 (2)Anti-NXP21 (1)23 (13)1 (1)0000025 (2)Anti-MDA59 (7)10 (6)1 (1)1 (2)01 (1)0022 (2)Anti-SRP8 (6)32 (18)00000040 (3)Anti-Ro52137 (100)16 (9)000140 (100)00293 (22)Anti-PMScl11 (8)1 (1)107 (100)00000119 (9)Anti-U1RNP079 (43)0003 (2)0082 (6)

*IIM patients negative for the tested autoantibodies.

Figure 1.

Forest plot of significant associations of HLA. *DRB1 alleles with autoantibody-defined subgroups. Scandinavia includes patients from Denmark, Norway, and Sweden.

Conclusion

Our study reveals that certain subgroups of IIM patients are characterized by overlap of myositis -specific and -associated autoantibodies, which in turn are associated with different HLA-DRB1 alleles including potential novel associations. These results point to different disease mechanisms in the subgroups, as well as suggest that IIM classification could be improved by integrating broader serological and genetic data.

References

[1]Parker MJS, Oldroyd A, Roberts ME, et al. The performance of the European League Against Rheumatism/American College of Rheumatology idiopathic inflammatory myopathies classification criteria in an expert-defined 10 year incident cohort. Rheumatology (Oxford). 2019;58(3):468-475.

Acknowledgements

We thank all the patients who participated in the study.

Disclosure of Interests

Valerie Leclair: None declared, Angeles Shunashy Galindo-Feria: None declared, Simon Rothwell: None declared, Olga Kryštůfková: None declared, Heřman Mann: None declared, Louise Pyndt Diederichsen: None declared, helena andersson: None declared, Martin Klein: None declared, Sarah Tansley: None declared, Neil McHugh: None declared, Janine Lamb: None declared, Jiří Vencovský Speakers bureau: Abbvie, Biogen, Boehringer, Eli Lilly, Gilead, MSD, Novartis, Pfizer, Roche, Sanofi, UCB, Werfen, Consultant of: Abbvie, Argenx, Boehringer, Eli Lilly, Gilead, Octapharma, Pfizer, UCB, Grant/research support from: Abbvie, Hector Chinoy: None declared, Marie Holmqvist: None declared, Leonid Padyukov: None declared, Ingrid E. Lundberg Shareholder of: Roche and Novartis, Consultant of: Corbus Pharmaceuticals Inc, Astra Zeneca, Bristol Myer´s Squibb, Corbus Pharmaceutical, EMD Serono Research & Development Institute, Argenx, Octapharma, Kezaar, Orphazyme, and Janssen, Grant/research support from: Astra Zeneca, Lina M. Diaz-Gallo: None declared

Evaluation of risk factors and biomarkers related to arterial and venous thrombotic events in idiopathic inflammatory myopathies

Objectives: This study aimed to assess the contribution of traditional/disease-related risk factors and biomarkers linked to arterial and venous thrombotic events (TEs) in patients with idiopathic inflammatory myopathies (IIMs).Method: The occurrence of arterial and/or venous TEs at the time of or after IIM diagnosis was retrospectively evaluated in a cohort of 253 patients with IIMs, resulting in a final population of 246 IIM patients, 51 with reported TE (cases) and 195 without a history of TE (comparators). Information on disease characteristics and traditional risk factors for arterial and venous TE (essential hypertension, diabetes, dyslipidaemia, smoking, malignancy) was retrieved. Serum levels of anti-phospholipid antibodies (aPLs) and adhesion molecules were analysed at the time of IIM diagnosis and at the time of the TE in cases.Results: One in five IIM patients (21%) had experienced a TE, arterial TE in 22 and venous TE in 29 patients, with a peak prevalence within 5 years after diagnosis. Among traditional/disease-related risk factors, only older age was associated with both arterial and venous TEs, after adjusting for other covariates. Low serum levels of e-selectin were associated with higher odds of developing a TE, without specific association with either arterial or venous TEs. Only 6% of IIM patients had aPLs, with no significant difference between cases and comparators.Conclusions: An increased risk of both venous and arterial TEs should be considered in IIM patients, particularly close to diagnosis and in elderly people. Low serum levels of e-selectin may predict TE in IIM patients, but the underlying biological mechanism is not known.

THU0343 AUTOANTIBODIES CAN PARTLY PREDICT SEVERITY OF DAMAGE BUT NOT EXTENT IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOSITIS

Background:

Patients with idiopathic inflammatory myopathies (IIM) might suffer from irreversible damage once inflammation has decreased. Autoantibodies are found in up to 80% of patients with IIM and are coupled with specific clinical features. Whether autoantibodies can be used as biomarkers to predict patterns of damage in IIM remains unknown.

Objectives:

To investigate the association between autoantibodies and organ damage in patients with IIM using longitudinal national register data.

Methods:

Data were retrieved from the electronic Swedish Rheumatology Quality Register (SRQ). Patients (n=302) with a clinical diagnosis of IIM (2017 EULAR/ACR criteria) were included. Autoantibody status was tested by either line blot or RNA- and protein immunoprecipitation; HMGCR and FHL-1 autoantibodies were tested by ELISA. Patients were grouped into six categories of autoantibodies (Table 1). TheMyositis Damage Index(MDI) score was applied to measure organ damage using both components (extentandseverity) as a continuous variable and were analyzed using generalized estimating equations (GEE). A categorical variable for each time point of MDI assessment since diagnosis was created to adjust for time (Table 2). A base model which included autoantibody group and time was fit. Other potential predictors included age at diagnosis, sex, disease duration from diagnosis to inclusion to SRQ, arthritis, Raynaud, mechanics’ hands and heart involvement at registry; core set measures at each MDI time point allowing multiple longitudinal observations were also tested.

Table 1.

Clinical diagnosis and autoantibody groups.

DiagnosisN (%)Polymyositis119 (38)Dermatomyositis (DM)99 (33)Inclusion body myositis35 (12)Amyopathic DM9 (3)Juvenile DM8 (3)Low probability myositis32 (11)Autoantibody286 (%)Antisynthetase (AS)74 (26)Necrotizing myopathy NM)20 (7)DM- specific44 (15)FHL-118 (6)Associated antibodies AA)50 (18)Negative to any80 (28)

AS: Jo1, PL7, PL12, EJ, OJ;NM: SRP, HMGCR;DM-specific: TIF1γ, Mi2, MDA5, SAE;AA: Ro52, PmScl, U1RNP, KU.

Table 2.

Predictors of damage severity and extent.

EstimateP valueSeverityTime#0.20NSAutoantibody group1Negativereference--Antisynthetase-0.6NSIMNM1.6NSDM- specific-2.6**FHL-10.4NSAssociated0.7NSMMT score1-0.1***ExtentTime#0.33NSCK, mkat/L2-0.006*

#Time from diagnosis to MDI. *<0.05**<0.01***<0.001

1. Adjusted for gender + disease duration + time.

2. Adjusted for disease duration + time.

Results:

Mean age at diagnosis was 54 years (SD 16), 205 were female (68%), median disease duration was 4 months (IQR 1-39). Clinical diagnosis and the autoantibody groups are shown in Table 1. The median time from diagnosis to the first MDI assessment was 2.2 years (IQR 1.2 – 5.5), 227 patients had a second MDI assessment at median 4.5 years (3.3-8.6 years) and 114 patients had a third assessment at 7.8 (5.8-9.9) years.Severity of damage:Only the DM-specific autoantibodies (P = 0.01) and manual muscle test score (MMT) (P = 0.007) were independent negative predictors; disease duration was a positive predictor (P = 0.01).Extent of damage: Autoantibodies were not significant predictors; creatine kinase (CK) levels were negative predictors (P = 0.01) (Table 2).

Conclusion:

Presence of DM-specific autoantibodies, a high MMT score over time and short disease duration seem to predict less damage severity whereas high CK levels seem to predict of less extent of damage. These findings indicate that some myositis specific autoantibodies may serve as predictors of damage along with other clinical measures.

References:

[1]Sultan SM, et al. Interrater reliability and aspects of validity of the myositis damage index. Annals of the Rheumatic Diseases. 2011;70:1272-6.

Disclosure of Interests:

Fabricio Espinosa-Ortega: None declared, Marie Holmqvist: None declared, Maryam Dastmalchi: None declared, Andrew Mammen: None declared, Ingrid E. Lundberg Grant/research support from: Bristol Meyer Squibb, Corbus Pharmaceuticals, Inc and Astra Zeneca, Helene Alexanderson: None declared

Concomitant Ro/SSA and La/SSB antibodies are biomarkers for the risk of venous thromboembolism and cerebral infarction in primary Sjögren's syndrome

BACKGROUND

To assess the risk of incident cardiovascular disease in patients with primary Sjögren's syndrome, overall and stratified by Ro/SSA and La/SSB autoantibody status.

METHODS

A cohort of patients with primary Sjögren's syndrome in Sweden (n = 960) and matched controls from the general population (n = 9035) were included, and data extracted from the National Patient Register to identify events of myocardial infarction, cerebral infarction and venous thromboembolism. Hazard ratios were estimated using cox proportional hazard regressions.

RESULTS

During a median follow-up of 9.5 years, the overall hazard ratio (HR) was 1.6 (95% CI 1.2-2.1) for myocardial infarction, 1.2 (95% CI 0.9-1.7) for cerebral infarction and 2.1 (95% CI 1.6-2.9) for venous thromboembolism. Patients positive for both Ro/SSA and La/SSB autoantibodies had a substantially higher risk of cerebral infarction (HR 1.7, 95% CI 1.0-2.9) and venous thromboembolism (HR 3.1, 95% CI 1.9-4.8) than the general population. These risks were not significantly increased in Ro/SSA- and La/SSB-negative patients. Among autoantibody-positive patients, the highest HR of cerebral infarction was seen after ≥10 years disease duration (HR 2.8, 95% CI 1.4-5.4), while the HR for venous thromboembolism was highest 0-5 years after disease diagnosis (HR 4.7, 95% CI 2.3-9.3) and remained high throughout disease duration.

CONCLUSIONS

Primary Sjögren's syndrome is associated with a markedly increased risk of cardiovascular disease and the presence of Ro/SSA and La/SSB autoantibodies identify the subgroup of patients carrying the highest risk. These findings suggest that monitoring and prevention of cardiovascular disease in this patient group should be considered.

Abstract P5-17-02: Treatment and prognosis of DCIS during twenty years. A population-based register study from a Swedish cohort

The increasing incidence of ductal carcinoma in situ (DCIS) of the breast has been attributed to the wide adoption of mammography screening programmes. The aim of the present study was to analyse trends in incidence, treatment and outcome of DCIS over a 20-year time period in a Swedish health care region, with a source population of two million, based on systemically collected data in a regional Breast Cancer Quality Registry started in 1992.

All patients registered with a diagnosis of primary DCIS in the Breast Cancer Quality Registry in the Uppsala-Örebro healthcare region between 1992 and 2012 were included. The study period was divided into four time periods.

The registry contains information on tumour characteristics, treatment and follow-up data and is linked to the Swedish cancer registry, to which reporting of all newly diagnosed malignant tumours in Sweden is mandated. To verify the validity of the Breast Cancer Quality Registry, 300 women recorded with a diagnosis of DCIS were randomly selected and their medical records were collected to compare clinical data, treatment data and subsequent breast cancer events compared to registry data. The completeness and reliability of the registration of most key variables were overall good, 91-99%.

A total of 2,952 patients with DCIS were registered, of which eight were men. The proportion of DCIS to all diagnosed breast cancers was 9.5%, with no clear increase over time. The majority of the DCIS cases were detected by screening (68%). Tumour size increased over time; in 1992-1997 36.4% were larger than 15mm compared to 64.8% in 2008-2012. The frequency of mastectomy increased from 23.0% to 39.0% and the proportion of patients receiving adjuvant radiotherapy after breast-conserving surgery increased from 30.1% to 67.6%. Axillary lymph node clearance declined over time while the proportion of patients who underwent sentinel node biopsy increased from 1.4% in 1998-2002 to 33.9% in 2003-2007 and 54.9% in 2008-2012.

 1992-19971998-20022003-20072008-2012P valueCases693628835796 DCIS size &gt; 15mm252(36.4%)257(40.9%)339(53.8%)511(64.2%)&lt;0.0001Mastectomy161(23.2%)150(23.9%)323(38.7%)313(39.3%)&lt;0.0001BCS519(74.9%)468(74.5%)506(60.6%)476(59.8%)&lt;0.0001BCS+RT156/519(30.0%)178/468(38.0%)347/506(68.6%)322/476(67.6%)&lt;0.0001BCS= Breast conserving surgery, RT= radiotherapy

There was no statistical difference in the cumulative incidence of recurrent breast events over time or between different treatment modalities. The relative 5- and 10- year survival rates were 99.0% and 97.0% respectively with no clear trend over time.

In conclusion, while the proportion of DCIS did not increase over time between 1992 and 2012, there was a trend towards more intensified management to achieve local control. The increased tumor size over time could be secondary to a higher diagnostic activity, which clearly is manifested by the increased use of sentinel node biopsy.

Citation Format: Wadsten C, Heyman H, Holmqvist M, Ahlgren J, Lambe M, Sund M, Wärnberg F. Treatment and prognosis of DCIS during twenty years. A population-based register study from a Swedish cohort. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-17-02.

Web- vs. telehealth-based delivery of cognitive behavioral therapy for insomnia: a randomized controlled trial

OBJECTIVES

The purpose of our study was to evaluate and compare two methods of service delivery (web-based and telehealth-based) for chronic insomnia with regard to patient preference, clinical effectiveness, and patient satisfaction.

METHODS

Our study was a randomized controlled trial with manualized telehealth- and web-based delivery conditions (nonblinded). The sample comprised 73 adults with chronic insomnia. Participants received web-based delivery from their homes or telehealth-based delivery from a nearby clinic. Both interventions consisted of identical psychoeducation, sleep hygiene and stimulus control instruction, sleep restriction treatment, relaxation training, cognitive therapy, mindfulness meditation, and medication-tapering assistance.

RESULTS

Using a linear mixed model analysis, results showed that both delivery methods produced equivalent changes in insomnia severity, with large effect sizes. Attendance patterns favored telehealth, whereas homework adherence and preference data favored web-based delivery.

CONCLUSIONS

Web- and telehealth-based delivery are both helpful in treating chronic insomnia in rural-dwelling adults.

The characterisation and risk factors of ischaemic heart disease in patients with coeliac disease

BACKGROUND

Studies have shown an increased risk of ischaemic heart disease (IHD) in patients with coeliac disease (CD), despite the patients' lack of traditional IHD risk factors.

AIM

To characterise IHD according to CD status.

METHODS

Data on duodenal or jejunal biopsies were collected in 2006-2008 from all 28 pathology departments in Sweden and were used to define CD (equal to villous atrophy; Marsh stage 3). We used the Swedish cardiac care register SWEDEHEART to identify IHD and to obtain data on clinical status and risk factors at time of first myocardial infarction for this case-only comparison. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). CD patients were compared with general population reference individuals.

RESULTS

We identified 1075 CD patients and 4142 reference individuals with subsequent IHD. CD patients with myocardial infarction had lower body mass index (P < 0.001) and cholesterol values (P < 0.001) and were less likely to be active smokers (OR = 0.74; 95% CI = 0.56-0.98) than reference individuals with myocardial infarction. CD patients had less extensive coronary artery disease at angiography (any stenosis: OR = 0.80; 95% CI = 0.66-0.97; three-vessel disease: OR = 0.73; 95% CI = 0.57-0.94); but there was no difference in the proportions of CD patients with positive biochemical markers of myocardial infarction (CD: 92.2% vs. reference individuals: 91.5%, P = 0.766).

CONCLUSION

Despite evidence of an increased risk of IHD and higher cardiovascular mortality, patients with coeliac disease with IHD have a more favourable cardiac risk profile compared with IHD in reference individuals.

Regional differences regarding risk of developing rheumatoid arthritis in Stockholm County, Sweden: results from the Swedish Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study

OBJECTIVES

Rheumatoid arthritis (RA) is a complex disease that is associated with genetic and environmental factors. We have investigated geospatial variation in the risk of developing RA within Stockholm County, Sweden, with respect to established environmental risk factors for RA, as well as serologically defined subgroups of RA.

METHOD

Information regarding geographical location for 1432 cases and 2529 controls from the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study, living in Stockholm County at RA symptom onset, or matched date for controls, was used to estimate geospatial variation in risk. We used generalized additive models (GAMs) to create a risk surface, calculate odds ratios (ORs), and adjust for potential confounding by smoking, education level, and RA within family. We performed a stratified analysis based on the presence/absence of anti-citrullinated peptide antibodies (ACPA).

RESULTS

We found significant spatial variation in the odds of developing RA in Stockholm County. After adjustment for smoking, education level, and family history of RA, this geospatial variation remained. The stratified analysis showed areas with higher ORs for ACPA-positive RA and ACPA-negative RA, after adjusting for smoking, education level, and having a family history of RA. Living in the city of Stockholm was associated with decreased risk of RA.

CONCLUSIONS

The risk of developing RA in Stockholm County is not distributed evenly and there are areas of increased risk that could not be explained by known factors. Further investigations of local exposures or social factors are warranted.

P4-19-04: Evaluation of Histopathological Parameters in Male Breast Cancer Reveals Differences Compared with Female Breast Cancer

Purpose: To characterize male breast cancer (MBC) by evaluating established histopathological parameters and their prognostic value.

Methods: 197 male patients with invasive breast cancer and available paraffin-embedded tumor tissue were retrospectively assessed. Patient files were reviewed for clinicopathological data. Tumors were re-evaluated for histologic grading on conventional sections. Immunohistochemical (IHC) stainings for estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), silver-enhanced in situ hybridization (SISH), Ki-67, CK5/6 and epidermal growth factor receptor (EGFR) were performed on tissue micro arrays. Data on vital status and cause of death were retrieved from the Cause of Death Registry. Cox proportional regression models were used for uni- and multivariate analyses.

Results: ER and PgR positivity was demonstrated in 93 and 78 % of patients, respectively. Nottingham histologic grade III was seen in 41% and HER2 positivity in 11% of all patients. Defining molecular phenotypes using IHC markers revealed luminal (ER+ and/or PgR+, and HER2−) in 83%, luminal/HER2+ (ER+ and/or PgR+, and HER2+) in 11%, basal-like (ER-,PgR-,HER2−,EGFR+ and/or CK5/6 +) in 1%, but no cases of HER2-like or unclassified. Node-positivity (HR 4.6; 95% CI 1.9−11.4), tumor size &gt; 20 mm (HR 2.3; 95% CI 1.1−5.0) and ER-negativity (HR 5.2; 95% CI 1.9−14.2) were significant risk factors for breast cancer death. Grade, HER2 status, Ki-67, or age did not demonstrate independent prognostic information. No difference in breast cancer deaths was demonstrated between luminal and luminal/HER2.

Conclusion: Male breast cancer tumors seem to be of grade III more often than female breast cancer, whereas HER2 expression appears equally common. In our study, the most important predictors for breast cancer death in male breast cancer were lymph nodes, tumor size and ER status. The most common molecular phenotype was luminal.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-19-04.

Alcohol prevention in Swedish occupational health care

BACKGROUND

Occupational health care (OHC) was part of the Swedish Risk Drinking Project, a government-supported continuing professional education (CPE) endeavour for health professionals, 2004-10.

AIMS

To investigate OHC professionals' perceived knowledge concerning patient counselling on alcohol, perceived efficiency in achieving patient changes, use of questionnaires and biomarkers, amount and content of their alcohol-related CPE, their reasons for participating in this CPE and improvements experienced in addressing alcohol issues in the last 3 years.

METHODS

Baseline 2005 and follow-up 2008 data were collected by means of anonymous questionnaires to all physicians and nurses in OHC.

RESULTS

Response rates ranged from 53 to 80%. The share of nurses and physicians who had taken part in ≥ 3 days training on risk drinking issues rose from 10 to 59% and from 7 to 59%, respectively. The OHC professionals' perceived knowledge and efficiency concerning lifestyle counselling improved from 2005 to 2008, considerably more so for alcohol than the other lifestyle issues. The most competent nurses and physicians were more likely to have participated in training lasting ≥ 3 days. The most competent nurses and physicians had become better at initiating conversations about alcohol and at informing, providing advice and discussing alcohol with their clients.

CONCLUSIONS

There were major improvements in the OHC professionals' perceived knowledge concerning alcohol counselling and efficiency in influencing patients' alcohol habits after participation in a comprehensive CPE project. Overall, the nurses achieved more improvements than the physicians.

Stage at Diagnosis and Management of Breast Cancer in Men and Women – A Population-Based Study (Sweden)

Background: Male breast cancer is an uncommon disease, representing less than 1% of all breast cancer. Due to the rareness of the disease there is a lack of prospective randomized studies to guide treatment decisions. While current guidelines recommend that male breast cancer should be treated in the same way as female breast cancer, concerns have been raised regarding the quality of management in men. Results from earlier studies indicate that men with breast cancer are not as aggressively treated as women and that outcomes are worse. The aim of this population based study was to assess and compare stage at presentation and management of breast cancer in men and women in Sweden.Material and methods: In a case-control approach, we identified male and female patients with a record of a breast cancer diagnosis in the Breast Cancer Register of Central Sweden between 1993 and 2007. 99 men (cases) with breast cancer were matched on age at and time of diagnosis to four women with breast cancer (controls). Data on tumor characteristics and treatment were retrieved from the Breast Cancer Register.Results: There was no difference in the distribution of stage at diagnosis between men and women; stage I (33% and 36%, respectively), stage II (42% and 41%), stage III (6% and 4%) and stage IV (3% and 4%,). At the time of diagnosis 31% of male patients and 32% of female patients were node positive. Men underwent mastectomy more often than women (95% versus 45%). The proportion of men receiving loco-regional radiotherapy postoperatively was lower compared to women (44% vs. 58%). There were no proportional differences regarding adjuvant chemotherapy (16% vs. 18%) and adjuvant hormonal therapy (60% vs. 55%).Conclusion: At the time of diagnosis, men and women presented with a similar distribution of stage of disease. Our concerns regarding less extensive treatment in male breast cancer patients were not supported by our findings. Additional data including survival analyses will be added and presented at SABCS.Clinical VariablesMale breast cancer patients (cases) N=99Female breast cancer patients (controls) N=396Stage  I33%36%II42%41%III6%4%IV3%4%Missing16%15%N+31%32%M13%4%Mastectomy95%45%Partial mastectomy5%54%No surgery2%4%No axillary surgery11%12%Preoperative radiotherapy1%1%Preoperative chemotherapy5%2%Preoperative hormonal treatment2%3%Chemotherapy16%18%Radiotherapy44%58%Tamoxifen58%45%Aromatase inhibitor2%10%No treatment21%14%    

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2111.

Cyclin B1 Is an Independent Prognostic Proliferation Marker with a High Reproducibility in a Population-Based Lymph Node Negative Breast Cancer Cohort

Purpose: A large proportion of women with lymph node negative breast cancer treated with chemotherapy do not benefit from such treatment. Proliferation markers can recognize patients at high risk for recurrence. However, no proliferation marker is generally accepted for clinical use. We investigated the independent prognostic importance of cyclin B1 in node negative breast cancer and included a study of the reproducibility.Study Design: In a population-based, case-control study, 190 women who died from breast cancer were defined as cases and 190 women alive at the time for the corresponding case's death as controls. Inclusion criteria were tumor size ≤ 50 mm, no lymph node metastases, and no adjuvant chemotherapy. Tumor tissue was immunostained for cyclin B1. Two investigators evaluated the staining independently by counting approximately 100, 200, 500, and 1000 cells.Results: Cyclin B1 was statistically significantly associated to breast cancer death, in both uni- and multivariate analyses (adjusted for tumor size, age, and endocrine therapy), with odds ratios 2-3 for both investigators. The reproducibility between the two investigators was good to very good, regardless of the number of counted cells (kappa values between 0.74 and 0.82).Conclusions: Cyclin B1 is a prognostic factor for breast cancer death in a population-based and node negative patient cohort and can identify high-risk node negative patients with a good to very good reproducibility.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6051.

High Expression of Cyclin E Increases the Risk for Breast Cancer Death by 2-3 Fold in Node Negative Breast Cancer Patients

Background: A large proportion of women with lymph node negative breast cancer treated with chemotherapy do not benefit from such treatment. Several studies have suggested that proliferation markers can identify patients at increased risk for recurrence. However, current international guidelines do not recommend proliferation markers for clinical use due to lack of well-powered studies and standardization of methodology. We wanted to investigate the prognostic value of cyclin E1 in a large population-based study on node negative breast cancer patients.Study Design: In a population-based, case-control study, 190 women who died from breast cancer were defined as cases and 190 women alive at the time for the corresponding case's death as controls. Inclusion criteria were tumor size ≤ 50 mm, no lymph node metastases and no adjuvant chemotherapy. The study was designed to detect an odds ratio (OR) of 2.5 with a power of 90% at a significance level of 0.05. Tumor tissue was immunostained for cyclin E1 with a commercial antibody. Statistical analyses were performed for 200 (cyclin E 200) and 500 cells (cyclin E 500) counted, respectively.Results: Cyclin E1 was highly correlated to histologic grade, Ki-67 and cyclins A/B (rs= 0.5-0.6; p&lt;0.001) and inversely correlated to hormone receptors (rs=-0.2--0.3; p&lt;0.001). There was a statistically significant association between cyclin E1 and breast cancer death both in uni- and multivariate (adjusted for tumor size and age) analyses with OR 2.6 -2.7 for cyclin E 200 and OR 2.1-1.9 for cyclin E 500.Conclusions: We found that cyclin E1 is a prognostic factor for breast cancer death in a population-based node negative patient cohort. Patients with tumors expressing high levels of cyclin E have a 2-3 fold increased risk for breast cancer death.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3033.

Feasibility of treatment of resectable rectal cancer with neoadjuvant treatment with pemetrexed

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Background: Multimodality strategies of chemo- and radiotherapy (RT) in the neoadjuvant setting of resectable rectal cancer are a challenge to optimize surgery outcome. Pemetrexed (P) has shown efficacy in colorectal cancer. This phase II trial evaluated its feasibility as neo-adjuvant monotherapy for patients (pts) with resectable rectal cancer. Methods: Between June’ 06 and January’ 08, 37 pts with a histologically proven diagnosis of operable rectal adenocarcinoma were enrolled. P was dosed at 500 mg/m2 every 3 weeks, during 3 cycles with standard co-medication (vitamin B12, folic acid, and dexamethasone) on an outpatient base. If RT was given, minimum interval between start of RT and last dose of P was 2 weeks, preferably 5 consecutive days of RT occurred from day 17 to day 21 in cycle 3 or after completion of cycle 3. The feasibility hypothesis was that at least 85% of pts would be able to receive the chemotherapy as planned. Secondary endpoints were evaluation of qualitative and quantitative toxicities including rate of postoperative complications, proportion of pts with sphincter saving surgery, proportion of pts with complete tumor resection rate and pathological response rate. Results: All patients were able to receive 3 cycles of chemotherapy. 33 patients (89.2%, CI: 74.6 to 97) completed their planned dosage in time. The reason for delay was inadequate vitamin supply for 1 pt and 3 pts due to other reasons. No dose reduction or study-drug related SAE was seen. The only grade 3 and 4 toxicities (neutropenia) occurred in 7 pts (18.9%). 28 pts received RT following chemotherapy. All pts underwent R0 resection. One pathological proven complete response was evaluated. 12 out of 13 planned pts had a rectum amputation. All others received sphincter saving surgery. Postoperative complications occurred in 54% of the pts. All events were considered related to study procedure (operation) and not to study drug. Conclusions: This explorative study suggests that the administration of 3 cycles of pemetrexed is feasible and well tolerated within a multimodality treatment strategy.

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ADHD in adult psychiatry. Minimum rates and clinical presentation in general psychiatry outpatients

The objective of the study was to determine the prevalence and comorbidity of persisting attention-deficit hyperactivity disorder (ADHD) in adult psychiatric outpatients. Consecutive patients, first visits excluded, at a general psychiatric outpatient clinic were offered a screening for childhood ADHD with the Wender Utah Rating Scale (WURS). One hundred and forty-one patients out of 398 (35%) completed and returned the scale. Patients above or near cut-off for ADHD (n=57) were offered an extensive clinical evaluation with psychiatric as well as neuropsychological examination. The attrition was analysed regarding age, sex and clinical diagnoses. Out of the screened sample, 40% had scores indicating possible childhood ADHD. These 57 patients were invited to the clinical part of the study, but 10 declined assessment, leaving 47 (37 women and 10 men) who were actually examined. Thirty of these (21 women and nine men) met diagnostic criteria for ADHD at the time of examination. Among the patients with ADHD, affective disorders were the most common psychiatric diagnoses. The rate of alcohol and/or substance abuse, as noted in the medical records, was also high in the ADHD group. In the WURS-screened group, 22% (30 patients assessed as part of this study and one person with ADHD previously clinically diagnosed) were shown to have persisting ADHD. Therefore, it is clearly relevant for psychiatrists working in general adult psychiatry to have ADHD in mind as a diagnostic option, either as the patient's main problem or as a functional impairment predisposing for other psychiatric disorders.

Usual drinking patterns and non-fatal injury among patients seeking emergency care

OBJECTIVES

To explore the association between drinking patterns, irrespective of whether alcohol was consumed in the event of the injury or not, and different injury variables; and to identify settings and situations in which risky drinkers have an increased likelihood of injury.

STUDY DESIGN

The study population consisted of all patients aged 18-70 years registered for an injury according to ICD-10 at a Swedish emergency department during an 18-month period. After informed consent, the injury patients were screened for drinking habits by the AUDIT-C questionnaire. The gender, age and drinking pattern of injury patients were compared with the general population.

METHODS

A total of 2782 patients aged 18-70 years were registered for an injury during the study period. The number of drop-outs was 631. Drop-outs include those who did not consent to participate, were severely injured, too intoxicated or did not fill out the questionnaire satisfactory. Thus, 77.3% of the target group were included for further analysis (1944 drinkers and 207 abstainers). The patients were categorized into three drinking categories: abstainers, non-risky and risky drinkers. Risky drinkers were defined according to usual weekly consumption of 80g or more of alcohol for women and 110g or more for men and/or heavy episodic drinking (i.e. having six glasses or more one glass=12g alcohol), or both, on one occasion at least once a month, valid for both women and men. To estimate the relationship between drinking patterns and the injury variables (environment, cause of injury, activity and diagnosis), odds ratios (OR) were calculated by logistic regression. Multiple logistic regression was used in order to control for age and sex differences between the various drinking and injury categories.

RESULTS

The proportion of risky drinkers was higher in the study population compared with the general population in the same area. When controlling for age and sex, risky drinkers (OR 6.4(adj) Confidence interval CI 1.9-21.2) and non-risky drinkers (OR .4.5(adj) CI 1.4-14.5) displayed an increased risk for injury compared with abstainers, in amusement locations, parks, by or on lakes or seas, especially while engaged in play, hobby or other leisure activities (risky drinkers: OR 2.8(adj) CI 1.3-5.6; non-risky drinkers: OR 2.4(adj) CI 1.2-4.6). All differences between drinking patterns in external cause of injury disappeared when age and sex were considered. During rest, meals and attending to personal hygiene, the non-risky drinkers had a lower probability of injury compared with abstainers (OR 0.3(adj) CI 0.1-0.8). Non-risky drinkers had a higher probability than abstainers of suffering luxation (dislocation) or distortion (OR 1.6(adj) CI 1.1-2.5). Nine per cent of the study population reported that they believed that their injury was related to intake of alcohol. Half of this group were non-risky drinkers (CI for the 13.7% difference was 9.7-17.6).

CONCLUSIONS

Few significant associations between drinking pattern and injury remained when age and sex were controlled for.

Risk factors for local recurrence after breast-conserving surgery

BACKGROUND

It is not clear whether risk factors for local recurrence after breast-conserving surgery differ in women having surgery for in situ or invasive cancer. Furthermore, the Nottingham Prognostic Index (NPI) and Nottingham Histological Grade (NHG) have been little studied as determinants of local recurrence risk.

METHOD

In a case-control study (491 cases and 1098 controls) nested within a cohort of 7502 women who had surgery for in situ or invasive cancer of the breast, patient characteristics, tumour characteristics and treatment-related variables were evaluated as risk factors for local recurrence.

RESULTS

Multivariate conditional logistic regression analyses showed that age below 40 years, tumour multicentricity and an unclear or unknown surgical margin were significant risk factors for local recurrence. Radiotherapy to the breast and adjuvant hormone therapy were protective. Cancer in situ was not associated with a higher risk of local recurrence than invasive cancer (odds ratio 1.0, 95 per cent confidence interval 0.8 to 1.3). NHG and NPI were not helpful in determining risk of local recurrence.

CONCLUSION

Margin status, age, tumour multicentricity, and use of radiotherapy and adjuvant hormone therapy were important determinants of risk of local recurrence. With the exception of surgical margin, variables related to the quality of surgical management did not predict risk of local recurrence.

Local recurrence in the breast after conservative surgery--a study of prognosis and prognostic factors in 391 women

In a population-based cohort of 6613 women with invasive breast cancer, who had breast-conserving surgery between 1981 and 1990, 391 recurrences in the operated breast were identified. The main aim of this study was to examine the prognosis and prognostic factors in different subgroups of local recurrences, characterised by the time to recurrence, location of recurrence and previously given radiotherapy. The median follow-up for women who had a local recurrence was 7.9 years. The life-table estimates for breast cancer-specific survival in women with local recurrences were 84.5% (standard error (S.E.) 1.8) at 5 years and 70.9% (S.E. 2.7) at 10 years. The risk of breast cancer death was highest among women who had an early (<or=2 years) recurrence in the same quadrant as the primary tumour, with a breast cancer-specific survival of 67.9% (S.E. 4.8) at 5 years and 56.0% (S.E. 5.9) at 10 years. There was a statistically significant difference in the probability of breast cancer-specific survival, as measured from the recurrence, between women who initially did or did not receive radiotherapy (P=0.0123). However, when measured from primary treatment, there was no significant difference, indicating that the difference in prognosis could be due to a lead-time bias. Independent prognostic factors for breast cancer-specific survival in women with local recurrences were time to local recurrence and the Nottingham Prognostic Index (NPI).

Consequences of axillary recurrence after conservative breast surgery

BACKGROUND

The aim was to study the incidence, time course and prognosis of patients who developed axillary recurrence after breast-conserving surgery, and to evaluate possible risk factors for axillary recurrence and prognostic factors after axillary recurrence.

METHODS

In a population-based cohort of 6613 women with invasive breast cancer who had breast-conserving surgery between 1981 and 1990, 92 recurrences in the ipsilateral axilla were identified. Risk factors for axillary recurrence were studied in a case-control study nested in the cohort, and late survival was documented in the women with axillary recurrence.

RESULTS

The overall risk of axillary recurrence was 1.0 per cent at 5 years and 1.7 per cent at 10 years. The risk of axillary recurrence increased with tumour size (P = 0.033) and was highest in younger women (odds ratio (OR) 3.9 for women aged less than 40 years compared with those aged 50-59 years). Radiotherapy to the breast reduced the risk of axillary recurrence (OR 0.1 (95 per cent confidence interval 0.1 to 0.4)). The breast cancer-specific survival rate after axillary recurrence, as measured from primary treatment, was 78.0 per cent at 5 years and 52.3 per cent at 10 years. Tumour size and node status had a statistically significant effect on death from breast cancer.

CONCLUSION

Axillary recurrence is rare, although more common in younger women with large tumours. Radiotherapy to the breast was protective. Tumour size and node status were the most important prognostic factors in women with axillary recurrence.

Compound exocytosis in voltage-clamped mouse pancreatic beta-cells revealed by carbon fibre amperometry

Capacitance measurements of exocytosis were combined with carbon fibre amperometry for time-resolved measurements of the properties of secretion in single, insulin-secreting, mouse pancreatic beta-cells pre-loaded with the amine serotonin (5-HT). Glucose-induced electrical activity was associated with the appearance of brief and transient amperometric currents reflecting the serotonin co-released with insulin. The integrated amperometric responses resulting from voltage-clamp depolarisations were proportional to the corresponding increase in cell capacitance. Both parameters exhibited U-shaped relationships to the membrane potential with maximums around 0 mV. There was a variable latency (40-730 ms, average 230 ms) between the onset of the depolarisation and the amperometric current. During high-frequency repetitive stimulation, a progressive decrease in the exocytotic capacity ("depression") was observed. This was paralleled by a corresponding reduction of the amperometric responses. Using the carbon fibre to map the beta-cell for release sites indicated that exocytosis was confined to the part of the cell containing the highest density of secretory granules. Two types of amperometric responses were observed. In about 50% of the cells, a smooth increase was observed with no discernible discrete events. In the remaining cells, the amperometric records contained large spikes. These were ten or more times larger than that expected for the fusion of individual secretory granules. We propose that these large spikes reflect the exocytosis of multigranular complexes formed inside the beta-cell prior to exocytosis.