OP0007 MUC5B PROMOTER VARIANT AND LONG-TERM INCIDENCE OF INTERSTITIAL LUNG DISEASE IN PATIENTS WITH RHEUMATOID ARTHRITIS: A POPULATION BIOBANK STUDY OF 250,000 INDIVIDUALS

Background:

The promoter variant rs35705950 in MUC5B is the strongest known genetic risk factor for rheumatoid arthritis-associated interstitial lung disease (RA-ILD) [1]. There is, however, no large-scale data on the impact of MUC5B on the long-term incidence of RA-ILD.

Objectives:

To describe long term risk of RA-ILD in RA patients carrying MUC5B variant compared to non-carriers with RA.

Methods:

FinnGen is a collection of epidemiological cohorts and hospital biobank samples, linking genotypes with up to 46 years of follow-up within nationwide registries. Diagnoses of RA and ILD were identified from the Finnish national hospital discharge, medication reimbursement and cause-of-death registries. We estimated lifetime risks of ILD by age 80. MUC5B is a common variant and has an allele frequency of 0.1 in the Finnish population.

Results:

Out of the 248,400 individuals, 5534 patients have been diagnosed with RA, out of whom 178 (3.2%) developed ILD. MUC5B was a strong predictor of ILD in RA patients (HR 2.14, 95%CI 1.56-2.92). In patients with RA, MUC5B conferred a lifetime risk of 14.5% (95%CI 10.7-18.1%), compared to 5.2% (4.1-6.2%) in MUC5B non-carriers with RA (Figure). In the population, MUC5B carriers and MUC5B non-carriers had lifetime risks of 3.9% and 1.3%, respectively. The risk difference started to emerge at age 65. The risk was highest in men with RA who are MUC5B carriers: 18.5% (11.1-25.2%) developed ILD, compared to 8.5% (6.1-10.9%) of MUC5B non-carriers with RA.

Conclusion:

We report findings from a large longitudinal study, showing that MUC5B confers a considerable lifetime risk of RA-ILD, and contributes to increased morbidity. These findings have clinical implications for improving identification of RA patients at high risk of developing ILD.

References:

[1]Juge P-A, Lee JS, Ebstein E, et al. MUC5B Promoter Variant and Rheumatoid Arthritis with Interstitial Lung Disease. N Engl J Med 2018;379:2209–19

Disclosure of Interests:

Antti Palomäki Speakers bureau: MSD, Pfizer, Sanofi, Consultant of: Pfizer, Abbvie, Tarja Laitinen: None declared, Jukka Koskela Speakers bureau: Pfizer, Aarno Palotie: None declared, Nina Mars: None declared

Primary aldosteronism: Higher volume load, cardiac output and arterial stiffness than in essential hypertension

BACKGROUND

The diagnostics of primary aldosteronism (PA) are usually carried out in patients taking antihypertensive medications. We compared haemodynamics between medicated PA, medicated essential hypertension (EH), never-medicated EH and normotensive controls (n = 130 in all groups).

METHODS

The hypertensive groups were matched for age (53 years), sex (84 male/46 female) and body mass index (BMI) (30 kg m^-2 ); normotensive controls had similar sex distribution (age 48 years, BMI 27 kg m^-2 ). Haemodynamics were recorded using whole-body impedance cardiography and radial pulse wave analysis, and the results were adjusted as appropriate. Radial blood pressure recordings were calibrated by brachial blood pressure measurements from the contralateral arm.

RESULTS

Radial and aortic systolic and diastolic blood pressure was similar in PA and never-medicated EH, and higher than in medicated EH and normotensive controls (P ≤ 0.001 for all comparisons). Extracellular water balance was ~ 4% higher in PA than in all other groups (P < 0.05 for all), whilst cardiac output was ~ 8% higher in PA than in medicated EH (P = 0.012). Systemic vascular resistance and augmentation index were similarly increased in PA and both EH groups when compared with controls. Pulse wave velocity was higher in PA and never-medicated EH than in medicated EH and normotensive controls (P ≤ 0.033 for all comparisons).

CONCLUSIONS

Medicated PA patients presented with corresponding systemic vascular resistance and wave reflection, but higher extracellular water volume, cardiac output and arterial stiffness than medicated EH patients. Whether the systematic evaluation of these features would benefit the clinical diagnostics of PA remains to be studied in future.

Response initiation in young adults at risk for psychosis in the Northern Finland 1986 Birth Cohort

INTRODUCTION

This is one of the very few studies to investigate the specific executive function/processing speed component of response initiation in subjects at familial risk (FR) for psychosis, and the first such study in subjects at clinical risk (CR) for psychosis.

METHODS

Participants (N = 177) were members of the general population-based Northern Finland 1986 Birth Cohort in the following four groups: FR for psychosis (n = 62), CR for psychosis (n = 21), psychosis (n = 25) and control subjects (n = 69). The response initiation of these groups was compared in three different tests: Semantic fluency, Stockings of Cambridge and Spatial working memory.

RESULTS

The two risk groups did not differ significantly from control group, but differed from, and outperformed the psychosis group in semantic fluency response initiation.

CONCLUSIONS

Response initiation deficits were not evident in a non-help seeking psychosis high-risk sample.

Longitudinal HRQoL shows divergent trends and identifies constant decliners in asthma and COPD

BACKGROUND/AIM

Monitoring of lung function alone does not adequately identify the high-risk patients among elderly asthma and COPD cohorts. The additional value of Health-Related Quality of Life (HRQoL) development in the detection of patients with a disabling disease in clinical practice is unclear. The aim of this study was to statistically examine the individual development of HRQoL measured using respiratory-specific AQ20 and generic 15D questionnaires.

MATERIALS AND METHODS

The HRQoL of COPD (N = 739) and asthma (N = 1329) patients was evaluated at 0, 1, 2, and 4 years after recruitment. To determine a five-year HRQoL change for each patient we used mixed-effects modelling for linear trend.

RESULTS

In COPD, the majority (60-80%) of the individuals showed declining trend, whereas in asthma, the majority (46-71%) showed no attenuation in HRQoL. The proportion of constant decliners was estimated higher with the 15D both in asthma (6.3%) and COPD (6.3%) than with AQ20 (3.5 and 4.5%, respectively). The first measurement of HRQoL was found to predict future development of HRQoL. In asthma, obesity-related diseases such as hypertension, diabetes and gastro-esophageal reflux disease best explained the decline, whereas in COPD, age and the level of bronchial obstruction were the main determinants.

CONCLUSION

Based on the five-year follow-up, the HRQoL trends significantly diverging from each other could be identified both among the asthma and COPD patients. Compared to cross-sectional HRQoL, the HRQoL trend over a clinically relevant period of time allows us to ignore, to a great extent, the random error of self-assessed HRQoL and thus, it may offer a more accurate measure to describe the disease process.

Potassium channel KCNH2 K897T polymorphism and cardiac repolarization during exercise test: The Finnish Cardiovascular Study

OBJECTIVE

Cardiac repolarization is regulated, in part, by the KCNH2 gene, which encodes a rapidly activating component of the delayed rectifier potassium channel. The gene expresses a functional single nucleotide polymorphism, K897T, which changes the biophysical properties of the channel. The objective of this study was to evaluate whether this polymorphism influences two indices of repolarization--the QT interval and T-wave alternans (TWA)--during different phases of a physical exercise test.

MATERIAL AND METHODS

The cohort consisted of 1,975 patients undergoing an exercise test during which on-line electrocardiographic data were registered. Information on coronary risk factors and medication was recorded. The 2690A>C nucleotide variation in the KCNH2 gene corresponding to the K897T amino acid change was analysed after polymerase chain reaction with allele-specific TaqMan probes.

RESULTS

Among all subjects, the QTc intervals did not differ between the three genotype groups (p> or =0.31, RANOVA). Women with the CC genotype tended to have longer QT intervals during the exercise test, but the difference was statistically significant only at rest (p = 0.011, ANOVA). This difference was also detected when the analysis was adjusted for several factors influencing the QT interval. No statistically significant effects of the K897T polymorphism on TWA were observed among all subjects (p = 0.16, RANOVA), nor in men and women separately.

CONCLUSIONS

The K897T polymorphism of the KCNH2 gene may not be a major genetic determinant for the TWA, but the influence of the CC genotype on QT interval deserves further research among women.

Genetic relationships of body composition and feed utilization traits in European whitefish (Coregonus lavaretus L.) and implications for selective breeding in fishmeal- and soybean meal-based diet environments

Body composition traits have potential use in fish breeding programs as indicator traits for selective improvement of feed efficiency. Moreover, feed companies are increasingly replacing traditional fish meal (FM) based ingredients in feeds for carnivorous farmed fish with plant protein ingredients. Therefore, genetic relationships of composition and feed utilization traits need to be quantified for both current FM-based and future plant-based aquaculture feeds. Individual whole-body lipid% and protein%, daily gain (DG), ADFI, and G:F (daily gain/daily feed intake) were measured on 1,505 European whitefish (Coregonus lavaretus) from 70 half/full-sib families reared in a split-family design with either a typical FM or a novel soybean meal (SBM) based diet. Diet-specific genetic parameters were estimated with multiple-trait animal models. Lipid% was significantly greater in the FM diet group than in the SBM group, even independent of final BW or total feed intake. In both diets, lipid% showed moderate heritability (0.12 to 0.22) and had positive phenotypic and genetic correlations with DG (0.37 to 0.82) and ADFI (0.36 to 0.88). Therefore, selection against lipid% can be used to indirectly select for lower feed intake. Protein% showed low heritability (0.05 to 0.07), and generally very weak or zero correlations with DG and ADFI. In contrast to many previous studies on terrestrial livestock, lipid% showed zero or very weak phenotypic and genetic correlations with G:F. However, selection index calculations demonstrated that simultaneous selection for high DG and reduced lipid% could be used to indirectly increase G:F; this strategy increased absolute genetic response in G:F by a factor of 1.5 to 1.6 compared with selection on DG alone. Lipid% and protein% were not greatly affected by genotype-diet environment interactions, and therefore, selection strategies for improving body composition within current FM diets should also improve populations for future SBM diets.

The effect of dietary phosphorus deficiency on the immune responses of European whitefish (Coregonus lavaretus L.)

Low phosphorous (P) feeds in aquaculture are recommended to reduce eutrophication of water systems. However, the feed should be adequate for normal growth and intact immune defence. Influence of low dietary P supply on non-specific and specific immune defence of European whitefish (Coregonus lavaretus) was studied in two trials. For Trial 1, a semi-purified, low-P diet was formulated and supplied with 0, 2.5, 5.0, 7.5, or 10.0 g P kg(-1)to obtain a P gradient of 4.4-14.9 g kg(-1)diet. Diets were fed to four replicate groups of fingerling whitefish for 42 days in a flow-through, freshwater system maintained at 15 degrees C. Fish fed with the P-unsupplemented diet had significantly lower plasma immunoglobulin M (IgM) levels than fish fed with the P-fortified diets (means 2.53 vs. 3.19 mg ml(-1); P=0.047). Plasma lysozyme activity did not differ between fish fed with the P-unsupplemented diet and fish fed with the P-fortified diets (means 21.8 vs. 25.5 U ml(-1); P=0.107). For Trial 2, fish were acclimated for 49 days by feeding the lowest or highest dietary P contents, and thereafter immunised with a single intraperitoneal injection of a novel antigen, bovine gamma globulin (BGG). A clear antibody response against BGG was elicited but the antibody levels did not differ between fish fed low-P or high-P contents. Similar to Trial 1, plasma IgM was lower in fish fed low-P diets, and low-P diet did not influence plasma lysozyme activity. In both trials the growth of fish, having received low-P diet, was significantly lowered. It is concluded that P deficiency has only minor effects on the immune parameters in whitefish, and the practical aquafeed with P contents sufficient for normal growth does not compromise immune functions of this species.

Programme sensitivity and effectiveness of mammography service screening in Helsinki, Finland

OBJECTIVES

To evaluate the effectiveness of mammography service screening.

SETTING

Helsinki (population 0.5 million), the capital of Finland, the breast cancer service screening programme was started gradually in 1986.

MATERIALS AND METHODS

The study was based on the data from the breast cancer screening programme in Helsinki. All incident cases of breast cancer and rates in the female population in Helsinki during the period 1970-97, and information on the subsequent breast cancer mortality were derived from the files of the Finnish Cancer Registry. To estimate the sensitivity of the programme, the number of screen detected cancers were compared with the overall number of breast cancers at the targeted age groups. Effects of screening were estimated for cumulative incidence and for the refined mortalities among the birth cohorts screened.

RESULTS

Altogether 144 400 invitations had been sent during 1986-97 among the 50-9 year old women as targeted in Helsinki. The average attendance rate was 82%; and 545 breast cancers were detected by screening, with a detection rate of 0.46%. In the birth cohort of women born between the start of 1935 and the end of 1939-namely, those subjected to most complete screening and long follow up time since the onset of the programme-there was an increase in the cumulative incidence of breast cancer (relative risk (RR) 1.18, 95% confidence interval (95% CI) 1.09 to 1.27). The estimated sensitivity of the screening programme was 58%; and 53% if corrected for overdiagnosis. There was also a decrease of 19% (RR 0.81, 95% CI 0.62 to 1.05) in the refined mortality within this screened birth cohort, compared with the death rate of women of comparable ages in the non-screened reference cohort.

CONCLUSION

The study provides further support to the hypothesis that service screening with mammography reduces the risk of breast cancer mortality.

Acoustic loss mechanisms in leaky SAW resonators on lithium tantalate

We discuss acoustic losses in synchronous leaky surface acoustic wave (LSAW) resonators on rotated Y-cut lithium tantalate (LiTaO3) substrates. Laser probe measurements and theoretical models are employed to identify and characterize the radiation of leaky waves into the busbars of the resonator and the excitation of bulk acoustic waves. Escaping LSAWs lead to a significant increase in the conductance, typically occurring in the vicinity of the resonance and in the stopband, but they do not explain the experimentally observed deterioration of the electrical response at the antiresonance. At frequencies above the stop-band, the generation of fast shear bulk acoustic waves is the dominant loss mechanism.

Surface acoustic wave impedance element ISM duplexer: modeling and optical analysis

Surface acoustic wave (SAW) impedance element antenna duplexers provide compact, high performance, front-end components apt for industrial fabrication. We describe investigations on the design and modeling of a compact ISM antenna duplexer fabricated on a 36 degrees YX-cut LiTaO3 substrate based on SAW impedance elements. In particular, we have performed 3-D modeling of the inductive and capacitive electromagnetic couplings caused by the package parasitics for the duplexer. The use of a 1:3 IDT structure for the reduction of the passband width is discussed. The frequency response of the duplexer is predicted with the help of circuit simulation; the modeling is refined by optimization of the model parameters to improve the fit between the measured and simulated responses. We also report scanning optical imaging of the acoustic field within the resonator structures with the help of laser interferometry; this provides insight into the loss mechanisms beyond that attainable in mere electric measurements.

Theory for shear horizontal surface acoustic waves in finite synchronous resonators

An analytic approach is developed for simulating synchronous resonators employing shear horizontally polarized surface acoustic waves, such as surface transverse waves, and leaky surface acoustic waves on LiTaO/sub 3/ and LiNbO/sub 3/ substrates. The approach, based on a simplified parametrized Green's function theory, allows the description of the localization of the wave and the interaction with bulk acoustic waves. An analytic expression is found for the harmonic admittance of an infinite periodic electrode array, and approximate corrections for finite structures are presented. The model enables fast computation of the admittance of synchronous resonators, and it compares favorably with experiments and numerical simulations.

SAW/LSAW COM parameter extraction from computer experiments with harmonic admittance of a periodic array of electrodes

A novel numerical method for determining the surface acoustic wave and the leaky surface acoustic wave characteristics is proposed. The Green's function method is used to simulate an infinite periodic transducer driven by a periodic voltage. We show that the coupling of modes parameters and the dispersion relation can be extracted from the change in the admittance as the periodicity of the driving voltage is slightly shifted. The method first introduced here leads to significant savings in computing time.

Suppression of the leaky SAW attenuation with heavy mechanical loading

We discuss effects on the propagation of surface acoustic waves (SAW) due to heavy mass loading on Y-cut lithium niobate and lithium tantalate substrates. An abrupt reduction in the leaky-SAW (LSAW) attenuation is observed in the measured admittance of a long resonator test structure on 64 degrees -YX-cut lithium niobate for aluminum electrodes of thickness h/lambda(0) beyond 9-10%. This experimental fact is explained theoretically as the slowing down of the leaky wave below the velocity of the slow shear surface-skimming bulk wave (SSBW), such that energy dissipation into bulk-wave emission becomes inhibited. An infinite transducer structure is modeled using the periodic Green's function and the boundary-element method (BEM); the computed theoretical properties well explain for the experimental findings. The model is further employed to quantify the leaky surface-wave attenuation characteristics as functions of the crystal-cut angle and the thickness of the electrodes. The resonance and antiresonance frequencies and the corresponding Q values are investigated to facilitate the selection of crystal cuts and electrode thicknesses. The transformation of the leaky SAW into a SAW-type nonleaky wave is also predicted to occur for gold electrodes, with considerably thinner finger structures.

Hb Helsinki: a variant with a high oxygen affinity and a substitution at a 2,3-DPG binding site (beta82[EF6] Lys replaced by Met)

A new haemoglobin, Hb Helsinki, in which beta 82-Lys (EF6) is replaced by Met, was found in a Finnish family. It was associated with familial erythrocytosis, and the oxygen affinity of the blood was higher than normal. The oxygen equilibrium curves of purified Hb Helsinki and HbA from the same haemolysate have been determined under vaious conditions. "Stripped' Hb Helsinki was found to show normal cooperativity, slightly low oxygen affinity and a reduced Bohr effect at physiological pH. However, the organic phosphates, 2,3-diphosphoglycerate (2,3-DPG) and inositol hexaphosphate (IHP) had a very small effect on Hb Helsinki, and the 2,3-DPG binding constant of deoxygenated Hb Helsinki is close to that of oxyhaemoglobin A. Thus, the replacement of Lys by Met at position 82 dramatically changes the nature of the central cavity of the tetramer and the effect of 2,3-DPG on the respiratory function of the molecule.