Hierarchical network structure as the source of hierarchical dynamics (power-law frequency spectra) in living and non-living systems: How state-trait continua (body plans, personalities) emerge from first principles in biophysics

Living systems are hierarchical control systems that display a small world network structure. In such structures, many smaller clusters are nested within fewer larger ones, producing a fractal-like structure with a 'power-law' cluster size distribution (a mereology). Just like their structure, the dynamics of living systems shows fractal-like qualities: the timeseries of inner message passing and overt behavior contain high frequencies or 'states' (treble) that are nested within lower frequencies or 'traits' (bass), producing a power-law frequency spectrum that is known as a 'state-trait continuum' in the behavioral sciences. Here, we argue that the power-law dynamics of living systems results from their power-law network structure: organisms 'vertically encode' the deep spatiotemporal structure of their (anticipated) environments, to the effect that many small clusters near the base of the hierarchy produce high frequency signal changes and fewer larger clusters at its top produce ultra-low frequencies. Such ultra-low frequencies exert a tonic regulatory pressure that produces morphological as well as behavioral traits (i.e., body plans and personalities). Nested-modular structure causes higher frequencies to be embedded within lower frequencies, producing a power-law state-trait continuum. At the heart of such dynamics lies the need for efficient energy dissipation through networks of coupled oscillators, which also governs the dynamics of non-living systems (e.q., earthquakes, stock market fluctuations). Since hierarchical structure produces hierarchical dynamics, the development and collapse of hierarchical structure (e.g., during maturation and disease) should leave specific traces in system dynamics (shifts in lower frequencies, i.e. morphological and behavioral traits) that may serve as early warning signs to system failure. The applications of this idea range from (bio)physics and phylogenesis to ontogenesis and clinical medicine.

Recurrence risk of venous thromboembolism associated with systemic lupus erythematosus: A retrospective cohort study

Background

Recurrence risk of systemic lupus erythematosus (SLE)-associated venous thromboembolism (VTE) is unclear.

Aim

To determine the recurrence risk of SLE-associated VTE overall and by presence of provoking factors and SLE flares.

Methods

A multicenter, retrospective cohort study was conducted among patients with first SLE-associated VTE who discontinued anticoagulation. SLE flares were defined as Systemic Lupus Erythematosus Disease Activity Index 2000 greater than 4. The primary outcome was recurrent VTE. Incidence rates and cumulative incidences were calculated by presence of provoking factors and antiphospholipid syndrome (APS) at index VTE. The hazard ratio (HR) for recurrence after SLE flare-associated index VTE was estimated with Cox regression, adjusted for provoking factor presence and APS.

Results

Eighty patients were included with 21 recurrent VTEs in median 8 years. For provoked index VTE, the recurrence rate in patients without APS was 1.1 per 100 person-years (PY; 95% confidence interval [CI], 0.1-3.1) and in the presence of APS 3.5 per 100 PY (95% CI, 0.9-8.9), yielding cumulative incidences of 7.5% (95% CI, 1.2%-21.7%) and 31.4% (95% CI, 6.3%-61.6%) respectively. For unprovoked index VTE, these analogous rates were 3.8 per 100 PY (95% CI, 1.2-9.0) and 16.7 per 100 PY (95% CI, 4.5-42.7), with cumulative incidences of 33.7% (95% CI, 10.7%-58.9%) and 54.2% (95% CI, 10.7%-84.5%), respectively. Forty-six index VTEs were flare associated, and the adjusted HR for recurrence was 0.4 (95% CI, 0.1-1.8) compared to those without flares at their index VTE.

Conclusion

Antiphospholipid syndrome is the main determinant for recurrence risk of SLE-associated VTE irrespective of presence of a provoking factor. Future research should attempt to confirm that flare-associated VTE has a lower recurrence risk.

Paternal inflammatory arthritis is associated with a higher risk of miscarriage: results of a large multicenter study (iFAME-Fertility)

Objectives

Paternal preconception health is recognized as an important contributor to pregnancy outcomes. Nonetheless, pregnancy outcomes of partners of men with inflammatory arthritis (IA) have never been studied. Our objective was to describe the pregnancy outcomes of partners of men diagnosed with IA.

Methods

We performed a multicentre cross-sectional retrospective study conducted in the Netherlands. Men with IA who were over 40 years old that reported at least one positive pregnancy test were included. To analyse the impact of IA on pregnancy outcomes, pregnancies were classified into two groups: pregnancies conceived after the diagnosis of IA and before the diagnosis of IA.

Results

In total, 408 male participants diagnosed with IA reported 897 singleton pregnancies that resulted in 794 live births. Pregnancies conceived after the diagnosis of IA had higher rate of miscarriage (12.27 vs 7.53%, P = <0.05). This increased risk was still present after adjusting for confounders [OR 2.03 (95% CI 1.12, 3.69) P = 0.015].

Conclusions

This is the largest study to describe the pregnancy outcomes of partners of men diagnosed with IA and the first to demonstrate that paternal IA is associated with a higher risk of miscarriage. Notwithstanding, the overall rate of miscarriage reported in our study could be comparable to previously reported population estimates.

New risk model is able to identify patients with a low risk of progression in systemic sclerosis

Objectives

To develop a prediction model to guide annual assessment of systemic sclerosis (SSc) patients tailored in accordance to disease activity.

Methods

A machine learning approach was used to develop a model that can identify patients without disease progression. SSc patients included in the prospective Leiden SSc cohort and fulfilling the ACR/EULAR 2013 criteria were included. Disease progression was defined as progression in ≥1 organ system, and/or start of immunosuppression or death. Using elastic-net-regularisation, and including 90 independent clinical variables (100% complete), we trained the model on 75% and validated it on 25% of the patients, optimising on negative predictive value (NPV) to minimise the likelihood of missing progression. Probability cutoffs were identified for low and high risk for disease progression by expert assessment.

Results

Of the 492 SSc patients (follow-up range: 2–10 years), disease progression during follow-up was observed in 52% (median time 4.9 years). Performance of the model in the test set showed an AUC-ROC of 0.66. Probability score cutoffs were defined: low risk for disease progression (<0.197, NPV:1.0; 29% of patients), intermediate risk (0.197–0.223, NPV:0.82; 27%) and high risk (>0.223, NPV:0.78; 44%). The relevant variables for the model were: previous use of cyclophosphamide or corticosteroids, start with immunosuppressive drugs, previous gastrointestinal progression, previous cardiovascular event, pulmonary arterial hypertension, modified Rodnan Skin Score, creatine kinase and diffusing capacity for carbon monoxide.

Conclusion

Our machine-learning-assisted model for progression enabled us to classify 29% of SSc patients as ‘low risk’. In this group, annual assessment programmes could be less extensive than indicated by international guidelines.

POS0470 GLUCOCORTICOID DISCONTINUATION IN EARLY RHEUMATOID AND UNDIFFERENTIATED ARTHRITIS PATIENTS. A SUB-ANALYSIS OF THE BeSt AND IMPROVED STUDIES

Background:

Discontinuation of glucocorticoids (GC) as bridging therapy in rheumatoid arthritis (RA) treatment is recommended as rapidly as clinically feasible. Little is known about the rate of, and possible characteristics associated with successful GC discontinuation.

Objectives:

To evaluate the success rate of GC discontinuation, and to study which factors are associated with successful GC discontinuation.

Methods:

Data from two treat-to-target studies; BeSt (target DAS ≤2.4, LDA), and IMPROVED (target DAS <1.6, remission) were evaluated for all patients initially treated with a tapered high-dose of oral GC with conventional DMARD(s). GCs were discontinued when DAS ≤2.4 was maintained for 28 weeks in BeSt, and as soon as DAS was <1.6 in IMPROVED. GC discontinuation could be attempted twice: first attempt called ‘primary’, second attempt after GC restart called ‘secondary’. Discontinuation was considered successful if the treatment target was maintained at the next visit. Univariable, and exploratory forward and backward multivariable logistic regression analyses were performed to identify potential characteristics associated with successful discontinuation (p-value <0.2 included in final model).

Results:

From the 131 patients initiating combination therapy with prednisone in the BeSt study, 93 attempted discontinuation. Primary discontinuation was successful in 60% (56/93) and secondary discontinuation in 54% (19/35). A lower DAS at the visit prior to GC discontinuation and ACPA negativity were associated with successful discontinuation (table 1). Of the 610 patients in the IMPROVED, 400 attempted discontinuation. Primary discontinuation was successful in 61% (242/400), and secondary in 51% (71/139). A lower DAS both at baseline and at the visit prior to GC discontinuation were associated with successful discontinuation (table 1).

Conclusion:

Primary GCs discontinuation was successful in approximately 60% and secondary in 50% of patients, independent of the treatment target and associated threshold for GC discontinuation. Most baseline characteristics were not predictive of successful GC discontinuation, but ACPA negativity (only in BeSt), baseline DAS (only in IMPROVED) and in both studies DAS prior to GC discontinuation were predictive for successful discontinuation. Based on this data it seems that ‘standard’ baseline characteristics are insufficient to ‘personalize’ the duration of temporary GC bridging but the DAS at the moment of GC discontinuation might give guidance.

Table 1.

Results logistic regression analyses

UnivariableMultivariableaR2= 0.173BeStOR (95% CI)p-valueOR (95% CI)p-valueAge, year1.00 (0.98; 1.03)0.98Gender, female0.51 (0.24; 1.09)0.08Symptom duration BL, weeks1.00 (0.99; 1.01)0.61DAS at BL0.92 (0.61; 1.40)0.70DAS prior to discontinuation0.13 (0.05; 0.33)<0.010.11 (0.04; 0.30)<0.01RF, positive1.28 (0.62; 2.69)0.502.24 (0.81; 6,17)0.12ACPA, positive0.70 (0.34; 1.43)0.320.32 (0.12; 0.86)0.02Erosions, present at BL0.65 (0.28; 1.49)0.31UnivariableMultivariableaR2= 0.065IMPROVEDOR (95% CI)p-valueOR (95% CI)p-valueAge, year1.00 (0.99; 1.02)0.64Gender, female0.62 (0.43; 0.89)0.010.75 (0.51; 1.11)0.15Symptom duration BL, weeks1.00 (0.99; 1.00)0.430.99 (0.99; 1.00)0.08DAS at BL0.80 (0.65; 0.98)0.030.78 (0.62; 0.98)0.03DAS prior to discontinuation0.24 (0.15; 0.38)<0.010.24 (0.14; 0.40)<0.01RF, positive0.82 (0.57; 1.17)0.27ACPA, positive0.95 (0.66; 1.35)0.76Erosions, present at BL0.80 (0.49; 1.29)0.35

ACPA: anti-citrullinated protein antibodies; BL: baseline; DAS: disease activity score; RF: rheumatoid factor. α The final multivariable logistic regression model was based on stepwise forward and backward selection of predictors, both resulting in the same final model.

Acknowledgements:

We would like to thank all patients for their contribution as well as the rheumatologists who participated in the BeSt study group and in the IMPROVED-study group. We would also like to thank all other rheumatologists and trainee rheumatologists who enrolled patients in these studies, and all research nurses for their contributions.

Disclosure of Interests:

Johanna M. Maassen: None declared, Raquel Dos-Santos: None declared, Sytske Anne Bergstra: None declared, Robbert Goekoop: None declared, Thomas Huizinga: None declared, Cornelia Allaart Grant/research support from: The original BeSt study was realized with a government grant from the Dutch College of Health Insurance Companies, with additional funding from Schering-Plough and Janssen. the IMPROVED study was financially supported by AbbVie in the first year.

OP0212 MEN DIAGNOSED WITH INFLAMMATORY ARTHRITIS BEFORE THE AGE OF 40 YEARS HAVE A LOWER FERTILITY RATE THAN THOSE DIAGNOSED AFTER THE AGE OF 40 YEARS: RESULTS OF A LARGE MULTICENTER STUDY (IFAME-FERTILITY)

Background:

The effect of inflammatory arthritis (IA) on fertility has been mainly studied in women. Multiple factors associated with lower fertility rate in women can also be present in male patients with IA (1). The fertility rate in men with IA, however, has never been studied.

Objectives:

To describe the fertility rate (number of biological children per individual) of men with IA.

Methods:

We performed a multicenter cross-sectional retrospective study conducted in eight Dutch hospitals. Men with IA (Rheumatoid Arthritis (RA), Juvenile Idiopathic Arthritis (JIA) and Spondyloarthritis (SpA)) who were over 40 years old and indicated that their family size was complete were invited to participate. Men who were still planning on having biological children were excluded. Participants completed a digital questionnaire that included fertility-related questions and questions regarding their demographic and clinical information. To analyze the impact of IA on male fertility rate, patients were divided into groups according to the age at the time of their diagnosis: age<30 years, age 31-40 years and age>41 years.

Results:

In total 628 participants diagnosed with IA were included. The response rate 34.87%. Information regarding their age, age at diagnosis, clinical diagnosis and number of children is presented per group in Table 1. Regarding the total number of children per man, there was a statistically significant difference between the three groups (p=<0.005). The mean total number of children was significantly lower in men diagnosed at age<30 years (1.39 {SD 1.41}) and at age 31-40 years (1.60 {SD 1.35}) compared to those diagnosed after at age>41 years (1.88 {SD 1.14}). Compared to men from the general population of the Netherlands, the total number of children of men diagnosed at age>41 years was not statistically different (1.88 vs 1.80, respectively).

Table 1.

Participants’ basic demographic and clinical characteristics, including the number of biological children per men.

All patientsIA diagnosed at age <30 yearsIA diagnosed at age 31-40 yearsIA diagnosed at age >41 yearsTotal, n (%)628137 (21.82)149 (23.73)342 (54.46)Age, mean (SD)57.17 (9.98)53.01 (9.96)52.76 (7.35)61.06 (9.47)Diagnosis, n (%)•iRA297 (47.29)42 (30.66)67 (44.97)188 (55.32)•AJIA10 (1.59)10 (6.25)0 (0)0 (0)•ISpA (incl. PsA)320 (50.96)90 (65.69)83 (55.70)147 (42.98)Age at diagnosis, mean (SD)41.29 (13.08)26.27 (9.15)36.99 (5.66)49.98 (9.70)Disease duration, mean (SD)15.89 (11.88)26.48 (12.57)15.70 (8.52)11.30 (9.87)Number of biological children, mean (95% CI)1.71 (1.60-1.81)1.39 (1.15-1.63)a,b1.60 (1.38-1.82)a1.88 (1.75 -2.01)

a p< 0.05 compared to those diagnosed age >41 years

b p< 0.05 compared to those diagnosed age >31-40 years

Conclusion:

This is the largest study ever conducted to evaluate the impact of IA on male fertility. We demonstrated that men diagnosed with IA before and during their reproductive years have a lower fertility rate than those men diagnosed with IA after their reproductive years. Multiple mechanisms (biological and non-biological) can be responsible for this association. More research is needed to identify the causes of these lower fertility rates in men with IA.

References:

[1]Perez-Garcia LF, Te Winkel B, Carrizales JP, Bramer W, Vorstenbosch S, van Puijenbroek E, et al. Sexual function and reproduction can be impaired in men with rheumatic diseases: A systematic review. Semin Arthritis Rheum. 2020;50(3):557-73.

Figure 1.

Total number of biological children (mean and SD) per group.

Acknowledgements:

The authors would like to acknowledge Ron Buijs, data manager of the Department of Rheumatology of the Erasmus MC, for his technical support with regards to data collection.

Disclosure of Interests:

Luis Fernando Perez-Garcia Consultant of: Galapagos, Esther Röder: None declared, Robbert Goekoop: None declared, Johanna Hazes: None declared, Marc R Kok Consultant of: Novartis, Grant/research support from: Novartis, Petra Kok: None declared, Hieronymus TW Smeele: None declared, Ilja Tchetverikov: None declared, J.H. van der Kaap: None declared, Annette van der Helm - van Mil: None declared, Bouwe Krijthe: None declared, Radboud Dolhain Speakers bureau: UCB, Roche, Abbvie, Genzyme, Novartis, Consultant of: Galapagos, Grant/research support from: UCB

POS0843 A NEW RISK MODEL IS ABLE TO IDENTIFY SYSTEMIC SCLEROSIS PATIENTS WITH A LOW RISK OF DISEASE PROGRESSION

Background:

Disease course in Systemic Sclerosis (SSc) ranges from mild, to severe with progressive organ involvement within months. Guidelines for follow-up are mainly based on expert consensus, and advocate annual assessment. So far, no data driven guidelines exist that describe tailormade systematic assessments for individual patients in line with individual disease course.

Objectives:

To develop a prediction model to guide annual assessment of SSc patients tailored in accordance to disease activity.

Methods:

A machine learning approach was used to develop a model that can identify patients without disease progression. SSc patients included in the prospective Leiden SSc cohort and fulfilling the ACR/EULAR 2013 criteria were included. The primary endpoint in the prediction model was disease progression which was defined as progression in ≥1 organ system, and/or start of immunosuppression or death between the two most recent visits. Using elastic-net-regularization, and including 90 independent clinical variables (100% complete), we trained the model on 75% and validated it on 25% of the patients in order to perform internal validation of the final model. We optimized the model on negative predictive value (NPV) to minimize the likelihood of missing progression. By expert assessment of the test characteristics, including swarm plots of the probability scores, cut-offs were identified for low, intermediate and high risk for disease progression.

Results:

Of the 492 SSc patients (range of follow-up: 2-10yrs), disease progression during follow-up was observed in 52% (median time 4.9yrs), including myocardial progression in 29%, lung progression in 23%, skin progression in 16%, and death in 12%. Performance of the model in the test set showed an AUC-ROC of 0.66. Probability score cutoffs were defined: low risk for disease progression (<0.197, NPV:1.0; 29% of patients), intermediate risk (0.197-0.223, NPV:0.82; 27%) and high risk (>0.223, NPV:0.78; 44%). The predictive variables included in the model were: previous use of cyclophosphamide or corticosteroids, start with immunosuppressive drugs, previous gastrointestinal progression, previous cardiovascular event, pulmonary arterial hypertension, modified Rodnan Skin Score, creatinine kinase, and diffusing capacity for carbon monoxide.

Conclusion:

Our machine-learning-assisted model for disease progression enabled us to classify 29% of SSc patients as ‘low risk’. In this group annual assessment programs could be less extensive than indicated by international guidelines.

Baseline characteristicsTotaln=492Non-ProgressorsN=235ProgressorsN=257DemographicsFemale, n (%)389 (79)193 (82)196 (76)Age, mean (SD)55 (14)55 (15)55 (13)Disease duration nonRP, median (IQR)3.2 (0.9-10.3)3.5 (0.8-10.5)3.6 (1.1-9.3)Organ involvementDcSSc, n (%)118 (24)34 (15)84 (33)DLCO% of pred, mean (SD)66 (18)69 (18)64 (17)FVC% of pred, mean (SD)98 (23)96 (24)97 (21)ILD on HRCT, n (%)183 (37)66 (28)117 (46)PAH, n (%)26 (5)10 (4)16 (6)GAVE, n (%)9 (2)4 (2)5 (2)Cardiac involvement, n (%)28 (6)14 (6)14 (5)Myositis, n (%)8 (2)6 (3)2 (1)Renal crisis, n (%)14 (3)6 (3)8 (3)AutoantibodiesAnti-centromere, n (%)194 (39)118 (50)76 (30)Anti-topoisomerase, n (%)116 (24)42 (18)74 (29)

RP=raynaud phenomenon, dcSSc= diffuse cutaneous systemic sclerosis, mRSS=modified rodnan skin score, DU=digital ulcera, DLCO= single-breath diffusing capacity for carbon monoxide, FVC= forced vital capacity, ILD=interstitial lung disease, HRCT= high resolution computed tomography, PAH= pulmonary arterial hypertension, GAVE= gastric antral vascular extasia.

Disclosure of Interests:

None declared

OP0211 PATERNAL INFLAMMATORY ARTHRITIS IS ASSOCIATED WITH A HIGHER RISK OF MISCARRIAGES: RESULTS OF A LARGE MULTICENTER STUDY (IFAME-FERTILITY)

Background:

The effect of inflammatory arthritis (IA) on pregnancy outcomes has been studied mainly in women. Paternal older age, sperm DNA integrity and certain genetic defects have been associated with worse pregnancy outcomes (1). However, pregnancy outcomes of partners of men with IA have never been studied.

Objectives:

To describe the pregnancy characteristics and outcomes of partners of men diagnosed with IA.

Methods:

We performed a multicenter cross-sectional retrospective study conducted in eight Dutch hospitals. Men with IA (Rheumatoid Arthritis (RA), Juvenile Idiopathic Arthritis (JIA) and Spondyloarthritis (SpA)) who were over 40 years old and indicated that their family size was complete were invited to participate. Participants completed a digital questionnaire that included pregnancy-related questions and questions regarding their demographic and clinical information. To analyze the impact of IA on pregnancy outcomes, pregnancies were classified into two groups; pregnancies that occurred after diagnosis of IA and before the diagnosis of IA.

Results:

In total 628 male participants diagnosed with IA were included. 408 men reported 897 singleton pregnancies that resulted in 794 live births. Regarding pregnancy characteristics, pregnancies conceived after diagnosis of IA had a higher mean paternal and maternal age at conception and a lower rate of spontaneous pregnancies (90.91 vs 96.60%, p=<0.005) (See Table 1). With regards to pregnancy outcomes, pregnancies conceived after receiving the diagnosis of IA had a lower rate of live births (86.36% and 89.22%, p=0.053) and a significant higher rate of miscarriages (12.27 vs 7.53%, p=<0.05). After correcting for maternal age and year of pregnancy, pregnancies conceived after the diagnosis of IA had a higher risk of miscarriages (OR 1.71 [CI 1.04-2.81], p<0.05). No statistically significant differences between the two groups were reported for the rates of abortions, preterm births and pregnancy complications.

Table 1.

Pregnancy characteristics and outcomes.

AllpregnanciesPregnancy afterdiagnosis of IAPregnancy before diagnosis of IAP valuePregnancy characteristicsTotal number of pregnancies897220677Maternal age at conception, mean (SD)29.00 (5.00)30.69 (5.16)28.45 (4.83)p<0.005Paternal age at conception, mean (SD)31.31 (5.72)34.27 (6.08)30.49 (5.34)p<0.005Spontaneous pregnancy, n (%)854 (95.21)200 (90.91)654 (96.60)p<0.005Pregnancy duration-months, median (IQR)39 (38-40)39 (38-40)39 (38-40)p=0.928Pregnancy outcomesLive births, n (%)794 (88.52)190 (86.36)604 (89.22)p=0.053Miscarriage, n (%)78 (8.70)27 (12.27)51 (7.53)p<0.05Abortion, n (%)25 (2.78)3 (1.36)22 (3.25)p=0.128*Medical indication5 (20.00)0 (0)5 (22.73)*Personal reasons20 (80.00)3 (100.00)17 (77.27)Pre-term birth149 (16.61)31 (14.09)118 (17.43)p=0.248Pregnancy complicationsNo complications during pregnancy, n (%)754 (84.34)184 (83.64)570 (84.57)p=0.741Hypertensive disorders(hypertension, pre/eclampsia), n (%)41 (4.57)8 (3.64)33 (4.87)p=0.445Gestational Diabetes Mellitus11 (1.28)2 (0.94)9 (1.38)p=0.619Growth restriction12 (1.34)1 (0.45)11 (1.65)p=0.193

Conclusion:

This is the largest study to describe the pregnancy characteristics and outcomes of partners of men diagnosed with IA and the first to demonstrate that paternal IA is associated with a higher risk of miscarriage. Prospective studies are needed to corroborate these findings.

References:

[1]Ibrahim Y, Johnstone E. The male contribution to recurrent pregnancy loss. Translational andrology and urology. 2018;7(Suppl 3):S317-S27.

Acknowledgements:

The authors would like to acknowledge Ron Buijs, data manager of the Department of Rheumatology of the Erasmus MC, for his technical support with regards to data collection.

Disclosure of Interests:

Luis Fernando Perez-Garcia Consultant of: Galapagos, Esther Röder: None declared, Robbert Goekoop: None declared, Marc R Kok Consultant of: Roche, Grant/research support from: Roche, Petra Kok: None declared, Hieronymus TW Smeele: None declared, Ilja Tchetverikov: None declared, Annette van der Helm - van Mil: None declared, J.H. van der Kaap: None declared, Bouwe Krijthe: None declared, Radboud Dolhain Speakers bureau: Abbvie, UCB, Genzyme, Novartis, Consultant of: Galapagos, Grant/research support from: UCB

Glucocorticoid discontinuation in patients with early rheumatoid and undifferentiated arthritis: a post-hoc analysis of the BeSt and IMPROVED studies

OBJECTIVES

To evaluate the success rate of glucocorticoid discontinuation and to study which factors are associated with successful discontinuation.

METHODS

Data from two treat-to-target studies, BeSt (target Disease Activity Score (DAS) ≤2.4) and IMPROVED (target DAS <1.6), were evaluated for all patients initially treated with a tapered high dose of prednisone with conventional synthetic disease-modifying antirheumatic drugs. Prednisone was discontinued when DAS ≤2.4 was maintained for 28 weeks in BeSt and as soon as DAS was <1.6 in IMPROVED. Discontinuation was considered successful if the target was maintained at the next visit. Logistic regression analyses were performed to identify predictors of successful discontinuation. A mixed effects logistic regression model was used to assess whether primary versus secondary discontinuation was as successful.

RESULTS

In the BeSt study, 40% (47 of 93) of patients flared after primary prednisone discontinuation, and of the other 60% (56 of 93), 38% had to restart later. Of those who restarted (secondary discontinuation), 47% (17 of 35) again flared. In IMPROVED, after primary discontinuation 39% (158 of 400) flared, and of the other 61% (242 of 400), 40% had to restart later. After secondary discontinuation 49% (68 of 139) flared. Only in IMPROVED a secondary attempt was less successful (BeSt OR 0.71, p=0.45; IMPROVED OR 0.60, p=0.01). A lower DAS both at baseline and stop visit and male gender (in IMPROVED) were associated with successful primary discontinuation.

CONCLUSION

Primary glucocorticoid discontinuation resulted in direct loss of disease control in approximately 40% and secondary in 50% of patients. 'Standard' baseline characteristics seem insufficient to personalise the duration of temporary glucocorticoid bridging, but the DAS at the time of discontinuation might provide guidance.

Simple and safe exclusion of pulmonary embolism in outpatients using quantitative D-dimer and Wells’ simplified decision rule

A safe and effective management strategy is pivotal in excluding pulmonary embolism (PE). The combination of Wells’ simplified dichotomous clinical decision rule and D-dimer test is non-invasive and could be highly efficient, though its safety has not been widely studied. We evaluated safety and efficiency of this combination in excluding PE. Wells clinical decision rule was performed in 941 consecutive patients with suspected PE and, if patients had a score ≤ 4.0 points, a VIDAS D-dimer test followed. Patients with a normal D-dimer concentration had no further tests, PE was considered excluded, and patients did not receive anticoagulant treatment. Patients, in whom PE was excluded, were followed up for three months. Four hundred fifty patients (51.2%) had a clinical decision score ≤ 4.0 points and a normal D-dimer concentration. In 45 of these patients, during the initial diagnostic period additional objective testing, although not indicated, was performed, and PE was established in two patients. During three months of follow up no venous thromboembolic events (VTE) occurred. Therefore, the overall VTE failure rate was two of 450 (0.4% [95%CI 0–1.1]); the overall prevalence of PE was 12.3%. The diagnostic protocol could be completed and allowed a decision to be made in 90% of the study patients. This study has prospectively established the safety of a combination of a dichotomized clinical decision rule and D-dimer test in ruling out PE. The strategy proved highly efficient, since more than 50% of patients could be managed without the need for more invasive and expensive tests.

[Network clusters of symptoms as elementary syndromes of psychopathology: implications for clinical practice]

BACKGROUND

In a recent publication we reported the existence of around 11 (to 15) 'elementary syndromes' that may combine in various ways, rather like 'building blocks', to explain the wide range of psychiatric symptoms. 'Bridge symptoms' seem to be responsible both for combining large sets of symptoms into elementary syndromes and for combining the various elementary syndromes to form one globally connected network structure.

AIM

To discuss the implication of these findings for clinical practice.

METHOD

We performed a network analysis of symptom scores.

RESULTS

Elementary syndromes provide a massive simplification of the description of psychiatric disease. Instead of the more than 300 categories in DSM-5, we now need to consider only a handful of elementary syndromes and personality domains. This modular representation of psychiatric illnesses allows us to make a complete, systematic and efficient assessment of patients and a systematic review of treatment options. Clinicians, patients, managerial staff and insurance companies can verify whether symptom reduction is taking place in the most important domains of psychopathology. Unlike classic multidimensional methods of disease description, network models of psychopathology can be used to explain comorbidity patterns, predict the clinical course of psychopathology and to designate primary targets for therapeutic interventions.

CONCLUSION

A network view on psychopathology could significantly improve everyday clinical practice.

Amnestic mild cognitive impairment: structural MR imaging findings predictive of conversion to Alzheimer disease

BACKGROUND AND PURPOSE

Mild cognitive impairment (MCI) is considered by many to be a prodromal phase of Alzheimer disease (AD). We used voxel-based morphometry (VBM) to find out whether structural differences on MR imaging could offer insight into the development of clinical AD in patients with amnestic MCI at 3-year follow-up.

MATERIALS AND METHODS

Twenty-four amnestic patients with MCI were included. After 3 years, 46% had progressed to AD (n = 11; age, 72.7 +/- 4.8 years; women/men, 8/3). For 13 patients (age, 72.4 +/- 8.6 years; women/men, 10/3), the diagnosis remained MCI. Baseline MR imaging at 1.5T included a coronal heavily T1-weighted 3D gradient-echo sequence. Localized gray matter differences were assessed with VBM.

RESULTS

The converters had less gray matter volume in medial (including the hippocampus) and lateral temporal lobe, parietal lobe, and lateral temporal lobe structures. After correction for age, sex, total gray matter volume, and neuropsychological evaluation, left-sided atrophy remained statistically significant. Specifically, converters had more left parietal atrophy (angular gyrus and inferior parietal lobule) and left lateral temporal lobe atrophy (superior and middle temporal gyrus) than stable patients with MCI.

CONCLUSION

By studying 2 MCI populations, converters versus nonconverters, we found atrophy beyond the medial temporal lobe to be characteristic of patients with MCI who will progress to dementia. Atrophy of structures such as the left lateral temporal lobe and left parietal cortex may independently predict conversion.

Not all age-related white matter hyperintensities are the same: a magnetization transfer imaging study

PURPOSE

Our aim was to assess whether presumed histologic heterogeneity of age-related white matter hyperintensities (WMH) is reflected in quantitative magnetization transfer imaging measures.

MATERIALS AND METHODS

From a group of patients participating in a double-blind placebo-controlled multicenter study on the effect of pravastatin (PROSPER), we selected 56 subjects with WMH. WMH were classified as periventricular WMH (PVWMH) and deep WMH (DWMH). PVWMH were subclassified as irregular or smooth, depending on the aspect of their border. Signal intensity of WMH on T1-weighted images was scored as iso- or hypointense. The mean magnetization transfer ratio (MTR) value of different types of WMH was assessed and compared. As a control group, we selected 19 subjects with no or limited WMH.

RESULTS

Mean (SE) MTR of PVWMH (frontal, 31.2% [0.2%]; occipital, 32.2% [0.2%]) was lower than that of DWMH (33.7% [0.5%]). The mean MTR of frontal PVWMH (31.2% [0.2%]) was lower than that of occipital PVWMH (32.2% [0.2%]). Compared with occipital PVWMH, frontal PVWMH more often had a smooth lining (72% frontal versus 8% occipital) and an area with low signal intensity on T1-weighted images (76% frontal versus 35% occipital). MTR did not differ between smooth (31.1% [0.3%]) and irregular (31.6% [0.5%]) PVWMH.

CONCLUSION

Age-related WMH are heterogeneous, despite their similar appearance on T2-weighted images. By taking into account heterogeneity of age-related WMH, both in terms of etiology and in terms of severity of tissue destruction, one may obtain better understanding on the causes and consequences of these lesions.

Raloxifene exposure enhances brain activation during memory performance in healthy elderly males; its possible relevance to behavior

Raloxifene is a selective estrogen receptor modulator (SERM) that is prescribed in females only, but its use in male subjects is increasingly considered. With a growing number of patients having potential benefit from raloxifene, the need for an assessment of its effects on brain function is growing. Effects of estrogens on brain function are very subtle and difficult to detect by neuropsychological assessment. Functional imaging techniques, however, have been relatively successful in detecting such changes. This study used functional magnetic resonance imaging (fMRI) to examine effects of raloxifene treatment on memory function. Healthy elderly males (n = 28; mean age 63.6 years, SD 2.4) were scanned during performance on a face encoding paradigm. Scans were made at baseline and after 3 months of treatment with either raloxifene (n = 14) or placebo (n = 14). Treatment effects were analyzed using mixed-effects statistical analysis (FSL). Activation during task performance involved bilateral parietal and prefrontal areas, anterior cingulate gyrus, and inferior prefrontal, occipital, and mediotemporal areas bilaterally. When compared to placebo, raloxifene treatment significantly enhanced activation in these structures (Z > 3.1), except for mediotemporal areas. Task performance accuracy diminished in the placebo group (P = 0.02), but remained constant in the raloxifene group (P = 0.60). In conclusion, raloxifene treatment enhanced brain activation in areas spanning a number of different cognitive domains, suggesting an effect on cortical arousal. Such effects may translate into small effects on behavior, including effects on attention and working memory performance, executive functions, verbal skills, and episodic memory. Further neuropsychological assessment is necessary to test the validity of these predictions.

Interindividual differences of medial temporal lobe activation during encoding in an elderly population studied by fMRI

Functional MRI (fMRI) is used to study medial temporal lobe (MTL) activation during encoding of new information into memory. In most studies, fMRI data of different subjects are averaged in standard coordinate space. However, interindividual differences in activation can be extensive, reflecting functional heterogeneity. Further, anatomical differences in brain structure cause additional variance and loss of registration accuracy. Such differences in structural and functional MTL characteristics may interfere with the efficiency of averaging data across subjects, and may become more significant with aging and dementia. The current study concerns the analysis of individual differences in MTL activation associated with episodic encoding.Twenty-nine healthy elderly men between 60 and 70 years old performed a simple face encoding task during fMRI scanning. Individual data were analyzed in native space, and compared to the group average in standard space (Talairach and Tournoux).MTL volumes between subjects varied between 6.34 and 11.27 cm(3), and had considerable variation when mapped to standard space. Eighteen of the 29 subjects showed MTL activity and activation patterns varied both in location and size (ranging from 0.11 to 1.78 cm(3)), with the strongest activation in the left posterior part of the MTL. In standard space, no region was significantly activated on a group level at a comparable alpha level. We conclude that while the majority of elderly subjects show MTL activation during episodic encoding of faces, there is considerable structural and functional variability between subjects. Group analysis in standard space may not be appropriate for studies of a complex structure such as the MTL, particularly not in aging and dementia.

Loss of frontal fMRI activation in early frontotemporal dementia compared to early AD

OBJECTIVE

To compare frontal cortex activation in patients with early frontotemporal dementia (FTD) with that in patients with early AD.

METHODS

Seven patients with FTD and seven patients with AD were studied (Clinical Dementia Rating: four patients with FTD 0.5, three patients with FTD 1, all patients with AD 1; mean Mini-Mental State Examination score: FTD 28.0 +/- 2.1, AD 23.1 +/- 2.7). Cerebral atrophy on MRI was mild, with no differences between FTD and AD. A parametric working memory task was applied to assess frontal activation as a function of working memory load.

RESULTS

The activated working memory network in FTD and AD included frontal and parietal lobe and thalamus. In frontal and parietal cortex, brain activation was significantly decreased in FTD. Frontal regions in patients with FTD showed less linear activation increase with working memory load than in AD. Possibly as a compensation mechanism, the cerebellum showed a stronger increasing response in FTD.

CONCLUSIONS

These data on regional functional loss in the frontal cortex in early FTD suggest that fMRI can identify FTD when results on structural MRI are normal.