Sick leave and disability pension following delivery in women with systemic lupus erythematosus

OBJECTIVE

To investigate sickness benefits following delivery in mothers with systemic lupus erythematosus (SLE) and mothers without SLE.

METHOD

SLE and non-SLE mothers, matched by age and month of delivery, with a singleton liveborn (2004-2008), were identified from the Swedish Lupus Linkage cohort. Work loss (sum of sick leave and disability pension) was studied from 1 year prenatally to 3 years postpartum. Adjusted logistic regression models of covariates associated with > 30 days of work loss in the first and second years postpartum were estimated in SLE mothers.

RESULTS

Among 130 SLE mothers and 440 non-SLE mothers, SLE mothers were more likely to have work loss from the prenatal year (42% vs 16%) to 3 years postpartum (49% vs 15%). In SLE mothers, work loss was on average 61 ± 112 days (mean ± sd) in the prenatal year and 38 ± 83 days in the first year postpartum, which increased to 71 ± 114 days in the third year postpartum. Having > 30 days of sick leave in the year of delivery [odds ratio (OR) 4.4, 95% confidence interval (CI) 1.5-12.9] and ≤ 12 years of education (OR 2.6, 95% CI 1.1-6.0) were associated with work loss in the first year postpartum. No covariates were associated with work loss in the second year postpartum.

CONCLUSION

SLE mothers more often had work loss in the prenatal year to 3 years postpartum compared to non-SLE mothers. Lower education and sick leave in the year of delivery were associated with a higher odds of work loss in the first year postpartum in SLE.

Factors associated with non-adherence to medications in systemic lupus erythematosus: Results from a Swedish survey

OBJECTIVE

To identify determinants of medication non-adherence in a Swedish population of systemic lupus erythematosus (SLE).

METHODS

Patients with SLE from Karolinska and Örebro University Hospitals participated in a survey-based cross-sectional study. Demographics, disease activity, organ damage, HRQoL (LupusQol, EQ-5D-5 L), medication non-adherence (<80% on CQR-19 or MASRI) and beliefs about medicines (BMQ) were registered. MASRI was used to report adherence to different drugs/drug classes, categorised into (i) antimalarial agents (AMA), (ii) glucocorticoids and (iii) other SLE medications. Multivariable logistic regression adjusted for age, sex, disease activity and organ damage.

RESULTS

Among 205 respondents, the median age was 52.0 years (IQR: 34.0-70.0), 86.3% were women, 66.8% were non-adherent to their medications according to CQR-19, and 6.6% and 6.3% were non-adherent to AMA and glucocorticoids, respectively, according to MASRI. Positive beliefs about glucocorticoids (OR; 95% CI: 0.77; 0.59-0.99; p = .039) and medications overall (0.71; 0.52-0.97; p = .029) were protective against non-adherence to glucocorticoids. Anxiety/depression (3.09; 1.12-8.54; p = .029), medication concerns (1.12; 1.05-1.20; p < .001) and belief that medications are overused (1.30; 1.15-1.46; p < .001) or harmful (1.36; 1.19-1.56; p < .001) were associated with medication non-adherence (CQR-19); beliefs in the necessity of medications (0.73; 0.65-0.82; p < .001) and positive beliefs in medications were protective (0.72; 0.60-0.86; p < .001). No associations were found between other investigated factors and medication non-adherence.

CONCLUSIONS

Beliefs about medications were a major determinant of medication non-adherence. Patient education may help alleviate the negative impact of misinformation/unawareness on adherence.

Epidemiology of Sarcoidosis

Sarcoidosis is a systemic, granulomatous disease with variable presentation earning it the term "the great mimicker." The current epidemiology confirms that the disease occurs worldwide, affecting both sexes, and all races, ethnicities, and ages. To date, no causal exposure or agent has been identified. The organ systems most frequently affected by sarcoidosis are also those with greatest exposure to the natural world suggesting environmental and lifestyle contributions to the disease. These include particulate matter, microorganisms, nicotine, and obesity. In this article, we review the epidemiology of sarcoidosis and discuss these non-genetic risk factors in the hope of providing important insight into sarcoidosis and stimulating future research.

Menopausal hormone therapy and risk of sarcoidosis: a population-based nested case-control study in Sweden

Sarcoidosis incidence peaks in women between 50 and 60 years old, which coincides with menopause, suggesting that certain sex hormones, mainly estrogen, may play a role in disease development. We investigated whether menopausal hormone therapy (MHT) was associated with sarcoidosis risk in women and whether the risk varied by treatment type. We performed a nested case-control study (2007-2020) including incident sarcoidosis cases from the Swedish National Patient Register (n = 2593) and matched (1:10) to general population controls (n = 20,003) on birth year, county, and living in Sweden at the time of sarcoidosis diagnosis. Dispensations of MHT were obtained from the Swedish Prescribed Drug Register before sarcoidosis diagnosis/matching. Adjusted odds ratios (aOR) of sarcoidosis were estimated using conditional logistic regression. Ever MHT use was associated with a 25% higher risk of sarcoidosis compared with never use (aOR 1.25, 95% CI 1.13-1.38). When MHT type and route of administration were considered together, systemic estrogen was associated with the highest risk of sarcoidosis (aOR 1.51, 95% CI 1.23-1.85), followed by local estrogen (aOR 1.25, 95% CI 1.11-1.42), while systemic estrogen-progestogen combined was associated with the lowest risk compared to never users (aOR 1.12, 95% CI 0.96-1.31). The aOR of sarcoidosis did not differ greatly by duration of MHT use. Our findings suggest that a history of MHT use is associated with increased risk of sarcoidosis, with women receiving estrogen administered systemically having the highest risk.

Pregnancy Weight Gain After Gastric Bypass or Sleeve Gastrectomy

Importance

Pregnancy weight gain may affect the association of bariatric surgery with postsurgery pregnancy outcomes. However, the association of pregnancy weight gain with bariatric surgery is unclear.

Objective

To compare pregnancy weight gain among women with a history of bariatric surgery vs those without and to investigate whether pregnancy weight gain differs by surgical procedure, surgery-to-conception interval, and/or surgery-to-conception weight loss.

Design, Setting, and Participants

This nationwide, population-based matched cohort study was conducted in Sweden from 2014 to 2021. Singleton pregnancies with a history of bariatric surgery were propensity score matched (1:1) to pregnancies without such a history according to early-pregnancy body mass index (BMI), prepregnancy diabetes, prepregnancy hypertension, maternal age, smoking status, education level, height, country of birth, and delivery year. In addition, post-gastric bypass pregnancies were matched to post-sleeve gastrectomy pregnancies using the same matching strategy. Data analysis was performed from November 2022 to May 2023.

Exposure

History of bariatric surgery.

Main Outcomes and Measures

Pregnancy weight gain was standardized by gestational age into early-pregnancy BMI-specific z scores.

Results

This study included 12 776 pregnancies, of which 6388 had a history of bariatric surgery and 6388 were matched controls. The mean (SD) age was 31.6 (4.9) years for the surgery group and 31.4 (5.2) for the matched controls, with an early-pregnancy mean (SD) BMI of 29.4 (5.2) in both groups. Across all early-pregnancy BMI strata, women with a history of bariatric surgery had lower pregnancy weight gain than matched controls. The differences in pregnancy weight gain z score values between the 2 groups were -0.33 (95% CI, -0.43 to -0.23) for normal weight, -0.33 (95% CI, -0.40 to -0.27) for overweight, -0.21 (95% CI, -0.29 to -0.13) for obese class I, -0.16 (95% CI, -0.29 to -0.03) for obese class II, and -0.08 (95% CI, -0.28 to 0.13) for obese class III. Pregnancy weight gain did not differ by surgical procedure. A shorter surgery-to-conception interval (particularly within 1 year) or lower surgery-to-conception weight loss was associated with lower pregnancy weight gain.

Conclusions and Relevance

In this nationwide matched cohort study, women with a history of bariatric surgery had lower pregnancy weight gain than matched controls with similar early-pregnancy characteristics. Pregnancy weight gain was lower in those with a shorter surgery-to-conception interval or lower surgery-to-conception weight loss, but did not differ by surgical procedure.

Sarcoidosis and its relation to other immune-mediated diseases: Epidemiological insights

Several epidemiological studies show a co-occurrence of sarcoidosis with other immune-mediated diseases (IMD). There are many similarities between sarcoidosis and IMDs in their geographical distribution and risk factors. Understanding these similarities and identifying the differences can help us to better understand sarcoidosis and put it into context with other IMDs. In this review, we present the current knowledge about the overlap between sarcoidosis and other IMDs derived from epidemiological studies. Epidemiologic methods utilize study design and statistical analysis to describe the patterns in data and, ideally, identify causal relationships between an exposure and a health outcome. We discuss how study design and analysis may affect the interpretation of epidemiological studies on this topic and highlight some theories that attempt to explain the relation between sarcoidosis and other IMDs.

"The chameleon among diseases" - an explorative view of sarcoidosis and identification of the consequences for affected patients and relatives using qualitative interviews

INTRODUCTION

Sarcoidosis is a multisystemic disease, with the lungs being the main site of manifestation. Although the exact etiology remains unclear, both genetic and environmental factors are being discussed. Diagnostic evaluation is challenging, and the management of chronic patients and assessment of their needs proves difficult, especially in the absence of targeted therapy. Studies on sarcoidosis patients have shown that quality of life is limited even after clinically measurable parameters have resolved. The question remains how patients and their relatives perceive medical care and the diagnostic process and how these affect their well-being.

METHODS

Qualitative, semi-structured interviews were conducted with patients and their relatives between September 2019 and February 2020. Interviews were recorded, transcribed verbatim, and analyzed using qualitative content analysis. Deductive hypotheses were then formed based on categories according to personal aspects, symptoms, diagnostic, daily life activity, therapy, psychological aspects and wishes.

RESULTS

Fourteen patients and five relatives were included. Most patients reported subacute symptoms before the first organ-related episode. A high degree of personal initiative was required from the majority of respondents in both the diagnostic and subsequent therapeutic processes. In addition, respondents reported so-called "doctor-hopping", a lack of specialists or contacts, and a lack of medical support. The Internet and self-help groups played a fundamental role for patients and relatives in exchanging information with other affected persons and to compensate for an existing information deficit.

CONCLUSION

The results provide new insights into patients' and relatives' perceptions of the sarcoidosis diagnosis and treatment process. Identification of barriers such as a lack of physicians and an information deficit highlights potential targets for strategies to optimize sarcoidosis management.

Epidemiology and Damage Accrual of Systemic Lupus Erythematosus in Central Sweden: A Single-Center Population-Based Cohort Study Over 14 Years From Östergötland County

OBJECTIVE

Variations in prevalence and incidence of systemic lupus erythematosus (SLE) within a geographically defined area of central Sweden over a time period of 14 years were examined. Longitudinal differences in disease activity, laboratory test results, and damage accrual were investigated.

METHODS

Adults (aged ≥18 years) residing in Östergötland County between 2008 and 2021 (mean adult population: 357,000 citizens) with confirmed SLE were identified and followed prospectively until death, December 31, 2021, or emigration. We estimated annual incidence per 100,000 inhabitants stratified by sex and age. Linear regression with year of diagnosis as the outcome assessed whether each clinical measurement at diagnosis varied over time.

RESULTS

Prevalence on December 31, 2021, was 71.5 of 100,000 (87% female). One hundred twenty-six new cases were identified during the study period, yielding a mean annual incidence of 3.0 of 100,000 inhabitants; this was higher in females (4.8/100,000) than in males (1.2/100,000). Mean age at diagnosis was 43.7 years (SD 17.3). Age at diagnosis and disease activity measures increased over the calendar year of diagnosis (P < 0.05) whereas disease manifestations, including lupus nephritis, did not vary significantly. Accrual of organ damage was demonstrated over time since diagnosis and stratified by sex, lupus nephritis, and corticosteroid-related damage. Approximately 40% developed damage within 5 years.

CONCLUSION

SLE prevalence and incidence estimates remained constant over 14 years, and disease phenotypes at SLE onset were similar. SLE was diagnosed also among older individuals with a smaller female-to-male ratio. Estimates of prevalence and incidence were comparable to previous Scandinavian reports but lower than observed in registry data from the US and the UK.

Rheumatoid arthritis and the risk of postpartum psychiatric disorders: a Nordic population-based cohort study

BACKGROUND

Postpartum psychiatric disorders (PPD) are common complications of childbirth. A common explanation for their development is that the psychological, hormonal, and immune changes associated with pregnancy and parturition may trigger psychiatric symptoms postpartum. Rheumatoid arthritis (RA) is characterized by abnormalities in the activity of the hypothalamic-pituitary-adrenal axis and of the immune system, but its association with PPD is unknown. We analyzed whether women with RA before childbirth have an increased risk of PPD.

METHODS

We conducted a large population-based cohort study including mothers of singleton births in the Danish (1995-2015), Finnish (1997-2013), and Swedish Medical Birth Registers (2001-2013) (N = 3,516,849). We linked data from the Medical Birth Registers with data from several national socioeconomic and health registers. Exposure was defined as having a diagnosis of RA before childbirth, while the main outcome was a clinical diagnosis of psychiatric disorders 90 days postpartum. We analyzed the association between RA and PPD using Cox proportional hazard models, stratified by a personal history of psychiatric disorders.

RESULTS

Among women without a history of psychiatric disorders, the PPD incidence rate was 32.2 in the exposed and 19.5 per 1000 person-years in the unexposed group; women with RA had a higher risk of overall PPD than their unexposed counterparts [adjusted hazard ratio (HR) = 1.52, 95% confidence intervals (CI) 1.17 to 1.98]. Similar associations were also observed for postpartum depression (HR = 1.65, 95% CI 1.09 to 2.48) and other PPD (HR = 1.59, 95% CI 1.13 to 2.24). Among women with a history of psychiatric disorders, the incidence rate of overall PPD was 339.6 in the exposed and 346.6 per 1000 person-years in the unexposed group; RA was not associated with PPD. We observed similar associations between preclinical RA (RA diagnosed after childbirth) and PPD to those corresponding to clinical RA.

CONCLUSIONS

Rheumatoid arthritis was associated with an increased PPD risk in women without, but not in those with a psychiatric history. If our findings are confirmed in future studies, new mothers with RA may benefit from increased surveillance for new-onset psychiatric disorders postpartum.

Sarcoidosis: Epidemiology and clinical insights

Sarcoidosis is characterized by noncaseating granulomas which form in almost any part of the body, primarily in the lungs and/or thoracic lymph nodes. Environmental exposures in genetically susceptible individuals are believed to cause sarcoidosis. There is variation in incidence and prevalence by region and race. Males and females are almost equally affected, although disease peaks at a later age in females than in males. The heterogeneity of presentation and disease course can make diagnosis and treatment challenging. Diagnosis is suggestive in a patient if one or more of the following is present: radiologic signs of sarcoidosis, evidence of systemic involvement, histologically confirmed noncaseating granulomas, sarcoidosis signs in bronchoalveolar lavage fluid (BALF), and low probability or exclusion of other causes of granulomatous inflammation. No sensitive or specific biomarkers for diagnosis and prognosis exist, but there are several that can be used to support clinical decisions, such as serum angiotensin-converting enzyme levels, human leukocyte antigen types, and CD4 Vα2.3+ T cells in BALF. Corticosteroids remain the mainstay of treatment for symptomatic patients with severely affected or declining organ function. Sarcoidosis is associated with a range of adverse long-term outcomes and complications, and with great variation in prognosis between populations. New data and technologies have moved sarcoidosis research forward, increasing our understanding of the disease. However, there is still much left to be discovered. The pervading challenge is how to account for patient variability. Future studies should focus on how to optimize current tools and develop new approaches so that treatment and follow-up can be targeted to individuals with more precision.

Exposure to specific tumour necrosis factor inhibitors and risk of demyelinating and inflammatory neuropathy in cohorts of patients with inflammatory arthritis: a collaborative observational study across five Nordic rheumatology registers

OBJECTIVE

To compare incidences of neuroinflammatory events, including demyelinating disease (DML), inflammatory polyneuropathies (IPN) and multiple sclerosis (MS), in patients with rheumatoid arthritis (RA) or spondyloarthritis (SpA; including psoriatic arthritis) starting a tumour necrosis factor inhibitor (TNFi), investigating whether monoclonal TNFi antibodies (other TNFis (oTNFis)) confer higher risk than etanercept.

METHODS

This is an observational cohort study including patients from the five Nordic countries starting a TNFi in 2001-2020. Time to first neuroinflammatory event was identified through register linkages. We calculated crude incidence rates (cIR) per 1000 person-years and used multivariable-adjusted Cox regression to compare incidences of neuroinflammatory events overall and for DML, IPN and MS with oTNFi versus etanercept. We further examined individual TNFis and indications.

RESULTS

33 883 patients with RA and 28 772 patients with SpA were included, initiating 52 704 and 46 572 treatment courses, respectively. In RA, we observed 135 neuroinflammatory events (65% DML) with cIR of 0.38 with oTNFi and 0.34 with etanercept. The HR of oTNFi versus etanercept was 1.07 (95% CI 0.74 to 1.54) for any neuroinflammatory event, 0.79 (95% CI 0.51 to 1.22) for DML, 2.20 (95% CI 1.05 to 4.63) for IPN and 0.73 (95% CI 0.34 to 1.56) for MS. In SpA, we observed 179 events (78% DML) with cIR of 0.68 with oTNFi and 0.65 with etanercept. The HR for any neuroinflammatory event, DML, IPN and MS was 1.06 (95% CI 0.75 to 1.50), 1.01 (95% CI 0.68 to 1.50), 1.28 (95% CI 0.61 to 2.69) and 0.94 (95% CI0.53 to 1.69), respectively.

CONCLUSION

The cIRs of neuroinflammatory events are higher in SpA than in RA, but the choice of specific TNFi does not seem to play an important role in the risk of neuroinflammatory events.

Modifiable lifestyle risk factors for sarcoidosis: a nested case-control study

We aimed to investigate whether obesity, tobacco use, alcohol consumption, and physical inactivity are associated with sarcoidosis risk. We conducted a matched case-control study nested within the Northern Sweden Health and Disease Study. Incident sarcoidosis cases (n=165) were identifiedviamedical records and matched to controls (n=660) on sub-cohort, sex, birth, and questionnaire date (1:4). Data on lifestyle factors were obtained through questionnaires, and physical measurements of height, weight and waist were collected prior to sarcoidosis diagnosis. Conditional logistic regression estimated adjusted odds ratios with 95% confidence intervals (aOR; 95%CI). Compared with never smoking, current smoking was associated with lower sarcoidosis odds (aOR 0.48; 95%CI 0.32–0.71), and former smoking with higher odds (aOR 1.33; 95%CI 0.98–1.81). Snus use was not associated with sarcoidosis. There was an increased odds of sarcoidosis associated with obesity (aOR 1.34 (95%CI 0.94–1.92) but not with overweight (aOR 0.99; 95%CI 0.76–1.30). Compared with those who were physically inactive, those who were active had a 25% higher odds (aOR 1.25; 95%CI 0.91–1.72). No association was found with moderate alcohol consumption (aOR 0.95; 95%CI 0.56–1.62). All results were similar when cases diagnosed within 5 years after exposure assessment were excluded, except the aOR for former smoking decreased to 1.1. We observed a reduced sarcoidosis risk associated with smoking, which cannot be fully explained by early symptoms of sarcoidosis influencing smoking habits. Results indicate an increased risk associated with obesity, but not overweight, and being physically active.

Risk of gestational diabetes mellitus in relation to early pregnancy and gestational weight gain before diagnosis: A population-based cohort study

INTRODUCTION

Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with adverse consequences for the mother and offspring in both short and long term. The aim of this study was to investigate associations between risk of GDM and gestational weight gain in early pregnancy and before diagnosis.

MATERIAL AND METHODS

Our population-based cohort study included 131 164 singleton pregnancies in the Stockholm-Gotland region in Sweden from 2008 through 2013. The exposures were weight gain in early pregnancy (<22 weeks) and weight gain before diagnosis, standardized into gestational age-specific z scores. The outcome was GDM. We used logistic regression models with a generalized estimating equations method to estimate odds ratios with 95% confidence intervals for GDM, stratified by early-pregnancy body mass index (BMI) category.

RESULTS

Above average weight gain before diagnosis (z score >0) was associated with increased risk of GDM among all BMI groups except for obese III. Early gestational weight gain above average was associated with increased risk for GDM in overweight women. Below average weight gain before diagnosis (z score <0) was only associated with decreased risk of GDM in obese III. Early gestational weight gain below average was associated with reduced risks of GDM in obese class I, II, and III women.

CONCLUSIONS

The risk of GDM increased with higher weight gain before diagnosis in all BMI groups except obese class III, whereas the risk was reduced with lower weight gain before diagnosis in obese III women only. The risk of GDM increased with higher early gestational weight gain in overweight women, while the risk was reduced with lower early gestational weight gain among obese women. Obese women may benefit from lower weight gain, especially in early pregnancy.

Gestational Diabetes Mellitus Risk in Pregnant Women With Systemic Lupus Erythematosus

OBJECTIVE

To investigate the risk of gestational diabetes mellitus (GDM) associated with systemic lupus erythematosus (SLE) by comparing pregnancies in women with SLE to general population controls.

METHODS

We identified singleton pregnancies among women with SLE and general population controls in the Swedish Medical Birth Register (MBR; 2006-2016), sampled from the population-based Swedish Lupus Linkage (SLINK) cohort (1987-2012). SLE was defined by ≥ 2 International Classification of Diseases (ICD)-coded visits in the National Patient Register (NPR) and MBR, with ≥ 1 visit before pregnancy. GDM was defined by ≥ 1 ICD-coded visit in the NPR or MBR. Glucocorticoid (GC) and hydroxychloroquine (HCQ) dispensations within 6 months before and during pregnancy were identified in the Prescribed Drug Register. Risk ratios (RRs) and 95% CIs of GDM associated with SLE were estimated using modified Poisson regression models, stratified by parity and adjusted for maternal age at delivery, year of birth, and obesity.

RESULTS

We identified 695 SLE pregnancies including 18 (2.6%) with GDM and 4644 non-SLE pregnancies including 65 (1.4%) with GDM. Adjusted RRs of GDM associated with SLE were 1.11 (95% CI 0.38-3.27) for first deliveries and 2.03 (95% CI 1.21-3.40) for all deliveries. Among SLE pregnancies, GDM occurred in 7/306 (2.3%) with ≥ 1 GC before and/or during pregnancy, 11/389 (2.8%) without GC, 7/287 (2.4%) with ≥ 1 HCQ before and/or during pregnancy, and in 11/408 (2.7%) without HCQ.

CONCLUSION

When looking at all deliveries, SLE was associated with a 2-fold higher risk of GDM. GDM occurrence did not differ by GC or HCQ.

Reproductive and hormonal risk factors for sarcoidosis: a nested case–control study

Background

Sarcoidosis incidence peaks in females around the fifth decade of life, which coincides with menopause, suggesting hormonal factors play a role in disease development. We investigated whether longer exposure to reproductive and hormonal factors is associated with reduced sarcoidosis risk.

Methods

We conducted a matched case–control study nested within the Mammography Screening Project. Incident sarcoidosis cases were identified via medical records and matched to controls on birth and questionnaire date (1:4). Information on hormonal factors was obtained through questionnaires prior to sarcoidosis diagnosis. Multilevel modelling was used to estimate adjusted odds ratios with 95% credible intervals (OR; 95% CI).

Results

In total, 32 sarcoidosis cases and 124 controls were included. Higher sarcoidosis odds were associated with older age at menarche (OR 1.19: 95% CI 0.92–1.55), natural menopause versus non-natural (OR 1.53: 95% CI 0.80–2.93), later age at first pregnancy (OR 1.11: 95% CI 0.76–1.63) and ever hormone replacement therapy (HRT) use (OR 1.40: 95% CI 0.76–2.59). Lower odds were associated with older age at menopause (OR 0.90: 95% CI 0.52–1.55), longer duration of oral contraceptive use (OR 0.70: 95% CI 0.45–1.07), longer duration of HRT use (OR 0.61: 95% CI 0.22–1.70), ever local estrogen therapy (LET) use (OR 0.83: 95% CI 0.34–2.04) and longer duration of LET use (OR 0.78: 95% CI 0.21–2.81). However, the CIs could not rule out null associations.

Conclusion

Given the inconsistency and modest magnitude in our estimates, and that the 95% credible intervals included one, it still remains unclear whether longer estrogen exposure is associated with reduced sarcoidosis risk.

Differences in disease presentation between men and women with sarcoidosis: A cohort study

BACKGROUND

Sarcoidosis is an elusive disease due to its heterogeneity. It is well recognized that the clinical picture is dependent on ethnicity, organ involvement and age. However, data on the role of sex is inconsistent. We aimed to study the gender-related differences in disease presentation in Swedish patients with sarcoidosis.

SUBJECTS AND METHODS

Clinical data was collected between 1996 and 2020, yielding a register with 1429 cases with sarcoidosis in a pulmonary clinic. The diagnosis was met according to WASOG criteria. Data on age, radiologic stage at the time of disease onset, and potential extra-pulmonary manifestations, was retrieved. Differences between men and women were analyzed with Fisher's Exact Test and t-test where appropriate.

RESULTS

In the register there were 61% men and they were approximately three years younger than the women at the time of diagnosis. Men presented with a more advanced radiographic stage on chest imaging compared to women, radiographic stage II (46% vs 36%, p < 0.001), while women compared to men more often had stage 0-I disease on pulmonary x-rays (6% vs 2%, p < 0.001 for stage 0 and 46% vs 38%, p < 0.01 for stage I). Women had more cutaneous involvement (13% vs 8%, p < 0.01) and more often involvement of salivary glands (3% vs 1%, p < 0.05).

CONCLUSIONS

In this cohort with sarcoidosis patients, there was a predominance of men. They presented with more severe disease at a younger age, while women more often were found to have involvement of the skin and salivary glands.

Direct modeling of relative and absolute risks in register data: Mortality risk in sarcoidosis

PURPOSE

This paper aims to illustrate the use and interpretation of regression based on pseudo-observations for estimating risks of time-to-event outcomes in epidemiological studies.

METHODS

We use pseudo-observation based regression for estimation of contrasts in the relative and absolute risks at specific times. This relaxes the proportional hazards assumption and directly estimates relative and absolute risks without the need for secondary calculations or standardization. Statistical software is available to use this method, and we demonstrate its use in a reanalysis of the mortality risk in sarcoidosis patients in Sweden.

RESULTS

We report estimated adjusted mortality risk differences and risk ratios by age, and at different years of follow up. Compared to the hazard ratio of 1.62, which is assumed to be time constant, we find risk ratios ranging from 1.7 at 2 years of follow-up to 1.3 at 10 years.

CONCLUSIONS

Pseudo-observation regression is a flexible and powerful tool for censored time-to-event data. The models are easy to run and interpret so they should be considered a standard tool alongside Cox regression and standardization. As with any statistical model, there are assumptions needed for valid inference, which should be assessed on a case-by-case basis.

Risk of acute myocardial infarction in sarcoidosis: A population-based cohort study from Sweden

Due to conflicting findings in previous studies, it remains unclear whether individuals with sarcoidosis are at a higher relative risk of acute myocardial infarction. In this cohort study, individuals with sarcoidosis and matched general population comparators were followed for acute myocardial infarction in Swedish nationwide registers. A small (20%) risk increase associated with sarcoidosis was identified, which did not markedly vary by age at diagnosis, sex, treatment status around diagnosis, and time since diagnosis. The highest relative risk (1.4) was observed in individuals who received immunosuppressant treatment around the time of sarcoidosis diagnosis. Future studies should examine the clinical characteristics of acute myocardial infarction in these patients and investigate whether early diagnostic or preventive interventions might be beneficial for these patients.

Infection hospitalisation in systemic lupus in Sweden

Objective

Immune dysregulation in SLE and the corresponding immune-modulating and immunosuppressive nature of the treatments may play key roles in infection risk. We compared serious infection rates among individuals with incident SLE with the general population, and examined the role of treatment initiation in SLE.

Methods

Newly diagnosed patients with SLE (2006–2013) and general population comparators from the Swedish Lupus Linkage cohort were followed for serious infection through 2016. Adjusted Cox and frailty models estimated the relative risk of first and recurrent infections, respectively. Using a new-user design, rates of serious infections were compared between disease-modifying antirheumatic drugs (DMARDs) and hydroxychloroquine (HCQ) initiators. We then evaluated three DMARDs (azathioprine, mycophenolate mofetil and methotrexate) in multivariable-adjusted models.

Results

Individuals with SLE experienced more infections (22% vs 6%), especially during the first year of follow-up, and recurrent serious infections were also more common (HR=2.22, 95% CI 1.93 to 2.56). DMARDs were associated with a higher rate of serious infection versus HCQ (HR=1.82, 95% CI 1.27 to 2.60), which attenuated after multivariable-adjustment (HR=1.30, 95% CI 0.86 to 1.95). Among DMARDs, azathioprine was associated with infection (HR=2.19, 95% CI 1.14 to 4.21) and mycophenolate mofetil yielded an HR=1.39 (95% CI 0.65 to 2.96) in multivariable-adjusted models compared with methotrexate. Results were comparable across numerous sensitivity analyses.

Conclusion

Individuals with incident SLE were 2–4 times more likely to be hospitalised for infection and experienced more recurrent infections than the general population. Among DMARD initiators, azathioprine was associated with the highest rate.

Evidence of under-reporting of early-onset preeclampsia using register data

BACKGROUND

Early-onset preeclampsia, traditionally defined as presenting before 34 gestational weeks, is associated with even higher risks of perinatal death, placental abruption, and stroke, than late-onset preeclampsia.

OBJECTIVE

We estimated the degree of misclassification in a high-risk population of lupus pregnancies and a general population comparator when gestational age at delivery defined preeclampsia phenotype compared to first preeclampsia diagnosis.

METHODS

Patients with lupus and general population comparators from Sweden with ≥1 singleton pregnancy in the Medical Birth Register with a documented ICD code for preeclampsia were included (2002-2016). We used gestational age at delivery (<34 versus ≥34 weeks) to phenotype preeclampsia early- versus late-onset and then reclassified based on first preeclampsia diagnosis date in the Patient Register. We cross-tabulated the two definitions and calculated sensitivity using the visit-based definition as the reference standard for general population and lupus pregnancies, overall and among nulliparous women.

RESULTS

331 pregnancies were diagnosed with preeclampsia, of which 322 were in both registers. Of those, 58 were early-onset based on gestational age at delivery (n = 29 in lupus pregnancies). Overall, 9% of early-onset preeclampsia in lupus (sensitivity 91%, 95% confidence interval [CI] 75, 98) was misclassified as late-onset compared to 19% in the general population (sensitivity 81%, 95% CI 64, 92). We noted similar misclassification (4% vs 22%) among nulliparous women.

CONCLUSIONS

In the general population, early-onset preeclampsia was more likely misclassified as late-onset than in the high-risk lupus population. Relying on gestational age at delivery to phenotype preeclampsia, this way underestimates the occurrence of early-onset preeclampsia. This also suggests that the burden of early-onset preeclampsia as a public health concern may be under-reported, although this may be more applicable to milder preeclampsia where expectant management is employed. Research of biological and maternal predictors of early-onset preeclampsia may be dealing with differentially misclassified outcomes or samples.

Incidence and prevalence of systemic sclerosis globally: a comprehensive systematic review and meta-analysis

OBJECTIVES

We aimed to conduct a systematic review and meta-analysis on the incidence and prevalence of SSc covering the entire literature.

METHODS

This study followed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement of 2009. We conducted a systematic search in MEDLINE, Web of Science and Embase to identify articles reporting incidence and/or prevalence of SSc. Two authors conducted the search, reviewed articles for inclusion and extracted relevant data. We used random-effects models to estimate the pooled prevalence and incidence of SSc and performed subgroup analyses by sex, case definition and region to investigate heterogeneity. We explored the association between calendar period and reported estimates using meta-regression.

RESULTS

Among 6983 unique records identified, we included 61 studies of prevalence and 39 studies of incidence in the systematic review. The overall pooled prevalence of SSc was 17.6 (95% CI 15.1, 20.5) per 100 000 and the overall pooled incidence rate of SSc was 1.4 (95% CI 1.1, 1.9) per 100 000 person-years. We observed significant regional variations in reported estimates; studies conducted in North America reported considerably higher estimates than other regions. The pooled incidence and prevalence in women were five times higher than in men. More recent studies reported higher estimates than older ones.

CONCLUSION

In this comprehensive review of the incidence and prevalence of SSc across the world, there was large heterogeneity among estimates, which should be taken into consideration when interpreting the results.

Type 2 diabetes risk in sarcoidosis patients untreated and treated with corticosteroids

Background

The rate of type 2 diabetes mellitus (T2D) is increased in sarcoidosis patients but it is unknown if corticosteroid treatment plays a role. We investigated whether the T2D risk is higher in untreated and corticosteroid-treated sarcoidosis patients compared with the general population.

Methods

In this cohort study, individuals with two or more International Statistical Classification of Diseases and Related Health Problems (ICD) codes for sarcoidosis were identified from the Swedish National Patient Register (NPR) (n=5754). Corticosteroid dispensations within 3 months before or after the first sarcoidosis diagnosis were identified from the Swedish Prescribed Drug Register (PDR). General population comparators without sarcoidosis were matched to cases 10:1 on age, sex and region of residence (n=61 297). Incident T2D was identified using ICD codes (NPR) and antidiabetic drug dispensations (PDR). Follow-up was from the second sarcoidosis diagnosis/matching date until T2D, emigration, death or study end (December 2013). Cox regression models adjusted for age, sex, education, country of birth, healthcare regions and family history of diabetes were used to estimate hazard ratios (HRs). We used flexible parametric models to examine the T2D risk over time.

Results

40% of sarcoidosis patients were treated with corticosteroid at diagnosis. The T2D rate was 7.7 per 1000 person-years in untreated sarcoidosis, 12.7 per 1000 person-years in corticosteroid-treated sarcoidosis and 5.5 per 1000 person-years in comparators. The HR for T2D was 1.4 (95% CI 1.2-1.8) associated with untreated sarcoidosis and 2.3 (95% CI 2.0-3.0) associated with corticosteroid-treated sarcoidosis. The T2D risk was highest for corticosteroid-treated sarcoidosis in the first 2 years after diagnosis.

Conclusions

Sarcoidosis is associated with an increased risk of T2D especially in older, male, corticosteroid-treated patients at diagnosis. Screening for T2D for these patients is advisable.

Risk and predictors of heart failure in sarcoidosis in a population-based cohort study from Sweden

OBJECTIVES

Previous studies showed a strong association between sarcoidosis and heart failure (HF) but did not consider risk stratification or risk factors to identify useful aetiological insights. We estimated overall and stratified HRs and identified risk factors for HF in sarcoidosis.

METHODS

Sarcoidosis cases were identified from the Swedish National Patient Register (NPR; ≥2 International Classification of Diseases-coded visits, 2003-2013) and matched to general population comparators. They were followed for HF in the NPR. Treated were cases who were dispensed ≥1 immunosuppressant ±3 months from the first sarcoidosis visit (2006-2013). Using Cox models, we estimated HRs adjusted for demographics and comorbidity and identified independent risk factors of HF together with their attributable fractions (AFs).

RESULTS

During follow-up, 204 of 8574 sarcoidosis cases and 721 of 84 192 comparators were diagnosed with HF (rate 2.2 vs 0.7/1000 person-years, respectively). The HR associated with sarcoidosis was 2.43 (95% CI 2.06 to 2.86) and did not vary by age, sex or treatment status. It was higher during the first 2 years after diagnosis (HR 3.7 vs 1.9) and in individuals without a history of ischaemic heart disease (IHD; HR 2.7 vs 1.7). Diabetes, atrial fibrillation and other arrhythmias were the strongest independent clinical predictors of HF (HR 2.5 each, 2-year AF 20%, 16% and 12%, respectively).

CONCLUSIONS

Although low, the HF rate was more than twofold increased in sarcoidosis compared with the general population, particularly right after diagnosis. IHD history cannot solely explain these risks, whereas ventricular arrhythmias indicating cardiac sarcoidosis appear to be a strong predictor of HF in sarcoidosis.

Positive Predictive Value of Sarcoidosis Identified in an Administrative Healthcare Registry: A Validation Study

BACKGROUND

International classification of disease (ICD) codes used to study sarcoidosis has previously been validated in only 1 study. We aimed to determine the accuracy of ICD codes to identify true sarcoidosis diagnoses in Sweden.

METHODS

We identified adults with at least 2 ICD codes for sarcoidosis (ICD-10 D86) at Karolinska University Hospital 2010-2013 from the National Patient Register. Of these, we randomly sampled 100 patients for validation. We collected clinical data and categorized the diagnosis of sarcoidosis as definite, probable, or unlikely. We estimated the positive predictive value for definite and probable sarcoidosis-identified with at least 2 ICD codes-with 95% confidence intervals.

RESULTS

We deemed 77% of the cases to be definite and 17% to be probable. The positive predictive value was 0.94 (95% confidence intervals = 0.87 to 0.98).

CONCLUSIONS

Using at least 2 visits listing an ICD-10 code for sarcoidosis accurately identified patients with sarcoidosis from administrative health data in Sweden.

Maternal Hypertensive Disorders in Pregnant Women With Systemic Lupus Erythematosus and Future Cardiovascular Outcomes

OBJECTIVE

Hypertensive disorders of pregnancy (HDPs) increase cardiovascular disease (CVD) risk. Pregnancy morbidities, including preeclampsia and CVD, are common in systemic lupus erythematosus (SLE). Possible connections are important to explore. In a population-based cohort, we investigated whether HDPs are associated with a higher risk of cardiovascular outcomes separately in women with SLE and those without SLE to examine the role of SLE.

METHODS

We identified first singleton births in the Medical Birth Register (1987-2012) among mothers with SLE and a large general population comparison group. Discharge diagnoses for HDPs, cardiovascular outcomes, and hypertension in the National Patient Register were identified using International Classification of Diseases codes. We estimated adjusted hazard ratios and 95% confidence intervals of the association between HDPs and outcomes in separate models in women with and without SLE. We then evaluated additive and multiplicative effect modification using relative excess risk due to interaction and Cox models jointly accounting for SLE and HDPs, respectively. Mediation analysis estimated the proportion of the association between SLE and outcome explained by HDPs.

RESULTS

HDPs were more common in pregnant women with SLE (20% versus 7%). In SLE, HDPs were associated with a 2-fold higher rate of cardiovascular outcomes and a 3-fold higher rate of incident hypertension. HDPs mediated 20% of the latter association. In women without SLE, HDPs were associated with higher incidence of hypertension later in life.

CONCLUSION

In women with SLE and those without SLE, HDPs were associated with a 3-fold higher rate of hypertension. In SLE, women with HDPs developed cardiovascular outcomes twice as often as women without HDPs.

Tuberculosis in Biologic-naïve Patients With Rheumatoid Arthritis: Risk Factors and Tuberculosis Characteristics

OBJECTIVE

To investigate risk factors and characteristics of active tuberculosis (TB) in biologic-naïve patients with rheumatoid arthritis (RA).

METHODS

We conducted a population-based case-control study using the Swedish Rheumatology Quality Register, the National Patient Register, and the Tuberculosis Register to identify RA patients with active TB and matched RA controls without TB between 2001-2014. Clinical data were obtained from medical records. TB risk was estimated as adjusted OR (aOR) with 95% CI using univariate and multivariable logistic regression analyses.

RESULTS

After validation of diagnoses, the study included 31 RA patients with TB and 122 matched RA controls. All except 3 cases had reactivation of latent TB. Pulmonary TB was most prevalent (84%). Ever use of methotrexate was not associated with increased TB risk (aOR 0.8, 95% CI 0.3-2.0), whereas ever treatment with leflunomide (aOR 6.0, 95% CI 1.5-24.7), azathioprine (aOR 3.8, 95% CI 1.1-13.8), and prednisolone (PSL; aOR 2.4, 95% CI 1.0-6.0) was. There were no significant differences between maximum dose of PSL, treatment duration with PSL before TB, or cumulative dose of PSL the year before TB diagnosis between cases and controls. Obstructive pulmonary disease was associated with an increased TB risk (aOR 3.9, 95% CI 1.5-10.7).

CONCLUSION

Several RA-associated factors may contribute to increased TB risk in biologic-naïve patients with RA, making the risk of TB activation difficult to predict in the individual patient. To further decrease TB in patients with RA, the results suggest that screening for latent TB should also be considered in biologic-naïve patients.

Infection risk in sarcoidosis patients treated with methotrexate compared to azathioprine: A retrospective 'target trial' emulated with Swedish real-world data

The 6‐month infection risk was 43% lower in patients with sarcoidosis who initiated methotrexate compared to those who started azathioprine. Our findings suggest that unless contraindications exist, methotrexate should be preferred over azathioprine as the primary steroid‐sparing choice in individuals with sarcoidosis.

Background and objective

No clinical trial has examined the risk of infection associated methotrexate and azathioprine, two advocated treatments for sarcoidosis. We aimed to compare the 6‐month risk of infection after the initiation of methotrexate or azathioprine.

Methods

We conducted a retrospective target trial emulation using Swedish pre‐existing data. We searched for eligible participants who were dispensed methotrexate or azathioprine in the Prescribed Drug Register (PDR) every day between January 2007 and June 2013. Adults were eligible if they had ≥2 ICD‐coded visits for sarcoidosis in the National Patient Register (NPR) and were dispensed ≥1 systemic corticosteroid but no methotrexate or azathioprine in the past 6 months (PDR). Within 6 months of methotrexate or azathioprine initiation, diagnosis of infectious disease was identified (visit in the NPR where infectious disease was the primary diagnosis). We estimated RR and risk differences comparing methotrexate (n = 667) to azathioprine initiations (n = 259) using targeted maximum likelihood estimation (TMLE) adjusting for demographic factors, comorbidity and sarcoidosis severity proxies.

Results

There were 43 infections in the methotrexate group (adjusted 6‐month risk 6.8%) and 29 infections in the azathioprine group (12.0%). The RR for infectious disease at 6 months associated with methotrexate compared to azathioprine initiation was 0.57 (95% CI: 0.39, 0.82) and the risk difference was −5.2% (95% CI: −8.5%, −1.8%). The RR at 9 months was attenuated to 0.77 (95% CI: 0.52, 1.14).

Conclusion

Methotrexate appears to be associated with a lower risk of infection in sarcoidosis than azathioprine, but randomized trials should confirm this finding.

Gestational weight gain and delivery outcomes: A population-based cohort study

BACKGROUND

Gestational weight gain is a modifiable factor that could impact maternal and infant health. However, its effect on delivery outcomes is not well established.

OBJECTIVES

To investigate the associations between gestational weight gain and delivery outcomes stratified by early-pregnancy body mass index (BMI).

METHODS

The study population included singleton livebirths in the Stockholm-Gotland obstetric cohort (January 2008 to October 2014; n = 174 953). The exposure was total gestational weight gain standardised into gestational-age-specific z-scores by using previously defined Swedish pregnancy weight gain-for-gestational age charts. The outcomes included caesarean delivery (overall, elective, and emergency), instrumental vaginal delivery, induction of labour, and postpartum haemorrhage. Confounders included maternal age, maternal height, parity, smoking status, cohabitation status, chronic hypertension, and pre-pregnancy diabetes. Logistic regression models with marginal standardisation were used to estimate risk ratios (RR) with 95% confidence intervals (CI) for each delivery outcome stratified by early-pregnancy BMI.

RESULTS

Above average weight gain (z-score ≥ 0.50 SD) increased risks of caesarean delivery (from RR 1.08, 95% CI 1.00, 1.15 to RR 1.45, 95% CI 1.35, 1.55 across BMI groups), induction of labour (from RR 1.14, 95% CI 1.04, 1.23 to RR 1.38, 95% CI 1.25, 1.51 across BMI groups except underweight), and postpartum haemorrhage (from RR 1.13, 95% CI 1.07, 1.19 to RR 1.25, 95% CI 1.09, 1.41 among normal and overweight). Below average weight gain (z-score <-0.50 SD) decreased caesarean delivery risk (from RR 0.77, 95% CI 0.61, 0.93 to RR 0.89, 95% CI 0.84, 0.95 across BMI groups except underweight).

CONCLUSIONS

In normal and overweight women, the risks of caesarean delivery, induction of labour, and postpartum haemorrhage increased with gestational weight gain. In obese women, higher gestational weight gain increased risks of caesarean delivery and induction of labour. Low gestational weight gain reduced risk of caesarean delivery in all BMI groups except underweight.

Risk of first and recurrent serious infection in sarcoidosis: a Swedish register-based cohort study

Serious infections impair quality of life and increase costs. Our aim was to determine if sarcoidosis is associated with a higher rate of serious infection and whether this varies by age, sex, time since diagnosis or treatment status around diagnosis.

We compared individuals with sarcoidosis (at least two International Classification of Diseases codes in the Swedish National Patient Register 2003–2013; n=8737) and general population comparators matched 10:1 on age, sex and residential location (n=86 376). Patients diagnosed in 2006–2013 who were dispensed at least one immunosuppressant ±3 months from diagnosis (Swedish Prescribed Drug Register) were identified. Cases and comparators were followed in the National Patient Register for hospitalisations for infection. Using Cox and flexible parametric models, we estimated adjusted hazard ratios (aHR) and 95% confidence intervals for first and recurrent serious infections (new serious infection >30 days after previous).

We identified 895 first serious infections in sarcoidosis patients and 3881 in comparators. The rate of serious infection was increased 1.8-fold in sarcoidosis compared to the general population (aHR 1.81, 95% CI 1.65–1.98). The aHR was higher in females than males and during the first 2 years of follow-up. Sarcoidosis cases treated with immunosuppressants around diagnosis had a three-fold increased risk, whereas nontreated patients had a 50% increased risk. The rate of serious infection recurrence was 2.8-fold higher in cases than in comparators.

Serious infections are more common in sarcoidosis than in the general population, particularly during the first few years after diagnosis. Patients who need immunosuppressant treatment around diagnosis are twice as likely to develop a serious infection than those who do not.

Sarcoidosis is associated with an increased risk of serious infections, especially during the first 2 years after diagnosis. Patients in need of immunosuppressants around diagnosis are twice as likely to develop serious infections than those who do not.https://bit.ly/2VFOvSo

Maternal and infant outcomes in sarcoidosis pregnancy: a Swedish population-based cohort study of first births

Background

It is unclear whether sarcoidosis, a multisystem inflammatory disease, is associated with adverse pregnancy outcomes. We aimed to assess the risk of adverse maternal and infant outcomes in sarcoidosis pregnancies, focused on first births.

Methods

Using a population-based cohort study design and Swedish national registers (2002–2013), we identified 182 singleton first pregnancies in the Medical Birth Register with at least two maternal ICD-coded sarcoidosis visits prior to pregnancy in the National Patient Register. Modified Poisson regression models estimated relative risks (RR) of adverse outcomes in sarcoidosis pregnancies compared to the general population adjusted for maternal age at delivery, calendar year and educational level. Some models were additionally adjusted for maternal body mass index and smoking status.

Results

The prevalence of pre-existing diabetes and hypertension was higher in mothers with sarcoidosis than those without sarcoidosis. Mothers with sarcoidosis had an increased risk of preeclampsia/eclampsia (RR 1.6; 95%CI 1.0, 2.6) and cesarean delivery (RR 1.3; 95%CI 1.0, 1.6). There were < 5 stillbirths and cases of infection and no cases of placental abruption, venous thromboembolism, cardiac arrest or maternal death. Newborns of first-time mothers with sarcoidosis had a 70% increased risk of preterm birth (RR 1.7; 95%CI 1.1, 2.5). There was an increased risk of birth defects (RR 1.6; 95%CI 0.9, 2.8) the majority of which were non-cardiac.

Conclusions

Sarcoidosis is associated with increased risks for preeclampsia/eclampsia, cesarean delivery, preterm birth and some birth defects. Awareness of these conditions may prevent possible pregnancy complications in mothers with sarcoidosis and their newborns.

Risk of neuroinflammatory events in arthritis patients treated with tumour necrosis factor alpha inhibitors: a collaborative population-based cohort study from Denmark and Sweden

Objectives

To investigate whether tumour necrosis factor alpha inhibitors (TNFis) are associated with an increased risk of neuroinflammatory diseases among patients with arthritic diseases.

Methods

Cohorts of patients with rheumatoid arthritis (RA, n=25 796), psoriatic arthritis (PsA, n=8586) and ankylosing spondylitis (AS, n=9527) who initiated a TNFi treatment year 2000–2017 were identified from nationwide clinical rheumatology registers in Sweden and Denmark. Information on demyelinating disease and inflammatory neuropathy diagnoses was retrieved from prospective linkage to National Patients Register. A Cox proportional hazard model was used to estimate HRs and 95% CI comparing TNFi exposed and non-exposed, by disease and country.

Results

Among 111 455 patients with RA, we identified 270 (Sweden) and 51 (Denmark) events (all types of neuroinflammatory diseases combined), corresponding to crude incidence rates (per 1000 person-years) of 0.37 (Sweden) and 0.39 (Denmark) in TNFi-treated patients vs 0.39 (Sweden) and 0.28 (Denmark) in unexposed patients, and an age-sex-calendar-period-adjusted HR (95% CI) of 0.97 (0.72 to 1.33) (Sweden) and 1.45 (0.74 to 2.81) (Denmark) in TNFi exposed compared with non-exposed patients. For a total of 64 065 AS/PsA patients, the corresponding numbers were: 196 and 32 events, crude incidence rates of 0.59 and 0.87 in TNFi-treated patients vs 0.40 and 0.19 in unexposed patients, and HRs of 1.50 (1.07 to 2.11) and 3.41 (1.30 to 8.96), for Sweden and Denmark, respectively. For multiple sclerosis, the patterns of HRs were similar.

Conclusions

Use of TNFi in AS/PsA, but not in RA, was associated with increased risk of incident neuroinflammatory disease, though the absolute risk was below one in 1000 patients/year.

Are infectious diseases risk factors for sarcoidosis or a result of reverse causation? Findings from a population-based nested case-control study

Findings from molecular studies suggesting that several infectious agents cause sarcoidosis are intriguing yet conflicting and likely biased due to their cross-sectional design. As done in other inflammatory diseases to overcome this issue, prospectively-collected register data could be used, but reverse causation is a threat when the onset of disease is difficult to establish. We investigated the association between infectious diseases and sarcoidosis to understand if they are etiologically related. We conducted a nested case-control study (2009-2013) using incident sarcoidosis cases from the Swedish National Patient Register (n = 4075) and matched general population controls (n = 40,688). Infectious disease was defined using inpatient/outpatient visits and/or antimicrobial dispensations starting 3 years before diagnosis/matching. Adjusted odds ratios (aOR) of sarcoidosis were estimated using conditional logistic regression and tested for robustness assuming the presence of reverse causation bias. The aOR of sarcoidosis associated with history of infectious disease was 1.19 (95% confidence interval [CI] 1.09, 1.29; 21% vs. 16% exposed cases and controls, respectively). Upper respiratory and ocular infections conferred the highest OR. Findings were similar when we altered the infection definition or varied the infection-sarcoidosis latency period (1-7 years). In bias analyses assuming one in 10 infections occurred because of preclinical sarcoidosis, the observed association was completely attenuated (aOR 1.02; 95% CI 0.90, 1.15). Our findings, likely induced by reverse causation due to preclinical sarcoidosis, do not support the hypothesis that common symptomatic infectious diseases are etiologically linked to sarcoidosis. Caution for reverse causation bias is required when the real disease onset is unknown.

Definitions of remission in systemic lupus erythematosus: a post-hoc analysis of two randomised clinical trials

BACKGROUND

The Definitions Of Remission In Systemic Lupus Erythematosus (DORIS) international task force has proposed remission definitions that are amenable to scientific testing. In this study, we aimed to evaluate their suitability as outcome measures in studies of systemic lupus erythematosus.

METHODS

In this post-hoc study, we applied remission definitions as specified by DORIS criteria at multiple timepoints in the BLISS-52 (n=865) and BLISS-76 (n=819) clinical trials. All definitions required physician's global assessment scores less than 0·5 (possible range 0-3). The DORIS 1 definitions required clinical systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K)=0 (with serological items excluded). The DORIS 2 definitions required a score of D or E in all British Isles Lupus Assessment Group (BILAG) domains. The definitions were assessed in the trial populations both with (on therapy) and without (off therapy) treatment allowance-ie, low-dose glucocorticoids (prednisone ≤5 mg/day) and maintenance immunosuppressive and biological agents. Antimalarial agents were allowed in all definitions. The definitions were applied irrespective of serological activity (anti-double stranded DNA positivity, or low C3 or C4) and with normal serology. Finally, we applied modifications similar to DORIS on therapy but allowing higher prednisone doses (≤10 mg/day).

FINDINGS

In the pooled dataset, the remission definition most frequently attained was the modified (prednisone ≤10 mg/day) DORIS 1a on therapy definition, which required a SLEDAI-2K score of 0 and permitted serological activity (237 [17·8%] of 1333 participants at week 52), followed by the unmodified (predisone ≤5 mg/day) DORIS 1 on therapy definition (140 [10·5%] of 1336 participants at week 52) based on these two definitions. We detected no significant difference between the placebo and belimumab groups. Proportions of patients achieving off therapy and BILAG-based definitions were low (≤0·9% at all timepoints). Sustained attainment of certain on therapy definitions showed an ability to discriminate between patients who received belimumab 10 mg/kg and patients who received placebo.

INTERPRETATION

Attainment of DORIS remission definitions was infrequent overall. Use of clinical SLEDAI-2K=0 in the definitions yielded higher proportions of attainment than did use of BILAG D or E. Attainment was also higher using definitions that allowed for serological activity and maintenance treatment. Addition of the durability aspect to on therapy definitions led to an ability to discriminate between belimumab and placebo.

FUNDING

Swedish Rheumatism Association, Professor Nanna Svartz Foundation, Ulla and Roland Gustafsson Foundation, Region Stockholm, and Karolinska Institutet Foundations.

Infections increase the risk of developing Sjögren's syndrome

OBJECTIVE

Environmental factors have been suggested in the pathogenesis of rheumatic diseases. We here investigated whether infections increase the risk of developing primary Sjögren's syndrome (pSS).

METHODS

Patients with pSS in Sweden (n = 945) and matched controls from the general population (n = 9048) were included, and data extracted from the National Patient Register to identify infections occurring before pSS diagnosis during a mean observational time of 16.0 years. Data were analysed using conditional logistic regression models. Sensitivity analyses were performed by varying exposure definition and adjusting for previous health care consumption.

RESULTS

A history of infection associated with an increased risk of pSS (OR 1.9, 95% CI 1.6-2.3). Infections were more prominently associated with the development of SSA/SSB autoantibody-positive pSS (OR 2.7, 95% CI 2.0-3.5). When stratifying the analysis by organ system infected, respiratory infections increased the risk of developing pSS, both in patients with (OR 2.9, 95% CI 1.8-4.7) and without autoantibodies (OR 2.1, 95% CI 1.1-3.8), whilst skin and urogenital infections only significantly associated with the development of autoantibody-positive pSS (OR 3.2, 95% CI 1.8-5.5 and OR 2.7, 95% CI 1.7-4.2). Furthermore, a dose-response relationship was observed for infections and a risk to develop pSS with Ro/SSA and La/SSB antibodies. Gastrointestinal infections were not significantly associated with a risk of pSS.

CONCLUSIONS

Infections increase the risk of developing pSS, most prominently SSA/SSB autoantibody-positive disease, suggesting that microbial triggers of immunity may partake in the pathogenetic process of pSS.

Risk of serious infections in patients with rheumatoid arthritis treated in routine care with abatacept, rituximab and tocilizumab in Denmark and Sweden

OBJECTIVE

To estimate (1) crude and age-and gender-adjusted incidence rates (IRs) of serious infections (SI) and (2) relative risks (RR) of SI in patients with rheumatoid arthritis (RA) initiating treatment with abatacept, rituximab or tocilizumab in routine care.

METHODS

This is an observational cohort study conducted in parallel in Denmark and Sweden including patients with RA in Denmark (DANBIO) and Sweden (Anti-Rheumatic Treatment in Sweden Register/Swedish Rheumatology Quality Register) who started abatacept/rituximab/tocilizumab in 2010-2015. Patients could contribute to more than one treatment course. Incident SI (hospitalisations listing infection) and potential confounders were identified through linkage to national registries. Age- and gender-adjusted IRs of SI per 100 person years and additionally adjusted RRs of SI during 0-12 and 0-24 months since start of treatment were assessed (Poisson regression). Country-specific RRs were pooled using inverse variance weighting.

RESULTS

We identified 8987 treatment courses (abatacept: 2725; rituximab: 3363; tocilizumab: 2899). At treatment start, rituximab-treated patients were older, had longer disease duration and more previous malignancies; tocilizumab-treated patients had higher C reactive protein. During 0-12 and 0-24 months of follow-up, 456 and 639 SI events were identified, respectively. The following were the age- and gender-adjusted 12-month IRs for abatacept/rituximab/tocilizumab: 7.1/8.1/6.1 for Denmark and 6.0/6.4/4.7 for Sweden. The 24-month IRs were 6.1/7.5/5.2 for Denmark and 5.6/5.8/4.3 for Sweden. Adjusted 12-month RRs for tocilizumab versus rituximab were 0.82 (0.50 to 1.36) for Denmark and 0.76 (0.57 to 1.02) for Sweden, pooled 0.78 (0.61 to 1.01); for abatacept versus rituximab 0.94 (0.55 to 1.60) for Denmark and 0.86 (0.66 to 1.13) for Sweden, pooled 0.88 (0.69 to 1.12); and for abatacept versus tocilizumab 1.15 (0.69 to 1.90) for Denmark and 1.14 (0.83 to 1.55) for Sweden, pooled 1.13 (0.91 to 1.42). The adjusted RRs for 0-24 months were similar.

CONCLUSION

For patients starting abatacept, rituximab or tocilizumab, differences in baseline characteristics were seen. Numerical differences in IR of SI between drugs were observed. RRs seemed to vary with drug (tocilizumab < abatacept < rituximab) but should be interpreted with caution due to few events and risk of residual confounding.

Childhood death rates declined in Sweden from 2000 to 2014 but deaths from external causes were not always investigated

AIM

Countries that conduct systematic child death reviews report a high proportion of modifiable characteristics among deaths from external causes, and this study examined the trends in Sweden.

METHODS

We analysed individual-level data on external, ill-defined and unknown causes from the Swedish cause of death register from 2000 to 2014, and mortality rates were estimated for children under the age of one and for those aged 1-14 and 15-17 years.

RESULTS

Child deaths from all causes were 7914, and 2006 (25%) were from external, ill-defined and unknown causes: 610 (30%) were infants, 692 (34%) were 1-14 and 704 (35%) were 15-17. The annual average was 134 cases (range 99-156) during the study period. Mortality rates from external, ill-defined and unknown causes in children under 18 fell 19%, from 7.4 to 6.0 per 100 000 population. A sizeable number of infant deaths (8.0%) were registered without a death certificate during the study period, but these counts were lower in children aged 1-14 (1.3%) and 15-17 (0.9%).

CONCLUSION

Childhood deaths showed a sustained decline from 2000 to 2014 in Sweden and a quarter were from external, ill-defined or unknown causes. Systematic, interagency death reviews could yield information that could prevent future deaths.

Epidemiology of sarcoidosis: current findings and future directions

Sarcoidosis is a granulomatous inflammatory disease with unknown etiology. Epidemiological studies have contributed greatly to our knowledge about sarcoidosis, providing critical information on the determinants and distribution of the disease. In this review, we summarize recently published findings from epidemiological studies on sarcoidosis. We review the epidemiological tools used, the incidence and prevalence of disease, mortality and cancer risk after sarcoidosis and nongenetic risk factors for sarcoidosis. Genetics studies have not been included as they deserve a separate review. Leveraging existing epidemiological data to conduct etiological studies aimed towards understanding and preventing disease is critical for future sarcoidosis research.

Tuberculosis Risk in Ankylosing Spondylitis, Other Spondyloarthritis, and Psoriatic Arthritis in Sweden: A Population-Based Cohort Study

OBJECTIVE

Rheumatoid arthritis is a risk factor for tuberculosis (TB), particularly following treatment with biologic agents. Since these therapies are increasingly used in ankylosing spondylitis (AS), other types of spondyloarthritis (SpA), and psoriatic arthritis (PsA), we investigated the corresponding TB risks in these patients.

METHODS

We identified individuals with AS/SpA/PsA, and non-AS/SpA/PsA comparators by linking Swedish national patient, population, TB, and rheumatology registers, and followed them for TB occurrence. Incidence rates were estimated for biologic-naive and biologic-exposed patients and the comparators. We calculated hazard ratios (HRs), adjusted for age, sex, and country of birth.

RESULTS

Included in this study were 38,702 patients with AS/SpA/PsA, and 200,417 persons from the general population. Among the patients, 11 active TB cases were identified, with an incidence rate (per 10⁵ ) of 22 (95% confidence interval [95% CI] 8.3-59.2) for biologic-exposed patients, 2.7 (95% CI 1.3-5.6) for biologic-naive patients, and 2.4 (95% CI 1.8-3.3) for non-AS/SpA/PsA comparators. The adjusted HR comparing biologic-naive patients to the general population was 1.2 (95% CI 0.5-2.7), and 7.5 (95% CI 1.9-29) comparing biologic-exposed to biologic-naive patients.

CONCLUSION

Biologic-naive AS/SpA/PsA patients are not at an increased TB risk in Sweden. Following treatment with biologic agents, the risk increased, but the absolute TB risk was low.

Asthma in Children of Mothers With Systemic Lupus Erythematosus and the Role of Preterm Birth

OBJECTIVE

Systemic lupus erythematosus (SLE) and asthma share inheritable IgE-related pathophysiology, but the association between maternal SLE and asthma in the offspring has not been explored. Our aim was to investigate the association between maternal SLE during pregnancy and childhood asthma and examine the role of preterm birth as a mediator of the association using Swedish register data.

METHODS

Information on 12,000 singleton live births (2001-2013) was collected from the Medical Birth Register. Childhood asthma was defined as at least 1 International Classification of Diseases-coded visit in the National Patient Register. Prevalent maternal SLE at delivery was identified from the Medical Birth Register and the National Patient Register. Risk ratios for asthma were estimated while controlling for confounders. Mediation analysis was used to estimate what percentage of the total effect can be explained by preterm birth (defined as either <34 or <37 weeks of gestation).

RESULTS

We compared 775 children born to mothers with SLE with 11,225 born to mothers without SLE. Ninety seven children of mothers with SLE (13%) were diagnosed with asthma, compared to 1,211 in the unexposed group (11%). The risk ratio for childhood asthma was 1.46 (95% confidence interval 1.16-1.84). In mediation analysis, 20-29% of the total effect of SLE was explained by preterm birth.

CONCLUSION

Prevalent maternal SLE during pregnancy is associated with an increased risk of asthma in the offspring. While preterm birth can explain a fair proportion of this association, additional unidentified mechanisms also likely play a role.

Sarcoidosis mortality in Sweden: a population-based cohort study

We aimed to investigate sarcoidosis mortality in a large, population-based cohort, taking into account disease heterogeneity.

Individuals with incident sarcoidosis (n=8207) were identified from the Swedish National Patient Register using International Classification of Disease codes (2003‒2013). In a subset, cases receiving treatment ±3 months from diagnosis were identified from the Prescribed Drug Register. Nonsarcoidosis comparators from the general population were matched to cases 10:1 on birth year, sex and county. Individuals were followed for all-cause death in the Cause of Death Register. Adjusted mortality rates, rate differences and hazard ratios (HRs) were estimated, stratifying by age, sex and treatment status.

The mortality rate was 11.0 per 1000 person-years in sarcoidosis versus 6.7 in comparators (rate difference 2.7 per 1000 person-years). The HR for death was 1.61 (95% CI 1.47‒1.76), with no large variation by age or sex. For cases not receiving treatment within the first 3 months, the HR was 1.13 (95% CI 0.94‒1.35). The HR was 2.34 (95% CI 1.99‒2.75) for those receiving treatment.

Individuals with sarcoidosis are at a higher risk of death compared to the general population. For the majority, the increased risk is small. However, patients whose disease leads to treatment around diagnosis have a two-fold increased risk of death. Future interventions should focus on this vulnerable group.

Sarcoidosis is associated with a higher risk of mortality; the risk varies greatly by severity at diagnosishttp://ow.ly/60Ll30h6my8

Mortality and Functionality after Stroke in Patients with Systemic Lupus Erythematosus

Objective.

To investigate mortality and functional impairment after stroke in systemic lupus erythematosus (SLE).

Methods.

Using Swedish nationwide registers, we identified 423 individuals with SLE and 1652 people without SLE who developed a first-ever ischemic or hemorrhagic stroke (1998–2013) and followed them until all-cause death or for 1 year. HR for death after ischemic or hemorrhagic stroke and the risk ratio of functional impairment (dependence in either transferring, toileting, or dressing) 3 months after ischemic stroke were estimated.

Results.

One year after stroke, 22% of patients with SLE versus 16% of those without SLE died. After ischemic stroke, patients with SLE had an increased risk of death (HR 1.85, 95% CI 1.39–2.45), which was attenuated after controlling for SLE-related comorbidities (HR 1.41, 95% CI 1.04–1.91). Functional impairment at 3 months was increased in SLE by almost 2-fold (risk ratio 1.73, 95% CI 1.16–2.57). After hemorrhagic stroke, patients with SLE had an HR of 2.30 (95% CI 1.38–3.82) for death, which was increased even during the first month.

Conclusion.

Compared to subjects without SLE, mortality after ischemic stroke increases after the first month in individuals with SLE, and functionality is worse at 3 months. SLE is associated with all-cause death after hemorrhagic stroke even during the first month. A shift of focus to patient functionality and prevention of hemorrhagic strokes is required.

Infections and respiratory tract disease as risk factors for idiopathic inflammatory myopathies: a population-based casecontrol study

OBJECTIVES

To investigate the association between infection or respiratory tract disease and future risk of developing idiopathic inflammatory myopathy (IIM).

METHODS

A case-control study was performed using Swedish nationwide registers. Adults with newly diagnosed IIM were identified (2002-2011) from the National Patient Register (NPR) and the Swedish Rheumatology Register (n=957). Controls were matched by age, sex and place of residence (n=9476). Outpatient visits and hospitalisations preceding IIM diagnosis indicating infection or respiratory disease were identified from NPR. Conditional logistic regression models were used to calculate OR and 95% CI. Sensitivity analyses were performed by varying the exposure definition, adjusting for previous healthcare consumption and excluding individuals with connective tissue disease, IIM lung phenotype or IIM-associated cancer.

RESULTS

Preceding infections were more common in IIM cases compared with controls (13% vs 9%) and were associated with an increased risk of IIM (OR 1.5, 95% CI 1.2 to 1.9). Gastrointestinal and respiratory tract infections were associated with an increased risk of IIM while cutaneous infections were not.Preceding respiratory tract disease was present in 10% of IIM cases and 4% of controls (OR 2.3, 95% CI 1.8 to 3.0). Both upper and lower respiratory tract diseases were associated with an increased risk of IIM.Variations in exposure and outcome definitions did not greatly affect the results.

CONCLUSIONS

Infections and respiratory tract diseases are associated with an increased risk of IIM which suggests that the triggering of the immune system may take place outside the skeletal muscle.

What to Expect When Expecting With Systemic Lupus Erythematosus (SLE): A Population-Based Study of Maternal and Fetal Outcomes in SLE and Pre-SLE

Objective

To assess maternal and fetal outcomes associated with subclinical (pre‐systemic lupus erythematosus [SLE] and SLE presenting up to 5 years postpartum) and prevalent maternal SLE during pregnancy compared with the general population.

Methods

This prospective cohort study used population‐based Swedish registers to identify 13,598 women with first singleton pregnancies registered in the Medical Birth Register (551 prevalent SLE, 65 pre‐SLE within 0–2 years, 133 pre‐SLE within 2–5 years, and 12,847 general population). SLE was defined as ≥2 SLE‐coded discharge diagnoses in the patient register with ≥1 diagnosis from a specialist. Unadjusted risks of adverse pregnancy or birth outcomes were calculated by SLE status, and Cochran‐Armitage tests evaluated trend across exposure groups.

Results

Maternal outcomes such as preeclampsia, hypothyroidism, stroke, and infection were more common among women with SLE. Sixteen percent of prevalent‐SLE pregnancies were diagnosed with preeclampsia compared with 5% of those from the general population. Among the pre‐SLE women, preeclampsia was found in 26% of those with SLE within 2 years postpartum and 13% in those with SLE within 2–5 years postpartum. Similarly, infant outcomes, such as preterm birth, infection, and mortality, were worse among those born to mothers with prevalent SLE and pre‐SLE during pregnancy. The test for trend was significant for most outcomes.

Conclusion

Our data demonstrate that adverse maternal and fetal outcomes are more common in SLE pregnancies. Furthermore, these unfavorable outcomes are observed in pregnancies occurring prior to the diagnosis of SLE. Thus, the underlying immunologic profile of SLE and alterations preceding clinical SLE may contribute to these pregnancy complications.