Kristjan Steinsson

Kristjan Steinsson
National University Hospital of Iceland | LSH · Center for Rheumatology research Landspitali University hospital Iceland

About

77
Publications
8,667
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
6,843
Citations

Publications

Publications (77)
Article
Full-text available
Objectives: To find causal genes for rheumatoid arthritis (RA) and its seropositive (RF and/or ACPA positive) and seronegative subsets. Methods: We performed a genome-wide association study (GWAS) of 31 313 RA cases (68% seropositive) and ~1 million controls from Northwestern Europe. We searched for causal genes outside the HLA-locus through eff...
Article
Full-text available
Objectives To evaluate systemic lupus erythematosus (SLE) flares following hydroxychloroquine (HCQ) reduction or discontinuation versus HCQ maintenance. Methods We analysed prospective data from the Systemic Lupus International Collaborating Clinics (SLICC) cohort, enrolled from 33 sites within 15 months of SLE diagnosis and followed annually (199...
Conference Paper
Full-text available
Background Hydroxychloroquine (HCQ) is a cornerstone treatment of systemic lupus erythematosus (SLE). We compared time to flare in SLE patients discontinuing/reducing HCQ versus those maintaining their dose, and identified factors associated with time to flare. Methods We analyzed prospective data from the Systemic Lupus International Collaboratin...
Article
Full-text available
Objective Anti-beta 2 glycoprotein I IgA is a common isotype of anti-beta 2 glycoprotein I in SLE. Anti-beta 2 glycoprotein I was not included in the American College of Rheumatology (ACR) SLE classification criteria, but was included in the Systemic Lupus International Collaborating Clinics (SLICC) criteria. We aimed to evaluate the prevalence of...
Article
Objectives: Vitamin D (25(OH)D) deficiency and metabolic syndrome (MetS) may both contribute to increased cardiovascular risk in systemic lupus erythematosus (SLE). We aimed to examine the association of demographic factors, SLE phenotype, therapy and vitamin D levels with MetS and insulin resistance. Methods: The Systemic Lupus International Co...
Article
Full-text available
Autoimmune thyroid disease is the most common autoimmune disease and is highly heritable1. Here, by using a genome-wide association study of 30,234 cases and 725,172 controls from Iceland and the UK Biobank, we find 99 sequence variants at 93 loci, of which 84 variants are previously unreported2–7. A low-frequency (1.36%) intronic variant in FLT3 (...
Article
Objective To assess cancer risk factors in incident SLE. Methods Clinical variables and cancer outcomes were assessed annually among incident SLE patients. Multivariate hazard regression models (over‐all risk, and most common cancers) included demographics and time‐dependent medications (corticosteroids, antimalarial drugs, immunosuppressants), sm...
Article
Objective The Systemic Lupus International Collaborating Clinics (SLICC) 2012 SLE classification criteria and the revised American College of Rheumatology (ACR) 1997 criteria are list‐based, counting each SLE manifestation equally. We derived a classification rule based on giving variable weights to the SLICC criteria, and compared its performance...
Article
Full-text available
Objective: The soluble urokinase plasminogen activator receptor (suPAR) has potential as a prognosis and severity biomarker in several inflammatory and infectious diseases. In a previous cross-sectional study, suPAR levels were shown to reflect damage accrual in cases of systemic lupus erythematosus (SLE). Herein, we evaluated suPAR as a predictor...
Article
Objectives: There is a paucity of data regarding healthcare costs associated with damage accrual in systemic lupus erythematosus (SLE). We describe costs associated with damage states across the disease course using multi-state modeling. Methods: Patients from 33 centres in 11 countries were enrolled in the Systemic Lupus International Collabora...
Article
Full-text available
Objectives: In a multi-ethnic/racial, prospective SLE inception cohort, to determine the frequency, clinical characteristics, associations and outcomes in different types of peripheral nervous system (PNS) disease. Methods: Patients were evaluated annually for 19 neuropsychiatric (NP) events including seven types of PNS disease. SLE disease acti...
Conference Paper
Background Central nervous system (CNS) involvement accounts for over 90% of neuropsychiatric (NP) events compared to involvement of the peripheral nervous system (PNS) which accounts for most of the other events. Although there is a large body of work on CNS disease in SLE patients, involvement of the PNS is less well established. Objectives In a...
Article
Objectives: To assess the prevalence of combined hormonal contraceptives (CHCs) in reproductive-age women with SLE with and without possible contraindications and to determine factors associated with their use in the presence of possible contraindications. Methods: This observational cohort study included premenopausal women ages 18-45 years enr...
Article
Objective To evaluate the properties of a frailty index (FI), constructed using data from the Systemic Lupus International Collaborating Clinics (SLICC) inception cohort, as a novel health measure in SLE. Methods For this secondary analysis, the baseline visit was defined as the first study visit at which both organ damage (SLICC/ACR Damage Index...
Article
Full-text available
Objective In cross-sectional studies, elevated osteopontin (OPN) levels have been proposed to reflect, and/or precede, progressive organ damage and disease severity in systemic lupus erythematosus (SLE). We aimed, in a cohort of patients with recent-onset SLE, to determine whether raised serum OPN levels precede damage and/or are associated with di...
Article
Full-text available
Objectives To determine, in a multi‐ethnic/racial, prospective SLE inception cohort, the frequency, attribution, clinical and autoantibody associations with lupus psychosis and the short and long‐term outcome as assessed by physicians and patients. Methods Patients were evaluated annually for 19 neuropsychiatric (NP) events including psychosis. SL...
Conference Paper
Background Little is known about the association of healthcare costs with damage accrual in SLE. We describe the costs associated with damage progression using multi-state modeling. Methods Patients fulfilling the revised ACR Classification Criteria for SLE from 32 centres in 11 countries were enrolled in the Systemic Lupus International Collabora...
Article
Objectives: The spectrum of antinuclear antibodies (ANA) is changing to include both nuclear staining as well as cytoplasmic and mitotic cell patterns (CMPs) and accordingly a change in terminology to anti-cellular antibodies. This study examined the prevalence of indirect immunofluorescence (IIF) anti-cellular antibody staining using the Systemic...
Article
Full-text available
In an effort to identify rare alleles associated with SLE, we have performed whole exome sequencing of the most distantly related affected individuals from two large Icelandic multicase SLE families followed by Ta targeted genotyping of additional relatives. We identified multiple rare likely pathogenic variants in nineteen genes co-segregating wit...
Article
Objectives: To describe glucocorticoid (GC) use in the SLICC inception cohort and to explore factors associated with GC use. In particular we aimed to assess temporal trends in GC use and to what extent physician-related factors may influence use. Methods: Patients were recruited within 15 months of diagnosis of SLE from 33 centres between 1999...
Article
Objective: To determine the frequency, associations and outcomes of cerebrovascular events (CerVEs) in a multi-ethnic/racial, prospective, SLE disease inception cohort. Methods: Patients were assessed annually for 19 neuropsychiatric (NP) events including 5 types of CerVEs: (i) Stroke; (ii) Transient ischemia; (iii) Chronic multifocal ischemia;...
Article
OBJECTIVE: To determine the frequency, associations and outcomes of cerebrovascular events (CerVEs) in a multi-ethnic/racial, prospective, SLE disease inception cohort. METHODS: Patients were assessed annually for 19 neuropsychiatric (NP) events including 5 types of CerVEs: (i) Stroke; (ii) Transient ischemia; (iii) Chronic multifocal ischemia; (iv...
Article
Full-text available
A meta-analysis of publicly available summary statistics on multiple sclerosis combined with three Nordic multiple sclerosis cohorts (21,079 cases, 371,198 controls) revealed seven sequence variants associating with multiple sclerosis, not reported previously. Using polygenic risk scores based on public summary statistics of variants outside the ma...
Article
OBJECTIVE: To study bidirectional change and predictors of change in estimated glomerular filtration rate (GFR) and proteinuria in lupus nephritis (LN) using a multistate modeling approach. METHODS: Patients in the Systemic Lupus International Collaborating Clinics inception cohort were classified annually into estimated GFR state 1 (>60 ml/minute)...
Article
Full-text available
Objective: To study bidirectional change and predictors of change in estimated glomerular filtration rate (eGFR) and proteinuria (ePrU) in lupus nephritis (LN) using a multistate modelling approach. Methods: In the SLICC inception cohort we determined annual eGFR state 1 (eGFR: >60 ml/min), 2 (eGFR: 30-60 mL/min), and 3 (eGFR: <30 ml/min); ePrU...
Article
Full-text available
OBJECTIVE: To study bidirectional change and predictors of change in estimated glomerular filtration rate (eGFR) and proteinuria (ePrU) in lupus nephritis (LN) using a multistate modelling approach. METHODS: In the SLICC inception cohort we determined annual eGFR state 1 (eGFR: >60 ml/min), 2 (eGFR: 30-60 mL/min), and 3 (eGFR: <30 ml/min); ePrU s...
Article
Full-text available
To determine nephritis outcomes in a prospective multi-ethnic/racial SLE inception cohort. Patients in the Systemic Lupus International Collaborating Clinics inception cohort (≤15 months of SLE diagnosis) were assessed annually for estimated glomerular filtration rate (eGFR), proteinuria and end-stage renal disease (ESRD). Health-related quality of...
Article
Full-text available
Background and aims: We studied damage accrual and factors determining development and progression of damage in an international cohort of systemic lupus erythematosus (SLE) patients. Methods: The Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort recruited patients within 15 months of developing four or more 1997 Americ...
Article
Objective To estimate the early prevalence of various electrocardiographic (EKG) abnormalities in patients with systemic lupus erythematosus (SLE) and to evaluate possible associations between repolarization changes (increased corrected QT [QTc] and QT dispersion [QTd]) and clinical and laboratory variables, including the anti-Ro/SSA level and spec...
Article
Full-text available
Objective: An association between 25-hydroxyvitamin D (25[OH]D; vitamin D) deficiency and increased cardiovascular (CV) risk factors and CV disease (CVD) has been shown in general population studies. Vitamin D deficiency has been noted in systemic lupus erythematosus (SLE), and CVD is a major cause of morbidity and mortality in SLE. The objectives...
Article
Full-text available
The metabolic syndrome (MetS) may contribute to the increased cardiovascular risk in systemic lupus erythematosus (SLE). We examined the association between MetS and disease activity, disease phenotype and corticosteroid exposure over time in patients with SLE. Recently diagnosed (<15 months) patients with SLE from 30 centres across 11 countries we...
Article
To determine the frequency of each American College of Rheumatology (ACR) criterion met at time of enrollment, and the increase in each of the criteria over 5 years. In 2000 the Systemic Lupus International Collaborating Clinics (SLICC) recruited an international inception cohort of patients with systemic lupus erythematosus (SLE; ≥ 4 ACR criteria)...
Article
To examine the frequency and characteristics of headaches and their association with global disease activity and health-related quality of life (HRQOL) in patients with systemic lupus erythematosus (SLE). A disease inception cohort was assessed annually for headache (5 types) and 18 other neuropsychiatric (NP) events. Global disease activity scores...
Article
Objective: To update estimates of cancer risk in SLE relative to the general population. Methods: A multisite international SLE cohort was linked with regional tumor registries. Standardized incidence ratios (SIRs) were calculated as the ratio of observed to expected cancers. Results: Across 30 centres, 16,409 patients were observed for 121,28...
Article
Full-text available
Background: The metabolic syndrome (MetS) may contribute to increased cardiovascular risk in systemic lupus erythematosus (SLE). We aimed to examine the association of demographic factors, lupus phenotype and therapy exposure with the presence of MetS. Methods: The Systemic Lupus International Collaborating Clinics Registry for Atherosclerosis i...
Article
Full-text available
The Systemic Lupus International Collaborating Clinics (SLICC) group revised and validated the American College of Rheumatology (ACR) systemic lupus erythematosus (SLE) classification criteria in order to improve clinical relevance, meet stringent methodology requirements, and incorporate new knowledge regarding the immunology of SLE. The classific...
Article
Full-text available
Objective The aim of this study was to describe the frequency, attribution, outcome and predictors of seizures in systemic lupus erythematosus (SLE). Methods The Systemic Lupus International Collaborating Clinics, or SLICC, performed a prospective inception cohort study. Demographic variables, global SLE disease activity (SLE Disease Activity Inde...
Article
Background The susceptibility to rheumatoid arthritis (RA) is partly heritable, whether the severity of RA is also influenced by genetics is not determined. Evaluation on the heritability of the severity of RA is basic to further studies on genetic factors. The authors aimed to determine whether joint destruction is heritable. Methods Iceland has a...
Article
Full-text available
Previous studies have provided inconsistent results on whether variants in the MBL2 gene, coding for the complement-activating mannan-binding lectin (MBL) protein, associate with rheumatoid arthritis (RA). We re-evaluated this in context of the main environmental and genetic risk factors (smoking, HLA-DRB1 'shared epitope' (SE), PTPN22*620W), which...
Article
A genetic polymorphism in the programmed death 1 (PD-1) gene encoding the coinhibitory PD-1 immunoreceptor, PD-1.3A, is associated with systemic lupus erythematosus (SLE). The aim of this study was to assess PD-1 receptor expression in patients with SLE, in comparison with relatives and unrelated healthy controls, and to identify correlations of lo...
Article
To study autoimmune diseases and autoantibodies in Icelandic multicase systemic lupus erythematosus (SLE) families and to determine the association of 3 SLE susceptibility factors, PD-1.3A, C4AQ0, and low levels of mannan-binding lectin (MBL), with autoimmune disease in this population. Eight SLE multicase families were studied, comprising a total...
Article
To assess the degree to which physicians agree with each other and with ratings obtained with 3 existing responder indices, in rating the response to treatment of lupus nephritis. Lupus nephritis patient medical records from 125 pairs of visits (6 months apart) were used to create renal response scenarios. Seven nephrologists and 22 rheumatologists...
Article
To develop a measure of renal activity in systemic lupus erythematosus and use it to develop a renal response index. Abstracted data from the medical records of 215 patients with lupus nephritis were sent to 8 nephrologists and 29 rheumatologists for rating. Seven nephrologists and 22 rheumatologists completed the ratings. Each physician rated each...
Article
Mannan-binding lectin (MBL) is present in serum and synovial fluid; its levels vary widely, and the variations are strongly associated with polymorphisms in the MBL2 gene. Studies have compared MBL in patients with rheumatoid arthritis (RA) and in unrelated controls, but the findings have been contradictory. In the first family-based study, we comp...
Article
Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease caused by both genetic and environmental factors. Genome scans in families with SLE point to multiple potential chromosomal regions that harbor SLE susceptibility genes, and association studies in different populations have suggested several susceptibility alleles for SLE....
Article
A 49-year old man suffered a superficial injury on the dorsum of the right hand. Subsequently, a wound developed which healed slowly despite several courses of oral antibiotics. Gradually, nodular lesions developed on the hand. A biopsy of the nodules showed granulomatous inflammation which was considered to be consistent with rheumatoid nodules. L...
Article
Full-text available
Systemic lupus erythematosus (SLE, OMIM 152700) is a complex autoimmune disease that affects 0.05% of the Western population, predominantly women. A number of susceptibility loci for SLE have been suggested in different populations, but the nature of the susceptibility genes and mutations is yet to be identified. We previously reported a susceptibi...
Article
Studies of an Icelandic cohort showed that susceptibility to systemic lupus erythematosus (SLE) in individuals with C4A deficiency was increased only in the presence of increased concentrations of immune complexes. We investigated the interaction of C4A deficiency with elevated concentrations of immune complexes in healthy individuals; i.e., how di...
Article
The genes coding for the two components of complement 4 (C4), C4A and C4B, are located within the major histocompatibility complex (MHC) on the short arm of chromosome 6. Several studies have shown that deficiency of C4A is associated with systemic lupus erythematosus (SLE), rheumatoid arthritis and scleroderma. A large deletion covering most of th...
Article
To identify chromosomal regions containing susceptibility loci for systemic lupus erythematosus (SLE), we performed genome scans in families with multiple SLE patients from Iceland, a geographical and genetic isolate, and from Sweden. A number of chromosomal regions showed maximum lod scores (Z) indicating possible linkage to SLE in both the Icelan...
Article
To identify chromosomal regions containing susceptibility loci for systemic lupus erythematosus (SLE), we performed genome scans in families with multiple SLE patients from Iceland, a geographical and genetic isolate, and from Sweden. A number of chromosomal regions showed maximum lod scores (Z) indicating possible linkage to SLE in both the Icelan...