Comorbidities in childhood atopic dermatitis: A population-based study.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease that is associated with allergic comorbidities. However, studies examining comorbidities in childhood AD are incomplete, which may contribute to suboptimal care. OBJECTIVE: The objective was to compare the risk of developing different allergic and non-allergic comorbidities among children with AD to that of a matched non-AD reference cohort in Sweden. METHODS: This was a nationwide population-based cohort study using longitudinal data from primary and specialist care registers. Patients with AD were identified by confirmed diagnosis in primary or specialist care. The non-AD reference cohort was randomly drawn from the general population and matched 1:1 with the AD patients. The risk of developing the following conditions was evaluated: hypersensitivity and allergic disorders, neurological disorders, psychiatric disorders, infections, immunological and inflammatory disorders, Type 1 diabetes (T1D), endocrine and metabolic disorders, skeletal disorders, ocular disorders and malignancies. RESULTS: This study included 165,145 patients with AD (mild-to-moderate [n = 126,681] and severe [n = 38,464]) and an equally sized reference cohort. Patients with AD displayed a higher risk of developing comorbid conditions for all investigated categories, except for T1D and skeletal disorders, compared with the reference cohort. The highest risk compared with the reference cohort was observed for hypersensitivity and allergic disorders (hazard ratio [HR]: 3.87), followed by malignancies (HR: 2.53) and immunological and inflammatory disorders (HR: 2.36). Patients with AD also had higher risk of developing multiple comorbidities (≥2). The risk of comorbidity onset increased alongside AD severity and patients with active AD were associated with increased risk of comorbidity onset compared with patients in remission. CONCLUSIONS: The clinical burden of AD is substantial for children with AD and patients are at an increased risk of developing several comorbid conditions extending beyond the atopic march. Our results also showed a positive association between worsening severity of AD and an increased risk of comorbidity onset.

Validation of Patient Identification Algorithms for Atopic Dermatitis Using Healthcare Databases.

INTRODUCTION: The use of real-world data offers a possibility to perform large-scale epidemiological studies in actual clinical settings. Despite their many advantages, administrative databases were not designed to be used in research, and the validation of diagnoses and treatments in administrative databases is needed. The primary objective of this study was to validate an existing algorithm based on dispensed prescriptions and diagnoses of skin conditions to identify pediatric patients with atopic dermatitis (AD), using a diagnosis of AD in primary care as a gold standard. METHODS: Retrospective observational data were collected from nation-wide secondary care and pharmacy-dispensed medication databases and two regional primary care databases in Sweden. An existing algorithm and a Modified algorithm, using skin-specific diagnoses from secondary care and/or pharmacy-dispensed prescriptions to identify patients with AD, were assessed. To verify the presence of AD, diagnoses from primary care were used in the base case and complemented with diagnoses from secondary care in a sensitivity analysis. RESULTS: The sensitivity (30.0%) and positive predictive value (PPV) (40.7%) of the existing algorithm were low in the pediatric patient population when using primary care data only but increased when secondary care visits were also included in the Modified algorithm (sensitivity, 62.1%; PPV, 66.3%). The specificity of the two algorithms was high in both the base case and sensitivity analysis (95.1% and 94.1%). In the adult population, sensitivity and PPV were 20.4% and 8.7%, respectively, and increased to 48.3% and 16.9% when secondary care visits were also included in the Modified algorithm. CONCLUSION: The Modified algorithm can be used to identify pediatric AD populations using primary and secondary administrative data with acceptable sensitivity and specificity, but further modifications are needed to accurately identify adult patients with AD.

Clinical and Economic Burden of Pediatric Mild-to-Moderate Atopic Dermatitis: A Population-Based Nested Case-Control Study in Sweden.

INTRODUCTION: Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin condition characterized by pruritic, eczematous lesions. Recent evidence suggests that AD may be a systemic disorder, implying that management of this disease extends beyond merely controlling symptoms associated with AD. Even though this disease is highly prevalent in children and patients typically present with mild-to-moderate symptoms, the disease burden is not well established. METHODS: A large, retrospective cohort study of Swedish population data was conducted to compare the clinical burden in terms of healthcare resource use and direct medical costs for pediatric mild-to-moderate (pM2M) AD patients (≤ 14 years of age, N = 87,721) with matched controls. The burden of a severe AD cohort was also evaluated. Severity of AD was defined by treatment usage and systemic treatment was used as a proxy for severe AD. A robust approach was used by including any type of secondary care visits known to be more common in AD patients than in the general population; however, data for primary care visits were not available. RESULTS: For healthcare resource use, the incidence rate ratio (pM2M AD versus reference cohort) of secondary care visits ranged from 1.56 to 2.35 during each of 5 years after AD onset (all p < 0.001), with largest differences seen in years 1-2. The average direct medical cost (SD) was €1111 (3416) and €524 (2446) in the pM2M AD and reference cohorts, respectively. The corresponding estimate in the severe AD cohort was €1906 (7067). Including all secondary care visits and pharmacy-dispensed medications, the pM2M AD cohort was shown to have an additional €118.9 million in direct medical costs over 5 years compared with the reference cohort. CONCLUSIONS: This study shows significant clinical and economic burden of pM2M AD with important secondary care resource utilization, suggesting a need for further research to increase treatment options and improve the management of these patients.

Synovial membrane immunohistology in early-untreated rheumatoid arthritis reveals high expression of catabolic bone markers that is modulated by methotrexate.

INTRODUCTION: We aimed to investigate the expression and therapeutic modulation of the receptor activator of the NF-κB ligand (RANKL) system in early-untreated rheumatoid arthritis (RA). METHODS: In this study, 15 patients with newly diagnosed RA (median symptom duration 7 months) were started on methotrexate (MTX) 20 mg weekly. Synovial biopsies were obtained by needle arthroscopy at baseline and 8 weeks after initiation of therapy. X-rays of the hands and feet were obtained at baseline and 1 year after diagnosis. Immunohistochemistry was performed to detect RANKL, receptor activator of nuclear factor-κB (RANK) and osteoprotegerin (OPG) in the synovial biopsies. The in vitro effect of MTX was tested on RA-derived primary fibroblasts and the osteoblasts-like osteosarcoma cell line (rtPCR, Western blot and ELISA) and in osteoclasts (tartrate-resistant acid phosphatase staining and dentine pit formation assay). RESULTS: MTX decreased synovial cellularity as well as RANK expression and the RANKL/OPG ratio. We confirmed this effect by a decrease of the mRNA and protein RANKL/OPG ratio in synovial-derived fibroblasts and osteoblasts-like tumoral cells exposed in vitro to methotrexate. Supernatants from MTX treated osteoblasts-like tumoral cells prevented pre-osteoclast formation in the absence of exogenous RANKL. Furthermore, MTX blocked osteoclastogenesis from peripheral blood mononuclear cells despite the presence of macrophage colony stimulating factor and RANKL, which indicates that MTX directly inhibits osteoclastogenesis. CONCLUSIONS: The synovial membrane of early-untreated RA is characterized by a high RANKL/OPG ratio that can be reversed by methotrexate.

The cathelicidins LL-37 and rCRAMP are associated with pathogenic events of arthritis in humans and rats.

BACKGROUND: In rheumatoid arthritis (RA), neutrophil granulocytes fuel inflammation and damage tissue in the joint by releasing cytotoxic agents, antimicrobial peptides, proteases and other inflammatory mediators. The human cathelicidin LL-37 has recently been implicated in the development of systemic lupus erythematosus and psoriasis. OBJECTIVE: To elucidate if antimicrobial peptides (AMPs) contribute to the pathogenesis of arthritis. METHODS: Expression of LL-37 was determined in synovial membranes from patients with arthritis and control subjects. Expression of the rat cathelicidin rCRAMP and defensins was characterised in joints, blood and secondary lymphoid organs during pristane-induced arthritis (PIA) in rats and in a transfer model of PIA induced by CD4 T cells. Serum samples of rats with arthritis were tested for IgG and IgM autoantibodies against rCRAMP by immunoblot and for interferon (IFNα) by ELISA. RESULTS: Cathelicidins are strongly upregulated in RA synovial membranes and in joints from rats with arthritis as compared with healthy joints. Expression was most prominent in neutrophil granulocytes and macrophages/osteoclasts. Cathelicidin expression is also upregulated in the blood and spleen of pristane-injected rats, with strongest expression detected in activated CD62L- cells coexpressing granulocyte and monocyte markers. Pristane injection caused accumulation of low-density granulocytes in the blood. After pristane injection, the increased expression of rCRAMP coincided with higher levels of cell death, raised levels of interferon (IFN)α and development of autoantibodies. CONCLUSIONS: Our results show strong upregulation of cathelicidins and ß-defensins coinciding with pathological events of arthritis. Higher expression and release of AMPs might contribute to development and/or maintenance of disease by systemic or local mechanisms.

Monocytes are essential for inhibition of synovial T-cell glucocorticoid-mediated apoptosis in rheumatoid arthritis.

INTRODUCTION: Rheumatoid arthritis (RA) is characterized by synovial inflammation with local accumulation of mononuclear cells such as macrophages and lymphocytes. We previously demonstrated that intra-articular glucocorticoids decrease the synovial tissue (ST) T-cell population and therefore aimed to investigate whether this is mediated through modulation of apoptosis. METHODS: Apoptosis and cell phenotype were evaluated by immunohistochemistry and dual-immunofluorescence in synovial biopsy sections from 12 RA patients before and after a mean of 11 days of an intra-articular triamcinolone knee injection. In vitro, RA synovial fluid (SF)-derived T cells were evaluated for Annexin V expression by multicolor flow cytometry after 24-hour exposure to dexamethasone, methylprednisolone, or triamcinolone. We also tested induction of apoptosis by dexamethasone on psoriatic arthritis SF-derived T cells using the same method. RESULTS: Intra-articular glucocorticoids reduced ST T cells but not macrophage number. ST apoptosis levels were unchanged following treatment, virtually absent from lymphoid aggregates, and minimal in CD3+ cells both before and after treatment. RA SF T cells were resistant to glucocorticoid-induced apoptosis when cultured in the presence of monocytes but were rendered sensitive to all three tested compounds upon SF isolation. Furthermore, transwell coculture of monocytes and T cells demonstrated that soluble factor(s) and not cellular contact are essential for T-cell resistance to glucocorticoid-mediated apoptosis. This feature is RA-specific as far as dexamethasone-induced apoptosis in nonisolated SF T cells obtained from psoriatic arthritis patients is concerned. CONCLUSIONS: We demonstrate that monocytes rescue synovial T cells from glucocorticoid-induced apoptosis, a feature that is specific for RA. To overcome this, we propose the use of monocyte-targeted therapies rather than T-cell apoptosis-inducing therapies.

Childbearing and the risk of scleroderma: a population-based study in Sweden.

This study examined associations between childbearing and risk of scleroderma by using national population-based registry data from Sweden. Women with a discharge diagnosis of scleroderma from 1964 to 1999 (n = 2,149) were identified in the Swedish Inpatient Register. These cases were matched by year and month of birth and region of residence to as many as five controls obtained from the Multi-Generation Register. Pregnancy history (number of births, age at each birth) was restricted to births before the first scleroderma-related hospitalization for cases and the corresponding age for their matched controls. Risk estimates, measured by the odds ratio and 95% confidence interval, were obtained by using conditional logistic regression. Nulliparity was associated with an increased risk of scleroderma (odds ratio = 1.37, 95% confidence interval: 1.22, 1.55). Risk decreased with increasing number of births. Similar results were found when analyses were limited to births up to 2 years or up to 5 years before hospitalization. Among parous women, younger age at first birth was associated with an increased risk of scleroderma. The association between lower parity and increased risk of scleroderma could reflect subfecundity caused by scleroderma before disease became clinically evident, possible common causes of infertility and scleroderma, or a protective effect of pregnancy through an unknown mechanism.