Kristofer Andréasson

Prevalence and incidence of systemic sclerosis in southern Sweden: population-based data with case ascertainment using the 1980 ARA criteria and the proposed ACR-EULAR classification criteria

Objectives To estimate the prevalence and incidence of systemic sclerosis (SSc) in southern Sweden. Methods In Skåne, the southernmost region of Sweden (total population 1.2 million), healthcare provided is registered in the Skåne Healthcare Register. We identified all Skåne residents who had received an International Classification of Diseases 10 diagnosis of SSc (M34) or Raynauds phenomenon (I73.0) between 1998 and 2010. Every single case was ascertained by review of medical records in reference to the 1980 American Rheumatism Association preliminary classification criteria for SSc and the proposed American College of Rheumatology (ACR)-European League Against Rheumatism (EULAR) classification criteria presented at the ACR/Association of Rheumatology Health Professionals Annual Meeting 2012. We calculated the point prevalence by the end of 2010 by linkage with the population register to exclude deceased persons and we also estimated the mean annual cumulative incidence for 2006–2010. Results Using the 1980 ARA criteria, the adult prevalence and annual incidence of SSc in the Skåne region were 235 and 14 per 1 million inhabitants respectively. Applying the proposed ACR-EULAR criteria, the corresponding figures were 305 and 19 per 1 million inhabitants. A majority (82%) of the prevalent cases had the limited cutaneous SSc subtype. Conclusions The prevalence and incidence of SSc in southern Sweden, based on the 1980 ARA criteria, are higher than previously reported in northern Europe and do not support the concept of a north-south gradient of SSc occurrence in Europe. Application of the proposed ACR-EULAR classification criteria in this population results in about 30–40% higher estimates of SSc prevalence and incidence compared to the 1980 ARA criteria.

Extracellular matrix alterations and acute inflammation; developing in parallel during early induction of pulmonary fibrosis.

Pulmonary fibrosis is a hallmark of several systemic diseases such as systemic sclerosis. Initiation and early development is not well characterized, as initiation usually is unnoticed in patients, yet fibrosis has been considered a late event, occurring after an inflammatory phase. By utilizing an animal model, the starting point can be defined and the initiation process and early development thoroughly investigated. To investigate these processes from a systemic perspective, we choose a systemic administration route, instead of the more commonly used local administration. The aim of this work was to study the initiation of pulmonary fibrosis in an animal model and to investigate early alterations in connective tissue, cell turnover and acute immune response in lung parenchyma. Animals were injected subcutaneously with bleomycin, three times a week (w) for 1–4w (controls received saline). Total collagen was histologically assessed by Picro Sirius Red and Massons Trichrome, collagen production by antibodies directed against N-terminal of procollagens I and III, proliferation by labeling with proliferating cell nuclear antigen, apoptosis by TUNEL and innate immunity by detecting neutrophils and macrophages. Total collagen was significantly increased at 1, 2 and 4w compared with controls. Procollagen I, was increased at 1w and remained increased, whereas procollagen III-staining was increased at 2w, compared with controls. Myofibroblasts were increased at all times as were proliferation, whereas apoptosis was increased from 2w. Neutrophils peaked at 1w (2779±820 cells/mm2) and gradually decreased, whereas macrophages peaked at 2w (135±29 cells/mm2). Subcutaneously administered bleomycin induces rapid alterations in connective tissue and cell turnover, suggesting a plasticity of the connective tissue. A transient neutrophilia is detected and increased number of macrophages likely represents a clearance process of said neutrophils. The study suggests fibrosis initiation and acute inflammation to occur in parallel in this model.

Enhanced deposition of cartilage oligomeric matrix protein is a common feature in fibrotic skin pathologies

Skin fibrosis is characterized by activated fibroblasts and an altered architecture of the extracellular matrix. Excessive deposition of extracellular matrix proteins and altered cytokine levels in the dermal collagen matrix are common to several pathological situations such as localized scleroderma and systemic sclerosis, keloids, dermatosclerosis associated with venous ulcers and the fibroproliferative tissue surrounding invasively growing tumors. Which factors contribute to altered organization of dermal collagen matrix in skin fibrosis is not well understood. We recently demonstrated that cartilage oligomeric matrix protein (COMP) functions as organizer of the dermal collagen I network in healthy human skin (Agarwal et al., 2012). Here we show that COMP deposition is enhanced in the dermis in various fibrotic conditions. COMP levels were significantly increased in fibrotic lesions derived from patients with localized scleroderma, in wound tissue and exudates of patients with venous leg ulcers and in the fibrotic stroma of biopsies from patients with basal cell carcinoma. We postulate enhanced deposition of COMP as one of the common factors altering the supramolecular architecture of collagen matrix in fibrotic skin pathologies. Interestingly, COMP remained nearly undetectable in normally healing wounds where myofibroblasts transiently accumulate in the granulation tissue. We conclude that COMP expression is restricted to a fibroblast differentiation state not identical to myofibroblasts which is induced by TGFβ and biomechanical forces.

Faecal calprotectin: a biomarker of gastrointestinal disease in systemic sclerosis

Abstract.  Andréasson K, Scheja A, Saxne T, Ohlsson B, Hesselstrand R (Section for Rheumatology; Section for Gastroenterology and Hepatology, Lund University, Lund, Sweden). Faecal calprotectin: a biomarker of gastrointestinal disease in systemic sclerosis. J Intern Med 2011; 270: 50–57.

Increased serum COMP predicts mortality in SSc: results from a longitudinal study of interstitial lung disease

OBJECTIVES COMP is a regulator of assembly and maintenance of the fibrillar collagen I and II networks. Serum COMP reflects skin fibrosis in SSc. The purpose of this study was to examine whether serum COMP reflects fibrotic lung involvement in SSc patients and to study if serum COMP predicts mortality. METHODS Three overlapping cohorts of 244 SSc patients were studied. Two hundred and eighteen patients were included to study survival, 80 patients to study longitudinal changes of pulmonary function tests and 64 to study pulmonary involvement assessed by high-resolution CT (HRCT). Serum COMP was measured by ELISA. Skin involvement was assessed with the modified Rodnan skin score (mRSS). Data about survival were obtained from the central population registry. RESULTS Serum COMP measured within 5 years after the first non-Raynauds manifestation was a predictor of death, and crude mortality increased by 6% for each COMP unit elevation. Serum COMP levels >15 U/l were associated with a 3.13-fold (95% CI 1.73, 5.64; P < 0.001) increased risk of death. During the first year of follow-up serum COMP and vital capacity (VC) changed inversely (r(s) = -0.32; P = 0.005), but there were no correlations between baseline serum COMP and concurrent findings by spirometry or HRCT. CONCLUSION Serum COMP early in disease is a predictor of mortality in SSc patients. Serum COMP changes in parallel with lung fibrosis as measured by VC, but the release from fibrotic skin possibly obscures the influx from the lungs and therefore serum COMP seems to have little utility as a marker of lung fibrosis.

Absence of fibromodulin affects matrix composition, collagen deposition and cell turnover in healthy and fibrotic lung parenchyma.

The ECM exerts great effects on cells, and changed composition may therefore have profound impact. Small leucine-rich proteoglycans, e.g. fibromodulin, are essential in collagen assembly. Our aim was to investigate the role of fibromodulin in healthy and fibrotic lung parenchyma, theorizing that fibromodulin-deficient animals would be protected against fibrosis. Repeated subcutaneous bleomycin-injections were given to wild type and fibromodulin-deficient mice, inducing pulmonary fibrosis. Development of fibrosis, ECM composition, cell turnover and inflammatory responses were investigated. Fibromodulin-deficient animals were not protected from fibrosis, but the composition of the matrix was affected, with decreased Collagen I in fibromodulin-deficient animals, both in controls (0.07 ± 0.04% vs. 0.18 ± 0.07% tissue area) and after bleomycin (0.37 ± 0.16% vs. 0.61 ± 0.21% tissue area). Biglycan was increased in fibromodulin-deficient animals, whereas decorin was decreased. Furthermore, bleomycin increased cell turnover in wild type, but only proliferation in fibromodulin-deficient animals, resulting in hyperplasia. In addition, the bleomycin-induced immune response was affected in fibromodulin-deficient animals. We thus conclude that fibromodulin has a profound effect on ECM, both in healthy and fibrotic lung parenchyma, and may be providing a permissive microenvironment affecting cell turnover. Furthermore, this study highlights the need to acknowledge specific ECM components, when assessing tissue properties and ultimately cell behaviour.

Multi-locus sequence analysis (MLSA) of clinical “CandidatusNeoehrlichia mikurensis” strains from Europe

ABSTRACT “Candidatus Neoehrlichia mikurensis” is the tick-borne agent of neoehrlichiosis, an infectious disease that primarily affects immunocompromised patients. So far, the genetic variability of “Ca. Neoehrlichia” has been studied only by comparing 16S rRNA genes and groEL operon sequences. We describe the development and use of a multilocus sequence analysis (MLSA) protocol to characterize the genetic diversity of clinical “Ca. Neoehrlichia” strains in Europe and their relatedness to other species within the Anaplasmataceae family. Six genes were selected: ftsZ, clpB, gatB, lipA, groEL, and 16S rRNA. Each MLSA locus was amplified by real-time PCR, and the PCR products were sequenced. Phylogenetic trees of MLSA locus relatedness were constructed from aligned sequences. Blood samples from 12 patients with confirmed “Ca. Neoehrlichia” infection from Sweden (n = 9), the Czech Republic (n = 2), and Germany (n = 1) were analyzed with the MLSA protocol. Three of the Swedish strains exhibited identical lipA sequences, while the lipA sequences of the strains from the other nine patients were identical to each other. One of the Czech strains had one differing nucleotide in the clpB sequence from the sequences of the other 11 strains. All 12 strains had identical sequences for the genes 16S rRNA, ftsZ, gatB, and groEL. According to the MLSA, among the Anaplasmataceae, “Ca. Neoehrlichia” is most closely related to Ehrlichia ruminantium, less so to Anaplasma phagocytophilum, and least to Wolbachia endosymbionts. To conclude, three sequence types of infectious “Ca. Neoehrlichia” were identified: one in the west of Sweden, one in the Czech Republic, and one spread throughout Europe.

Cartilage oligomeric matrix protein: a new promising biomarker of liver fibrosis in chronic hepatitis C

Abstract Cartilage oligomeric matrix protein (COMP) is a biomarker of fibrosis in lung and skin. In this exploratory study we investigated the biomarker potential of COMP in chronic hepatitis C (CHC). We included consecutive patients with CHC admitted to the Department of Infectious Diseases, Lund University Hospital. COMP was analysed in serum using ELISA. The correlations between COMP and liver fibrosis, determined by transient elastography (TE) (n = 47) and liver biopsy (n = 28) were assessed. We also studied COMP prospectively in relation to antiviral treatment (n = 10). COMP correlated with the degree of liver fibrosis as assessed by TE (r = 0.71, p < 0.001) and liver biopsy (rs = 0.65, p < 0.001). After successful treatment of CHC, COMP decreased from 18 to 13 U/l (p = 0.011). We suggest that COMP is associated with the stage of liver fibrosis in CHC. The biomarker potential of COMP in CHC warrants further investigation.

Vascular events are risk factors for anal incontinence in systemic sclerosis: a study of morphology and functional properties measured by anal endosonography and manometry

Objectives: To study anal sphincter morphology, anal sphincter pressure, and rectoanal inhibitory reflex (RAIR) in patients with systemic sclerosis (SSc) complicated by anal incontinence (AI) and to investigate possible risk factors for AI in SSc. Method: Nineteen SSc patients with severe AI were investigated using anal endosonography, anal manometry, and rectal manovolumetry. To determine risk factors for AI, disease characteristics of SSc patients with AI were compared with those of 95 SSc patients without AI; there were five matched SSc patients without AI for each SSc patient with AI. Results: The mean (SD) internal sphincter thickness was 1.3 (0.46) mm in patients with AI, which was thinner (p < 0.001) than reference data from healthy individuals whose internal sphincter measured 2.2 (0.45) mm, whereas the external sphincter thickness did not differ. The mean (SD) resting pressure in AI patients was lower than the reference data from healthy individuals [60 (22) vs. 94 (29) mmHg, p < 0.002] whereas the squeeze pressure did not differ. Centromeric antibodies and features of vascular disease [i.e. the presence of pulmonary arterial hypertension (PAH), digital ulcers, pitting scars, or the need for iloprost infusions] were associated with AI whereas fibrotic manifestations [i.e. modified Rodnan skin score (mRss), the diffuse cutaneous SSc (dcSSc) subset, or low vital capacity (VC)] were not. Conclusions: SSc patients with AI have a thin internal anal sphincter and a low resting pressure. Risk factors for AI among SSc patients are centromeric antibodies and vascular disease, which supports the hypothesis that gastrointestinal involvement in SSc is in part a vascular manifestation of the disease.

Faecal levels of calprotectin in systemic sclerosis are stable over time and are higher compared to primary Sjögren’s syndrome and rheumatoid arthritis

IntroductionFaecal calprotectin (FC) has been proposed to be a biomarker of gastrointestinal (GI) disease in systemic sclerosis (SSc). The purpose of this study was to extend cross-sectional observations and prospectively assess the variability of FC over time in SSc patients. We also aimed to examine FC in relation to immunosuppressive therapy. Finally we wanted to analyse FC in other rheumatic diseases to evaluate the specificity of FC for SSc GI disease.MethodsFC was measured in consecutive patients with SSc, primary Sjögren’s syndrome (pSS), rheumatoid arthritis (RA) and in healthy hospital workers. The intraindividual variability of FC in SSc was assessed with intra class correlation (ICC) and κ statistics. Associations between FC and objective markers of GI disease and immunosuppressive medication were investigated.ResultsFC was associated with micronutrient deficiency and GI pathology as assessed by cineradiography confirming our previous results. FC showed only a limited intra-individual variation in SSc, ICC = 0.69 (95% confidence interval, CI: 0.57-0.78) and κ = 0.64 (95% CI: 0.56-0.73). Generalised immunosuppression did not have any significant impact on FC. FC was significantly higher in SSc patients compared to patients with pSS or RA as well as compared to healthy subjects.ConclusionsFC is a promising non-invasive biomarker for GI disease in SSc. In view of stable levels over time, FC could be a useful marker when novel, more specific drugs targeting the GI tract in SSc will be introduced.