Anti-SMN autoantibodies in mixed connective tissue disease are associated with a severe systemic sclerosis phenotype.

OBJECTIVES: The survival of motor neuron (SMN) complex has an essential role in the assembly of small nuclear ribonucleoproteins (RNP). Recent reports have described autoantibodies (aAbs) to the SMN complex as novel biomarkers in anti-U1RNP+ myositis patients. The aim of this study was to compare phenotypic features of anti-U1RNP+ mixed connective tissue disease (MCTD) patients with and without anti-SMN aAbs. METHODS: A retrospective MCTD cohort was studied. Addressable laser bead immunoassay was used to detect specific anti-SMN aAbs with <300 mean fluorescence intensity (MFI) as normal reference range, 300-999 MFI as low-titre and ≥1000 MFI as high-titre positivity. Comparison of clinical features between anti-SMN+ and anti-SMN- subgroups used two-tailed Fisher's exact test, and logistic regression analyses. RESULTS: Sixty-six patients were included. Median age at MCTD diagnosis was 40.6 years, and duration of follow-up was 12 years. Based on the highest available titre, 39 (59%) were anti-SMN+: 10 (26%) had low titre and 29 (74%) had high titre. Anti-SMN+ patients had a higher frequency of fingertip pitting scars (anti-SMN+ 23% vs anti-SMN- 4%, p=0.04), lower gastrointestinal (GI) involvement (26% vs 4%, p=0.04), and myocarditis (16% vs 0%, p=0.04). The combined outcome of pitting scars and/or lower GI involvement and/or myositis and/or myocarditis was highest among high-titre anti-SMN+ patients: adjusted OR 7.79 (2.33 to 30.45, p=0.002). CONCLUSIONS: Anti-SMN aAbs were present in 59% of our MCTD cohort. Their presence, especially at high-titres, was associated with a severe systemic sclerosis (scleroderma) phenotype including myositis, myocarditis and lower GI involvement.

Capillary pathology with prominent basement membrane reduplication is the hallmark histopathological feature of scleromyositis.

AIMS: We aim to perform ultrastructural and histopathological analysis of muscle biopsies from a large group of systemic sclerosis (SSc) patients, including some with early/mild SSc features, and examine whether capillary pathology differentiates 'scleromyositis' (SM) from other auto-immune myositis (AIM) subsets. METHODS: Muscle biopsies from a total of 60 SM patients and 43 AIM controls from two independent cohorts were examined by electron microscopy, collagen-4 immunofluorescence (Col4IF) and routine light microscopy. RESULTS: Ultrastructural examination revealed prominent capillary basement membrane (BM) reduplication (4+ layers in >50% of capillaries) in 65% of SM vs 0% of AIM controls (p < 0.001). In SM cases without prominent BM reduplication, capillary dilation was the most distinctive feature, present in 8% of capillaries in SM vs 2% in controls (p = 0.001). Accumulation of ensheathed pericyte processes was another characteristic feature of SM and closely correlated with the degree of BM reduplication (r = 0.833, p < 0.001). On light microscopy, BM marker Col4IF revealed more frequent capillary enlargement in SM than in controls (84% vs 21%, p < 0.001). SM cases were classified as non-inflammatory myopathy (36%), non-specific myositis (33%) or immune-mediated necrotizing myopathy (31%), but despite this histopathological heterogeneity, prominent BM reduplication remained a constant finding. In the 16 SM patients with early/mild SSc features, 63% showed prominent BM reduplication. CONCLUSIONS: These results show that capillary pathology, and in particular prominent capillary BM reduplication, is the hallmark histopathological feature of SM even in patients with early/mild SSc and support the concept of SM as an organ manifestation of SSc and a distinct subset of AIM.

Screening and management of subclinical interstitial lung disease in systemic sclerosis: an international survey.

OBJECTIVE: Interstitial lung disease (ILD) is the leading cause of mortality in SSc. Experts now recommend high-resolution CT (HRCT) screening in all SSc patients and treatment of subclinical ILD in SSc patients with high-risk phenotypes. We undertook an international survey to understand current screening and treatment practices in subclinical SSc-ILD. METHODS: An electronic REDCap survey was distributed to 611 general rheumatologists, 348 national and international SSc experts, 285 general respirologists and 57 ILD experts. RESULTS: One hundred and ninety-eight participants responded to the survey, including 135 (68%) rheumatologists and 54 (27%) respirologists. Over half (59%) of respondents routinely ordered HRCTs in all newly diagnosed SSc patients, although this practice was more common in Europe (83%), the USA (68%), Asia (73%) and Latin America (100%) compared with Canada (40%) and Australia (40%). Nearly half (48%) of respondents would not treat subclinical SSc-ILD, whereas 52% would treat or consider treatment. At least 70% would likely treat subclinical ILD in the setting of diffuse SSc, anti-topoisomerase-I autoantibodies, disease duration below 18 months, ground-glass opacities, oxygen desaturation, or significant ILD progression on imaging or pulmonary function tests. The majority (67%) of respirologists would not treat subclinical ILD. MMF was the preferred first-line drug for the treatment of subclinical SSc-ILD. CONCLUSION: This international survey highlights important regional variations in SSc-ILD screening and significant heterogeneity among rheumatologists and respirologists in the treatment of subclinical SSc-ILD. High-quality research addressing these questions is needed to produce evidence-based guidelines and harmonize the approach to identification and treatment of subclinical SSc-ILD.

Association between autoantibodies in systemic sclerosis and cancer in a national registry.

OBJECTIVE: A close temporal relationship between SSc onset and cancer has been reported in anti-RNA polymerase III-positive patients. We investigated the association between cancer and other SSc autoantibodies in a national SSc registry. METHODS: SSc patients enrolled in the Canadian Scleroderma Research Group registry from 2004 to 2019 were characterized according to autoantibodies to centromere, topoisomerase I/Scl70, RNA polymerase III, fibrillarin, Th/To (hPOP1), PM/Scl, Ku, NOR90, Ro52/TRIM21 and U1RNP. Logistic regression was used to examine the association between a close cancer-SSc interval and autoantibody status, adjusted for age, sex, race and smoking history. RESULTS: Of 1698 SSc patients, 1481 (87%) had available autoantibody data. Cancer was diagnosed within 2, 3 and 5 years of the first non-Raynaud manifestation in 1.3%, 2.1% and 3.5% of patients. The most frequent cancers diagnosed within 2 years were breast (33%), gynaecological (19%) and haematological (14%) cancers. The risk of cancer within 2 years was increased among anti-topoisomerase I [odds ratio (OR) 3.43, 95% CI: 1.04, 10.05] and anti-U1-RNP-positive patients (OR 5.54, 95% CI: 1.16, 20.40), but not with anti-RNA polymerase III. None of the anti-fibrillarin, Th/To, PM/Scl, Ku and NOR90-positive patients had cancer within 2 years. Patients with anti-centromere or none of the tested autoantibodies had numerically lower risks of developing cancer within two years. CONCLUSION: Synchronous cancer was rare in this large cohort of predominantly female and White SSc patients. The risk of cancer within 2 years was increased among anti-topoisomerase I and anti-U1-RNP-positive patients. Screening strategies guided by autoantibodies require further careful consideration.

Risk of rheumatic disease in breast implant users: a qualitative systematic review.

BACKGROUND: Recent studies on the risk of rheumatic disease among breast implant users have reported conflicting results. The primary objective of this study was to provide a systematic and critical review of the literature on the association between breast implants and the risk of rheumatic disease. METHODS: A qualitative systematic review was conducted in PubMed, MEDLINE, EMBASE, EBM-Reviews and CINAHL Complete from database inception to June 23rd, 2021. Eligible papers were full-length articles in English or French reporting original data on the incident risk of rheumatic disease among individuals with and without breast implants. Data were extracted from published reports and appraised using the Newcastle-Ottawa scale. The main outcome was incident risk of systemic sclerosis (SSc), Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), fibromyalgia and other rheumatic disorders and symptoms. RESULTS: Out of 3,425 identified citations, 86 met inclusion criteria. Two cohort studies suggested a two-fold increase in risk of SSc, whereas three case-control studies showed no increase in risk. Three cohort studies did not find an increased risk of incident and confirmed SS among breast implant users, however symptoms of sicca, myalgia and fatigue were reported more frequently. A meta-analysis of heterogenous studies reported a less than two-fold increase in risk of RA. Studies did not support an association with SLE. Insufficient evidence was available for autoimmune myositis and other rheumatic diseases. Implant rupture detected on imaging was not clearly associated with incident rheumatic disease, although no studies specifically examined the risk associated with acute/traumatic rupture. Little data was available on the safety of saline breast implants. Explantation often led to temporary improvement. CONCLUSIONS: Based on a small number of high-quality and methodologically robust studies, an association between breast implants and a small increase in risk of SSc and RA could not be excluded. Symptoms of sicca, myalgia and fatigue were reported more frequently among breast implant users. Overall, there remains much uncertainty in regard to the association between breast implants and the risk of incident rheumatic diseases. Individuals considering the placement of breast implants should be informed of this uncertainty. TRIAL REGISTRATION: This study was registered in the PROSPERO database (#CRD42019133616).

Immunosuppression does not prevent severe gastrointestinal tract involvement in systemic sclerosis.

OBJECTIVES: We aimed to test the hypothesis that exposure to immunosuppression in early systemic sclerosis (SSc) could modify the risk of developing new onset severe gastrointestinal (GIT) involvement. METHODS: A total of 762 subjects with <3 years of disease duration and without severe GIT disease at baseline study visit were identified from combined longitudinal cohort data from the Canadian Scleroderma Research Group (CSRG) and Australian Scleroderma Interest Group (ASIG). The primary exposure was ever use of methotrexate, cyclophosphamide, mycophenolate mofetil and/or azathioprine during the study period. Severe GIT disease was defined as: 1-malabsorption, 2-hyperalimentation, 3-pseudo-obstruction, and/or 4-≥10% weight loss in association with the use of antibiotics for bacterial overgrowth or oesophageal stricture. The change in the hazard of severe GIT disease due to exposure was estimated using a marginal structural Cox proportional hazards model fit by inverse probability of treatment weights (IPTW) to address potential confounding. RESULTS: Study subjects were 81.5% female, had a mean age of 53.7±13.0 years and mean disease duration at baseline of 1.4±0.8 years. During a mean follow-up of 4.0±2.6 years, severe GIT involvement developed in 11.6% of the 319 subjects exposed to immunosuppression and in 6.8% of the 443 unexposed subjects. In an IPTW-adjusted analysis, exposure to immunosuppression was not associated with severe GIT disease (weighted hazard ratio 0.91, 95% confidence interval 0.52-1.58). CONCLUSIONS: In this large inception SSc cohort, the risk of severe GIT involvement was not modified by exposure to immunosuppression.

Association between gastroprotective agents and risk of incident interstitial lung disease in systemic sclerosis.

OBJECTIVES: Although interstitial lung disease (ILD) occurs in over half of systemic sclerosis (SSc) patients and represents a leading cause of mortality, there are currently no preventative strategies. We evaluated if gastroprotective agents were associated with a lower incident risk of SSc-ILD. METHODS: An SSc cohort without clinically apparent ILD at baseline was constructed from the Canadian Scleroderma Research Group registry. The primary exposure was any use of gastroprotective agents. Treatment with promotility agents was assessed as a secondary exposure. Time to development of clinically apparent ILD was compared between exposed and unexposed person-time, using a multivariable marginal structural Cox model incorporating inverse probability of treatment weights to address time-varying confounding. RESULTS: In total, 798 subjects met inclusion criteria. At cohort entry, median disease duration was 7.6 (IQR 3.9-15.6) years. During a median 4.4 (IQR 2.6-7.2) years of follow-up, 158 new ILD cases were diagnosed, for a crude incidence of 4.4 (95% CI 3.8-5.1) events per 100 person-years. Most (2085, 73.4%) person-visits were exposed to gastroprotective agents, 579 (20.4%) were exposed to promotility agents, and 554 (19.5%) were exposed to both agents. The marginal structural weighted hazard ratio (HR) for incident ILD related to gastroprotective agents was 0.86 (95% CI 0.52-1.41). When exposure was defined as treatment with promotility agents, the weighted adjusted HR was 0.79 (95% CI: 0.35-1.77). CONCLUSION: In this large retrospective cohort study, we were unable to demonstrate a protective role for gastroprotective and promotility agents in preventing clinically apparent SSc-ILD.

Histopathological features of systemic sclerosis-associated myopathy: A scoping review.

BACKGROUND: Scleromyositis (SM) is an emerging subset of myositis associated with features of systemic sclerosis (SSc) but it is currently not recognized as a distinct histopathological subset by the European NeuroMuscular Center (ENMC). Our aim was to review studies reporting muscle biopsies from SSc patients with myositis and to identify unique histopathological features of SM. METHODS: A scoping review was conducted and included all studies reporting histopathological findings in SSc patients with myositis searching the following databases: PubMed, MEDLINE, EMBASE, CINAHL and EBM-Reviews. Clinical, serological, and histopathological data were extracted using a standardized protocol. RESULTS: Out of 371 citations, 77 studies that included 559 muscle biopsies were extracted. Fifty-seven percent (n = 227/400) had inflammatory infiltrates, predominantly T cells, which were endomysial (49%), perimysial (42%) and perivascular (41%). Few studies (18%, n = 8/44) evaluated the presence of B-cells. Myofiber atrophy was present in 48% (n = 104/218) of biopsies, and was predominantly perifascicular in 19% (n = 6/31), with necrosis reported in 56% (n = 162/290) of cases. Sarcolemmal MHC-I upregulation was found in 72% (n = 64/89) of biopsies. Non-specified C5b-9 deposition was described in 39% of muscle biopsies (n = 28/72). Neurogenic features were present in 23% (n = 44/191); endomysial fibrosis was reported in 35% (n = 120/340); and rimmed vacuoles were observed in 32% (n = 11/34) of biopsies. Capillaropathy, such as capillary dropout and/or ultrastructural endothelial abnormalities, was reported in 33% (n = 43/129) of cases. Reported ENMC categories were mainly polymyositis (21%), non-specific myositis (19%), immune-mediated necrotizing myopathy (16%), and dermatomyositis (8%). Histopathological features were analyzed according to serological subtypes in 28 studies, including anti-PM-Scl (n = 48), -Ku (n = 23) and -U1RNP (n = 90). Most of these biopsies demonstrated inflammatory infiltrates (range 49-85%) as well as MHC-I expression (range 63-81%). Necrosis was associated with anti-Ku (85%) and anti-U1RNP (73%), while anti-Ku was also associated with neurogenic features and rimmed vacuoles in 57% and 25% of cases, respectively. CONCLUSION: Our review suggests that SM is characterized by heterogeneous pathological features using definitions included in current histopathological criteria. Whether a distinct histopathological signature exists in SM remains to be determined. SSc-specific and SSc-associated autoantibodies may help define more homogeneous histopathological subsets.

Preexisting autoimmune disease and immune-related adverse events associated with anti-PD-1 cancer immunotherapy: a national case series from the Canadian Research Group of Rheumatology in Immuno-Oncology.

BACKGROUND: Limited data are available on the safety and efficacy of immune checkpoint inhibitors (ICI) in patients with preexisting autoimmune diseases (PAD). METHODS: Retrospective study of patients with PAD referred for rheumatologic evaluation prior to starting or during immunotherapy between January 2013 and July 2019 from 10 academic sites across Canada. Data were extracted by chart review using a standardized form. RESULTS: Twenty-seven patients with PAD on ICI therapy were identified. The most common PADs were rheumatoid arthritis (30%), psoriasis/psoriatic arthritis (30%), inflammatory bowel disease (IBD, 15%) and axial spondyloarthritis (11%), and the most frequently observed cancers were lung cancer and melanoma. All patients received anti-PD-1 therapies, and 2 received additional sequential anti-CTLA-4 therapy. PAD exacerbations occurred in 52% over a median (IQR) follow-up of 11.0 (6.0-17.5) months, with 14% being severe, 57% requiring corticosteroids, 50% requiring immunosuppression and 14% requiring ICI discontinuation. Flares were generally more frequent and severe in patients who previously required more intensive immunosuppression (i.e., biologics). Flares occurred despite background immunosuppression at the time of ICI initiation. In patients with preexisting psoriasis, IBD and axial spondyloarthritis, rheumatic immune-related adverse events (irAEs), mostly polyarthritis and tenosynovitis, were frequently observed. Tumor progression was not associated with exposure to immunosuppressive drugs before or after ICI initiation and was numerically less frequent in patients with irAEs. CONCLUSION: PAD exacerbations in the context of ICI treatment are common, although generally mild, and occur despite background immunosuppression. Exacerbations are more frequent and severe in patients on more intensive immunosuppressive therapies pre-immunotherapy.

Mortality and morbidity in scleroderma renal crisis: A systematic literature review.

Objectives: The objective of this study was to systematically review the mortality and morbidity associated with scleroderma renal crisis and to determine temporal trends. Methods: We searched MEDLINE, Embase and the Cochrane Database of Systematic Reviews from database inception to 10 February 2020. Bibliographies of selected articles were hand-searched for additional references. Data were extracted using a standardized extraction form. Study quality was assessed using the Newcastle-Ottawa scale. Results were analysed qualitatively. Results: Twenty studies with 14,059 systemic sclerosis subjects, of which 854 had scleroderma renal crisis and 4095 had systemic sclerosis-associated end-stage renal disease, met inclusion criteria. Study quality was generally moderate. Cumulative mortality in the post-angiotensin-converting enzyme inhibitor era was approximately 20% at 6 months, 30%-36% at 1 year, 19%-40% at 3 years and almost 50% at 10 years from scleroderma renal crisis onset. Although the introduction of angiotensin-converting enzyme inhibitors in the early 1970s resulted in a 50% improvement in scleroderma renal crisis mortality, there was no further improvement thereafter. Scleroderma renal crisis mortality rates were proportionally higher than mortality rates associated with other systemic sclerosis organ involvement. The rate of permanent dialysis after scleroderma renal crisis in the post-angiotensin-converting enzyme inhibitor era ranged from 19%-40%. Three to 17% of systemic sclerosis patients underwent renal transplant. Survival was better in patients post-renal transplant (54%-91%) compared to those on dialysis (31%-56%). Graft survival improved over time and appeared similar to that of patients with other types of end-stage renal disease. Conclusion: While there has been considerable improvement in scleroderma renal crisis-related outcomes since the introduction of angiotensin-converting enzyme inhibitors, morbidity and mortality remain high for affected patients without convincing evidence of further improvement in the post-angiotensin-converting enzyme inhibitor era. Novel treatments are required to improve outcomes of scleroderma renal crisis.

Recognising the spectrum of scleromyositis: HEp-2 ANA patterns allow identification of a novel clinical subset with anti-SMN autoantibodies.

OBJECTIVE: To describe systemic sclerosis (SSc) with myopathy in patients without classic SSc-specific and SSc-overlap autoantibodies (aAbs), referred to as seronegative scleromyositis. METHODS: Twenty patients with seronegative scleromyositis diagnosed by expert opinion were analysed retrospectively for SSc features at myositis diagnosis and follow-up, and stratified based on HEp-2 nuclear patterns by indirect immunofluorescence (IIF) according to International Consensus of Autoantibody Patterns. Specificities were analysed by protein A-assisted immunoprecipitation. Myopathy was considered an organ involvement of SSc. RESULTS: SSc sine scleroderma was a frequent presentation (45%) at myositis diagnosis. Myositis was the most common first non-Raynaud manifestation of SSc (55%). Lower oesophagal dysmotility was present in 10 of 11 (91%) investigated patients. At follow-up, 80% of the patients met the American College of Rheumatology/EULAR SSc classification criteria. Two-thirds of patients had a positive HEp-2 IIF nuclear pattern (all with titers ≥1/320), defining three novel scleromyositis subsets. First, antinuclear antibody (ANA)-negative scleromyositis was associated with interstitial lung disease (ILD) and renal crisis. Second, a speckled pattern uncovered multiple rare SSc-specific aAbs. Third, the nuclear dots pattern was associated with aAbs to survival of motor neuron (SMN) complex and a novel scleromyositis subset characteriszed by calcinosis but infrequent ILD and renal crisis. CONCLUSIONS: SSc skin involvement is often absent in early seronegative scleromyositis. ANA positivity, Raynaud phenomenon, SSc-type capillaroscopy and/or lower oesophagal dysmotility may be clues for scleromyositis. Using HEp-2 IIF patterns, three novel clinicoserological subsets of scleromyositis emerged, notably (1) ANA-negative, (2) ANA-positive with a speckled pattern and (3) ANA-positive with nuclear dots and anti-SMN aAbs.

Rheumatic immune-related adverse events associated with cancer immunotherapy: A nationwide multi-center cohort.

OBJECTIVE: Although immune checkpoint inhibitors (ICI) have revolutionized cancer therapy, their use is associated with immune toxicities referred to as immune-related adverse events (irAE). Here we describe the clinical presentation and management of rheumatic immune-related adverse events (Rh-irAE) in a national multi-center cohort. METHODS: All patients presenting with Rh-irAE at 9 academic sites across Canada between January 2013 and January 2019 were identified and included in this retrospective cohort study. Standardized data were extracted by chart review. RESULTS: 117 patients who developed 136 Rh-irAE were identified. The most frequent Rh-irAE was symmetric polyarthritis (n = 45). Other Rh-irAE included non-inflammatory musculoskeletal symptoms (n = 18), polymyalgia rheumatica (n = 17) and myositis (n = 9). Prednisone was the most commonly used treatment (n = 76) with a mean maximum dose of 60 ± 74 mg/d and duration of treatment of 8.4 ± 11 months. Forty-two patients required conventional synthetic disease-modifying anti-rheumatic drugs (DMARD) and two required biologic DMARD to control the Rh-irAE. ICI was discontinued due to the Rh-irAE in 22 patients. There were no deaths related to Rh-irAE. Treatment of the Rh-irAE did not appear to negatively impact the tumor response to immunotherapy with 23 patients experiencing tumor progression prior to treatment of the Rh-irAE and 13 following treatment. CONCLUSION: In this largest multi-center cohort of Rh-irAE described to date, symmetric polyarthritis was the most common Rh-irAE. There was considerable heterogeneity of treatment, although this did not appear to negatively impact the anti-tumor response. This study can inform the development of evidence-based recommendations to optimize Rh-irAE and cancer outcomes in patients treated with ICI.

Statin-induced anti-HMGCR myopathy: successful therapeutic strategies for corticosteroid-free remission in 55 patients.

OBJECTIVE: To describe successful therapeutic strategies in statin-induced anti-HMGCR myopathy. METHODS: Retrospective data from a cohort of 55 patients with statin-induced anti-HMGCR myopathy, sequentially stratified by the presence of proximal weakness, early remission, and corticosteroid and IVIG use at treatment induction, were analyzed for optimal successful induction and maintenance of remission strategies. RESULTS: A total of 14 patients achieved remission with a corticosteroid-free induction strategy (25%). In 41 patients treated with corticosteroids, only 4 patients (10%) failed an initial triple steroid/IVIG/steroid-sparing immunosuppressant (SSI) induction strategy. Delay in treatment initiation was independently associated with lower odds of successful maintenance with immunosuppressant monotherapy (OR 0.92, 95% CI 0.85 to 0.97, P = 0.015). While 22 patients (40%) presented with normal strength, only 9 had normal strength at initiation of treatment. CONCLUSION: While corticosteroid-free treatment of anti-HMGCR myopathy is now a safe option in selected cases, initial triple steroid/IVIG/SSI was very efficacious in induction. Delays in treatment initiation and, as a corollary, delays in achieving remission decrease the odds of achieving successful maintenance with an SSI alone. Avoiding such delays, most notably in patients with normal strength, may reset the natural history of anti-HMGCR myopathy from a refractory entity to a treatable disease.

Pathogenic roles of autoantibodies in systemic sclerosis: Current understandings in pathogenesis.

The potential pathogenic role for autoantibodies in systemic sclerosis has captivated researchers for the past 40 years. This review answers the question whether there is yet sufficient knowledge to conclude that certain serum autoantibodies associated with systemic sclerosis contribute to its pathogenesis. Definitions for pathogenic, pathogenetic and functional autoantibodies are formulated, and the need to differentiate these autoantibodies from natural autoantibodies is emphasized. In addition, seven criteria for the identification of pathogenic autoantibodies are proposed. Experimental evidence is reviewed relevant to the classic systemic sclerosis antinuclear autoantibodies, anti-topoisomerase I and anticentromere, and to functional autoantibodies to endothelin 1 type A receptor, angiotensin II type 1 receptor, muscarinic receptor 3, platelet-derived growth factor receptor, chemokine receptors CXCR3 and CXCR4, estrogen receptor α, and CD22. Pathogenic evidence is also reviewed for anti-matrix metalloproteinases 1 and 3, anti-fibrillin 1, anti-IFI16, anti-eIF2B, anti-ICAM-1, and anti-RuvBL1/RuvBL2 autoantibodies. For each autoantibody, objective evidence for a pathogenic role is scored qualitatively according to the seven pathogenicity criteria. It is concluded that anti-topoisomerase I is the single autoantibody specificity with the most evidence in favor of a pathogenic role in systemic sclerosis, followed by anticentromere. However, these autoantibodies have not been demonstrated yet to fulfill completely the seven proposed criteria for pathogenicity. Their contributory roles to the pathogenesis of systemic sclerosis remain possible but not yet conclusively demonstrated. With respect to functional autoantibodies and other autoantibodies, only a few criteria for pathogenicity are fulfilled. Their common presence in healthy and disease controls suggests that major subsets of these immunoglobulins are natural autoantibodies. While some of these autoantibodies may be pathogenetic in systemic sclerosis, establishing that they are truly pathogenic is a work in progress. Experimental data are difficult to interpret because high serum autoantibody levels may be due to polyclonal B-cell activation. Other limitations in experimental design are the use of total serum immunoglobulin G rather than affinity-purified autoantibodies, the confounding effect of other systemic sclerosis autoantibodies present in total immunoglobulin G and the lack of longitudinal studies to determine if autoantibody titers fluctuate with systemic sclerosis activity and severity. These intriguing new specificities expand the spectrum of autoantibodies observed in systemic sclerosis. Continuing elucidation of their potential mechanistic roles raises hope of a better understanding of systemic sclerosis pathogenesis leading to improved therapies.

Association between immunosuppressive therapy and course of mild interstitial lung disease in systemic sclerosis.

OBJECTIVE: Interstitial lung disease (ILD) is a leading cause of mortality in SSc. Little is known about the benefits of immunosuppressive drugs in mild ILD. Our aim was to determine whether use of CYC or MMF was associated with an improved ILD course in patients with normal or mildly impaired lung function. METHODS: A retrospective cohort of SSc subjects with ILD, disease duration below seven years and no exposure to CYC or MMF prior to the baseline visit was constructed from the Canadian Scleroderma Research Group registry. Subjects were categorized as having mild ILD if baseline forced vital capacity (FVC % predicted) was >85%. The primary exposure was any use of CYC or MMF at the baseline visit. FVC at one year was compared between exposed and unexposed subjects, using multivariate linear regression. RESULTS: Out of 294 eligible SSc-ILD subjects, 116 met criteria for mild ILD. In this subgroup, mean (s.d.) disease duration was 3.7 (2.0) years. Thirteen (11.2%) subjects were exposed to CYC or MMF at baseline. The one-year FVC was higher in exposed subjects compared with unexposed subjects, by a difference of 8.49% (95% CI: 0.01-16.98%). None of the exposed subjects experienced clinically meaningful progression over two years, whereas 24.6% of unexposed subjects did. CONCLUSION: In this real-world setting, CYC/MMF exposure at baseline was associated with higher FVC values and a lower risk of progression among subjects with mild ILD. These data suggest a window of opportunity to preserve lung function in SSc-ILD.

Generation of a Core Set of Items to Develop Classification Criteria for Scleroderma Renal Crisis Using Consensus Methodology.

OBJECTIVE: To generate a core set of items to develop classification criteria for scleroderma renal crisis (SRC) using consensus methodology. METHODS: An international, multidisciplinary panel of experts was invited to participate in a 3-round Delphi exercise developed using a survey based on items identified by a scoping review. In round 1, participants were asked to identify omissions and clarify ambiguities regarding the items in the survey. In round 2, participants were asked to rate the validity and feasibility of the items using Likert-type scales ranging from 1 to 9 (where 1 = very invalid/unfeasible, 5 = uncertain, and 9 = very valid/feasible). In round 3, participants reviewed the results and comments from round 2 and were asked to provide final ratings. Items rated as highly valid and feasible (median scores ≥7 for each) in round 3 were selected as the provisional core set of items. A consensus meeting using a nominal group technique was conducted to further reduce the core set of items. RESULTS: Ninety-nine experts from 16 countries participated in the Delphi exercise. Of the 31 items in the survey, consensus was achieved on 13, in the categories hypertension, renal insufficiency, proteinuria, and hemolysis. Eleven experts took part in the nominal group technique discussion, where consensus was achieved in 5 domains: blood pressure, acute kidney injury, microangiopathic hemolytic anemia, target organ dysfunction, and renal histopathology. CONCLUSION: A core set of items that characterize SRC was identified using consensus methodology. This core set will be used in future data-driven phases of this project to develop classification criteria for SRC.

Pulmonary function tests as outcomes for systemic sclerosis interstitial lung disease.

Interstitial lung disease (ILD) is the leading cause of morbidity and mortality in systemic sclerosis (SSc). We performed a systematic review to characterise the use and validation of pulmonary function tests (PFTs) as surrogate markers for systemic sclerosis-associated interstitial lung disease (SSc-ILD) progression.Five electronic databases were searched to identify all relevant studies. Included studies either used at least one PFT measure as a longitudinal outcome for SSc-ILD progression (i.e. outcome studies) and/or reported at least one classical measure of validity for the PFTs in SSc-ILD (i.e. validation studies).This systematic review included 169 outcome studies and 50 validation studies. Diffusing capacity of the lung for carbon monoxide (DLCO) was cumulatively the most commonly used outcome until 2010 when it was surpassed by forced vital capacity (FVC). FVC (% predicted) was the primary endpoint in 70.4% of studies, compared to 11.3% for % predicted DLCO Only five studies specifically aimed to validate the PFTs: two concluded that DLCO was the best measure of SSc-ILD extent, while the others did not favour any PFT. These studies also showed respectable validity measures for total lung capacity (TLC).Despite the current preference for FVC, available evidence suggests that DLCO and TLC should not yet be discounted as potential surrogate markers for SSc-ILD progression.

Towards developing criteria for scleroderma renal crisis: A scoping review.

OBJECTIVE: The absence of a gold standard for scleroderma renal crisis (SRC) has hindered our understanding of this problem. The objective of this scoping review was to identify the criteria used to define SRC in order to guide the development of a consensus definition for SRC. METHODS: We conducted a search in three databases: Medline, Embase and non-Ovid Pubmed. Papers were eligible for inclusion if they were full-length articles in English whose main topic was SRC or scleroderma renal disease. Two reviewers independently screened eligible papers for final study selection. Data was extracted using a customized form. A web-based survey of members of the Scleroderma Clinical Trials Consortium was used to identify unpublished definitions of SRC. RESULTS: We identified 415 papers that met inclusion criteria. Forty original definitions of SRC were identified from 36 studies, 9 reviews and 2 editorials. There was significant heterogeneity in definitions. As a rule, though, in addition to new-onset hypertension and acute kidney injury, other common items used to define SRC included hypertensive encephalopathy and seizures, microangiopathic hemolytic anemia and characteristic changes on kidney biopsy. The web-based survey identified unpublished definitions of SRC that were largely consistent with the results of the published literature. CONCLUSION: SRC was defined in a minority of studies and criteria were heterogeneous. A consensus definition of SRC is urgently needed to standardize data collection on SRC and further our understanding of this serious problem.