Screening for interstitial lung disease in systemic sclerosis: performance of high-resolution CT with limited number of slices: a prospective study

The Value of Ultrasound for Detecting and Following Subclinical Interstitial Lung Disease in Systemic Sclerosis

BACKGROUND

Interstitial lung disease (ILD) is a complication in patients with systemic sclerosis (SSc). Accurate strategies to identify its presence in early phases are essential. We conducted the study aiming to determine the validity of ultrasound (US) in detecting subclinical ILD in SSc, and to ascertain its potential in determining the disease progression.

METHODS

133 patients without respiratory symptoms and 133 healthy controls were included. Borg scale, Rodnan skin score (RSS), auscultation, chest radiographs, and respiratory function tests (RFT) were performed. A rheumatologist performed the lung US. High-resolution CT (HRCT) was also performed. The patients were followed every 12 weeks for 48 weeks.

RESULTS

A total of 79 of 133 patients (59.4%) showed US signs of ILD in contrast to healthy controls (4.8%) (p = 0.0001). Anti-centromere antibodies (p = 0.005) and RSS (p = 0.004) showed an association with ILD. A positive correlation was demonstrated between the US and HRCT findings (p = 0.001). The sensitivity and specificity of US in detecting ILD were 91.2% and 88.6%, respectively. In the follow-up, a total of 30 patients out of 79 (37.9%) who demonstrated US signs of ILD at baseline, showed changes in the ILD score by US.

CONCLUSIONS

US showed a high prevalence of subclinical ILD in SSc patients. It proved to be a valid, reliable, and feasible tool to detect ILD in SSc and to monitor disease progression.

KL6 and IL-18 levels are negatively correlated with respiratory function tests and ILD extent assessed on HRCT in patients with systemic sclerosis-related interstitial lung disease (SSc-ILD)

BACKGROUND

Interstitial lung disease (ILD) is one of the leading causes of mortality in patients with systemic sclerosis (SSc). Serum biomarkers have been suggested as indicators for pulmonary damage with clinical value in the diagnosis and prognosis of SSc-ILD.

OBJECTIVES

To investigate the role of serum biomarkers (Krebs von den Lungen-6 KL-6, IL-18 and IL-18BP) as a potential biomarker reflecting the severity of SSc-ILD as assessed through high-resolution computed tomography (HRCT) and pulmonary function tests (PFT), including forced vital capacity (%FVC) and diffusing capacity of the lung for carbon monoxide (%DLCO).

METHODS

A cross-sectional study including patients with SSc fulfilling the 2013 ACR/EULAR criteria was performed. Patients were classified according to disease duration and pulmonary involvement (presence of ILD). All SSc patients underwent chest HRCT scans and pulmonary function test at baseline. Serum concentration of KL-6, IL8 and IL18BP were determined using the quantitative ELISA technique, sandwich type (solid phase sandwich Enzyme Linked-Immuno-Sorbent Assay), with kits from MyBiosource for KL-6 and from Invitrogen for IL18 and IL18BP. A semiquantitative grade of ILD extent was evaluated through HRCT scan (grade 1, 0-20%; grade 2, >20%). Extensive disease was defined as >20% lung involvement on HRCT, and FVC <70% predicted and limited lung involvement as ≤20% ILD involvement on HRCT, and an FVC ≥70% predicted.

RESULTS

74 patients were included, 27% were male. The mean age at diagnosis was 57.5±15 years and the mean time since diagnosis was 7.67±8 years. 28 patients had ILD (38%). 64% of patients had <20% ILD extent classified through HRCT scan. SSc-ILD patients had elevated serum KL-6 and IL-18 levels compared to patients without ILD (p=0.003 and p=0.04), and those findings were preserved after adjusting for age and sex. Negative correlation between KL-6 levels and%FVC (β=-0.25, p 0.037) and% DLCO (β=-0.28, p 0.02) and between IL-18 levels and%FVC (β=-0.38, p 0.001) and%DLCO (β=-0.27, p 0.03) were found. Serum KL-6 and IL-18 levels successfully differentiated grades 1 and 2 of the semiquantitative grades of ILD extent (p = 0.028 and p = 0.022). Semiquantitative grades of ILD on the HRCT scan were significantly proportional to the KL-6 (p = 0.01) and IL-18 (p = 0.03). A positive correlation between extensive lung disease and KL-6 (β=0.42, p = 0.007) but not with IL-18 was found.

CONCLUSIONS

Serum KL-6 levels and IL-18 were increased in patients with SSc-ILD and showed a positive correlation with ILD severity as measured using a semiquantitative CT grading scale and negative correlation with PFT parameters. Serum KL-6 and IL-18 could be a clinically useful biomarker in screening and evaluating SSc-ILD.

Prevalence of the limited vs. extensive scleroderma-related interstitial lung disease at the time of diagnosis of SSc-ILD based on Goh et al. criteria. Systematic review and meta-analysis

INTRODUCTION

Goh et al. proposed in 2008 a classificatory algorithm of limited or extensive SSc-ILD. The prevalence of both at the time of diagnosis of SSc-ILD is not known with exactitude.

METHODS

The review was undertaken by means of MEDLINE and SCOPUS from 2008 to 2023 and using the terms: "systemic", "scleroderma" or "interstitial lung disease" [MesH]. The Newcastle-Ottawa Scale was used for the qualifying assessment for observational studies and the Jadad scale for clinical trials. The inverse variance-weighted method was performed.

RESULTS

Twenty-seven studies were initially included in the systematic review and meta-analysis (SRMA). Of these, 17 studies had no overlapping data. They reported data from 2,149 patients, 1,369 (81.2%) were female. The mean age was 52.4 (SD 6.6) years. 45.2% of the patients had the diffuse subtype and 54.8% had the limited or sine scleroderma subtype. A total of 38.7% of the patients showed positive antitopoisomerase antibodies (ATA) and 14.2% positive anticentromere antibodies (ACA). The mean percentage of forced vital capacity (FVC) at baseline was 80.5% (SD 6.9) and of diffusing capacity of the lungs for carbon monoxide (DLco) was 59.1% (SD 9.6). Twelve studies presented SSc-ILD extension data adjusted for PFTs and were included in the meta-analysis. The 10 observational cohort studies were analyzed separately. The overall percentage of limited extension was estimated at 63.5% (95%CI 55.3-73; p < 0.001) using the random-effects model. Heterogeneity between studies (I2) was 9.8% (95%CI 0-68.2%) with the random-effects model. Extensive pulmonary involvement was estimated at 34.3% (95%CI 26-45.4; p < 0.001). Heterogeneity between studies (I2) was 0% (95%CI 0-61.6%) with the random-effects model.

CONCLUSION

The overall percentage of limited SSc-ILD at the time of diagnosis of SSc-ILD was estimated at 63.5% and extensive at 34.3%.

Histogram-Based Densitometry Index to Assess the Severity of Interstitial Lung Disease in Systemic Sclerosis in Standard and Low-Dose Computed Tomography

OBJECTIVE

Mean lung attenuation, skewness, and kurtosis are histogram-based densitometry variables that quantify systemic sclerosis-associated interstitial lung disease (SSc-ILD) and were recently merged into a computerized integrated index (CII). Our work tested the CII in low-dose 9-slice (reduced) and standard high-resolution computed tomography (CT) scans to evaluate extensive SSc-ILD and predict mortality.

METHODS

CT scans from patients with SSc-ILD were assessed using the software Horos to compute standard and reduced CIIs. Extensive ILD was determined following the Goh staging system. The association between CIIs and extensive ILD was analyzed with a generalized estimating equation regression model, the predictive ability of CIIs by the area under the receiver-operation characteristic curve (AUC), and the association between CIIs and death by Kaplan-Meier analysis.

RESULTS

Among 243 patients with standard and reduced CT scans available, 157 CT scans from 119 patients with SSc-ILD constituted the derivation cohort. The validation cohort included 116 standard and 175 reduced CT scans. Both CIIs from standard (odds ratio [OR] 0.53, 95% CI 0.37-0.75; AUC 0.77, 95% CI 0.68-0.87) and reduced CT scans (OR 0.54, 95% CI 0.35-0.82; AUC 0.78, 95% CI 0.70-0.87) were significantly associated with extensive ILD. A threshold of CII ≤ -0.96 for standard CT scans and CII ≤ -1.85 for reduced CT scans detected extensive ILD with high sensitivity in both derivation and validation cohorts. Extensive ILD according to Goh staging (OR 2.94, 95% CI 1.10-7.82) and standard CII ≤ -0.96 (OR 1.78, 95% CI 1.24-2.56) significantly predicted mortality; a marginal P value was observed for reduced CII ≤ -1.85 (OR 1.27, 95% CI 0.93-1.75).

CONCLUSION

Thresholds for both standard and reduced CII to identify extensive ILD were developed and validated, with an additional association with mortality. CIIs might help in clinical practice when radiology expertise is missing.

Interstitial Lung Disease in Rheumatoid Arthritis: A Review

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder. Although the joints are typically the first area affected in RA, it can also involve extra-articular regions. This article provides an overview on rheumatoid arthritis-associated interstitial lung disease (RA-ILD), a component of the disease manifestations leading to significant morbidity and mortality. Managing these pulmonary symptoms in people with RA poses a number of difficulties for medical professionals. In this review article, we shed light on the prevalence of RA-ILD and the common pulmonary manifestations of RA, while focusing on the evolving pathogenesis concepts that link them to RA's autoimmune cascade. We also address the diagnostic challenges and the available screening modalities that aid in the early recognition and effective management of these pulmonary complications. Furthermore, glucocorticoids, disease-modifying antirheumatic medications, immunosuppressive medications, and biological agents are among the pharmacological approaches that have been explored in this review study.

Systemic sclerosis interstitial lung disease: unmet needs and potential solutions

Systemic sclerosis (SSc), or scleroderma, is a rare, complex, systemic autoimmune disease of unknown aetiology, characterized by high morbidity and mortality often resulting from cardiopulmonary complications such as interstitial lung disease and pulmonary arterial hypertension. Despite substantial progress in unravelling the pathways involved in the pathogenesis of SSc and the increasing number of therapeutic targets tested in clinical trials, there is still no cure for this disease, although several proposed treatments might limit the involvement of specific organs, thereby slowing the natural history of the disease. A specific focus of recent research has been to address the plethora of unmet needs regarding the global management of SSc-related interstitial lung disease, including its pathogenesis, early diagnosis, risk stratification of patients, appropriate treatment regimens and monitoring of treatment response, as well as the definition of progression and predictors of progression and mortality. More refined stratification of patients on the basis of clinical features, molecular signatures, identification of subpopulations with distinct clinical trajectories and implementation of outcome measures for future clinical trials could also improve therapeutic management strategies, helping to avoid poor outcomes related to lung involvement.

Heterogeneity of determining disease severity, clinical course and outcomes in systemic sclerosis-associated interstitial lung disease: a systematic literature review

Objective The course of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is highly variable and different from continuously progressive idiopathic pulmonary fibrosis (IPF). Most proposed definitions of progressive pulmonary fibrosis or SSc-ILD severity are based on the research data from patients with IPF and are not validated for patients with SSc-ILD. Our study aimed to gather the current evidence for severity, progression and outcomes of SSc-ILD.Methods A systematic literature review to search for definitions of severity, progression and outcomes recorded for SSc-ILD was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in Medline, Embase, Web of Science and Cochrane Library up to 1 August 2023.Results A total of 9054 papers were reviewed and 342 were finally included. The most frequent tools used for the definition of SSc-ILD progression and severity were combined changes of carbon monoxide diffusing capacity (DLCO) and forced vital capacity (FVC), isolated FVC or DLCO changes, high-resolution CT (HRCT) extension and composite algorithms including pulmonary function test, clinical signs and HRCT data. Mortality was the most frequently reported long-term event, both from all causes or ILD related.Conclusions The studies presenting definitions of SSc-ILD 'progression', 'severity' and 'outcome' show a large heterogeneity. These results emphasise the need for developing a standardised, consensus definition of severe SSc-ILD, to link a disease specific definition of progression as a surrogate outcome for clinical trials and clinical practice.PROSPERO registration number CRD42022379254.Cite Now.

Impact of radiation dose on the detection of interstitial lung changes and image quality in low-dose chest CT - Assessment in multiple dose levels from a single patient scan

PURPOSE

To assess image quality and detectability of interstitial lung changes using multiple radiation doses from the same chest CT scan of patients with suspected interstitial lung disease (ILD).

METHOD

Retrospective study of consecutive adult patients with suspected ILD receiving unenhanced chest CT as single-energy dual-source acquisition at 100 kVp (Dual-split mode). 67% and 33% of the overall tube current time product were assigned to tube A and B, respectively. 100%-dose was 2.34 ± 0.97 mGy. Five different radiation doses (100%, 67%, 45%, 39%, 33%) were reconstructed from this single acquisition using linear-blending technique. Two blinded radiologists assessed reticulations, ground-glass opacities (GGO) and honeycombing as well as subjective image noise. Percentage agreement (PA) as compared to 100%-dose were calculated. Non-parametric statistical tests were used.

RESULTS

A total of 228 patients were included (61.2 ± 14.6 years,146 female). PA was highest for honeycombing (>96%) and independent of dose reduction (P > 0.8). PA for reticulations and GGO decreased when reducing the radiation dose from 100% to 67% for both readers (reticulations: 83.3% and 93.9%; GGO: 87.7% and 79.8% for reader 1 and 2, respectively). Additional dose reduction did not significantly change PA for both readers (all P > 0.05). Subjective image noise increased with decreasing radiation dose (Spearman Rho of ρ = 0.34 and ρ = 0.53 for reader 1 and 2, respectively, P < 0.001).

CONCLUSIONS

Radiation dose reduction had a stronger impact on subtle interstitial lung changes. Detectability decreased with initial dose reduction indicating that a minimum dose is needed to maintain diagnostic accuracy in chest CT for suspected ILD.

Recent innovations in the screening and diagnosis of systemic sclerosis-associated interstitial lung disease

INTRODUCTION

Interstitial lung disease (ILD) is the leading cause of mortality in patients with systemic sclerosis (SSc). Risk of developing progressive ILD is highest among patients with diffuse cutaneous disease, positive anti-topoisomerase I antibody, and elevated acute phase reactants. With the FDA approval of two medications and a pipeline of novel therapeutics in trials, early recognition and intervention is critical. High-resolution computed tomography of the chest is the current gold standard test for diagnosis of ILD. Yet, it is not offered as a screening tool to all patients due to which ILD can be missed in up to a third of patients. There is a need to develop and validate more innovative screening modalities.

AREAS COVERED

In this review, we provide an overview of screening and diagnosis of SSc-ILD, highlighting the recent innovations particularly the role of soluble serologic, radiomic (quantitative lung imaging, lung ultrasound), and breathomic (exhaled breath analysis) biomarkers in the early detection of SSc-ILD.

EXPERT OPINION

There is remarkable progress in the development of new radiomics and serum biomarkers in diagnosing SSc-ILD. There is an urgent need for conceptualizing and testing composite ILD screening strategies that incorporate these biomarkers.

Viewpoint: a multidisciplinary approach to the assessment of patients with systemic sclerosis-associated interstitial lung disease

Systemic sclerosis (SSc) is a rare and heterogeneous disease affecting the skin and internal organs. SSc-associated ILD (SSc-ILD) is a common and often early manifestation of SSc. This article discusses the rationale for a multidisciplinary approach (MDA) to the early identification and assessment of patients with SSc-ILD. Diagnosis of SSc-ILD is often challenging as patients with early disease can be asymptomatic, and SSc-ILD symptoms, such as exertional dyspnea and cough, are non-specific. High-resolution computed tomography (HRCT) of the lungs is the gold standard for diagnosis of SSc-ILD since pulmonary function tests lack sensitivity and specificity, especially in early disease. On HRCT, most patients with SSc-ILD have a non-specific interstitial pneumonia (NSIP) pattern. In addition, findings of pulmonary hypertension and esophageal dysmotility may be present. The multi-organ involvement of SSc and the diverse spectrum of symptoms support an MDA for the diagnosis and assessment of patients with SSc-ILD, with input from rheumatologists, pulmonologists, gastroenterologists, radiologists, and other specialists. Key Points • Interstitial lung disease (ILD) is a common manifestation of systemic sclerosis (SSc). • Early diagnosis is key to reducing the morbidity and mortality associated with SSc-ILD and other manifestations of SSc. • The multi-organ involvement of SSc supports a multidisciplinary approach to the diagnosis and assessment of patients with SSc-ILD, with input from rheumatologists, pulmonologists, gastroenterologists, radiologists, and other specialists.

Potential of Photon-Counting Detector CT for Radiation Dose Reduction for the Assessment of Interstitial Lung Disease in Patients With Systemic Sclerosis

OBJECTIVE

The aim of this study was to determine the potential of photon-counting detector computed tomography (PCD-CT) for radiation dose reduction compared with conventional energy-integrated detector CT (EID-CT) in the assessment of interstitial lung disease (ILD) in systemic sclerosis (SSc) patients.

METHODS

In this retrospective study, SSc patients receiving a follow-up noncontrast chest examination on a PCD-CT were included between May 2021 and December 2021. Baseline scans were generated on a dual-source EID-CT by selecting the tube current-time product for each of the 2 x-ray tubes to obtain a 100% (D 100 ), a 66% (D 66 ), and a 33% dose image (D 33 ) from the same data set. Slice thickness and kernel were adjusted between the 2 scans. Image noise was assessed by placing a fixed region of interest in the subcutaneous fat. Two independent readers rated subjective image quality (5-point Likert scale), presence, extent, diagnostic confidence, and accuracy of SSc-ILD. D 100 interpreted by a radiologist with 22 years of experience served as reference standard. Interobserver agreement was calculated with Cohen κ, and mean variables were compared by a paired t test.

RESULTS

Eighty patients (mean 56 ± 14; 64 women) were included. Although CTDI vol of PCD-CT was comparable to D 33 (0.72 vs 0.76 mGy, P = 0.091), mean image noise of PCD-CT was comparable to D 100 (131 ± 15 vs 113 ± 12, P > 0.05). Overall subjective image quality of PCD-CT was comparable to D 100 (4.72 vs 4.71; P = 0.874). Diagnostic accuracy was higher in PCD-CT compared with D 33 /D 66 (97.6% and 92.5%/96.3%, respectively) and comparable to D 100 (98.1%).

CONCLUSIONS

With PCD-CT, a radiation dose reduction of 66% compared with EID-CT is feasible, without penalty in image quality and diagnostic performance for the evaluation of ILD.

Influence of CT Image Matrix Size and Kernel Type on the Assessment of HRCT in Patients with SSC-ILD

Background: Interstitial lung disease (ILD) is a frequent complication of systemic sclerosis (SSc), and its early detection and treatment may prevent deterioration of lung function. Different vendors have recently made larger image matrices available as a post-processing option for computed tomography (CT), which could facilitate the diagnosis of SSc-ILD. Therefore, the objective of this study was to assess the effect of matrix size on lung image quality in patients with SSc by comparing a 1024-pixel matrix to a standard 512-pixel matrix and applying different reconstruction kernels. Methods: Lung scans of 50 patients (mean age 54 years, range 23−85 years) with SSc were reconstructed with these two different matrix sizes, after determining the most appropriate kernel in a first step. Four observers scored the images on a five-point Likert scale regarding image quality and detectability of clinically relevant findings. Results: Among the eight tested kernels, the Br59-kernel (sharp) reached the highest score (19.48 ± 3.99), although differences did not reach statistical significance. The 1024-pixel matrix scored higher than the 512-pixel matrix HRCT overall (p = 0.01) and in the subcategories sharpness (p < 0.01), depiction of bronchiole (p < 0.01) and overall image impression (p < 0.01), and lower for the detection of ground-glass opacities (GGO) (p = 0.04). No significant differences were found for detection of extent of reticulations/bronchiectasis/fibrosis (p = 0.50) and image noise (p = 0.09). Conclusions: Our results show that with the use of a sharp kernel, the 1024-pixel matrix HRCT, provides a slightly better subjective image quality in terms of assessing interstitial lung changes, whereby GGO are more visible on the 512-pixel matrix. However, it remains to be answered to what extent this is related to the improved representation of the smallest structures.

The Role of the Multidisciplinary Health Care Team in the Management of Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a rare connective tissue disease characterised by immune dysfunction, vascular damage and fibrosis affecting the skin and multiple internal organs. The clinical spectrum of SSc is wide and its manifestations may lead to severe morbidity and mortality, in addition to a great impact on patients’ quality of life. Due to the multifaceted clinical manifestations of SSc, its management requires a combined expertise of different medical specialists to guarantee an adequate disease control and prevent organ complications. Multi-disciplinary teams (MDT), which are composed by physicians and other specialized health professionals, represent therefore a key element for the comprehensive management of SSc patients. Moreover, MTD can improve communication and patients’ empowerment while the presence of dedicated nurses can help patients to ask questions about their condition. The scope of this narrative review is to analyse the available evidences regarding the role of MDT in the management of SSc patients, and how this holistic approach may improve different disease domains and the overall prognosis. MDT regarding the cardiovascular and lung complication are the more represented in literature, given the great impact in prognosis. Nonetheless, MDT have been shown to be fundamental also in other disease domains as they can intercept early manifestations, thus stratifying patients based on the individual risks in order to personalize patients’ follow-up. MDTs may also minimize the treatment delay, enabling fast-track specialist referral. On the other hand, there are few trials specifically studying MDT in SSc and several authors have highlight the lack of standardization.

Diagnosis and monitoring of systemic sclerosis-associated interstitial lung disease using high-resolution computed tomography

Patients with systemic sclerosis are at high risk of developing systemic sclerosis–associated interstitial lung disease. Symptoms and outcomes of systemic sclerosis–associated interstitial lung disease range from subclinical lung involvement to respiratory failure and death. Early and accurate diagnosis of systemic sclerosis–associated interstitial lung disease is therefore important to enable appropriate intervention. The most sensitive and specific way to diagnose systemic sclerosis–associated interstitial lung disease is by high-resolution computed tomography, and experts recommend that high-resolution computed tomography should be performed in all patients with systemic sclerosis at the time of initial diagnosis. In addition to being an important screening and diagnostic tool, high-resolution computed tomography can be used to evaluate disease extent in systemic sclerosis–associated interstitial lung disease and may be helpful in assessing prognosis in some patients. Currently, there is no consensus with regards to frequency and scanning intervals in patients at risk of interstitial lung disease development and/or progression. However, expert guidance does suggest that frequency of screening using high-resolution computed tomography should be guided by risk of developing interstitial lung disease. Most experienced clinicians would not repeat high-resolution computed tomography more than once a year or every other year for the first few years unless symptoms arose. Several computed tomography techniques have been developed in recent years that are suitable for regular monitoring, including low-radiation protocols, which, together with other technologies, such as lung ultrasound and magnetic resonance imaging, may further assist in the evaluation and monitoring of patients with systemic sclerosis–associated interstitial lung disease. A video abstract to accompany this article is available at: https://www.globalmedcomms.com/respiratory/Khanna/HRCTinSScILD

High-Resolution Computed Tomography: Lights and Shadows in Improving Care for SSc-ILD Patients

The diagnosis and classification of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is essential to improve the prognosis of systemic sclerosis (SSc) patients. The risk-stratification of disease severity and follow-up requires a multidisciplinary approach, integrating high-resolution computed tomography (HRTC) of the lung, pulmonary function tests (PFT), along with clinical and symptomatic evaluations. The use of HRCT in detecting SSc-ILD is not so much based on a definitive validation, but rather reflects the widespread clinician recognition of dissatisfaction with other modalities. However, due to the heterogeneity of SSc-ILD and the potential absence of symptoms in early or mild disease, it is prudent to consider as many parameters as possible in the assessment and monitoring of newly diagnosed patients. An early diagnosis meets the primary goal, i.e., the prevention of disease progression. The current first line treatment regimens are mainly centered on immunosuppressive therapy. This review assesses the role HRCT plays in optimizing care and improving clinical outcomes in SSc-ILD patients.

The role of lung ultrasound B-lines and serum KL-6 in the screening and follow-up of rheumatoid arthritis patients for an identification of interstitial lung disease: review of the literature, proposal for a preliminary algorithm, and clinical application to cases

Screening and follow-up of interstitial lung disease associated with rheumatoid arthritis (RA-ILD) is a challenge in clinical practice. In fact, the majority of RA-ILD patients are asymptomatic and optimal tools for early screening and regular follow-up are lacking. Furthermore, some patients may remain oligosymptomatic despite significant radiological abnormalities. In RA-ILD, usual interstitial pneumonia (UIP) is the most frequent radiological and pathological pattern, associated with a poor prognosis and a high risk to develop acute exacerbations and infections. If RA-ILD can be identified early, there may be an opportunity for an early treatment and close follow-up that might delay ILD progression and improve the long-term outcome.In connective tissue disease-associated interstitial lung disease (CTD-ILD), lung ultrasound (LUS) with the assessment of B-lines and serum Krebs von den Lungen-6 antigen (KL-6) has been recognized as sensitive biomarkers for the early detection of ILD. B-line number and serum KL-6 level were found to correlate with high-resolution computed tomography (HRCT), pulmonary function tests (PFTs), and other clinical parameters in systemic sclerosis-associated ILD (SSc-ILD). Recently, the significant correlation between B-lines and KL-6, two non-ionizing and non-invasive biomarkers, was demonstrated. Hence, the combined use of LUS and KL-6 to screen and follow up ILD in RA patients might be useful in clinical practice in addition to existing tools. Herein, we review relevant literature to support this concept, propose a preliminary screening algorithm, and present 2 cases where the algorithm was used.

Anti-centromere antibody levels and isotypes and the development of systemic sclerosis

Objective

Little is known on the disease course of very early systemic sclerosis (SSc). Among the information yet to be elucidated is whether anticentromere antibody (ACA) isotype levels can serve as biomarkers for future SSc development and for organ involvement. This study was undertaken to evaluate whether IgG, IgM, and IgA ACA levels in IgG ACA–positive patients are associated with disease severity and/or progression from very early SSc to definite SSc.

Methods

IgG ACA–positive patients from 5 different cohorts who had very early SSc or SSc fulfilling the American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) 2013 criteria were included. A diagnosis of very early SSc was based on the presence of IgG ACAs and Raynaud’s phenomenon, and/or puffy fingers and/or abnormal nailfold capillaroscopy, but not fulfilling the ACR/EULAR 2013 criteria for SSc. Multivariable regression analyses were performed to determine the association between baseline ACA isotype levels and progression to definite SSc with organ involvement.

Results

Six hundred twenty‐five IgG ACA–positive patients were included, of whom 138 (22%) fulfilled the criteria for very early SSc and 487 (78%) had definite SSc. Levels of IgG ACAs (odds ratio 2.5 [95% confidence interval 1.8–3.7]) and IgM ACAs (odds ratio 1.8 [95% confidence interval 1.3–2.3]) were significantly higher in patients with definite SSc. Of 115 patients with very early SSc with follow‐up, progression to definite SSc occurred within 5 years in 48 (42%). Progression to definite SSc was associated with higher IgG ACA levels at baseline (odds ratio 4.3 [95% confidence interval 1.7–10.7]).

Conclusion

ACA isotype levels may serve as biomarkers to identify patients with very early SSc who are at risk for disease progression to definite SSc.

The Relationship between Pulmonary Damage and Peripheral Vascular Manifestations in Systemic Sclerosis Patients

Systemic sclerosis (SSc) is an autoimmune disease, characterized by the presence of generalized vasculopathy and tissue fibrosis. Collagen vascular disorder in SSc is due to fibroblast and endothelial cell dysfunctions. This leads to collagen overproduction, vascular impairment and immune system abnormalities and, in the last stage, multi-organ damage. Thus, to avoid organ damage, which has a poor prognosis, all patients should be carefully evaluated and followed. This is particularly important in the initial disease phase, so as to facilitate early identification of any organ involvement and to allow for appropriate therapy. Pulmonary disease in SSc mainly involves interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). High-resolution computed tomography (HRCT) and pulmonary function tests (PFT) have been proposed to monitor parenchymal damage. Although transthoracic echocardiography is the most commonly used screening tool for PAH in SSc patients, definitive diagnosis necessitates confirmation by right heart catheterization (RHC). Moreover, some studies have demonstrated that nailfold videocapillaroscopy (NVC) provides an accurate evaluation of the microvascular damage in SSc and is able to predict internal organ involvement, such as lung impairment. This review provides an overview of the correlation between lung damage and microvascular involvement in SSc patients.

Body composition and bone status in relation to microvascular damage in systemic sclerosis patients

AIM

To evaluate, in Systemic sclerosis (SSc) patients, the body composition and the bone status according to the peripheral microcirculatory condition, assessed and scored by nailfold videocapillaroscopy (NVC, "Early", "Active", "Late" patterns).

METHODS

Body composition and bone mineral density (BMD) were assessed by Dual X-ray absorptiometry and dedicated software (GE Lunar USA) in 37 female SSc patients classified according to the 2013 EULAR/ACR criteria and 40 sex-matched healthy subjects. Clinical, laboratory, body composition and bone parameters were analyzed according to the different NVC patterns. Means were compared by the Student's t test or one-way analysis of variance; medians were compared by the Kruskal-Wallis test; and frequencies by the chi-square test.

RESULTS

Higher prevalence of vertebral (21% vs 7%) and femoral (35% vs 7%) osteoporosis (OP) was found in SSc. Particularly SSc patients with "Late" NVC pattern showed a significantly higher prevalence of vertebral (p = 0.018) and femoral OP (p = 0.016). Regional assessment of bone mass (BM) in seven different body areas showed a significantly lower BMD only at the total spine (p = 0.008) and femoral neck (p = 0.027) in advanced microvascular damage. Patients with "Late" NVC pattern showed a lower whole-body lean mass (LM) compared to "Early" and "Active" NVC patterns, particularly at upper limbs. To note, in all body sites, BMD correlates with LM and BMC according to NVC pattern severity.

CONCLUSIONS

SSc patients with most severe microvascular damage show a significantly altered body composition and bone status suggesting a strong link between microvascular failure and associated muscle/bone sufferance.

Assessment of recent evidence for the management of patients with systemic sclerosis-associated interstitial lung disease: a systematic review

This systematic review summarises current evidence to help guide treatment decisions for patients with systemic sclerosis (SSc)-associated interstitial lung disease (ILD). A systematic search of the literature (January 2012 to April 2018), including grey literature (searched between 1992 and 2011), was conducted using multiple electronic databases. Guidelines, meta-analyses, randomised controlled trials and observational studies reporting on risk stratification, screening, diagnosis, treatment and management outcomes for patients with SSc-ILD were included. A quality assessment of the included evidence was undertaken. In total, 2464 publications were identified and 280 included. Multiple independent risk factors for ILD in patients with SSc were identified, including older age, male sex and baseline pulmonary function. High-resolution computed tomography (HRCT) has been used for characterising ILD in patients with SSc, and pulmonary function tests are a key adjunctive component in the diagnostic and monitoring pathway. The clinical value of biomarkers relating to SSc-ILD diagnosis or assessment for disease progression is unknown at present. Immunosuppressive therapy (monotherapy or combined therapy) is the current standard of care for SSc-ILD; long-term evidence for effective and safe treatment of SSc-ILD is limited. Identification of patients at risk for SSc-ILD remains challenging. HRCT and pulmonary function tests are key to diagnosing and monitoring for disease progression. Although immunosuppressive therapy is considered current first-line treatment, it is partly associated with adverse effects and long-term follow-up evidence is limited. Novel therapies and biomarkers should be further explored in well-controlled clinical studies.

Association of Anti-Topoisomerase I Antibodies of the IgM Isotype With Disease Progression in Anti-Topoisomerase I-Positive Systemic Sclerosis

Objective

Anti–topoisomerase I (anti–topo I) autoantibodies in systemic sclerosis (SSc) are associated with diffuse skin involvement and interstitial lung fibrosis. Thus far, however, the relationship between anti–topo I antibody response and disease course has not yet been fully evaluated. This study was undertaken to gain insight into the association between characteristics of the anti–topo I antibody response and clinical disease course in SSc patients positive for anti–topo I antibodies.

Methods

Levels of anti–topo I IgG, anti–topo I IgM, and anti–topo I IgA were assessed in consecutive serum samples obtained from patients at baseline who were positive for anti–topo I IgG in the Leiden Combined Care In Systemic Sclerosis (CCISS) cohort. One‐year disease progression was defined by a relevant increase in modified Rodnan skin thickness score (MRSS), decline in pulmonary function, development of digital ulcers, renal crisis, and pulmonary hypertension, and/or mortality. Validation was performed in SSc patients who were positive for anti–topo I from the Oslo University Hospital and University Hospital Zurich.

Results

Of the 103 patients with anti–topo I IgG in the CCISS cohort, clinical data were available to assess 1‐year disease progression in 81 patients. Of these 81 patients, 23 (28%) had disease progression. At baseline, patients with disease progression were significantly more often anti–topo I IgM–positive than those who did not experience disease progression (21 [91%] of 23 versus 33 [57%] of 58; P < 0.01). This finding was confirmed in the independent validation samples.

Conclusion

In SSc patients who were anti–topo I IgG–positive, presence of anti–topo I IgM, which might be considered as a surrogate for an ongoing autoreactive B cell immune response, is associated with disease progression.

Multimodality imaging in connective tissue disease-related interstitial lung disease

Interstitial lung disease is a well-recognised manifestation and a major cause of morbidity and mortality in patients with connective tissue diseases. Interstitial lung disease may arise in the context of an established connective tissue disease or be the initial manifestation of an otherwise occult autoimmune disorder. Early detection and characterisation are paramount for adequate patient management and require a multidisciplinary approach, in which imaging plays a vital role. Computed tomography is currently the imaging method of choice; however, other imaging techniques have recently been investigated, namely ultrasound, magnetic resonance imaging, and positron-emission tomography, with promising results. The aim of this review is to describe the imaging findings of connective tissue disease-related interstitial lung disease and explain the role of each imaging technique in diagnosis and disease characterisation.

Lower urinary tract symptoms in systemic sclerosis: a detailed investigation

OBJECTIVES

Urinary tract involvement is a seldom-reported manifestation of SSc that could compromise patients' quality of life. This study compares lower urinary tract symptoms (LUTS) in SSc patients and in healthy subjects and their association with clinical and diagnostic parameters.

METHODS

LUTS were assessed through self-reported questionnaires in 42 SSc patients and 50 matched healthy subjects. Statistical analyses were performed to explore LUTS in the two populations and their association with SSc variables, including nailfold videocapillaroscopy patterns, SSc-related antibodies and DXA parameters.

RESULTS

SSc patients showed significantly higher prevalence and severity of urinary incontinence (UI) and overactive bladder (OAB) than healthy controls (P < 0.005, P < 0.01). SSc was a strong predictor of LUTS, independent of demographic data, comorbidities and treatments (odds ratio 5.57, 95% CI 1.64-18.88). In SSc patients OAB positively correlated with sarcopenia (P < 0.001), and both OAB and UI significantly correlated with reduced BMD (P < 0.05, P = 0.001). UI positively correlated with Scl70 antibodies (P < 0.05) and ciclosporin treatment (P = 0.001) and negatively with RNA polymerase III antibodies (P < 0.05); OAB positively correlated with calcinosis (P < 0.005) and negatively with methotrexate treatment (P < 0.05). Nailfold videocapillaroscopy 'active' and 'late' patterns were predominant among SSc patients presenting urinary symptoms, although no statistical correlation was found.

CONCLUSION

For the first time urinary tract involvement was found to be significantly higher in SSc patients than in healthy matched controls. In addition, sarcopenia, bone damage and calcinosis appeared significantly correlated with LUTS, suggesting a possible interplay.

Predictors of progression in systemic sclerosis patients with interstitial lung disease

Systemic sclerosis (SSc) is a systemic autoimmune disease affecting multiple organ systems, including the lungs. Interstitial lung disease (ILD) is the leading cause of death in SSc.

There are no valid biomarkers to predict the occurrence of SSc-ILD, although auto-antibodies against anti-topoisomerase I and several inflammatory markers are candidate biomarkers that need further evaluation. Chest auscultation, presence of shortness of breath and pulmonary function testing are important diagnostic tools, but lack sensitivity to detect early ILD. Baseline screening with high-resolution computed tomography (HRCT) is therefore necessary to confirm an SSc-ILD diagnosis. Once diagnosed with SSc-ILD, patients' clinical courses are variable and difficult to predict, although certain patient characteristics and biomarkers are associated with disease progression. It is important to monitor patients with SSc-ILD for signs of disease progression, although there is no consensus about which diagnostic tools to use or how often monitoring should occur. In this article, we review methods used to define and predict disease progression in SSc-ILD.

There is no valid definition of SSc-ILD disease progression, but we suggest that either a decline in forced vital capacity (FVC) from baseline of ≥10%, or a decline in FVC of 5–9% in association with a decline in diffusing capacity of the lung for carbon monoxide of ≥15% represents progression. An increase in the radiographic extent of ILD on HRCT imaging would also signify progression. A time period of 1–2 years is generally used for this definition, but a decline over a longer time period may also reflect clinically relevant disease progression.

Lung function tests and chest imaging help predict who has SSc-associated ILD and whether it will progress. In the absence of standardised methods for doctors, we recommend a strategy that combines both lung function tests and chest imaging.http://bit.ly/2uK9ZD2

Systemic sclerosis-associated interstitial lung disease

Systemic sclerosis is an autoimmune connective tissue disease, which is characterised by immune dysregulation and progressive fibrosis that typically affects the skin, with variable internal organ involvement. It is a rare condition that affects mostly young and middle-aged women, resulting in disproportionate morbidity and mortality. Currently, interstitial lung disease is the most common cause of death among patients with systemic sclerosis, with a prevalence of up to 30% and a 10-year mortality of up to 40%. Interstitial lung disease is more common among African Americans and in people with the diffuse cutaneous form of systemic sclerosis or anti-topoisomerase 1 antibodies. Systemic sclerosis-associated interstitial lung disease most commonly presents with dyspnoea, cough, and a non-specific interstitial pneumonia pattern on CT scan, with a minority of cases fulfilling the criteria for usual interstitial pneumonia. The standard therapy has traditionally been combinations of immunosuppressants, particularly mycophenolate mofetil or cyclophosphamide. These immunosuppressants can be supplemented by targeted biological and antifibrotic therapies, whereas autologous haematopoietic stem-cell transplantation and lung transplantation are reserved for refractory cases.

The identification and management of interstitial lung disease in systemic sclerosis: evidence-based European consensus statements

BACKGROUND

Systemic sclerosis-associated interstitial lung disease (ILD) carries a high mortality risk; expert guidance is required to aid early recognition and treatment. We aimed to develop the first expert consensus and define an algorithm for the identification and management of the condition through application of well established methods.

METHODS

Evidence-based consensus statements for systemic sclerosis-associated ILD management were established for six domains (ie, risk factors, screening, diagnosis and severity assessment, treatment initiation and options, disease progression, and treatment escalation) using a modified Delphi process based on a systematic literature analysis. A panel of 27 Europe-based pulmonologists, rheumatologists, and internists with expertise in systemic sclerosis-associated ILD participated in three rounds of online surveys, a face-to-face discussion, and a WebEx meeting, followed by two supplemental Delphi rounds, to establish consensus and define a management algorithm. Consensus was considered achieved if at least 80% of panellists indicated agreement or disagreement.

FINDINGS

Between July 1, 2018, and Aug 27, 2019, consensus agreement was reached for 52 primary statements and six supplemental statements across six domains of management, and an algorithm was defined for clinical practice use. The agreed statements most important for clinical use included: all patients with systemic sclerosis should be screened for systemic sclerosis-associated ILD using high-resolution CT; high-resolution CT is the primary tool for diagnosing ILD in systemic sclerosis; pulmonary function tests support screening and diagnosis; systemic sclerosis-associated ILD severity should be measured with more than one indicator; it is appropriate to treat all severe cases; no pharmacological treatment is an option for some patients; follow-up assessments enable identification of disease progression; progression pace, alongside disease severity, drives decisions to escalate treatment.

INTERPRETATION

Through a robust modified Delphi process developed by a diverse panel of experts, the first evidence-based consensus statements were established on guidance for the identification and medical management of systemic sclerosis-associated ILD.

FUNDING

An unrestricted grant from Boehringer Ingelheim International.

Interstitial Lung Disease in Systemic Sclerosis: Focus on Early Detection and Intervention

Systemic sclerosis (SSc) is a progressive and often devastating disease characterized by autoimmune dysfunction, vasculopathy, and fibrosis. Interstitial lung disease (ILD) is identified in the majority of patients with SSc and is the leading cause of SSc-related mortality. Although clinical manifestations and ILD severity vary among patients, lung function typically declines to the greatest extent during the first 3-4 years after disease onset. We aim to provide an overview of SSc-associated ILD (SSc-ILD) with a focus on current and emerging tools for early diagnosis of ILD and current and novel treatments under investigation. Early detection of ILD provides the opportunity for early therapeutic intervention, which could improve patient outcomes. Thoracic high-resolution computed tomography is the most effective method of identifying ILD in patients with SSc; it enables detection of mild lung abnormalities and plays an important role in monitoring disease progression. Cyclophosphamide and mycophenolate mofetil are the most commonly prescribed treatments for SSc-ILD. Recently, nintedanib (an antifibrotic) was approved by the Food and Drug Administration for patients with SSc-ILD; it is indicated for slowing the rate of decline in pulmonary function. However, there is a need for additional effective and well-tolerated disease-modifying therapy. Ongoing studies are evaluating other antifibrotics and novel agents. We envision that early detection of lung involvement, combined with the emergence and integration of novel therapies, will lead to improved outcomes in patients with SSc-ILD.

Quantitative CT texture analysis for diagnosing systemic sclerosis: Effect of iterative reconstructions and radiation doses

To test whether texture analysis (TA) can discriminate between Systemic Sclerosis (SSc) and non-SSc patients in computed tomography (CT) with different radiation doses and reconstruction algorithms.In this IRB-approved retrospective study, 85 CT scans at different radiation doses [49 standard dose CT (SDCT) with a volume CT dose index (CTDIvol) of 4.86 ± 2.1 mGy and 36 low-dose (LDCT) with a CTDIvol of 2.5 ± 1.5 mGy] were selected; 61 patients had Ssc ("cases"), and 24 patients had no SSc ("controls"). CT scans were reconstructed with filtered-back projection (FBP) and with sinogram-affirmed iterative reconstruction (SAFIRE) algorithms. 304 TA features were extracted from each manually drawn region-of-interest at 6 pre-defined levels: at the midpoint between lung apices and tracheal carina, at the level of the tracheal carina, and 4 between the carina and pleural recesses. Each TA feature was averaged between these 6 pre-defined levels and was used as input in the machine learning algorithm artificial neural network (ANN) with backpropagation (MultilayerPerceptron) for differentiating between SSc and non-SSc patients.Results were compared regarding correctly/incorrectly classified instances and ROC-AUCs.ANN correctly classified individuals in 93.8% (AUC = 0.981) of FBP-LDCT, in 78.5% (AUC = 0.859) of FBP-SDCT, in 91.1% (AUC = 0.922) of SAFIRE3-LDCT and 75.7% (AUC = 0.815) of SAFIRE3-SDCT, in 88.1% (AUC = 0.929) of SAFIRE5-LDCT and 74% (AUC = 0.815) of SAFIRE5-SDCT.Quantitative TA-based discrimination of CT of SSc patients is possible showing highest discriminatory power in FBP-LDCT images.

Novel Imaging Approaches in Systemic Sclerosis-Associated Interstitial Lung Disease

PURPOSE OF THE REVIEW

Novel imaging approaches, such as quantitative computed tomography (CT), magnetic resonance imaging (MRI), and molecular imaging, are being applied to interstitial lung diseases to provide prognostic, functional, and molecular information. Here, we review such imaging approaches and their applicability to systemic sclerosis-associated interstitial lung disease (SSc-ILD).

RECENT FINDINGS

Quantitative CT can be used to quantify the radiographic response to SSc-ILD therapy. Due to advances in MRI sequence development, MRI can detect the presence of SSc-ILD with high accuracy. MRI can also be utilized to provide functional information as to SSc-ILD and paired with molecular probes to provide non-invasive molecular information. MRI and ultrasound have promising test characteristics for diagnosing ILD in SSc without the use of ionizing radiation. Novel imaging approaches can detect SSc-ILD without the use of ionizing radiation, provide non-invasive functional and molecular information, and quantify treatment response in SSc-ILD. These techniques hold promise for translation into clinical care and clinical trials.

Abnormal esophageal motility during a solid test meal in systemic sclerosis-detection even in very early disease and association with disease progression

OBJECTIVE

This study assessed whether high-resolution manometry (HRM) with a test meal can detect clinically relevant, abnormal motility already in very early systemic sclerosis (SSc) and whether this finding is associated with subsequent disease progression.

METHODS

This prospective, longitudinal cohort study recruited 68 consecutive SSc patients (group #1: 32 established disease (ACR, American College of Rheumatology /EULAR, The European League against Rheumatism 2013 and ACR 1980 criteria fulfilled); group #2: 24 early disease (only ACR/EULAR 2013 fulfilled); group #3: 12 very early disease (clinical expert diagnosis of SSc) and 72 healthy controls. HRM evaluated esophageal motility for water swallows and a solid test meal.

RESULTS

Systemic sclerosis patients had less frequent effective esophageal contractions during the test meal compared to healthy controls even in very early disease (0.15, 1.0, 2.1 per minute for groups #1, #2, and #3, vs 2.5 per minute in health; P < 0.001, P < 0.001, and P < 0.0085, respectively). Ineffective motility at HRM was associated with a higher modified Rodnan skin score at baseline. Moreover, at mean 18 (10-31) months of follow-up, the presence of ineffective motility at baseline was associated with progression of skin disease (P = 0.01). Cox proportional hazard regression analysis identified hypotensive peristalsis in the test meal (<15% effective solid swallows) and low distal contractile integral (DCI; <400 mm Hg·cm·s) as predictors for skin aggravation, but not for new organ involvement.

CONCLUSION

Ineffective motility during a test meal is present already in patients with very early SSc. Findings on HRM studies are associated with disease severity at baseline, and low percentage of effective swallows in test meal and low mean DCI are both predictors of skin progression during follow-up.

Interstitial lung disease in systemic sclerosis: challenges in early diagnosis and management

Interstitial lung disease (ILD) is a group of lung diseases characterized by thickening of the interstitium surrounding pulmonary alveolar walls. It is related to specific radiographic features in lung imaging and/or the presence of restrictive disorders in pulmonary function tests (PFTs). ILD is one of the leading causes of death in systemic sclerosis patients. Major risk factors of ILD associated with SSc (SSc-ILD) include male sex, diffuse type of cutaneous SSc and presence of anti-Scl-70 antibodies.

SSc-ILD is challenging to diagnose at an early stage as the symptoms are non-specific. The greatest risk of its development is during the 4–5 years after the initial diagnosis of systemic sclerosis. Clinical vigilance at the time, including regular pulmonary function tests and/or high-resolution com-puted tomography (HRCT), is needed. The aim of this paper is to summarize the current knowledge on early diagnostic methods and progression risk factors for SSc-ILD.

Prediction of progression of interstitial lung disease in patients with systemic sclerosis: the SPAR model

OBJECTIVES

To identify the predictive clinical characteristics and establish a prediction model for the progression of mild interstitial lung disease (ILD) in patients with systemic sclerosis (SSc).

METHODS

Patients with SSc from two independent prospective cohorts were included in this observational study. All patients fulfilled the 2013 American College of Rheumatology/European League Against Rheumatism criteria, had mild ILD at baseline diagnosed by High-Resolution Computed Tomography (HRCT), available baseline and ≥1 annual follow-up pulmonary function tests and no concomitant pulmonary hypertension or airflow obstruction. ILD progression was defined as a relative decrease in forced vital capacity (FVC)%≥15%, or FVC%≥10% combined with diffusing capacity for carbon monoxide %≥15% at 1-year follow-up. Candidate predictors for multivariate logistic regression were selected by expert opinion based on clinical significance. A prediction model for ILD progression was established in the derivation cohort and validated in the multinational validation cohort.

RESULTS

A total of 25/98 and 25/117 patients with SSc showed ILD progression in the derivation cohort and the validation cohort, respectively. Lower SpO₂ after 6 min walk test (6MWT) and arthritis ever were identified as independent predictors for ILD progression in both cohorts. The optimal cut-off value of SpO₂ after 6MWT for predicting ILD progression was determined as 94% by receiver operating characteristic curve analysis. The derived SPAR model combining both predictors (SPO₂ and ARthritis) increased the prediction rate from 25.5% to 91.7% with an area under the curve (95% CI) of 0.83 (0.73 to 0.93).

CONCLUSIONS

The evidence-based SPAR prediction model developed in our study might be helpful for the risk stratification of patients with mild SSc-ILD in clinical practice and cohort enrichment for future clinical trial design.

Diagnostic criteria, severity classification and guidelines of systemic sclerosis

Several effective drugs have been identified for the treatment of systemic sclerosis (SSc). However, in advanced cases, not only their effectiveness is reduced but they may be also harmful due to their side-effects. Therefore, early diagnosis and early treatment is most important for the treatment of SSc. We established diagnostic criteria for SSc in 2003 and early diagnostic criteria for SSc in 2011, for the purpose of developing evaluation of each organ in SSc. Moreover, in November 2013, the American College of Rheumatology and the European Rheumatology Association jointly developed new diagnostic criteria for increasing their sensitivity and specificity, so we revised our diagnostic criteria and severity classification of SSc. Furthermore, we have revised the clinical guideline based on the newest evidence. In particular, the clinical guideline was established by clinical questions based on evidence-based medicine according to the New Minds Clinical Practice Guideline Creation Manual (version 1.0). We aimed to make the guideline easy to use and reliable based on the newest evidence, and to present guidance as specific as possible for various clinical problems in treatment of SSc.

The impact of slice-reduced computed tomography on histogram-based densitometry assessment of lung fibrosis in patients with systemic sclerosis

Background

To evaluate usability of slice-reduced sequential computed tomography (CT) compared to standard high-resolution CT (HRCT) in patients with systemic sclerosis (SSc) for qualitative and quantitative assessment of interstitial lung disease (ILD) with respect to (I) detection of lung parenchymal abnormalities, (II) qualitative and semiquantitative visual assessment, (III) quantification of ILD by histograms and (IV) accuracy for the 20%-cut off discrimination.

Methods

From standard chest HRCT of 60 SSc patients sequential 9-slice-computed tomography (reduced HRCT) was retrospectively reconstructed. ILD was assessed by visual scoring and quantitative histogram parameters. Results from standard and reduced HRCT were compared using non-parametric tests and analysed by univariate linear regression analyses.

Results

With respect to the detection of parenchymal abnormalities, only the detection of intrapulmonary bronchiectasis was significantly lower in reduced HRCT compared to standard HRCT (P=0.039). No differences were found comparing visual scores for fibrosis severity and extension from standard and reduced HRCT (P=0.051-0.073). All scores correlated significantly (P<0.001) to histogram parameters derived from both, standard and reduced HRCT. Significant higher values of kurtosis and skewness for reduced HRCT were found (both P<0.001). In contrast to standard HRCT histogram parameters from reduced HRCT showed significant discrimination at cut-off 20% fibrosis (sensitivity 88% kurtosis and skewness; specificity 81% kurtosis and 86% skewness; cut-off kurtosis ≤26, cut-off skewness ≤4; both P<0.001).

Conclusions

Reduced HRCT is a robust method to assess lung fibrosis in SSc with minimal radiation dose with no difference in scoring assessment of lung fibrosis severity and extension in comparison to standard HRCT. In contrast to standard HRCT histogram parameters derived from the approach of reduced HRCT could discriminate at a threshold of 20% lung fibrosis with high sensitivity and specificity. Hence it might be used to detect early disease progression of lung fibrosis in context of monitoring and treatment of SSc patients.

Mechanistic and clinical insights at the scleroderma-cancer interface

Emerging data suggest tantalizing links between cancer and systemic inflammatory rheumatic syndromes. In scleroderma, patients may have an increased risk of cancer secondary to chronic inflammation and damage from the disease, malignant transformation promoted by immunosuppressive therapies, a shared susceptibility to both cancer and autoimmunity, or a common inciting exposure. However, it is increasingly recognized that a subset of patients develop cancer around the time that scleroderma clinically manifests, raising the question of cancer-induced autoimmunity. In this review, we discuss data suggesting a mechanistic link between cancer and the development of scleroderma, and the clinical implications of these findings.

Interstitial lung disease in systemic sclerosis: progress in screening and early diagnosis

PURPOSE OF REVIEW

Interstitial lung disease (ILD) is the major determinant of morbidity and mortality in systemic sclerosis (SSc). In highly selected SSc patients, it was recently shown that stem cell therapy early in the disease course improved survival and reduced the extent of ILD, providing a rationale for early ILD detection strategies in this disease. Here, we review recent progress on ILD screening and early diagnosis in SSc.

RECENT FINDINGS

Two studies showed that over 60% of unselected SSc cases with ILD by high-resolution computer tomography (HRCT) had normal range pulmonary function tests (PFTs); indicating poor performance of PFTs for ILD screening purposes. Serial, paired HRCT and PFT analyses indicated that screening by HRCT at baseline predicted risk for lung fibrosis development, progression rate of fibrosis and PFT decline. Analyses of circulating biomarkers, like CCL18, and nonradiating lung imaging modalities, like ultrasound and MRI, showed promise as tools for early ILD detection; but further work is needed.

SUMMARY

Prospective cohort data indicated poor performance of PFT as a stand-alone method for ILD screening. Lung HRCT appeared promising, but radiation is an issue. Promising biomarker data indicate the possibility of new ILD screening algorithms in SSc.

Correlation of delta high-resolution computed tomography (HRCT) score with delta clinical variables in early systemic sclerosis (SSc) patients

BACKGROUND

The correlation of changes (delta: Δ) of high-resolution computed tomography (HRCT) score with the Δ of other clinical variables has not been well studied. The purpose of this study was to determine the correlation of Δ HRCT score with Δ percent predicted forced vital capacity (%pFVC), Δ modified Rodnan Skin Score (mRSS), Δ erythrocyte sedimentation rate (ESR), and Δ percent of oxygen saturation at room air (%SpO₂) in patients with early systemic sclerosis (SSc).

METHODS

We used an inception cohort of early-SSc patients seen at the Rheumatology Clinic, Chiang Mai University, Thailand, between January 2010 and June 2014. All patients underwent HRCT at study entry and every 12 months thereafter. Thirty-one SSc patients who underwent pulmonary function test (PFT) within 12 weeks of their corresponding HRCT at baseline and last visit were identified. The extent of ground glass (GG), lung fibrosis (Fib), bronchiectasis (B), and honeycombing (HC) was scored, and then aggregated to produce a total (t) HRCT score.

RESULTS

Mean ± SD age and disease duration from non-Raynaud's phenomenon (NRP) to undergo HRCT at baseline were 52.2±8.8 years and 11.7±7.1 months, respectively. Seventeen (54.8%) patients were female and 20 (64.5%) were classified as dcSSc. The mean ± SD interval between the two HRCT tests was 16.0±7.2 months. The Δ HRCT scores [total fibrosis scores (t-Fib), total bronchiectasis scores (t-B), and total HRCT score (t-HRCT) scores] and Δ mRSS, but not Δ %pFVC, showed significant change over the observation period. We found significant correlation of Δ total honeycombing scores (t-HC) with Δ ESR (r=-0.44, P<0.05), and Δ t-Fib with Δ %SpO₂ (r=-0.38, P<0.05). However, no significant correlation of any Δ HRCT scores with Δ %pFVC and Δ mRSS were observed.

CONCLUSIONS

In this study, the changes in the HRCT scores were greater than %pFVC; this, along with their correlations with the changes in ESR and %SpO₂, suggest that HRCT scores are a useful and sensitive method for monitoring disease progression in early SSc-related ILD (SSc-ILD).

Interstitial lung disease in systemic sclerosis: where do we stand?

Interstitial lung disease (ILD) is common in systemic sclerosis (SSc) patients and despite recent advances in the treatment is, at present, the major cause of death. Today, an early diagnosis of ILD is possible, and is mandatory to improve the prognosis of the disease. Pulmonary function tests and high-resolution computed tomography remain the mainstay for the diagnosis of SSc-ILD, but there is a growing interest in lung ultrasound. Recently, the correlation between severity of fibrosis and some peripheral blood biomarkers has been described. Nonselective immunosuppressors are still the main treatment for ILD, with cyclophosphamide (CYC) most widely used to obtain remission. Novel therapies towards specific molecular and cellular targets have been suggested; in particular, rituximab (RTX) has shown promising results, but further research is needed. It is of paramount importance to define the severity of the disease and the risk of progression in order to define the need for treatment and the treatment intensity. We propose the division of the treatment strategies at our disposal to induce remission into three categories: high intensity (haematopoietic stem cell transplantation), medium intensity (CYC and RTX) and low intensity (azathioprine (AZA) and mycophenolate mofetil (MMF)). After obtaining remission, maintenance treatment with AZA or MMF should be started. In this review we explore new advances in the pathogenesis, diagnosis and treatment of SSc-ILD.

Fast 1.5 T chest MRI for the assessment of interstitial lung disease extent secondary to systemic sclerosis

This study aims to evaluate the utility of magnetic resonance imaging (MRI) to assess interstitial lung disease (ILD) extent in patients with systemic sclerosis (SSc). Patients with SSc and varying degrees of ILD with a high-resolution computed tomography (HRCT), pulmonary function tests (PFTs), and a chest MRI containing an ultrafast SE sequence performed less than 1 year apart were included in the study. Wells global disease extent and Goh's staging algorithm were used to measure and categorize ILD both for MRI and HRCT. Correlation and diagnostic performance of MRI compared with HRCT and PFTs were calculated. Eighteen SSc patients were studied. MRI showed a good performance to detect ILD (AUC = 0.96) and was correlated with forced vital capacity (r = -0.60, p = 0.01), diffusing capacity of the lung for carbon monoxide (r = -0.79, p = 0.04), and also with HRCT (r = 0.85, p < 0.001), but MRI extent values were consistently lower than HRCT and, thus, not directly comparable. Goh's algorithm using HRCT and transformed to be used with MRI showed a good agreement (kappa = 0.73, p < 0.001) and MRI-measured ILD extent presented good intra-observer (ICC = 0.86) and inter-observer (ICC = 0.90) reliability. In SSc patients, MRI proved to be a good technique to detect and categorize ILD extent compared with HRCT, suggesting that it may be a valuable x-ray sparing technique for selected cases.

Recent Treatments of Interstitial Lung Disease with Systemic Sclerosis

Systemic sclerosis (SSc) is a disorder characterized by immune dysfunction, microvascular injury, and fibrosis. Organ involvement in patients with SSc is variable; however, pulmonary involvement occurs in up to 90% of patients with SSc. Interstitial lung disease (ILD) is a major cause of mortality and, thus, a major determinant in the prognosis of patients with SSc. This review summarizes current findings about the characteristics of ILD in patients with SSc, selection of patients with SSc-ILD who are candidates for the treatment, and current treatment options.

Transitions to different patterns of interstitial lung disease in scleroderma with and without treatment

OBJECTIVES

The aim is to investigate whether the 12-month quantitative changes in high-resolution CT (HRCT) measures of interstitial lung disease (ILD) are different, and to understand how they change, in patients with scleroderma-related ILD who receive drug therapy versus placebo.

METHODS

HRCT images were acquired at baseline and at 12 months in 83 participants in Scleroderma Lung Study I, a clinical trial comparing treatment with oral cyclophosphamide versus placebo. A computer-aided model was used to quantify the extent of fibrotic reticulation, ground glass and honeycomb patterns and quantitative ILD (QILD: sum of these patterns) in the whole lung and the lung zone (upper, middle or lower) of maximal disease involvement.

RESULTS

Mean QILD score decreased by 3.9% in the cyclophosphamide group while increasing by 4.2% in the placebo group in the most severe zone (p=0.01) and decreased by 3.2% in the cyclophosphamide group while increasing by 2.2% in the placebo group in the whole lung (p=0.03). Transitional probabilities demonstrated greater changes from a fibrotic to either a ground glass or normal pattern in the cyclophosphamide group and the reverse in the placebo group.

CONCLUSIONS

Changes in quantitative HRCT measures of ILD provide a sensitive indication of disease progression and response to treatment.

TRIAL REGISTRATION NUMBER

NCT00004563; Post-results.

Evaluation of pulmonary nodules and infection on chest CT with radiation dose equivalent to chest radiography: Prospective intra-individual comparison study to standard dose CT

PURPOSE

To compare prospectively, in patients undergoing chest computed tomography (CT) for pulmonary-nodules or infection, image-quality and accuracy of standard dose (SD) and reduced dose (RD) CT with tin-filtration.

MATERIAL AND METHODS

This IRB-approved study included 100 consecutive patients (36 female;median age 56 years) referred for follow-up of pulmonary-nodules (n=43) or suspicion of infection (n=57) undergoing single-energy CT with SD and RD using tin-filtration at 100 kVp (CTDIvol 2.47 mGy and 0.07 mGy, respectively). Images were reconstructed with advanced modeled iterative reconstruction (ADMIRE) at strength 3 and 5. Image-noise was measured. Two independent readers evaluated nodules and pulmonary-infection. SD CT served as reference standard.

RESULTS

No significant difference was found in noise between RD with ADMIRE5 and SD with ADMIRE3 (118HU ± 14 vs. 120HU ± 17; p=0.08). Sensitivity for detection of atelectasis and interstitial lung changes was higher in images reconstructed with ADMIRE5 (93% and 88%; respectively) than in those reconstructed with ADIMRE3 (77% and 78%; respectively). Sensitivity for detection of consolidations was 90% for ADMIRE3 and 89% for ADMIRE5. Sensitivity for nodule detection was 71% for ADMIRE3 and 81% for ADMIRE5. Specificity for detection of atelectasis and interstitial lung changes was 99% and 96% with ADMIRE5 and 99% and 96% with ADMIRE3. Specificity for detection of consolidations was 99% for ADMIRE3 and 5. Specificity for detection of nodules was 87% for both ADMIRE3 and 5.

CONCLUSION

Chest CT with a radiation dose equivalent to conventional radiography is feasible and allows for detection of pulmonary infection with high sensitivity, whereas the accuracy for detecting nodules is only moderate.

Ultrasound signs of pulmonary fibrosis in systemic sclerosis as timely indicators for chest computed tomography

OBJECTIVES

Systemic sclerosis (SSc) patients in the early stages of pulmonary fibrosis (PF) often have few or no symptoms, normal to borderline pulmonary function tests, and negative chest X-ray (CXR); high-resolution computed tomography (HRCT) is the only reliable means of detecting the early signs of PF. However, thoracic ultrasound (TUS) enables detection of pleural thickening, pleural/subpleural nodules, and other subpleural lung abnormalities across 70% of the subpleural surface. We reassessed concordance between TUS abnormalities and HRCT findings in SSc patients, to see whether TUS pleural line thickness (normally <3.0 mm) could be used to earmark those with asymptomatic PF for timely HRCT assessment.

METHOD

In total, 175 SSc patients (nine males, 166 females), aged 46.46±15.33 years, were given CXR, TUS, HRCT, echocardiography, and pulmonary function tests.

RESULTS

In the 26 patients without HRCT signs of PF, pleural line thickness was ≤3.0 mm. In diffuse SSc, 97/137 patients showed pleural line thickening (between 3.0 and 5 mm) and subpleural nodules in 32/97; and 35/137 showed major pleural line thickening (≥5.0 mm) with nodules, with good concordance with HRCT patterns indicating lung fibrosis severity. HRCT was normal in 5/137, with pleural line thickness≤3.0 mm.

CONCLUSIONS

TUS imaging of pleural/subpleural structures can detect ultrasonographic signs of initial PF prior to the onset of respiratory symptoms and function test abnormalities and, together with current criteria, could thereby enable exclusion of PF in SSc patients. Indicating some patients for selective referral to HRCT can thereby delay unwarranted procedures, provided that pulmonary function and TUS images are stable.

Systemic sclerosis

Systemic sclerosis is a complex autoimmune disease characterized by a chronic and frequently progressive course and by extensive patient-to-patient variability. Like other autoimmune diseases, systemic sclerosis occurs more frequently in women, with a peak of onset in the fifth decade of life. The exact cause of systemic sclerosis remains elusive but is likely to involve environmental factors in a genetically primed individual. Pathogenesis is dominated by vascular changes; evidence of autoimmunity with distinct autoantibodies and activation of both innate and adaptive immunity; and fibrosis of the skin and visceral organs that results in irreversible scarring and organ failure. Intractable progression of vascular and fibrotic organ damage accounts for the chronic morbidity and high mortality. Early and accurate diagnosis and classification might improve patient outcomes. Screening strategies facilitate timely recognition of life-threatening complications and initiation of targeted therapies to halt their progression. Effective treatments of organ-based complications are now within reach. Discovery of biomarkers - including autoantibodies that identify patient subsets at high risk for particular disease complications or rapid progression - is a research priority. Understanding the key pathogenetic pathways, cell types and mediators underlying disease manifestations opens the door for the development of targeted therapies with true disease-modifying potential. For an illustrated summary of this Primer, visit: http://go.nature.com/lchkcA.