Calcinosis in systemic sclerosis

Can we define difficult-to-treat systemic sclerosis?

INTRODUCTION

Systemic sclerosis (SSc) is a chronic autoimmune rheumatic disease characterized by microvascular alterations, immunopathology, and widespread fibrosis involving various organs. It is considered difficult to treat due to several reasons: complex pathogenesis, heterogeneity, late diagnosis, limited treatment options for certain organ manifestations, lack of personalized medicine.

AREAS COVERED

This review presents the heterogeneity, survival and organ manifestations with their risk factors of systemic sclerosis and their current treatment options, while drawing attention to difficult-to-treat forms of the disease, based on literature indexed in PubMed.

EXPERT OPINION

Despite recent advances in the management of SSc over the last decades, the disease presents significant morbidity and mortality. Although available treatment protocols brought significant advancements in terms of survival in SSc-associated interstitial lung disease and pulmonary arterial hypertension, less success has been achieved in the treatment of Raynaud's phenomenon and digital ulcers and the results are modest in case of heart, gastrointestinal, and renal manifestations. There are patients who do not respond to treatment and deteriorate even with adequate therapy. They can be considered difficult-to treat (D2T) cases. We have created a possible score system based on the individual organ manifestations and highlighted treatment options for the D2T SSc category.

Calcinosis in systemic sclerosis: An update on pathogenesis, related complications, and management: A heavy burden still waiting to be lifted off patients' hands

In SSc, dystrophic calcinosis is one of the major clinical manifestations, characterized by the deposition of insoluble calcific substances in tissues, predominantly in the chemical form of calcium hydroxyapatite. Furthermore, calcinosis might lead to compressive neuropathies and severe pain. Current evidence suggests that tissue ischemia and repeated trauma are implicated in the development of calcinosis; however, there are still too many unknown areas that need to be investigated. Detection of calcinosis is commonly performed using X-ray or ultrasound. Moreover, quantification of calcinosis with X-ray and dual-energy computed tomography might be useful for the assessment of disease burden and monitoring of the disease. Despite its prevalence and clinical outcomes, there are no approved disease-modifying treatments for calcinosis in SSc. Debulking or surgical intervention might be preferred for calcinosis complicated with infection, compressive symptoms, or relief of pain. Therefore, innovative investigations and tailored therapeutic approaches are urgently needed to lift the burden of calcinosis from the hands of SSc patients.

Protein profiling in systemic sclerosis patients with different pulmonary complications using proteomic antibody microarray

BACKGROUND

Pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD) are leading causes of systemic sclerosis (SSc)-related death. In this study, we aimed to identify biomarkers for detecting SSc pulmonary complications that are mild and in the early stages to improve the prognosis.

METHODS

We screened for serum biomarkers using a proteomic antibody microarray that simultaneously assessed 1000 proteins. Differentially expressed proteins were further verified using ELISA. Finally, we performed a correlation analysis using clinical data.

RESULTS

We identified 125 differentially expressed proteins, of which calcitonin, sclerostin (SOST), CD40, and fibronectin were selected for further verification. Serum calcitonin and SOST levels were significantly elevated in all SSc pulmonary complication subgroups, whereas serum calcitonin levels were higher in the SSc with PAH subgroup than in the SSc without PAH and ILD subgroup. Serum SOST levels were possibly associated with the presence of ILD and positively related to the presence of cardiac and gastrointestinal involvement. Serum CD40 and calcitonin levels appeared to be positively related to the presence of renal involvement, and serum calcitonin was also positively related to the presence of gastrointestinal involvement.

CONCLUSIONS

This study indicated that serum calcitonin and SOST levels may be promising biomarkers for SSc-related PAH and ILD, respectively. Further research is needed to verify this result and understand the underlying mechanisms.

Bone but not Bone: Systemic Calcinosis Presenting as Lumbar Facet Pseudohypertrophy with Neurogenic Claudication

Systemic sclerosis affects 14-21 per million persons annually and can present with calcinosis-deposition in the skin and subcutaneous tissues. In rare circumstances, paraspinal depositions are also seen, which can cause neural element compression requiring surgical intervention. Here we present the case of a 61-year-old woman with systemic sclerosis on goal-directed therapy who presented with neurogenic pseudoclaudication and imaging suggesting severe joint hypertrophy. The case illustrates that calcinosis in scleroderma can cause facet joint pseudohypertrophy that is difficult to distinguish from true hypertrophy on imaging. Such pseudohypertrophy is often refractory to medical therapy, necessitating surgical intervention. Last, owing to the fluid nature of the calcinotic fluid, decompression is often easier than would be expected based on preoperative imaging alone.

Biomarkers in the Pathogenesis, Diagnosis, and Treatment of Systemic Sclerosis

Systemic sclerosis (SSc) is a complex autoimmune disease characterized by vascular damage, vasoinstability, and decreased perfusion with ischemia, inflammation, and exuberant fibrosis of the skin and internal organs. Biomarkers are analytic indicators of the biological and disease processes within an individual that can be accurately and reproducibly measured. The field of biomarkers in SSc is complex as recent studies have implicated at least 240 pathways and dysregulated proteins in SSc pathogenesis. Anti-nuclear antibodies (ANA) are classical biomarkers with well-described clinical classifications and are present in more than 90% of SSc patients and include anti-centromere, anti-Th/To, anti-RNA polymerase III, and anti-topoisomerase I antibodies. Transforming growth factor-β (TGF-β) is central to the fibrotic process of SSc and is intimately intertwined with other biomarkers. Tyrosine kinases, interferon-1 signaling, IL-6 signaling, endogenous thrombin, peroxisome proliferator-activated receptors (PPARs), lysophosphatidic acid receptors, and amino acid metabolites are new biomarkers with the potential for developing new therapeutic agents. Other biomarkers implicated in SSc-ILD include signal transducer and activator of transcription 4 (STAT4), CD226 (DNAX accessory molecule 1), interferon regulatory factor 5 (IRF5), interleukin-1 receptor-associated kinase-1 (IRAK1), connective tissue growth factor (CTGF), pyrin domain containing 1 (NLRP1), T-cell surface glycoprotein zeta chain (CD3ζ) or CD247, the NLR family, SP-D (surfactant protein), KL-6, leucine-rich α2-glycoprotein-1 (LRG1), CCL19, genetic factors including DRB1 alleles, the interleukins (IL-1, IL-4, IL-6, IL-8, IL-10 IL-13, IL-16, IL-17, IL-18, IL-22, IL-32, and IL-35), the chemokines CCL (2,3,5,13,20,21,23), CXC (8,9,10,11,16), CX3CL1 (fractalkine), and GDF15. Adiponectin (an indicator of PPAR activation) and maresin 1 are reduced in SSc patients. A new trend has been the use of biomarker panels with combined complex multifactor analysis, machine learning, and artificial intelligence to determine disease activity and response to therapy. The present review is an update of the various biomarker molecules, pathways, and receptors involved in the pathology of SSc.

Assessment of calcinosis in Portuguese patients with systemic sclerosis - a multicenter study

INTRODUCTION/OBJECTIVES

The study aims to define the clinical and subclinical calcinosis prevalence, the sensitivity of radiographed site and clinical method for its diagnosis, and the phenotype of Portuguese systemic sclerosis (SSc) patients with calcinosis.

METHOD

A cross-sectional multicenter study was conducted with SSc patients fulfilling Leroy/Medsger 2001 or ACR/EULAR 2013 classification criteria, registered in the Reuma.pt. Calcinosis was assessed through clinical examination and radiographs of hands, elbows, knees, and feet. Independent parametric or non-parametric tests, multivariate logistic regression, and sensitivity calculation of radiographed site and clinical method for calcinosis detection were performed.

RESULTS

We included 226 patients. Clinical calcinosis was described in 63 (28.1%) and radiological calcinosis in 91 (40.3%) patients, of which 37 (40.7%) were subclinical. The most sensitive location to detect calcinosis was the hand (74.7%). Sensitivity of the clinical method was 58.2%. Calcinosis patients were more often female (p = 0.008) and older (p < 0.001) and had more frequently longer disease duration (p < 0.001), limited SSc (p = 0.017), telangiectasia (p = 0.039), digital ulcers (p = 0.001), esophageal (p < 0.001) and intestinal (p = 0.003) involvements, osteoporosis (p = 0.028), and late capillaroscopic pattern (p < 0.001). In multivariate analysis, digital ulcers (OR 2.63, 95% CI 1.02-6.78, p = 0.045) predicted overall calcinosis, esophageal involvement (OR 3.52, 95% CI 1.28-9.67, p = 0.015) and osteoporosis (OR 4.1, 95% CI 1.2-14.2, p = 0.027) predicted hand calcinosis, and late capillaroscopic pattern (OR 7.6, 95% CI 1.7-34.9, p = 0.009) predicted knee calcinosis. Anti-nuclear antibody positivity was associated with less knee calcinosis (OR 0.021, 95% CI 0.001-0477, p = 0.015).

CONCLUSIONS

Subclinical calcinosis high prevalence suggests that calcinosis is underdiagnosed and radiographic screening might be relevant. Multifactorial pathogenesis may explain calcinosis predictors' variability. Key Points • Prevalence of subclinical calcinosis in SSc patients is substantial. • Hand radiographs are more sensitive to detect calcinosis than other locations or clinical method. • Digital ulcers were associated with overall calcinosis, esophageal involvement and osteoporosis were associated with hand calcinosis, and late sclerodermic pattern in nailfold capillaroscopy was associated with knee calcinosis. • Anti-nuclear antibody positivity may be a protective factor for knee calcinosis.

Novel therapies and innovation for systemic sclerosis skin ulceration

Skin ulceration is an important cause of morbidity in systemic sclerosis and can occur at anytime during disease progression. Incident disease cohorts are important for understanding whether skin ulceration represents active vasculopathy versus resultant damage. Biomarkers for skin ulcer pathogenesis, both serum and imaging, are under investigation to elucidate the functional consequences of the structural abnormalities. Novel therapeutics for the treatment of vasculopathy benefit from reliable biomarkers able to predict the disease evolution remains an important unmet need. Nonetheless, a diagnostic approach that captures early skin ulceration and treatments that restore vascular and immune homeostasis is critical for effective systemic sclerosis (SSc) vasculopathy management.