Osteoclastogenesis in Patients With Systemic Sclerosis With and Without Calcinosis Cutis

Antonia Valenzuela; Guillermo Pérez; Lorinda Chung; Felipe Sánchez; Carolina Iturriaga; Rebeca Montalva; Arturo Borzutzky

doi:10.1002/acr2.70029

. 2025 Apr 2;7(4):e70029. doi: 10.1002/acr2.70029

Osteoclastogenesis in Patients With Systemic Sclerosis With and Without Calcinosis Cutis

Antonia Valenzuela ^1,^✉, Guillermo Pérez ¹, Lorinda Chung ², Felipe Sánchez ¹, Carolina Iturriaga ¹, Rebeca Montalva ¹, Arturo Borzutzky ¹

PMCID: PMC11965697 PMID: 40176384

Abstract

Objective

We aimed to assess whether the presence of radiographically confirmed calcinosis of the hands in patients with systemic sclerosis (SSc) is associated with increased osteoclastogenesis.

Methods

We recruited 20 patients with SSc (10 with calcinosis and 10 without calcinosis) and 10 age‐ and gender‐matched healthy controls. Hand radiographs were scored using the validated Scleroderma Clinical Trials Consortium (SCTC) radiographic severity score for calcinosis. To evaluate osteoclastogenesis, peripheral blood mononuclear cells (PBMCs) were cultured with RANKL and macrophage colony‐stimulating factor; osteoclasts were identified using tartrate‐resistant acid phosphatase staining. Measures of bone resorption (RANKL, osteoprotegerin [OPG]) and ischemia or endothelial function (vascular endothelial growth factor, angiopoietin‐1, and angiopoietin‐2 [Ang‐2]) were also evaluated.

Results

Patients with SSc were all women and Hispanic, and the majority (n = 12, 60%) had limited SSc skin type. Mean ± SD age was 55.2 ± 14.8 years; mean ± SD disease duration was 9.5 ± 6.5 years from first non‐Raynaud phenomenon symptom. Patients with SSc with calcinosis had more digital ischemia than patients without calcinosis. Median SCTC score in patients with SSc with calcinosis was 11.1 (range 0.7–286). After 9 days in culture, PBMCs from patients with calcinosis originated a significantly higher number of osteoclasts (33.0 ± 20.3 cells/well) than patients without calcinosis (15.3 ± 6.9 cells/well) and healthy individuals (11.2 ± 2.6 cells/well) (P = 0.001). The severity of calcinosis was not correlated with the number of osteoclasts per well (r = 0.27, P = 0.5); however, it was correlated with RANKL (r = 0.82, P = 0.004), RANKL/OPG ratio (r = 0.86, P = 0.002), and Ang‐2 levels (r = 0.86, P = 0.002).

Conclusion

Calcinosis in patients with SSc is associated with an increased propensity of peripheral blood cells to form osteoclasts. Targeted inhibition of osteoclastogenesis may provide a specific therapeutic option for patients with SSc‐associated calcinosis.

INTRODUCTION

Calcinosis cutis, the deposition of insoluble calcium in the skin and subcutaneous tissues, is a common manifestation of systemic sclerosis (SSc). It affects up to 40% of patients with SSc and is associated with a high burden of disability and hand dysfunction, contributing as much as arthritis to the patient's impaired ability to use their hands. ¹ The management of treatment for patients with SSc‐calcinosis remains an unmet need because current treatment options have yielded inconsistent results, and the available evidence is primarily based on smaller case series and case reports. ²

Although the pathogenesis of SSc‐related calcinosis remains unknown, growing evidence suggests a connection between calcinosis and vascular ischemia. ² A large multicenter study with 5,218 patients with SSc demonstrated a strong correlation between digital ulcers (DU) and acro‐osteolysis (AO) with the presence of calcinosis. ³ Additionally, research has revealed increased expression of hypoxia‐associated molecules, such as glucose transporter 1 (GLUT‐1), in skin biopsies of patients with SSc with calcinosis. ⁴ Elevated levels of oxidative stress markers and their receptors have also been observed in the dermis of patients with SSc, particularly in those with calcinosis, further supporting the role of vascular injury in calcinosis development. ⁵

Abnormalities in bone matrix proteins have also been proposed as a mechanism involved in the pathogenesis of calcinosis. ² Osteoclasts are large multinucleated giant cells that participate in bone remodeling and can be induced by hypoxia, as shown in patients with SSc and AO. ⁶ Osteoclast activity is regulated by the balance between the RANKL and osteoprotegerin (OPG). The RANKL/OPG ratio is crucial in this regulatory process. RANKL binds to its receptor, RANK, on osteoclast precursors, promoting their growth and activity, which leads to bone resorption. OPG, on the other hand, acts as a decoy receptor for RANKL, preventing it from binding to RANK and thus reducing osteoclast activity. A high RANKL/OPG ratio means more bone resorption, whereas a lower ratio means less bone resorption. ⁷

Hypoxia can induce vascular endothelial growth factor (VEGF), a potent angiogenic factor that has been verified as a biomarker of ischemia. ⁸ Interestingly, some studies have found elevated levels of VEGF in sera and skin biopsies of patients with SSc as compared with the healthy control group. ⁴ , ⁹ The expression of VEGF correlates with increased osteoclast generation and degree of AO in patients with SSc. ⁶ Angiopoietins are ligands for the endothelium‐specific tyrosine kinase with immunoglobulin‐like and EGF‐like domains 2 receptor and may act alongside VEGF. ¹⁰ Angiopoietin‐1 (Ang‐1) enhances blood vessel stability and survival, protecting tissues during ischemic events by maintaining blood supply. Conversely, angiopoietin‐2 (Ang‐2) acts as a vessel‐destabilizing cytokine and, in combination with factors like VEGF, facilitates angiogenesis, helping to restore blood flow during ischemia.

Hence, the available data suggest a connection between vascular ischemia, dysregulation of bone matrix proteins, and the presence of calcinosis in patients with SSc. However, the specific mechanism by which these factors contribute to calcinosis development remains unclear. We aimed to investigate whether the presence of radiographically confirmed calcinosis of the hands in patients with SSc is associated with increased osteoclastogenesis and elevated blood levels of VEGF, independent of the presence or development of AO.

PATIENTS AND METHODS

Study population

We recruited 20 patients with SSc who fulfilled 2013 revised American College of Rheumatology/EULAR criteria for SSc ¹¹ (10 with calcinosis and 10 without calcinosis) from Pontificia Universidad Católica and Red de Salud UC CHRISTUS Rheumatology Clinics and 10 age‐ and gender‐matched healthy individuals between September 2021 and April 2022. Patients with AO were excluded given the known association between AO and increased osteoclastogenesis. All participants provided written informed consent. This study was approved by the Institutional Review Board of Pontificia Universidad Católica de Chile. We adhered to the guidelines set by the Declaration of Helsinki (modified 1989) and Good Clinical Practice.

Study measures

Demographic and clinical information including age, gender, race and ethnicity (self‐reported from a fixed set of categories), smoking status, disease duration from the onset of Raynaud phenomenon (RP) and from the first non‐RP symptom, SSc skin subtype, internal organ involvement, auto‐antibody profiles (including SSc‐specific and antiphospholipid antibodies), and medication usage at the time of blood sampling was gathered and recorded in a REDCap database hosted at Pontificia Universidad Católica de Chile servers. The presence of ischemic DU and clinically evident calcinosis were assessed through physical examination. In addition, patients were asked to complete paper forms consisting of patient‐reported outcome measures related to disability, such as the Cochin Hand Function Scale, scleroderma health assessment questionnaire, patient global assessment of calcinosis using a visual analog scale (VAS, 0–10), and the newly developed Mawdsley calcinosis questionnaire. ¹² All patients with SSc had their autoantibodies measured using the commercial immunoblot assay EUROLINE ANA Profile 23 Ag (IgG), developed by Euroimmun, at the main laboratory of Pontificia Universidad Católica.

All patients with SSc had antero‐posterior radiographs of both hands to confirm the presence or absence of calcinosis. In addition, all patients with SSc and the control group had bone densitometry with morpho densitometry to evaluate the presence or absence of osteoporosis and bone fractures during the same visit as the blood sampling.

Calcinosis severity was measured using the validated Scleroderma Clinical Trials Consortium (SCTC) radiographic severity score for calcinosis. ¹³ Radiographs were de‐identified and independently reviewed and scored by two expert readers (AV and LC), and an average score was used for all analyses.

Plasma and cell preparation

Blood from all participants was obtained by peripheral venous puncture and collected in sodium citrate‐containing tubes and EDTA tubes. Plasma samples were isolated from blood collected in sodium citrate‐containing tubes after centrifugation for 10 minutes at 1500g, further spun at 15,000g for 5 minutes, and immediately stored at −80°C.

VEGF, Ang‐1, and Ang‐2 measurement

Plasma levels of VEGF (pg/mL) were quantified by enzyme‐linked immunosorbent assay (ELISA) according to the recommendations of the manufacturer (R&D Systems). ELISA plates precoated with a monoclonal antibody specific for human VEGF were used. 100μL of standard, control, or sample were added per well, and incubated for 2 hours at room temperature. After three washes with wash buffer, 200 μL of human VEGF conjugate was added and incubated for 2 hours. Following additional washes, 200 μL of substrate solution was added and incubated for 25 minutes. The reaction was stopped with stop solution and optical density was measured at 450nm within 30 minutes, using a microplate reader. Ang‐1 and Ang‐2 levels were measured using the Human Angiopoietin‐1 and Human Angiopoietin‐2 ELISA Kit (Quantikine) from R&D Systems.

Bone turnover markers

C‐telopeptide of Type I collagen (CTX), a marker of bone resorption, was measured by commercial electrochemiluminescence immunoassay developed by Roche at Pontificia Universidad Católica main laboratory. Human OPG and RANKL ELISA kits were used following the manufacturers’ recommendations (My BioSource). Human tartrate‐resistant acid phosphatase (TRAP) was measured using TRAP ELISA Kit (Sigma‐Aldrich Diagnostics).

Determination of circulating osteoclast precursor cells

Peripheral blood mononuclear cells (PBMCs) were cultured in Opti‐MEM I (Gibco Invitrogen), supplemented with 10% heat‐inactivated fetal bovine serum, 100 IU/mol penicillin and 100 IU/mol streptomycin in the presence of 100 ng/mL RANKL (R&D), and 25 ng/mL macrophage colony‐stimulating factor (R&D) in a 96‐well plate in 5% CO₂ at 37 C. On day nine, cells were fixed with 3% formaldehyde and stained for expression of TRAP according to the manufacturer's protocol (Sigma‐Aldrich). TRAP‐positive cells with three or more nuclei visible under light microscopy using an Euromex Serie Oxion Inverso Fluo microscope with a magnification of 20× were counted as osteoclasts.

Statistical analysis

The sample size was determined using G‐power Version 3.1.9.4. Based on prior research, it was calculated that a total of 30 patients (10 per group) would be needed to detect a difference among patients with SSc with calcinosis, patients with SSc without calcinosis, and the healthy control group, with an effect size of 0.7, 80% power, and a significance level of 0.05. We used Student's t‐test, and chi‐square or Fisher's exact test as appropriate for crude bivariate analysis, Kruskal‐Wallis to compare groups with respect to the primary outcome, and Spearman's rank correlation coefficient test for linear associations. P < 0.5 was considered statistically significant.

RESULTS

Patient characteristics

We recruited 30 participants in total: 10 patients with SSc and calcinosis, 10 patients with SSc without calcinosis, and 10 age and gender‐matched healthy individuals. Patients with SSc were all women and Hispanic, and the majority (n = 12, 60%) had limited SSc skin type. Mean ± SD age was 55.2 ± 14.8 years, mean disease duration was 13.3 ± 7 years from RP onset and 9.5 ± 6.5 from first non‐RP symptom, mean modified Rodnan Skin Score (mRSS) was 9.5 ± 7. Patients with and without calcinosis were similar with regard to demographic and clinical characteristics, including smoking history, osteoporosis, autoantibody status, internal organ involvement, and use of medications. Digital ischemia (defined as the presence of DU, loss of digital pulp, or digital pitting) was significantly more frequent in the calcinosis group. However, RP severity, assessed by the Raynaud Condition Score, was higher for patients with SSc without calcinosis. Additionally, patients with SSc with calcinosis were more likely to have concomitant positive Ro‐52 antibodies compared to those without calcinosis. (Supplementary Table 1)

Calcinosis characteristics

Calcinosis was most frequently found on fingers, especially the right thumb. One third of patients had calcinosis that was greater than 1 cm at physical examination, 20% had subclinical calcinosis, and most patients (80%) had calcinosis on multiple locations. (Supplementary Table 2) In terms of severity, the patient global calcinosis VAS was 49 (range 10–90), and the median SCTC radiologic score was 11.1 (within a range from 0.7–286.6). (Supplementary Figure 1)

Osteoclastogenesis

After 9 days in culture, PBMCs from patients with calcinosis originated a significantly higher number of osteoclasts (mean ± SD 33.0 ± 20.3 cells/well) than patients without calcinosis (15.3 ± 6.9 cells/well) and healthy individuals (mean ± SD 11.2 ± 2.6 cells/well; P = 0.001; Figures 1 and 2). The severity of calcinosis, as assessed by SCTC radiologic scoring, did not show a significant correlation with the number of osteoclasts per well (r = 0.27, P = 0.5). Although the sample size was small, with only eight patients having calcinosis in multiple locations (defined as two or more body areas involved), there was a numerical trend indicating that these patients tended to generate more osteoclasts compared to those with calcinosis in a single location (mean ± SD 37.6 ± 19.7 vs mean ± SD 17 ± 16 cells/well).

Number of osteoclasts in healthy controls (HCs), patients without calcinosis, and patients with calcinosis. A significant increase in the number of osteoclasts is observed in patients with calcinosis compared with HCs (P < 0.05). N^o, number of.

Tartrate‐resistant acid phosphatase–stained multinucleated giant cells obtained from (A) PBMCs from a healthy individual and (B) a patient with SSc‐related calcinosis. PBMCs, peripheral blood mononuclear cells, SSc, systemic sclerosis.

VEGF, Ang‐1, and Ang‐2 measurement

VEGF plasma levels were numerically lower in patients with SSc with calcinosis than in patients with SSc without calcinosis and in healthy individuals; however, this did not reach statistical significance (patients with SSc‐calcinosis, mean ± SD 28.7 ± 22 pg/mL vs healthy control group, mean ± SD 61.1 ± 73.2 pg/mL vs patients with SSC without calcinosis, mean ± SD 80.93 ± 137 pg/mL; P = 0.440). There was not a significant correlation between levels of VEGF and osteoclast number in patients with SSc without calcinosis (r = 0.19, P = 0.4) nor in patients with calcinosis (r = −0.17, P = 0.654). In patients with SSc with calcinosis, the severity of calcinosis was correlated with Ang‐2 (r = 0.86, P = 0.002).

Markers of bone resorption

There were no statistically significant differences in markers of calcium turnover in patients with SSc with and without calcinosis and the healthy control group, except for OPG was significantly lower in patients with SSc as compared with healthy individuals (mean ± SD 1,415 ± 731 vs mean ± SD 5,510 ± 5,141; P = 0.001; Table 1) In patients with SSc with calcinosis, the severity of calcinosis was correlated with RANKL (r = 0.82, P = 0.004), and RANKL/OPG ratio (r = 0.86, P = 0.002).

Table 1.

Markers of bone resorption in patients with SSc without and with calcinosis and healthy individuals^*

Characteristic	Without calcinosis	With calcinosis	Healthy control group	P value
Calcium level, mean ± SD, mg/dL	9.3 ± 0.36	9.3 ± 0.6	9.2 ± 0.3	0.820
Phosphate level, mean ± SD, mg/dL	3.9 ± 0.6	3.7 ± 0.7	3.5 ± 0.6	0.360
CTX level, mean ± SD, ng/mL	0.5 ± 0.2	0.4 ± 0.1	0.4 ± 0.2	0.478
PTH level, mean ± SD, pg/mL	47 ± 24.5	50.3 ± 31.5	49.4 ± 10.9	0.949
T‐score lumbar spine	−0.750 ± 0.715	−1.000 ± 1.068	−1.030 ± 1.191	0.795
T‐score right femur	−1.278 ± 1.043	−1.190 ± 0.940	−0.940 ± 0.965	0.737
T‐score left femur	−1.170 ± 0.973	−1.140 ± 0.886	−1.050 ± 0.912	0.955
Osteopenia, n (%)	5 ± 50	5 ± 50	8 ± 80	0.287
Osteoporosis, n (%)	2 ± 20	1 ± 10	2 ± 20	0.787
Vertebral fracture, n (%)	0 ± 0	1 ± 10	1 ± 10	0.618
RANKL level, mean ± SD, pg/mL	2598.7 ± 4443.1	2356.2 ± 4504.2	225.9 ± 416.7	0.297
OPG level, mean ± SD, pg/mL	1130 ± 258.4	1700 ± 939.3	5510 ± 5141.9	0.006
Ratio RANKL/OPG, mean ± SD	2.832 ± 5.2	1.514 ± 2.9	0.111 ± 0.2	0.229

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n = 10 for all participant groups. CTX, C‐telopeptide of Type I collagen; OPG, osteoprotegerin; PTH, parathyroid hormone; SSc, systemic sclerosis.

DISCUSSION

Calcinosis cutis is a common and underrecognized condition in patients with SSc; the pathogenesis is poorly understood, resulting in a lack of effective treatment options. ² Osteoclastogenesis, the process of osteoclast formation, was investigated in this study to explore its potential involvement in calcinosis pathogenesis. We demonstrated that calcinosis in patients with SSc was associated with an increased propensity of peripheral blood cells to form osteoclasts. This finding suggests that an increased osteoclast activity may contribute to the development of calcinosis in patients with SSc. Conceptually, a shift of calcium from the skeleton toward the subcutaneous tissues could be a mechanism involved. It is also possible that osteoclasts are attempting to dissolve these aberrant deposits, but further research is needed to fully understand their role in this process.

Importantly, a previous study of PBMCs and VEGF plasma levels obtained from 26 patients with SSc and 14 healthy individuals showed that VEGF was associated with increased osteoclastogenesis and osteoclast activity in patients with SSc with AO, the resorption or destruction of the bone tissue in the distal parts of the fingers. Notably, 73% of these patients also had calcinosis. ⁶ Although our study confirmed elevated osteoclastogenesis in patients with SSc with calcinosis, we found that VEGF plasma levels were numerically lower in patients with SSc with calcinosis compared with both patients with SSc without calcinosis and healthy individuals. Furthermore, we did not observe a significant correlation between VEGF levels and the number of osteoclasts in patients with SSc, suggesting that factors other than ischemia might regulate osteoclastogenesis in calcinosis without AO.

It has been hypothesized that in patients with SSc, a shifting cellular phenotype in which dermal fibroblasts adopt a pro‐osteogenic profile creates a microenvironment conducive to soft tissue calcification. Key drivers of this osteogenic differentiation might include the release of inorganic phosphates into surrounding soft tissue following ischemia‐induced AO, as well as vascular damage leading to platelet activation. ¹⁴ In the absence of AO, however, hypoxia‐driven mechanisms may be less prominent, allowing alternative pathways for calcification to emerge. The lack of a significant correlation between the severity of calcinosis (as assessed by the SCTC radiologic score) and the number of osteoclasts per well reinforces the idea that factors other than osteoclastogenesis may contribute to calcinosis severity in patients with SSc. Interestingly, levels of Ang‐2, a marker of disrupted angiogenesis, were significantly correlated with the severity of calcinosis, further supporting the hypothesis that vascular damage plays a key role in driving calcinosis. Elevated Ang‐2 levels have shown to be associated with greater disease severity and activity in patients with SSc, potentially serving as a new biomarker for disease activity in patients with SSc. ¹⁵

Osteoprotegerin (OPG) levels were significantly lower in patients with SSc as compared with the healthy control group. Although the differences in OPG levels between patients with SSc with and without calcinosis were not statistically significant, there was a noticeable trend toward higher OPG levels in patients with calcinosis. Similarly, a study involving 60 patients with SSc and 60 age‐ and sex‐matched healthy individuals found that although OPG levels were generally similar between the two groups, they were notably higher in patients with calcinosis and DUs. In a multivariate regression analysis, which included factors such as active ulcers, calcinosis, coronary risk, and CTX as potential independent predictors of OPG, calcinosis was significantly associated with elevated OPG levels. ¹⁶ As mentioned, OPG is a soluble decoy receptor of the tumor necrosis factor receptor (TNF) superfamily that plays a crucial role in regulating bone resorption by inhibiting osteoclast activity. It is secreted by various cell types, including osteoblasts, and functions as a receptor antagonist, blocking the interaction between RANKL and its cellular receptor RANK, which is expressed on osteoclasts. ¹⁷ Additionally, circulating OPG levels have also been associated with the extent of vascular calcification. ¹⁸ The higher levels of OPG observed in patients with calcinosis could suggest a potential compensatory mechanism to counterbalance increased osteoclast activity. However, further research is needed to determine the clinical significance of this trend and its implications for calcinosis development and progression in patients with SSc.

In the bone microenvironment, RANKL is primarily expressed by stromal and osteoblastic lineage cells. When RANKL binds to its receptor, RANK, it stimulates the differentiation and fusion of osteoclast precursors, activates mature osteoclasts, and prolongs their life span by inhibiting apoptosis, leading to increased bone resorption. Interestingly, although RANKL is virtually absent in normal vasculature, it is overexpressed in vulnerable atherosclerotic lesions prone to rupture, where it has been implicated in plaque destabilization. In vascular smooth muscle cells, RANKL also enhances matrix metalloproteinase activity and promotes osteogenic differentiation and calcification. ¹⁶ In our study, we observed a positive correlation between the severity of calcinosis and both RANKL levels and the RANKL/OPG ratio, suggesting heightened osteoclast activity and increased bone resorption associated with calcinosis. However, the numerically higher levels of RANKL in patients with SSc without calcinosis, despite their lower osteoclast numbers, are intriguing. This discrepancy suggests that factors other than the RANK/RANKL/OPG pathway may be influencing osteoclast activity and calcinosis formation in these patients. Several alternative pathways could be involved in regulating osteoclast activity. For instance, infiltrating inflammatory cells and the cytokine milieu provide multiple routes to bone destruction, as shown in inflammatory arthritis, in which pro‐inflammatory cytokines such as TNF‐α and IL‐1 can promote osteoclastogenesis and bone resorption. ¹⁹

Bisphosphonates may be useful in reversing the calcification process by inhibiting macrophage proinflammatory cytokine production and reducing bone resorption. Bisphosphonates are the most likely treatment to be used by experienced physicians for calcinosis in juvenile dermatomyositis (JDM). There are reports of calcinosis improving or even disappearing after various regimens of bisphosphonates in patients with JDM. ²⁰ However, there are limited data available for patients with SSc. Given the increased systemic tendency to form osteoclasts that we observed in patients with SSc with calcinosis, using RANKL inhibitors like bisphosphonates or denosumab, which specifically target osteoclastogenesis, could be a potential approach for managing calcinosis in patients with SSc.

Our study has several limitations. The cross‐sectional design limits our ability to evaluate the dynamics of the associations observed, particularly in terms of causality and the directionality of these relationships. Additionally, the relatively small sample size reduces the statistical power of our findings, making subgroup analyses more exploratory and hypothesis‐generating rather than conclusive. Nonetheless, this study is the first to suggest a potential link between osteoclastogenesis and calcinosis, offering new insights into the mechanisms that may be involved in the pathogenesis of calcinosis.

In conclusion, in the present study osteoclastogenesis was significantly higher in patients with SSc with calcinosis, suggesting a potential involvement of osteoclasts in calcinosis pathogenesis. Markers of bone resorption did not differ significantly between the groups, but OPG levels showed a trend toward higher values in patients with calcinosis and the severity of calcinosis positively correlated with both RANKL levels and the RANKL/OPG ratio. Targeted inhibition of osteoclastogenesis may provide a specific therapeutic option for patients with SSc‐associated calcinosis. Further research is needed to better understand the underlying mechanisms and clinical implications of calcinosis in patients with SSc.

AUTHOR CONTRIBUTIONS

All authors contributed to at least one of the following manuscript preparation roles: conceptualization AND/OR methodology, software, investigation, formal analysis, data curation, visualization, and validation AND drafting or reviewing/editing the final draft. As corresponding author, Dr Valenzuela confirms that all authors have provided the final approval of the version to be published and takes responsibility for the affirmations regarding article submission (eg, not under consideration by another journal), the integrity of the data presented, and the statements regarding compliance with institutional review board/Declaration of Helsinki requirements.

Supporting information

Disclosure form.

ACR2-7-e70029-s002.pdf^{(125.4KB, pdf)}

Supplementary Figure 1A: Hand radiograph of a patient with the highest calcinosis SCTC radiographic score, demonstrating extensive calcinosis (SCTC radiographic score=286.6)

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Supplementary Figure 1B: Hand radiograph of a patient with the lowest calcinosis SCTC radiographic score, showing minimal calcinosis (SCTC radiographic score=0.7).

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Supplementary Figure 1C: Hand radiograph of a patient with a median calcinosis SCTC radiographic score, illustrating close to median calcinosis (SCTC radiographic score=13.1).

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Table S1: Demographics and clinical characteristics of SSc patients

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Table S2: Characteristics of calcinosis in SSc patients

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Dr Valenzuela'swork was supported by an Agencia Nacional de Investigación y Desarrollo (ANID) Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT) de Iniciación en Investigación development grant (11190426) and a Scleroderma Clinical Trial Consortium Working Group grant.

¹Antonia Valenzuela, MD, MS, Guillermo Pérez, BS, Felipe Sánchez, PhD, Carolina Iturriaga, RN, Rebeca Montalva, BS, Arturo Borzutzky, MD: Pontificia Universidad Católica de Chile, Santiago, Chile; ²Lorinda Chung, MD, MS: Stanford University School of Medicine, Palo Alto, California.

Additional supplementary information cited in this article can be found online in the Supporting Information section (https://acrjournals.onlinelibrary.wiley.com/doi/10.1002/acr2.70029).

Author disclosures are available at https://onlinelibrary.wiley.com/doi/10.1002/acr2.70029.

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Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

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ACR2-7-e70029-s002.pdf^{(125.4KB, pdf)}

Supplementary Figure 1A: Hand radiograph of a patient with the highest calcinosis SCTC radiographic score, demonstrating extensive calcinosis (SCTC radiographic score=286.6)

ACR2-7-e70029-s004.png^{(4.9MB, png)}

Supplementary Figure 1B: Hand radiograph of a patient with the lowest calcinosis SCTC radiographic score, showing minimal calcinosis (SCTC radiographic score=0.7).

ACR2-7-e70029-s001.png^{(4.6MB, png)}

Supplementary Figure 1C: Hand radiograph of a patient with a median calcinosis SCTC radiographic score, illustrating close to median calcinosis (SCTC radiographic score=13.1).

ACR2-7-e70029-s003.png^{(4.8MB, png)}

Table S1: Demographics and clinical characteristics of SSc patients

ACR2-7-e70029-s006.docx^{(18.6KB, docx)}

Table S2: Characteristics of calcinosis in SSc patients

ACR2-7-e70029-s005.docx^{(16.1KB, docx)}

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PERMALINK

Osteoclastogenesis in Patients With Systemic Sclerosis With and Without Calcinosis Cutis

Antonia Valenzuela

Guillermo Pérez

Lorinda Chung

Felipe Sánchez

Carolina Iturriaga

Rebeca Montalva

Arturo Borzutzky

Abstract

Objective

Methods

Results

Conclusion

INTRODUCTION

PATIENTS AND METHODS

Study population

Study measures

Plasma and cell preparation

VEGF, Ang‐1, and Ang‐2 measurement

Bone turnover markers

Determination of circulating osteoclast precursor cells

Statistical analysis

RESULTS

Patient characteristics

Calcinosis characteristics

Osteoclastogenesis

Figure 1.

Figure 2.

VEGF, Ang‐1, and Ang‐2 measurement

Markers of bone resorption

Table 1.

DISCUSSION

AUTHOR CONTRIBUTIONS

Supporting information

REFERENCES

Associated Data

Supplementary Materials

ACTIONS

PERMALINK

RESOURCES

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