Undifferentiated connective tissue disease at risk for systemic sclerosis: Which patients might be labeled prescleroderma?

What have we learned on pre, very early, and early systemic sclerosis microcirculatory pathophysiology? A scoping review

OBJECTIVE

Microvascular dysfunction is an early event in the pathogenesis of systemic sclerosis (SSc). The objective of this scoping review is to update the current information and the level of knowledge about the mechanisms of microvascular dysfunction in pre-SSc, very early diagnosis of SSc (VEDOSS) and early SSc.

METHODS

A PubMed® database search allowed us to include original data from full-length articles in English in which the main topic was microvascular dysfunction in pre-SSC, VEDOSS or early SSc. Data was extracted using a customized form.

RESULTS

In the present review 437 articles were identified, and 42 studies included, reporting data from a total of 1069 patients with pre-SSc, VEDOSS or early-SSc. Distinct mechanisms of microvascular injury were identified comprising, angiogenesis and vasculogenesis, cell surface proteins and adhesion, molecules expression, cytokines profile, inflammatory and oxidation pathways, and skin perfusion determinants. Most of the studies were conducted in early SSc, with a reduced number in pre-disease stages, in which the prompt recognition of specific mechanisms and biomarkers may allow targeted treatment to prevent disease progression.

CONCLUSIONS

Although different molecular expression patterns and signaling pathways related to microvascular dysfunction in pre-SSc, VEDOSS, and early SSc were identified, additional prospective longitudinal studies and combined work with functional evaluation of peripheral skin perfusion are needed.

The Value of Nailfold Capillaroscopy in the Classification and Differential Diagnosis of Raynaud's Phenomenon in Rheumatology

Among instrumental techniques, nailfold capillaroscopy plays a leading role in the assessment of Raynaud's phenomenon (RP) patients because it is the only method that provides opportunities for morphological assessment of capillaroscopic findings in the nailfold area, with proven diagnostic and prognostic significance in rheumatology. The discussion about updating the classification of RP in rheumatology is interesting given the current understanding of capillaroscopic findings in rheumatic diseases and improvements in immunological diagnostics. The presence of dilation of the "true" capillary diameters in primary RP could be observed. There are some cases of primary RP where the capillaroscopic pattern is completely normal and there are no dilated capillaries present, which could be related to the duration and severity of the symptoms. It is possible that longer duration and greater severity are associated with the appearance of capillary dilations, but more research is needed to confirm it. Rarely, pathological capillaroscpic features of microangiopathy could be observed in RP patients in whom clinical, laboratory and immunological findings are compatible with the diagnosis "primary RP". These cases should be defined as "suspected secondary RP" and require closer follow-up for the assessment of symptom evolution. Abnormal "scleroderma" type capillaroscopic pattern has been established as a new classification criterion for systemic sclerosis (SSc) in 2013. Similar changes ("scleroderma-like" pattern) could be observed in other rheumatic diseases, i.e., undifferentiated connective tissue disease (UCTD), systemic lupus erythematosus, dermatomyositis, rheumatoid arthritis, including without evidence of overlap with scleroderma. The appearance of such microvascular abnormalities at disease presentation is less well studied in diseases different from SSc. However, "scleroderma-like" microangiopathy has also been reported as an initial sign in some systemic rheumatic diseases, such as UCTD and systemic lupus erythematosus. Thus, interpretation of capillaroscopic findings is performed in overall context, including clinical findings and laboratory and immunological test results.

Microvascular damage in autoimmune connective tissue diseases: a capillaroscopic analysis from 20 years of experience in a EULAR training and research referral centre for imaging

OBJECTIVE

Nailfold videocapillaroscopy (NVC) allows the detection of microvascular damage in autoimmune connective tissue diseases (CTDs). The prevalence of the morphological capillary findings was retrospectively evaluated in a wide cohort of patients with Raynaud's phenomenon secondary to a CTD at the time of the first single NVC, independently from their current treatment, autoantibody profile and comorbidities.

METHODS

One-thousand-one-hundred-eighty-one patients affected by CTDs were included from 2001 to 2021. The considered CTDs were systemic sclerosis (SSc), undifferentiated connective tissue disease (UCTD), mixed connective tissue disease (MCTD), dermatomyositis (DM), systemic lupus erythematosus, Sjögren's syndrome and primary antiphospholipid syndrome (aPS). The capillaroscopic parameters were distinguished between scleroderma patterns and non-scleroderma patterns.

RESULTS

Giant capillaries were significantly more frequent in SSc, DM and MCTD than in other CTDs (respectively, in 73%, 73% and 61% of patients, p<0.001 when comparing each rate vs the other CTDs). The mean capillary count was significantly lower in SSc, DM and MCTD (respectively, 7.04±0.18 vs 6.5±0.75 vs 7.7±2 capillaries/linear mm) compared with the other CTDs (p<0.001 for each rate vs the other CTDs). The non-specific abnormalities of capillary morphology were significantly more frequent in SSc, MCTD and aPS (respectively, in 48%, 41% and 36% of cases, all p<0.001 vs each other CTDs).

CONCLUSION

This large size sample of patients with CTDs, collected over 20 years of analysis, confirms the highest prevalence of specific capillaroscopic alterations in patients with SSc, DM and MCTD, when compared with other CTDs.

Skin disorders and interstitial lung disease: Part II-The spectrum of cutaneous diseases with lung disease association

Part 2 of this 2-part CME introduces dermatologists to noninfectious inflammatory skin diseases associated with pulmonary involvement. In many cases, dermatologists may be the first physicians recognizing respiratory complications associated with these diagnoses. Because pulmonary involvement is often the leading cause of morbidity and mortality, dermatologists should be comfortable screening and monitoring for lung disease in high-risk patients, recognizing cutaneous stigmata of lung disease in these patients and referring to pulmonary specialists, when appropriate, for prompt treatment initiation. Some treatments used for skin disease may not be appropriate in the context of lung disease and hence, choosing a holistic approach is important. Interstitial lung disease and pulmonary hypertension are the most common pulmonary complications and a significant cause of mortality in autoimmune connective tissue diseases, especially systemic sclerosis, dermatomyositis, and mixed connective tissue disease. Pulmonary complications, notably interstitial lung disease, are also common and life-threatening in sarcoidosis and vasculitis, while they are variable in neutrophilic and autoimmune blistering diseases.

Can Antinuclear Antibodies Have a Pathogenic Role in Systemic Sclerosis?

Systemic sclerosis (SSc) is a connective tissue disease characterized by extensive fibrosis of the skin and internal organs, associated with vasculopathy and autoimmune features. Antinuclear antibodies (ANA) are found in almost all SSc patients and constitute strong diagnosis and prognosis biomarkers. However, it remains unclear whether ANA are simple bystanders or if they can have a role in the pathophysiology of the disease. One might think that the nuclear nature of their targets prevents any accessibility to autoantibodies. Nevertheless, recent data suggest that ANA could be pathogenic or at least contribute to the perennation of the disease. We review here first the indirect clues of the contribution of ANA to SSc: they are associated to the disease subtypes, they may precede disease onset, their titer correlates with disease activity and severity, there is an association between molecular subsets, and some patients can respond to B-cell targeting therapy. Then, we describe in a second part the mechanisms of ANA production in SSc from individual genetic background to post-transcriptional modifications of neoantigens. Finally, we elaborate on the potential mechanisms of pathogenicity: ANA could be pathogenic through immune-complex-mediated mechanisms; other processes potentially involve molecular mimicry and ANA penetration into the target cell, with a focus on anti-topoisomerase-I antibodies, which are the most probable candidate to play a role in the pathophysiology of SSc. Finally, we outline some technical and conceptual ways to improve our understanding in this field.

Precursors to Systemic Sclerosis and Systemic Lupus Erythematosus: From Undifferentiated Connective Tissue Disease to the Development of Identifiable Connective Tissue Diseases

The pathogenesis of connective tissue diseases (CTDs), such as systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), is characterized by derangements of the innate and adaptive immune system, and inflammatory pathways leading to autoimmunity, chronic cytokine production, and chronic inflammation. The diagnosis of these diseases is based on meeting established criteria with symptoms, signs and autoantibodies. However, there are pre-clinical states where criteria are not fulfilled but biochemical and autoimmune derangements are present. Understanding the underlying processes responsible for disease pathogenesis in pre-clinical states, which place patients at increased risk for the development of established connective tissue diseases, represents an opportunity for early identification and potentially enables timely treatment with the goal of limiting disease progression and improved prognosis. This scoping review describes the role of the innate and adaptive immune responses in the pre-clinical states of undifferentiated CTD at risk for SSc and prescleroderma, the evolution of antibodies from nonspecific to specific antinuclear antibodies prior to SLE development, and the signaling pathways and inflammatory markers of fibroblast, endothelial, and T cell activation underlying immune dysregulation in these pre-clinical states.

A Narrative Review of Pathogenetic and Histopathologic Aspects, Epidemiology, Classification Systems, and Disease Outcome Measures in Systemic Sclerosis

Systemic sclerosis (SSc) is a rare systemic autoimmune disease, characterized by the presence of three main actors: vasculopathy, immune activation, and fibrosis. This pathologic process is then translated in a clinical picture with great variability among different patients in terms of type of organ involvement, disease severity and prognosis. This heterogeneity is a main feature of SSc, which, in addition to the presence of early phases of the disease characterized by mild symptoms, can explain the high difficulty in establishing classification criteria, and in defining patients' subsets and disease outcomes. The definition of disease outcomes is particularly relevant in the setting of clinical trials, where the aim is to provide reliable endpoints, able to measure the magnitude of the efficacy of a certain drug or intervention. For this reason, in the last years, increasing efforts have been done to design measures of disease activity, damage, severity, and response to treatment, often in the context of composite indexes. When considering disease outcomes, the experience of the patient represents a relevant and complementary aspect. The tools able to capture this experience, the patient-reported outcomes, have been increasingly used in the last years in clinical practice and in clinical trials, both as primary and secondary endpoints. This comprehensive narrative review on SSc will therefore cover pathogenetic and histopathologic aspects, epidemiology, classification systems, and disease outcome measures, in order to focus on issues that are relevant for clinical research and design of clinical trials.

Polycystic ovary syndrome: epidemiologic assessment of prevalence of systemic rheumatic and autoimmune diseases

BACKGROUND

Polycystic ovary syndrome (PCOS) causes anovulation and hyperandrogenism. Hormonal imbalance is known to contribute to systemic autoimmune diseases.

OBJECTIVE

To examine the frequency of certain rheumatic diseases in PCOS.

METHODS

This retrospective study utilized and analyzed electronic medical records from January 2004 through February 2020. A diagnosis of PCOS and specified rheumatic diseases was searched using ICD-9 and ICD-10 codes. A total of 754 adult patients with PCOS and 1,508 age- and body mass index-matched patients without PCOS were included. Frequencies of the rheumatic diseases were compared between PCOS and non-PCOS subjects or literature data.

RESULTS

The prevalence of rheumatoid arthritis (RA) was found to be 2.25% (17/737) in the PCOS patients, numerically higher than 1.26% (19/1489) in the non-PCOS subjects. The difference was significant with a confidence level of 90% (1.04-3.15) but not at 95% with an odds ratio of 1.808 (95% CI = 0.934-3.4, p = 0.0747). When compared with the literature data from the US female population, the prevalence of RA in PCOS patients was significantly higher (2.25% vs. 1.40%, p < 0.0001). Among the autoimmune diseases examined, both systemic sclerosis (0.40% vs. 0.0%, p = 0.0369) and undifferentiated connective tissue disease (0.53% vs. 0.0%, p = 0.0123) were significantly more frequent in the PCOS patients than the non-PCOS. Additionally, PCOS patients had a significantly higher frequency of osteoarthritis than non-PCOS patients (5.44% vs. 2.92%, p = 0.0030) with an odds ratio of 1.913 (95% CI = 1.239-2.955).

CONCLUSION

We have shown unprecedentedly that certain rheumatic diseases are more prevalent in PCOS. This study provides important insight into autoimmunity in association with PCOS. Key Points • Polycystic ovary syndrome is postulated to cause systemic autoimmune disease due to its hormonal imbalance. • We conducted the first epidemiologic assessment of the prevalence of systemic autoimmune diseases. • Certain autoimmune and rheumatic diseases are more prevalent in polycystic ovary syndrome.

New Autoantibody Specificities in Systemic Sclerosis and Very Early Systemic Sclerosis

Chemokine (C-X-C motif) ligand 4 (CXCL4) is a biomarker of unfavorable prognosis in Systemic Sclerosis (SSc), a potentially severe autoimmune condition, characterized by vasculitis, fibrosis and interferon (IFN)-I-signature. We recently reported that autoantibodies to CXCL4 circulate in SSc patients and correlate with IFN-α. Here, we used shorter versions of CXCL4 and CXCL4-L1, the CXCL4 non-allelic variant, to search for autoantibodies exclusively reacting to one or the other CXCL4 form. Moreover, to address whether anti-CXCL4/CXCL4-L1 antibodies were present before SSc onset and predicted SSc-progression, we longitudinally studied two VEDOSS (Very Early Diagnosis of Systemic Sclerosis) patient cohorts, separating SSc-progressors from SSc-non-progressors. We found that anti-CXCL4-specific autoantibodies were present in both SSc and VEDOSS patients (both SSc-progressors and SSc-non-progressors). Anti-CXCL4-L1-specific autoantibodies were especially detected in long-standing SSc (lsSSc). Anti-CXCL4/CXCL4-L1 antibodies correlated with IFN-α and with specific SSc-skin features but only in lsSSc and not in early SSc (eaSSc) or VEDOSS. Thus, a broader antibody response, with reactivity spreading to CXCL4-L1, is characteristic of lsSSc. The early anti-CXCL4 autoantibody response seems qualitatively different from, and likely less pathogenic than, that observed in advanced SSc. Lastly, we confirm that anti-CXCL4 autoantibodies are SSc-biomarkers and uncover that also CXCL4-L1 becomes an autoantigen in lsSSc.

Scleroderma epidemiology update

PURPOSE OF REVIEW

Systemic sclerosis (scleroderma, SSc) is a rare multisystem autoimmune disease characterized by autoantibodies, vasculopathy, and fibrosis of the skin and internal organs. This review aims to provide an overview and summary of the recent epidemiological studies in systemic sclerosis.

RECENT FINDINGS

Global trends of scleroderma demonstrate greater prevalence of SSc in European, North, and South American patients compared with East Asian patients. However, the greatest prevalence (47 in 100 000), was found among the indigenous peoples in Canada. Phenotypical differences exist depending on the age of presentation with greater internal organ involvement and disease acceleration present in older patients. Sex differences include greater severity of disease expression, relative prevalence of diffuse cutaneous SSc, and organ involvement in males versus females. New studies conflict with previous data reporting greater proportion of pulmonary arterial hypertension in females. Furthermore, the effect of low median household income is demonstrated as a factor increasing risk of death in SSc patients.

SUMMARY

Understanding the epidemiological factors in SSc enables patient care through patient classification, prognostication, and monitoring. Future research may emphasize enrichment of SSc patients in randomized trials who are more likely to progress or be treatment responsive, focused screening, and personalized patient care through the creation and validation of new SSc criteria and subsets.