Sublingual Abnormalities in Systemic Sclerosis

Does sublingual microscopy correlate with nailfold videocapillaroscopy in systemic sclerosis?

In this study, we examine sublingual videomicroscopy and nailfold videocapillaroscopy (NVC) features in systemic sclerosis (SSc) patients presenting for routine care. Consented participants met classification criteria for SSc. Sublingual videomicroscopy testing was performed in each subject, followed by a NVC assessment. Sublingual assessment provided a density measurement, red blood cell fraction (RBC fract), and perfused boundary region (PBR) score. NVC evaluator defined nailfold findings as normal; specific changes for "early," "active," and "late" scleroderma pattern; or "non-specific" changes. Microangiopathy evolution score was calculated for each participant. Statistical evaluation was performed by non-parametric tests to assess the correlation of the two tools. Thirty-nine SSc patients with limited cutaneous disease participated in this study. Most participants had late pattern NVC. There was a highly significant association between the total sublingual microvascular density and number of capillaries measured by NVC (r = 0.569, P = 0.0002), and statistically significant negative correlation between sublingual total microvascular density and microangiopathy evolution score (r = 0.532, P = 0.0006). There was significant, negative correlation between the total sublingual microvascular density and disorganization of vascular array and capillary ramification (r = 0.461, P = 0.003) and degree of giant capillaries (r = 0.387, P = 0.01). There was no correlation between RBC fract and PBR with NVC parameters. This study showed a significant correlation between sublingual videomicroscopy and NVC in terms of sublingual total microvascular density and microangiopathy evolution score. These preliminary results further support the serial use of a non-invasive and automated sublingual microvascular function testing and glycocalyx measurement in the clinical setting. KEY POINTS: • Tools that longitudinally assess microvascular function and morphologic features are important for monitoring SSc vasculopathy. • Nailfold and sublingual microscopy can identify a loss of capillary density in SSc patients.

Gastrointestinal and Hepatic Disease in Systemic Sclerosis

Although classification criteria for systemic sclerosis (SSc) do not incorporate gastrointestinal tract (GIT) manifestations often present in this disease, the GIT is the most common internal organ involved. Pathophysiology of GIT involvement is thought to be similar to other organs in SSc with fibroproliferative vascular lesions of small arteries and arterioles, increased production of profibrotic growth factors, and alterations of innate, humoral, and cellular immunity. These processes result in neuropathy progressing to myopathy with eventual fibrosis. Proper diagnostics and therapeutics for SSc-GIT involvement require the treating physician to have an understanding of an integrated approach and potential medication adverse effects.

Orofacial manifestations of systemic sclerosis

Systemic sclerosis (SSc) is a multisystem disease of unknown aetiology characterised by microangiopathy, dysregulated immune function and tissue remodelling, which commonly involves the oral cavity. Orofacial manifestations of SSc contribute greatly to overall disease burden and yet are regularly overlooked and under-treated. This may reflect a pre-occupation amongst rheumatology clinicians on potentially life-threatening internal organ involvement, but is also a consequence of insufficient engagement between rheumatologists and dental professionals. A high proportion of SSc patients report difficulty accessing a dentist with knowledge of the disease and there is recognition amongst dentists that this could impact negatively on patient care. This review shall describe the clinical features and burden of orofacial manifestations of SSc and the management of such problems. The case is made for greater collaborative working between rheumatologists and dental professionals with an interest in SSc in both the research and clinical setting.

Automated Measurement of Microvascular Function Reveals Dysfunction in Systemic Sclerosis: A Cross-sectional Study

OBJECTIVE

The aim of our study was to determine whether an automated capture and analysis system could detect differences in structure and function of sublingual microvessels in patients with systemic sclerosis (SSc) compared to healthy controls.

METHODS

Intravital microscopy of the sublingual microcirculation was automatically captured and analyzed in 40 patients with SSc and 10 age-matched healthy controls.

RESULTS

Total and perfused microvascular density were lower in patients with SSc compared with controls (total microvascular density: 2471 ± 134 µm/mm² vs 3067 ± 197 µm/mm², p = 0.020; perfused microvascular density: 1708 ± 92 µm/mm² vs 2192 ± 144 µm/mm², p = 0.009). However, the relative percentage of perfused to total microvascular density was similar between SSc and controls (72 ± 2% vs 71 ± 2%, respectively, p = 0.429). Mean red blood cell (RBC) fraction, which indicates the longitudinal tube hematocrit of microvessel segments, was lower in patients with SSc compared with controls (69 ± 1% vs 77 ± 1%, respectively, p < 0.001). Perfused boundary region (PBR), a marker of endothelial glycocalyx barrier properties, was higher in patients with SSc compared with controls (2.1 ± 0.0 µm vs 1.9 ± 0.0 µm, respectively, p = 0.012), suggestive of a dysfunctional glycocalyx. There was an inverse association of PBR with perfused microvascular density (r = -0.40, p = 0.004) and RBC fraction (r = -0.80, p < 0.001).

CONCLUSION

Our results indicate that automated capture and analysis of sublingual microvessel segments produces detailed, objective microvascular structural and functional data that have allowed us to distinguish patients with SSc from controls. These data suggest that microvascular structural and functional abnormalities present in patients with SSc could be at least partly due to a dysfunctional glycocalyx.

Review article: pathogenesis and clinical manifestations of gastrointestinal involvement in systemic sclerosis

BACKGROUND

Gastrointestinal tract (GIT) involvement is a common cause of debilitating symptoms in patients with systemic sclerosis (SSc). There are no disease modifying therapies for this condition and the treatment remains symptomatic, largely owing to the lack of a clear understanding of its pathogenesis.

AIMS

To investigate novel aspects of the pathogenesis of gastrointestinal involvement in SSc. To summarise existing knowledge regarding the cardinal clinical gastrointestinal manifestations of SSc and its pathogenesis, emphasising recent investigations that may be valuable in identifying potentially novel therapeutic targets.

METHODS

Electronic (PubMed/Medline) and manual Google search.

RESULTS

The GIT is the most common internal organ involved in SSc. Any part of the GIT from the mouth to the anus can be affected. There is substantial variability in clinical manifestations and disease course and symptoms are nonspecific and overlapping for a particular anatomical site. Gastrointestinal involvement can occur in the absence of cutaneous disease. Up to 8% of SSc patients develop severe GIT symptoms. This subset of patients display increased mortality with only 15% survival at 9 years. Dysmotiity of the GIT causes the majority of symptoms. Recent investigations have identified a novel mechanism in the pathogenesis of GIT dysmotility mediated by functional anti-muscarinic receptor autoantibodies.

CONCLUSIONS

Despite extensive investigation, the pathogenesis of gastrointestinal involvement in systemic sclerosis remains elusive. Although treatment currently remains symptomatic, an improved understanding of novel pathogenic mechanisms may allow the development of potentially highly effective approaches including intravenous immunoglobulin and microRNA based therapeutic interventions.

Systemic sclerosis: The need for structured care

Autoimmune connective tissue diseases (CTDs) have a propensity to affect multiple organ systems as well as physical function, quality of life, and survival. Their clinical heterogeneity, multisystem involvement, and low worldwide prevalence present challenges for researchers to establish a study design to help better understand the course and outcomes of CTDs. Systemic sclerosis (SSc) is a notable example of a CTD, wherein longitudinal cohort studies (LCS) have enabled us to elucidate disease manifestations, disease course, and risk and prognostic factors for clinically important outcomes, by embedding research in clinical practice. Nevertheless, further efforts are needed to better understand SSc especially with regard to recognizing organ involvement early, developing new therapies, optimizing the use of existing therapies, and defining treatment targets. The heterogeneous multi-organ nature of SSc would lend itself well to a structured model of care, wherein step-up treatment algorithms are used with the goal of attaining a prespecified treatment target. In this chapter, we discuss the rationale for a structured treatment approach in SSc and propose possible treatment algorithms for three of the more common disease manifestations, namely skin involvement, digital ulcers and gastrointestinal tract involvement. We discuss possible strategies for evaluating and implementing these algorithms in the setting of LCS. We conclude by presenting a research agenda for the development of structured models of care in SSc.