Association of Raynaud's phenomenon with a polymorphism in the NOS1 gene

Painful Raynaud's mimics

Raynaud's syndrome is a common finding in many autoimmune conditions. Accurately diagnosing Raynaud's, and differentiating it from mimicking conditions, is imperative in rheumatologic diseases. Raynaud's syndrome and Raynaud's mimickers, especially painful Raynaud's mimickers, can prove a diagnostic challenge for the practicing rheumatologist. Painful Raynaud's mimickers can lead to increased patient stress and unnecessary medical work up; Healthcare providers need to be aware of Raynaud's mimickers when evaluating patient concerns of skin color changes and pain. The present narrative review aims to highlight Raynaud's syndrome, important painful mimickers that may be seen, diagnosis, and updated management recommendations.

ADRA2A and IRX1 are putative risk genes for Raynaud's phenomenon

Raynaud's phenomenon (RP) is a common vasospastic disorder that causes severe pain and ulcers, but despite its high reported heritability, no causal genes have been robustly identified. We conducted a genome-wide association study including 5,147 RP cases and 439,294 controls, based on diagnoses from electronic health records, and identified three unreported genomic regions associated with the risk of RP (p < 5 × 10-8). We prioritized ADRA2A (rs7090046, odds ratio (OR) per allele: 1.26; 95%-CI: 1.20-1.31; p < 9.6 × 10-27) and IRX1 (rs12653958, OR: 1.17; 95%-CI: 1.12-1.22, p < 4.8 × 10-13) as candidate causal genes through integration of gene expression in disease relevant tissues. We further identified a likely causal detrimental effect of low fasting glucose levels on RP risk (rG = -0.21; p-value = 2.3 × 10-3), and systematically highlighted drug repurposing opportunities, like the antidepressant mirtazapine. Our results provide the first robust evidence for a strong genetic contribution to RP and highlight a so far underrated role of α2A-adrenoreceptor signalling, encoded at ADRA2A, as a possible mechanism for hypersensitivity to catecholamine-induced vasospasms.

Raynaud's Phenomenon with Focus on Systemic Sclerosis

Raynaud’s phenomenon is a painful vascular condition in which abnormal vasoconstriction of the digital arteries causes blanching of the skin. The treatment approach can vary depending on the underlying cause of disease. Raynaud’s phenomenon can present as a primary symptom, in which there is no evidence of underlying disease, or secondary to a range of medical conditions or therapies. Systemic sclerosis is one of the most frequent causes of secondary Raynaud’s phenomenon; its appearance may occur long before other signs and symptoms. Timely, accurate identification of secondary Raynaud’s phenomenon may accelerate a final diagnosis and positively alter prognosis. Capillaroscopy is fundamental in the diagnosis and differentiation of primary and secondary Raynaud’s phenomenon. It is helpful in the very early stages of systemic sclerosis, along with its role in disease monitoring. An extensive range of pharmacotherapies with various routes of administration are available for Raynaud’s phenomenon but a standardized therapeutic plan is still lacking. This review provides insight into recent advances in the understanding of Raynaud’s phenomenon pathophysiology, diagnostic methods, and treatment approaches.

Raynaud's phenomenon

Raynaud's phenomenon (RP) is a common vasospastic condition which affects ~5% of the general population. The majority of individuals have primary RP; however, Raynaud's can also occur secondary to a broad range of underlying medical conditions and drug therapies. RP is a cardinal feature in patients with systemic sclerosis and is often the earliest symptom of the disease. Unlike primary RP, patients with secondary RP can develop persistent digital ischaemia, including ulcers and gangrene. Patients require a comprehensive clinical assessment and investigation, in particular, the detection of autoantibodies and nailfold capillaroscopic abnormalities. Non-pharmacological management is indicated in all patients. There are a wide range of available drug therapies to treat RP, including when complicated by digital ulceration, and surgical intervention is sometimes required. Future research is needed to understand the complex pathogenesis of RP and to measure the impact and severity of RP to develop optimised approaches to management.

Clinical features and risk factors of Raynaud's phenomenon in primary Sjögren's syndrome

Objective

The aim at the current study was to investigate the clinical characteristics and risk factors of Raynaud’s phenomenon (RP) in patients with primary Sjögren’s syndrome (pSS).

Methods

Retrospective analysis of the medical records of 333 new-onset pSS patients was performed. Demographic, clinical, and serological data were compared between individuals with and without RP. Logistic regression analysis was used to identify risk factors.

Results

RP was present in 11.41% of the pSS patients. pSS-RP patients were younger (49.74±14.56 years vs. 54.46±13.20 years, p=0.04) and exhibited higher disease activity (11 [5.75–15] vs. 7 [4–12], p=0.03) than those without. The prevalence of lung involvement was significantly higher in pSS patients with RP (60.53% vs. 17.29%; p<0.001). A significantly higher proportion of patients with pSS-RP tested positive about antinuclear (ANA), anti-RNP, and anti-centromere antibodies (ACA) compared to those without (p=0.003, <0.001, and 0.01, respectively). Multivariate analysis identified lung involvement (odds ratio [OR]=8.81, 95% confidence interval [CI] 2.02–38.47; p=0.04), anti-RNP positive status (OR=79.41, 95% CI 12.57–501.78; p<0.0001), as well as ACA (OR=13.17, 95% CI 2.60–66.72; p=0.002) as prognostic factors for pSS-RP.

Conclusion

The presence of RP defined a subset of pSS with a unique phenotype, manifesting as increased lung involvement and a higher frequency of anti-RNP antibodies and ACA, as well as greater disease activity. These results suggest that RP has clinical and prognostic value of pSS patients. Further prospective studies with a larger number of subjects are warranted to confirm our findings and assess the prognostic and treatment implications of RP in pSS patients.

Key Points • Raynaud’s phenomenon (RP) was present in 38 (11.41%) of 333 patients with primary Sjögren’s syndrome (pSS), with patients with RP exhibiting a younger age and higher disease activity. • The presence of RP indicates a subset of pSS with a unique phenotype, with manifestations including increased lung involvement and a higher frequency of anti-RNP antibodies and anti-centromere antibodies. • Patients with pSS and RP need close follow-up and long-term observation (including assessment of microangiopathy), with specific attention paid to the possible development of clinical features of systemic sclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10067-021-05749-w.

Richter J. Raynaud's Phenomenon: A Vascular Acrosyndrome That Requires Long-Term Care

BACKGROUND

Some 5-10% of the German population are affected by Raynaud's phenomenon (RP). In around 10-20% of cases RP arises from an underlying disease, most commonly a connective tissue disease. This review encompasses the diagnosis and differential diagnosis of RP and examines the efficacy of the currently available pharmaceutical and non-pharmaceutical treatment options.

METHODS

We conducted a selective literature search in PubMed using the search terms "Raynaud's phenomenon", "Raynaud's syndrome," "vasospasm," "vascular acrosyndrome," and "systemic sclerosis," together with a search of the Cochrane Database of Systematic Reviews up to April 2020.

RESULTS

Raynaud's phenomenon mainly affects the fingers or toes and is typically triggered by cold or emotional stressors. The most important diagnostic steps are demonstration of a tendency towards digital vasospasm, exclusion of occlusions in the afferent arteries and acral vessels, nail-fold capillaroscopy, and determination of autoantibody status. Tumor screening should be arranged in the presence of B symptoms or first manifestation of RP in old age. The onset of RP in childhood is a rare occurrence and points to a secondary origin. The principal options for treatment are protection against cold and administration of calcium antagonists, which reduces the occurrence of RP by around 20-40 %. The treatment of RP in patients with systemic sclerosis is described in the recommendations of the European League Against Rheumatism (EULAR).

CONCLUSION

At onset or after years of latency, patients with Raynaud phenomenon may have an underlying disease (most commonly a connective tissue disease). Long-term specialist care is necessary for asymptomatic patients with risk factors and for those with clinically manifest symptoms of an underlying condition alike.

Raynaud's phenomenon

Raynaud's phenomenon (RP) is common, affecting approximately 5% of the population, and is important to the rheumatologist because it is often the presenting symptom of connective tissue disease, especially of systemic sclerosis (SSc)-spectrum disorders. RP therefore provides a window of opportunity for early diagnosis. When RP is associated with SSc it is particularly challenging to treat. This review begins with a discussion of some of the recent advances in our understanding of the pathogenesis of RP: it is through increased understanding of the complex pathophysiology of RP that we are most likely to develop new therapies. The following questions are then addressed (with three clinical scenarios demonstrating key principles of assessment and management): 1. How can we predict underlying connective tissue disease in the patient presenting with Raynaud's? 2. How can we measure severity of Raynaud's? 3. What are the latest advances in treatment of connective tissue disease-related digital vasculopathy?

Association between DIO2 polymorphism and the risk of Kashin-Beck disease in the Tibetan population

BACKGROUND

Kashin-Beck disease (KBD) is a local, multiple and deformable osteoarthropathy, mostly occurring in Tibet. Type 2 iodothyronine deiodinase (DIO2) is implicated in the activation of thyroid hormones to which the bones are very sensitive. Therefore, it is necessary to explore the association between KBD and DIO2 in the Tibetan population.

METHODS

We carried out a case-control study among 316 cases and 320 controls from a Tibetan population. Seven single nucleotide polymorphisms in DIO2 were selected and genotyped using the Agena MassARRAY platform (Agena Bioscience, San Diego, CA, USA). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression analysis. HaploReg (https://pubs.broadinstitute.org/mammals/haploreg/haploreg.php) and GTEx (http://www.gtexportal.org) databases were applied for functional assessment of the polymorphisms.

RESULTS

The "A/C" genotype of rs1352815 (OR = 3.18, 95% CI = 1.14-8.85, p = 0.027) and the "A/G" genotype of rs1388382 (OR = 3.80, 95% CI = 1.30-11.11, p = 0.015) were associated with the susceptibility of KBD under the co-dominant model. With gender stratification analysis, rs1388382 showed obvious evidence for correlation with an elevated risk of KBD in females under the co-dominant model (OR = 3.32, 95% CI = 1.06-10.41, p = 0.039).

CONCLUSIONS

The results obtained in the present study indicate that DIO2 polymorphisms rs1352815 and rs1388382 were correlated with KBD susceptibility among Tibetans, which also sheds new light on the role of DIO2 in the development of KBD.

Raynaud's phenomenon-an update on diagnosis, classification and management

Raynaud's phenomenon (RP) is used to describe a symptom complex caused by digital vascular compromise. RP is a clinical diagnosis. The typically episodic nature of RP has resulted in a reliance upon patient self-report for diagnosis. The term 'primary RP' is generally applied when no underlying pathology can be demonstrated. Whilst 'primary RP' is currently considered a distinct disorder, there is evidence that the term may comprise several entities that include a functional vasospastic disorder, a physiologically appropriate thermoregulatory response, subclinical atherosclerosis and 'cold intolerance'. Optimal management may differ depending on cause. The term 'secondary RP' encompasses a broad range of rheumatological, haematological, endocrinological and vascular pathology. RP can range from relatively benign but intrusive vasospasm, to the progressive obliterative microangiopathy of systemic sclerosis (SSc), in which severe digital ischaemia can threaten tissue viability. SSc has formed the focus of much of the research into RP but, consistent with most medical symptom complexes, the aetiopathogenesis of RP varies greatly dependent on cause. Vasospasm within the digital macro- and microvasculature occurs in SSc, but digital ischaemia is further compounded by a progressive obliterative microangiopathy. Recent work exploring the patient experience of SSc-RP is challenging the 'episodic' paradigm of 'Raynaud's', with important implications for clinical trials utilising diary-based patient-reported outcome instruments for assessing Raynaud's symptoms. This review shall examine the causes, pathogenesis, clinical features, classification and management of RP. A practical approach to the evaluation and management of RP is outlined, highlighting important knowledge gaps and unmet research needs where applicable. Key Points • Raynaud's phenomenon is a symptom complex related to digital vascular compromise secondary to broad-ranging pathology. • Raynaud's phenomenon, as currently classified, likely encompasses a number of aetiopathogenic processes. • Raynaud's phenomenon causes significant disease-related morbidity in autoimmune rheumatic diseases such as systemic sclerosis.

Raynaud's phenomenon

Raynaud's phenomenon can be either primary (idiopathic) or secondary to underlying disease including systemic sclerosis. Primary Raynaud's phenomenon is very common, affecting approximately 3%-5% of the general population. Although much rarer, systemic sclerosis-related Raynaud's phenomenon can be particularly severe, progressing to digital ulceration in approximately 50% of patients. Raynaud's phenomenon can have a major impact on quality of life. This review has a focus on the systemic sclerosis-related Raynaud's phenomenon (which is the most researched form of Raynaud's phenomenon and probably the most challenging to treat) and on recent advances. Epidemiology (including transition from 'isolated' to systemic sclerosis-related Raynaud's phenomenon), pathogenesis, diagnosis and assessment are discussed, followed by the treatment of both 'uncomplicated' and 'complicated' Raynaud's phenomena (i.e. Raynaud's phenomenon which has progressed to digital ulceration and/or critical ischaemia). Finally, some of the major challenges for the next 5-10 years are highlighted.