U1-RNP and Toll-like receptors in the pathogenesis of mixed connective tissue diseasePart II. Endosomal TLRs and their biological significance in the pathogenesis of mixed connective tissue disease

A rare event of perioperative spinal subarachnoid hemorrhage in mixed connective tissue disease: a case report

Background

Spinal subarachnoid hemorrhage (SSH) is an extremely rare event and its causes include trauma, vascular malformation, anticoagulant therapy, and autoimmune disease. Although connective disorders are associated with an increased risk of cerebral subarachnoid hemorrhage (SAH), to our knowledge, the occurrence of SSH associated with mixed connective tissue disease (MCTD) have not been addressed in the literature. We report the unique occurrence of SSH in a patient with anti-U1 ribonucleoprotein (U1-RNP) and anti-nuclear antibodies (ANA) positive MCTD triggered by abdominal surgery.

Case Description

A 69-year-old woman with MCTD was admitted to our hospital because of vomiting and abdominal pain. Surgical treatment of adhesion ileus with small bowel resection was followed on the second postoperative day by sudden back pain radiating to the legs and abdominal belt-shaped lumbar exanthema. A spinal anesthesia was not performed. Neurological examination revealed loss of sensation and muscle strength in both legs. Magnetic resonance imaging (MRI) showed an SSH beyond T6 and the lumbosacral junction with ventral displacement of the spinal cord without myelopathy. Rapid improvement in motor function and sensitivity allowed a conservative management. The patient recovered successfully and was discharged without neurological deficits.

Conclusions

We postulate that vascular rupture causing SSH was triggered by perioperative increased intraluminal abdominal pressure combined with fragility of the spinal arachnoid mater due to MCTD. The decision to undergo a conservative treatment of the SSH was triggered by the rapid improvement of the neurological presentation and the disappearance of symptoms in a few days. We recommend caution in patients with connective tissue diseases who undergo thoracic or abdominal surgery and be aware for neurosurgeons that SSH is possible although rare and that conservative treatment may be considered.

Pulmonary effects of e-liquid flavors: a systematic review

Electronic cigarettes (ECs) are purported to be tobacco harm-reduction products whose degree of harm has been highly debated. EC use is considered less hazardous than smoking but is not expected to be harmless. Following the banning of e-liquid flavors in countries such as the US, Finland, Ukraine, and Hungary, there are growing concerns regarding the safety profile of e-liquid flavors used in ECs. While these are employed extensively in the food industry and are generally regarded as safe (GRAS) when ingested, GRAS status after inhalation is unclear. The aim of this review was to assess evidence from 38 reports on the adverse effects of flavored e-liquids on the respiratory system in both in vitro and in vivo studies published between 2006 and 2021. Data collected demonstrated greater detrimental effects in vitro with cinnamon (9 articles), strawberry (5 articles), and menthol (10 articles), flavors than other flavors. The most reported effects among these investigations were perturbations of pro-inflammatory biomarkers and enhanced cytotoxicity. There is sufficient evidence to support the toxicological impacts of diacetyl- and cinnamaldehyde-containing e-liquids following human inhalation; however, safety profiles on other flavors are elusive. The latter may result from inconsistencies between experimental approaches and uncertainties due to the contributions from other e-liquid constituents. Further, the relevance of the concentration ranges to human exposure levels is uncertain. Evidence indicates that an adequately controlled and consistent, systematic toxicological investigation of a broad spectrum of e-liquid flavors may be required at biologically relevant concentrations to better inform public health authorities on the risk assessment following exposure to EC flavor ingredients.

Innate Immunity in Calcinosis Cutis

Calcinosis cutis is the deposition of calcium salts in the skin and subcutaneous tissue, manifesting as variably shaped papules, nodules, and plaques that can substantially impair quality of life. The pathophysiology of calcinosis cutis involves dysregulation of proinflammatory cytokines, leukocytes, and other components of the innate immune system. In some conditions associated with calcinosis cutis, elevated serum calcium, phosphate, and vitamin D may also perturb innate immunity. The mechanisms by which these lead to cutaneous and subcutaneous calcification likely parallel those seen in vascular calcification. The role of aberrant innate immunity is further supported by the association between various autoantibodies with calcinosis cutis, such as anti-MDA5, anti-NXP2, anti-centromere, and anti-topoisomerase I. Treatments for calcinosis cutis remain limited and largely experimental, although mechanistically many therapies appear to focus on dampening innate immune responses. Further research is needed to better understand the innate immune pathophysiology and establish treatment options based on randomized-controlled trials.

Connective Tissue Diseases in the Skin: Emerging Concepts and Updates on Molecular and Immune Drivers of Disease

Cutaneous manifestations are common across the spectrum of autoimmune diseases. Connective tissue diseases manifesting in the skin are often difficult to classify and require integration of clinical, histopathologic, and serologic findings. This review focuses on the current understanding of the molecular and immune drivers involved in the pathogenesis of cutaneous lupus erythematosus, dermatomyositis, scleroderma/systemic sclerosis, and mixed connective tissue disease. Recent research advances have led to the emergence of new ancillary tools and useful diagnostic clues of which dermatopathologists should be aware to improve diagnostic accuracy for these diseases.

Variety of endosomal TLRs and Interferons (IFN-α, IFN-β, IFN-γ) expression profiles in patients with SLE, SSc and MCTD

We investigated Toll-like receptor (TLR)-3/-7/-8/-9 and interferon (IFN)-α/β/γ mRNA expression in whole blood and serum IFN-α/β/γ levels in patients with mixed connective tissue disease (MCTD), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) and in healthy subjects to assess the association between the TLR-IFN expression and severity of and susceptibility to diseases, and identify potential biomarkers. Expression of the IFN-γ, TLR-3 and TLR-8 was detected only in SLE patients. TLR-7, IFN-α and IFN-β expression was highest in SLE, while TLR-9 expression was highest in SSc patients. In SLE and MCTD patients a strong correlation was observed between TLR-7 and IFN-α expression and IFN-β and IFN-α expression. In MCTD patients, negative correlation between IFN-α and TLR-9 and TLR-7 and TLR-9 was revealed. TLR-9 expression in anti-U1-70k-negative, anti-C negative and anti-SmB-negative MCTD patients was higher than in MCTD-positive patients. We observed negative correlations between serum IFN-α levels and TLR-7 expression and C3 and C4 levels in SLE patients. In SLE patients we observed that with increased IFN-γ, TLR-3 and TLR-8 expression increased the value of C3 and C4. Our results confirmed that the endosomal TLR-IFN pathway seems to be more important in SLE than in MCTD or SSc, and that IFN-α and IFN-β may be possible biomarkers for SLE.

Anti-RNP positivity in primary Sjögren's syndrome is associated with a more active disease and a more frequent muscular and pulmonary involvement

Objectives

To describe and compare the clinical and biological characteristics of subjects with primary Sjögren’s syndrome (pSS) with and without anti-RNP antibodies.

Methods

Patients fulfilling the American College of Rheumatology (ACR)/EULAR 2016 criteria for pSS and having anti-RNP antibodies, without other connective tissue disease diagnosed and no anti-dsDNA antibodies were retrieved from the database from our French National Reference Center. These patients were compared with all other patients with pSS with negative anti-Sm, anti-RNP and anti-dsDNA antibodies.

Results

Overall, 21 patients with pSS positive for anti-RNP antibodies and 446 negative for anti-RNP antibodies were retrieved. Anti-RNP-positive patients had a lower median age at onset of pSS symptoms (41.0 vs 50.0 years, p=0.01), a higher median EULAR Sjögren’s syndrome disease activity index at inclusion (8.0 vs 3.0, p<0.01), more frequently constitutional symptoms (14.3% vs 0.01%, p<0.01), myositis (19.0% vs 2.3%, p<0.01) and pulmonary (19.0% vs 5.7%, p=0.04) involvement. Moreover, anti-RNP-positive patients had higher median gammaglobulin levels (22.5 vs 13 g/L, p<0.01), more frequently anti-SSA antibodies (90.5% vs 67.1%, p=0.03), but less frequent lymphocytic sialadenitis with a focus score ≥1 (66.7% vs 85.5%, p=0.03). If the analysis is restricted to anti-SSA-positive patients, anti-RNP positivity is associated with the same clinicobiologic features except the pulmonary involvement.

Conclusion

Patients with pSS with anti-RNP antibodies displayed a more active systemic disease, with more frequent muscular and pulmonary involvement, and increased gammaglobulin level, compared with anti-RNP-negative patients.

Management of multiple neurological complications in mixed connective tissue disease: A case report

RATIONALE

Mixed connective tissue disease (MCTD) refers to an overlapping condition of different autoimmune disorders such as systemic lupus erythematosus, cutaneous systemic sclerosis, rheumatoid arthritis, polymyositis, and dermatomyositis. However, MCTD manifesting as transverse myelitis is extremely rare. Herein, we report a case of MCTD with both central and peripheral nervous system involvement.

PATIENT CONCERNS

We describe and discuss the clinical findings and management of a 36-year-old man presented with a 2-week history of sudden bilateral lower-limb paralysis and dysuresia. Further investigation of his medical history showed a 6-month history of autoimmune symptoms.

DIAGNOSES

The patient was diagnosed with MCTD, transverse myelitis, mononeuritis multiplex, and multiple lacunar infarctions.

INTERVENTIONS

A combination of low-dose methylprednisolone (40 mg/d) and hydroxychloroquine sulfate (400 mg/d) was administered.

OUTCOMES

After treatment, the symptoms were significantly improved. The patient recovered well after 1 year follow-up and the sequela was urinary incontinence and grade 4/5 lower-extremity muscle strength.

LESSONS

MCTD with multiple neurological complications is extremely rare and poses diagnostic and therapeutic challenges. Our experience suggests a combination of low-dose corticosteroids and hydroxychloroquine sulfate may be an effective therapeutic approach.