Nervous system involvement of connective tissue disease: mechanisms and diagnostic approach

Comparison of the clinical and laboratory characteristics of neuromyelitis optica spectrum disorder with or without cerebrospinal fluid oligoclonal bands: a cohort with 36-month follow-up

Purpose

This study aimed to explore the significance of cerebrospinal fluid (CSF) oligoclonal bands (OCBs) in the clinical diagnosis and evaluation of neuromyelitis optica spectrum disorder (NMOSD).

Methods

The demographic and clinical data of 143 aquaporin-4 immunoglobulin G (AQP4-IgG)-positive NMOSD patients were collected and analyzed, including the gender, age, clinical symptoms and signs, status of CSF OCBs, location and length of the affected spinal cord vertebral segments, Expanded Disability Status Scale (EDSS) at the first attack and at 36-month follow-up, relapse times within 36 months, concomitant connective tissue disease (CTD), and status of other autoimmune antibodies (oAIA).

Results

There were 15 patients (10.5%) who were positive for OCBs (OCBs+). In contrast to those with negative OCBs (OCBs-), more OCBs+ cases had concomitant CTD [5/15 (33.3%) vs. 11/128 (8.6%), p = 0.014] and oAIA [9/15 (60.0%) vs. 37/128 (28.9%), p = 0.020]. OCBs+ patients had higher CSF cell counts [15.0 (27.0)/mm3 vs. 5.0 (12.0)/mm3, p = 0.008], higher IgG index [0.68 (0.23) vs. 0.52 (0.15), p < 0.001], and more relapses within 36 months [2.0 (3.0) vs. 1.0 (2.0), p = 0.039] than OCBs- patients. More OCBs+ patients had polynuclear cell predominance in the CSF than OCBs- patients (p = 0.032). There were no significant differences between the OCBs+ and the OCBs- patients in the distribution of lesion locations; the length of the affected spinal cord vertebral segments; the concentration of CSF protein and the albumin quotient; the EDSS score at the time of lumbar puncture and at 36-month follow-up, and the onset episode, the relapse, and cumulative clinical syndrome profiles (all p > 0.05).

Conclusions

For AQP4-IgG-positive NMOSD patients, positivity for CSF OCBs is associated with higher CSF cell counts and a higher likelihood to have concomitant CTD and oAIA. OCBs+ is not uncommon in NMOSD and may predict more frequent relapses, but not a more serious illness.

Central nervous system manifestations in rheumatic diseases

As the role of neurologists in managing patients with rheumatic diseases expands, collaboration between rheumatologists and neurologists becomes increasingly vital. This literature review provides an overview of the central nervous system (CNS) manifestations of major autoimmune rheumatic disorders, which may include parenchymal brain and meningeal disease (stroke, meningoencephalitis, meningitis), myelopathies, psychosis, chorea, seizure disorders, and various forms of cephalea. Novel findings linking specific autoimmune markers to CNS damage reveal a direct, previously underestimated link between systemic inflammation and neural injury. Besides, with the increasing use of biological therapies, it is crucial to recognize when neurological manifestations are related to adverse events of therapy, as this may significantly influence treatment decisions. Neurologists play a key role in this assessment, working closely with rheumatologists. Overall, addressing CNS involvement in rheumatic diseases is important for improving patient outcomes and advancing medical knowledge in this complex field. A thorough understanding of the neurologic aspects of rheumatic diseases is essential for optimal patient care, necessitating a multidisciplinary approach to management.

Prevalence of Subclinical Peripheral Neuropathy in Patients With Autoimmune Connective Tissue Disorders: An Observational Cross-Sectional Study

Background Autoimmune connective tissue disorders (AICTDs) are a group of chronic inflammatory diseases characterized by immune responses targeting the body's own tissues. Peripheral neuropathy, which can be symmetrical or asymmetrical, is a common complication in AICTD patients. Early detection of subclinical peripheral neuropathy remains challenging, as nerve conduction studies are not routinely performed. This study aimed to determine the prevalence of subclinical peripheral neuropathy among patients with AICTD and to assess its association with potential predictor variables, including laboratory parameters and autoimmune markers. Materials and methods This observational cross-sectional study included 100 patients undergoing treatment for AICTDs for over three years, conducted over 15 months. Ethical approval and informed consent were obtained before detecting subclinical peripheral neuropathy through nerve conduction studies on bilateral ulnar, radial, sural, peroneal, and tibial nerves at a tertiary-level medical college hospital. Inclusion criteria encompassed patients treated at the tertiary hospital, not on immunosuppressants other than steroids, with at least three years of treatment, while exclusions were made for established peripheral neuropathy and other specified conditions. Descriptive statistics, Chi-square/Fisher's exact tests, independent samples t-tests, and logistic regression were used for data analysis at a 0.05 significance level, with IBM SPSS Statistics for Windows, Version 20 (Released 2011; IBM Corp., Armonk, NY, USA). Results Subclinical peripheral neuropathy was present in 18% (n = 18) of the study participants, while 82% (n = 82) did not exhibit neuropathy. Patients with subclinical neuropathy had a significantly higher mean age (49.66 ± 4.77 years) compared to those without neuropathy (46.02 ± 12.7 years, p = 0.047). The majority of the study population was female, 79 (79%), and there was no significant gender difference between the groups (p = 0.513). There was no significant association between inflammatory markers (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR)) and neuropathy. However, patients with subclinical neuropathy were more likely to test positive for rheumatoid factor (RF) (8 (66.7%) vs. 71 (58.5%), p = 0.011) and anti-cyclic citrullinated peptide (Anti-CCP) antibodies (11 (78.5%) vs. 32 (47%), p = 0.032). Steroid use did not significantly affect the presence of neuropathy (p = 0.769). Conclusion The study found a high prevalence of subclinical peripheral neuropathy in AICTD patients, detectable only by nerve conduction studies. RF and Anti-CCP antibodies were associated with subclinical neuropathy, suggesting these markers could guide early detection, and inform treatment intensification to reduce neuropathy prevalence among AICTD patients.

Mapping multimorbidity progression among 190 diseases

BACKGROUND

Current clustering of multimorbidity based on the frequency of common disease combinations is inadequate. We estimated the causal relationships among prevalent diseases and mapped out the clusters of multimorbidity progression among them.

METHODS

In this cohort study, we examined the progression of multimorbidity among 190 diseases among over 500,000 UK Biobank participants over 12.7 years of follow-up. Using a machine learning method for causal inference, we analyzed patterns of how diseases influenced and were influenced by others in females and males. We used clustering analysis and visualization algorithms to identify multimorbidity progress constellations.

RESULTS

We show the top influential and influenced diseases largely overlap between sexes in chronic diseases, with sex-specific ones tending to be acute diseases. Patterns of diseases that influence and are influenced by other diseases also emerged (clustering significance Pau > 0.87), with the top influential diseases affecting many clusters and the top influenced diseases concentrating on a few, suggesting that complex mechanisms are at play for the diseases that increase the development of other diseases while share underlying causes exist among the diseases whose development are increased by others. Bi-directional multimorbidity progress presents substantial clustering tendencies both within and across International Classification Disease chapters, compared to uni-directional ones, which can inform future studies for developing cross-specialty strategies for multimorbidity. Finally, we identify 10 multimorbidity progress constellations for females and 9 for males (clustering stability, adjusted Rand index >0.75), showing interesting differences between sexes.

CONCLUSION

Our findings could inform the future development of targeted interventions and provide an essential foundation for future studies seeking to improve the prevention and management of multimorbidity.

Association between toxoplasmosis and autoimmune rheumatic diseases in Egyptian patients

PURPOSE

To explore the association between T. gondii and autoimmune rheumatic diseases (ARDs).

METHODS

This study involved 82 patients with ARDs: 44 rheumatoid arthritis (RA), 28 systemic lupus erythematosus (SLE), and 10 systemic sclerosis (SSc) and 61 age- and sex-matched controls. Sociodemographic, clinical, and laboratory data were collected, and disease activity was assessed. Exposure to toxoplasmosis risk factors was investigated. Serological tests for anti-Toxoplasma IgM and IgG antibodies were assessed using ELISA.

RESULTS

In SLE patients, a significant difference of T. gondii IgM versus controls was detected (P=.03). In RA and SLE patients, T. gondii IgG showed a significant difference versus controls (34 (77.3%) P=.001 and 18 (64.3%) P=.03, respectively). There was no significant difference in SSc versus controls. Fetal congenital anomalies displayed a significant difference in IgM seropositive compared to seronegative patients (P=.04). Cat exposure showed a significant difference between IgM and IgG seropositive versus seronegative patients (12 (80.0%) P=.02 and 34 (59.6) P=.04, respectively). There was no significant difference in seropositive patients regarding history of abortion, neuro-psychiatric manifestations, disease activity parameters (ESR, CRP), or different regimens of medications.

CONCLUSION

Toxoplasma IgM seropositivity is associated with SLE patients. T. gondii IgG seropositivity is associated with both RA and SLE patients. However, Toxoplasma seropositivity had no association with SSc patients. An association between fetal congenital anomalies and IgM seropositivity was demonstrated. A linkage between cat exposure as a risk factor and toxoplasmosis was suggested among ARD patiants. Exploration of impact of toxoplasmosis on ARDs is a necessity through randomized controlled trials.

Systemic autoimmune disease as a cause of death: mortality burden and comorbidities

Objectives

Systemic autoimmune diseases (SAIDs) have chronic trajectories and share characteristics of self-directed inflammation, as well as aspects of clinical expression. Nonetheless, burden-of-disease studies rarely investigate them as a distinct category. This study aims to assess the mortality rate of SAIDs as a group and to evaluate co-occurring causes of death.

Methods

We used death certificate data in the Netherlands, 2013–2017 (N = 711 247), and constructed a SAIDs list at the fourth-position ICD-10 level. The mortality rate of SAIDs as underlying cause of death (CoD), non-underlying CoD, and any-mention CoD was calculated. We estimated age-sex-standardized observed/expected (O/E) ratios to assess comorbidities in deaths with SAID relative to the general deceased population.

Results

We observed 3335 deaths with SAID on their death certificate (0.47% of all deaths). The mortality rate of SAID was 14.6 per million population as underlying CoD, 28.0 as non-underlying CoD, and 39.7 as any-mention CoD. The mortality rate was higher for females and increased exponentially with age. SAID-related deaths were positively associated with all comorbidities except for solid neoplasms and mental conditions. Particularly strong was the association with diseases of the musculoskeletal system (O/E = 3.38; 95% CI: 2.98, 3.82), other diseases of the genitourinary system (O/E = 2.73; 95% CI: 2.18, 3.38), influenza (O/E = 2.71; 95% CI: 1.74, 4.03), blood diseases (O/E = 2.02; 95% CI: 1.70, 2.39), skin and subcutaneous tissue diseases (O/E = 1.95; 95% CI: 1.54, 2.45), and infectious diseases (O/E = 1.85; 95% CI: 1.70, 2.01).

Conclusion

Systemic autoimmune diseases constitute a rare group of causes of death, but contribute to mortality through multiple comorbidities. Classification systems could be adapted to better encompass these diseases as a category.

Peripheral neuropathies in rheumatic diseases: More diverse and frequent than expected. A cross-sectional study

BACKGROUND/OBJECTIVE

Peripheral neuropathies (PN) are heterogeneous nerve disorders; frequently rheumatic patients have neuropathic symptoms. In some rheumatic diseases (RD) PN are secondary to nerve compression while others are related to metabolic abnormalities, inflammation or vasculitis. Our aim was to explore the frequency of neuropathic symptoms with three neuropathy questionnaires (NQ) and nerve conduction studies (NCS) in RD.

METHODS

This is a cross-sectional study in patients with any RD attending for the first time to a rheumatology outpatient clinic. We included all patients who accepted to participate and who answered three NQ and received a physical evaluation. Twenty patients were randomly selected to perform NCS and 10 healthy subjects were included as controls. The topographic diagnoses were: mononeuropathy, multiplex mononeuropathy, and/or polyneuropathy.

STATISTICAL ANALYSIS

descriptive statistics (mean, median, standard deviation, interquartile range and frequency, odds ratios and Pearson correlation test).

RESULTS

One hundred patients and 10 healthy subjects were included. Sixty-nine were female, mean age 40.6 ± 15.7 years. Rheumatic diagnoses were: systemic lupus erythematosus (26%), rheumatoid arthritis (16%), gout (14%), and osteoarthritis (11%). Fifty-two patients had neuropathic signs during physical examination and 67% had positive questionnaires with variable scores among several RD. Abnormal NCS was reported in 14 patients (70%): 6 (42.8%) median nerve mononeuropathies, 4 (28.5%) multiplex mononeuropathies and 4 (28.5%) polyneuropathies. None of the healthy subjects had neuropathy (NQ, physical evaluation, or NCS). Risk of being NCS positive is higher when the patients were NQ positive.

CONCLUSION

PN has variable distribution and high frequency in patients with RD; NQ+ increases the risk of presenting NCS+ for PN.

A Systematic Review of Peripheral and Central Nervous System Involvement of Rheumatoid Arthritis, Systemic Lupus Erythematosus, Primary Sjögren's Syndrome, and Associated Immunological Profiles

Both central (CNS) and peripheral nervous system (PNS) complications are frequent and varied in connective tissue diseases. A systematic review was conducted between 1989 and 2014 in the databases Medline, Scopus, and Cochrane Library using the search terms, peripheral and central nervous complications and immunological profiles, to identify studies in specific connective tissue disorders such as rheumatoid arthritis, systemic lupus erythematosus, and primary Sjögren's syndrome. A total of 675 references were identified, of which 118 were selected for detailed analysis and 22 were included in the final review with a total of 2338 participants. Our search focused only on studies upon connective tissue disorders such as rheumatoid arthritis, systemic lupus erythematosus, and primary Sjögren's syndrome associated with seroimmunological data. The reported prevalence of CNS involvement ranges from 9 to 92% across the reported studies. However, the association between CNS and PNS manifestations and seroimmunological profiles remains controversial. Τo date, no laboratory test has been shown as pathognomonic neither for CNS nor for PNS involvement.

Vasculitic neuropathy

Vasculitis is a primary phenomenon in autoimmune diseases such as polyarteritis nodosa, Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, and essential mixed cryoglobulinemia. As a secondary feature vasculitis may complicate, for example, connective tissue diseases, infections, malignancies, and diabetes. Vasculitic neuropathy is a consequence of destruction of the vessel wall and occlusion of the vessel lumen of small epineurial arteries. Sometimes patients present with nonsystemic vasculitic neuropathy, i.e., vasculitis limited to peripheral nerves and muscles with no evidence of further systemic involvement. Treatment with corticosteroids, sometimes in combination with other immunosuppressants, is required to control the inflammatory process and prevent further ischemic nerve damage.