Autoantibodies and pain

Exploring the terminological validity of 'chronic pain' nursing diagnosis: A retrospective descriptive study using nursing diaries

AIM

The aim of this study is to generate empirical evidence, drawing from clinical records, with the goal of elevating the level of evidence supporting the nursing diagnosis (ND) of 'chronic pain'.

BACKGROUND

Chronic pain is a prevalent condition that affects all age groups. Patients often feel disbelieved about their pain perception, leading to adverse psychological effects, difficulty accessing healthcare and poor rehabilitation outcomes.

DESIGN

Retrospective descriptive study. Standards for Reporting Diagnostic Accuracy Studies guidelines were followed in this study.

METHODS

Data were extracted from Electronic Health Records (EHR) of patients admitted to the University Hospital of Perugia, Italy, between March 2016 and December 2022. The study sample comprised individuals without a specific medical diagnosis or high-risk population. Out of 1,048,565 EHR, 43,341 clinical-nursing diaries with the keyword 'pain' were identified, from which 283 clinical-nursing notes were selected based on a keyword-based retrieval technique and diagnostic definition for further analysis.

RESULTS

Our study findings support the diagnostic descriptors of the 'chronic pain' ND in clinical-nursing diaries. We observed the presence of 9 out of 11 defining characteristics, 7 out of 10 related factors, 4 out of 8 at-risk populations and 11 out of 17 associated conditions.

CONCLUSIONS

The study validated diagnostic criteria for chronic pain and proposed 'haematological pathology' as a new associated condition. The findings were presented to the Diagnosis Development Committee of NANDA-International for further review. However, limitations of the study prompted the need for further analysis using natural language processing and artificial neural network techniques. As a result, a new research direction using artificial intelligence (AI) tools was initiated.

RELEVANCE TO CLINICAL PRACTICE

The study validates diagnostic descriptors for chronic pain and proposes future directions in semantic analysis and AI tools, aiming to enhance clinical practice and decision-making in nursing care.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution.

Insights into FcγR involvement in pain-like behavior induced by an RA-derived anti-modified protein autoantibody

Joint pain is one of the most debilitating symptoms of rheumatoid arthritis (RA) and patients frequently rate improvements in pain management as their priority. RA is hallmarked by the presence of anti-modified protein autoantibodies (AMPA) against post-translationally modified citrullinated, carbamylated and acetylated proteins. It has been suggested that autoantibody-mediated processes represent distinct mechanisms contributing to pain in RA. In this study, we investigated the pronociceptive properties of monoclonal AMPA 1325:01B09 (B09 mAb) derived from the plasma cell of an RA patient. We found that B09 mAb induces pain-like behavior in mice that is not associated with any visual, histological or transcriptional signs of inflammation in the joints, and not alleviated by non-steroidal anti-inflammatory drugs (NSAIDs). Instead, we found that B09 mAb is retained in dorsal root ganglia (DRG) and alters the expression of several satellite glia cell (SGC), neuron and macrophage-related factors in DRGs. Using mice that lack activating FcγRs, we uncovered that FcγRs are critical for the development of B09-induced pain-like behavior, and partially drive the transcriptional changes in the DRGs. Finally, we observed that B09 mAb binds SGC in vitro and in combination with external stimuli like ATP enhances transcriptional changes and protein release of pronociceptive factors from SGCs. We propose that certain RA antibodies bind epitopes in the DRG, here on SGCs, form immune complexes and activate resident macrophages via FcγR cross-linking. Our work supports the growing notion that autoantibodies can alter nociceptor signaling via mechanisms that are at large independent of local inflammatory processes in the joint.

Autoimmune regulation of chronic pain

Chronic pain is an unpleasant and debilitating condition that is often poorly managed by existing therapeutics. Reciprocal interactions between the nervous system and the immune system have been recognized as playing an essential role in the initiation and maintenance of pain. In this review, we discuss how neuroimmune signaling can contribute to peripheral and central sensitization and promote chronic pain through various autoimmune mechanisms. These pathogenic autoimmune mechanisms involve the production and release of autoreactive antibodies from B cells. Autoantibodies-ie, antibodies that recognize self-antigens-have been identified as potential molecules that can modulate the function of nociceptive neurons and thereby induce persistent pain. Autoantibodies can influence neuronal excitability by activating the complement pathway; by directly signaling at sensory neurons expressing Fc gamma receptors, the receptors for the Fc fragment of immunoglobulin G immune complexes; or by binding and disrupting ion channels expressed by nociceptors. Using examples primarily from rheumatoid arthritis, complex regional pain syndrome, and channelopathies from potassium channel complex autoimmunity, we suggest that autoantibody signaling at the central nervous system has therapeutic implications for designing novel disease-modifying treatments for chronic pain.

Pain in NMOSD and MOGAD: A Systematic Literature Review of Pathophysiology, Symptoms, and Current Treatment Strategies

Neuromyelitis optica spectrum disorders (NMOSDs) and myelin oligodendrocyte glycoprotein-antibody-associated disease (MOGAD) are autoimmune inflammatory disorders of the central nervous system (CNS). Pain is highly prevalent and debilitating in NMOSD and MOGAD with a severe impact on quality of life, and there is a critical need for further studies to successfully treat and manage pain in these rare disorders. In NMOSD, pain has a prevalence of over 80%, and pain syndromes include neuropathic, nociceptive, and mixed pain, which can emerge in acute relapse or become chronic during the disease course. The impact of pain in MOGAD has only recently received increased attention, with an estimated prevalence of over 70%. These patients typically experience not only severe headache, retrobulbar pain, and/or pain on eye movement in optic neuritis but also neuropathic and nociceptive pain. Given the high relevance of pain in MOGAD and NMOSD, this article provides a systematic review of the current literature pertaining to pain in both disorders, focusing on the etiology of their respective pain syndromes and their pathophysiological background. Acknowledging the challenge and complexity of diagnosing pain, we also provide a mechanism-based classification of NMOSD- and MOGAD-related pain syndromes and summarize current treatment strategies.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Association of Leucine-Rich Glioma Inactivated Protein 1, Contactin-Associated Protein 2, and Contactin 2 Antibodies With Clinical Features and Patient-Reported Pain in Acquired Neuromyotonia

Questions

Which specific targets of voltage-gated potassium channel–complex antibodies are found in acquired neuromyotonia, and are these antibodies associated with additional clinical features of tumors, pain, or autonomic or central disorders?

Findings

This cohort study combined with a patient-led survey found that antibodies to the extracellular aspects of leucine-rich glioma inactivated protein, contactin-associated protein 2, and contactin 2 were variably present in 45% of patients with neuromyotonia. Paresthesia and various pain manifestations were common in neuromyotonia, and the type and severity of pain were found to exert a substantial influence on quality of life.

Meaning

Antibodies to voltage-gated potassium channel–complex proteins are not found in all patients with neuromyotonia and do not individually relate to specific clinical features, but the presence of pain and its effects on quality of life need greater recognition.

Importance

Although acquired autoimmune neuromyotonia (NMT) is associated with voltage-gated potassium channel (VGKC)–complex antibodies, to date there has been no systematic study of autoantibodies to the specific antigens leucine-rich glioma inactivated protein 1 (LGI1), contactin-associated protein 2 (CASPR2), and contactin 2 together with the full clinical syndrome, particularly pain and autonomic and central nervous system involvement.

Objectives

To study the full spectrum of clinical features and serum autoantibodies in patients with NMT, including the effects of pain on quality of life.

Design, Setting, and Participants

A cohort study of clinical features and serologic testing in 38 patients with electrophysiologically-confirmed NMT, reviewed clinically between February 2007 and August 2009, in the Universities of Sydney and Kagoshima and followed up across 2 to 4 years. Association of NMT with quality of life was researched in an independent, patient-led, online pain survey conducted from April 2012 to May 2012. Serologic analyses were performed in 2012, and final data analysis was performed in 2016.

Main Outcomes and Measures

Clinical data and scores on the modified Rankin Scale (mRS), which measures disability on a range of 0 to 6, with 0 indicating normal and 6 indicating death, before and after treatments were combined with CASPR2, LGI1, and contactin 2 antibody status.

Results

Among the 38-person NMT cohort, 25 (65.8%) were male and the median (range) age was 55 (12-85) years. Twenty-three (60.5%) were Japanese and 15 (39.5%) were of white race/ethnicity. Symptomatic treatments (mainly antiepileptic drugs) were used in most patients with mild disease (12 patients with mRS <3), whereas immunotherapies were successful in most patients with mRS scores greater than 2. Autoantibodies to VGKC-complex antigens (17 patients [45%]), bound to CASPR2 (5 [13%]), contactin 2 (5 patients, 1 with CASPR2 [13%]), LGI1 (2 [5%]), or both LGI1 and CASPR2 (6 [16%]). The last group of 6 patients had high mRS scores (mean [SD], 3.8 [1.7]), thymoma (4 patients), pain (5 patients), autonomic (6 patients) and sleep (5 patients) disturbance, suggesting Morvan syndrome. The 56 responders to the independent patient-led survey reported pain that could be severe, anatomically widespread, and that often resulted in unemployment, domestic problems, and poor quality of life.

Conclusions and Relevance

The cohort study detailed underrecognized aspects of the clinical and serologic spectrum of NMT. The heterogeneity of clinical features and of specific antibodies limit associations, but the common existence of thymoma, pain, and autonomic and central nervous system features, often with both LGI1 and CASPR2 antibodies, should be better recognized to more completely address the range of comorbidities and consequences of the disease regarding quality of life.

Divergent roles of immune cells and their mediators in pain

Chronic pain is a major debilitating condition that is difficult to treat. Although chronic pain may appear to be a disorder of the nervous system, crucial roles for immune cells and their mediators have been identified as important contributors in various types of pain. This review focuses on how the immune system regulates pain and discusses the emerging roles of immune cells in the initiation or maintenance of chronic pain. We highlight which immune cells infiltrate damaged nerves, the dorsal root ganglia, spinal cord and tissues around free nerve endings and discuss through which mechanisms they control pain. Finally we discuss emerging roles of the immune system in resolving pain and how the immune system contributes to the transition from acute to chronic pain. We propose that targeting some of these immune processes may provide novel therapeutic opportunities for the treatment of chronic pain.