Aetiology and pathogenesis of paraneoplastic autoimmune disorders

The prevalence of cancer in patients with multiple sclerosis (MS) who received rituximab: a systematic review and meta-analysis

OBJECTIVE

To estimate the pooled prevalence of cancer in patients with multiple sclerosis (MS) cases who were under treatment with rituximab.

METHODS

We searched PubMed, Scopus, EMBASE, Web of Science, and google scholar along with gray literature up to April 2021. The search strategy included the MeSH and text words as (("CD20 Antibody" AND Rituximab) OR "Rituximab CD20 Antibody" OR Mabthera OR "IDEC-C2B8 Antibody" OR "IDEC C2B8 Antibody" OR IDEC-C2B8 OR "IDEC C2B8" OR GP2013 OR Rituxan OR rituximab) AND ((Sclerosis AND multiple) OR (sclerosis AND disseminated) OR "disseminated sclerosis" OR "multiple sclerosis" OR "acute fulminating").

RESULTS

The literature search revealed 3577 articles, after deleting duplicates 2066 remained. For the meta-analysis, 22 studies were included. Totally, 15599 patients were enrolled while 133 cancers were detected. The pooled prevalence of cancer in MS patients under treatment with rituximab is 1in 100,000 (I2 = 99.9%, p < 0.001).

CONCLUSION

The results of this systematic review and meta-analysis show that the pooled prevalence of cancer in MS patients who received rituximab is 1 in 100,000 cases.

Paraneoplastic arthritis: a series of 92 cases

OBJECTIVES

Paraneoplastic arthritis (PA) is one of the paraneoplastic syndromes. Both laboratory and clinical findings similar to rheumatological diseases can be seen. In this study we aimed to present the clinical and laboratory findings, malignancy types and pathological diagnoses of patients with paraneoplastic arthritis.

METHODS

In a multicentre retrospective study, 92 patients with PA from the last 10 years were included.

RESULTS

Patients with PA and haematological malignancies exhibited the highest ratio of lymphomas (25.6%). The most common cancer detected in patients with solid malignancy and PA was lung cancer (41.5%). All malignant patients with PA had significant anti-CCP positivity compared with the healthy control group (P = 0.014).

CONCLUSION

Although PA is a rare condition, it can be confused with many rheumatological diseases. The most commonly involved joint is the knee joint, followed by the ankle and hand/wrist. Autoantibody negativity, high lactate dehydrogenase level and arthritis unresponsive to treatment constitute important clues for diagnosis.

Autoimmune Glial Fibrillary Acidic Protein Astrocytopathy Is Associated with HLA-A*3303 and HLA-DPB1*0501

We determined the genetic association between specific human leucocyte antigen (HLA) loci and autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy. Our results showed that autoimmune GFAP astrocytopathy was associated with HLA-A*3303 (odds ratio [OR] = 2.02, 95% confidence interval [CI] = 1.32-3.06, p = 0.00072, padj. = 0.046) and HLA-DBP1*0501 (OR = 0.51, 95% CI = 0.36-0.71, p = 0.000048, padj. = 0.0062). Moreover, HLA-A*3303 carriers with the disease had a longer hospital stay (p = 0.0005) than non-carriers. This study for the first time provides evidence for a role of genetic factor in the development of autoimmune GFAP astrocytopathy. ANN NEUROL 2024;95:901-906.

Prevalence and Factor Associated with Anti-N-Methyl-D-Aspartate Receptor Encephalitis Among Patients with Medical Conditions: A Systematic Review and Meta-Analysis

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe autoimmune encephalitis due to immune production of anti-NMDAR antibodies against the NR1 subunit of the NMDA receptor which is present throughout the central nervous system. This condition had been reported to be prevalent in patients with certain medical conditions; however so far, there have been limited systematic reviews and meta-analyses on the prevalence and factors associated.

OBJECTIVE

This study was to determine the prevalence and factors associated with anti-NMDAR encephalitis among affected patients.

MATERIAL AND METHODS

The protocol of this study has been registered (2019: CRD42019142002) with the International Prospective Register of Systematic Reviews (PROSPERO). The primary outcome was the incidence or prevalence of anti-NMDAR encephalitis and secondary outcomes were factors associated with anti-NMDAR encephalitis.

RESULTS

There were 11 studies and a total of 873 million patients taken from high-risk populations across 11 countries that were included in the primary analysis. The overall pooled prevalence of anti-NMDAR encephalitis among patients with medical conditions was 7.0% (95% CI = 4.4, 9.6). Those with first episode of psychosis or schizophrenia were at a higher risk of developing anti-NMDAR encephalitis with an odds ratio of 5.976 (95% CI = 1.122, 31.825).

CONCLUSION

We found that almost one-tenth of patients with medical conditions had anti-NMDAR encephalitis; particularly those with first episode of psychosis or schizophrenia were among the high-risk medical conditions.

Clinical outcomes and safety of immune checkpoint inhibitors in patients with solid tumors and paraneoplastic syndromes

BACKGROUND

Patients with paraneoplastic syndromes (PNS) are excluded from clinical trials involving immune checkpoint inhibitors (ICIs) due to safety concerns. Moreover, real-world data on efficacy and safety is scarce.

METHODS

In this retrospective study, data were collected on patients with PNS and solid tumors receiving ICI between 2015 and 2022 at nine institutions. Patients were classified into: Cohort 1 (pre-existing PNS before ICI initiation), cohort 2 (PNS during ICI treatment), and cohort 3 (PNS after ICI discontinuation). Patients with metastatic non-small cell lung cancer (NSCLC) (mNSCLC) from cohort 1 were matched to patients who were PNS-free at each institution up to a 1:3 ratio for age, sex, type of ICI, use of concurrent chemotherapy, and number of lines of systemic therapy prior to ICI initiation. Kaplan-Meier method was used to assess overall survival (OS) and time-to-next treatment (TTNT).

RESULTS

Among 109 patients with PNS treated with ICIs, median age at ICI initiation was 67 years (IQR: 58-74). The most represented cancer type was NSCLC (n=39, 36%). In cohort 1 (n=55), PNS exacerbations occurred in 16 (29%) patients with median time to exacerbation after ICI of 1.1 months (IQR: 0.7-3.3). Exacerbation or de novo PNS prompted temporary/permanent interruption of ICIs in 14 (13%) patients. For cohort 2 (n=16), median time between ICI initiation and de novo PNS was 1.2 months (IQR: 0.4-3.5). Treatment-related adverse events (trAEs) occurred in 43 (39%) patients. Grade ≥3 trAEs occurred in 18 (17%) patients. PNS-directed immunosuppressive therapy was required in 55 (50%) patients. We matched 18 patients with mNSCLC and PNS (cohort 1) to 40 without PNS, treated with ICIs. There was no significant difference in OS or TTNT between patients with mNSCLC with and without PNS, although a trend was seen towards worse outcomes in patients with PNS. TrAEs occurred in 6/18 (33%) and 14/40 (35%), respectively. Grade ≥3 trAEs occurred in 4 (22%) patients with PNS and 7 (18%) patients without PNS.

CONCLUSIONS

Exacerbations of pre-existing PNS occurred in 29% of patients treated with ICIs and both exacerbations and de novo PNS occur early in the ICI course. TrAE from ICIs were similar between patients with and without PNS. Our data suggest that pre-existing PNS should not preclude consideration of ICI therapy although patients may not derive the same clinical benefit compared with patients without PNS.

Clinical features of anti-pituitary-specific transcription factor-1 (PIT-1) hypophysitis: a new aspect of paraneoplastic autoimmune condition

The pathogenesis of anti-pituitary-specific transcription factor-1 (PIT-1) hypophysitis was gradually revealed as cases emerged. Our comprehensive analysis, including all reported cases, identified a new instance of anti-PIT-1 hypophysitis postimmune checkpoint inhibitor therapy. All 9 patients exhibited extremely low growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH) levels; 2 had a slightly atrophic pituitary gland; 4 had thymoma, and 5 had malignant neoplasms of diffuse large B-cell lymphoma (DLBCL) and other origins. Patients with thymoma showed multiple autoimmune diseases. HLA-A*24:02 and/or A*02:06 were present in six and DR53 in 5 cases analyzed. High anti-PIT-1 antibody titers and ectopic PIT-1 expression in the cytosol and nucleus of the tumor tissues were observed in patients with thymoma or DLBCL, whereas it was exclusively observed in the nuclei of a bladder cancer patient. These findings provide new insights into the pathophysiology of paraneoplastic autoimmune hypophysitis.

Systemic autoimmune rheumatic diseases as paraneoplastic phenomena: 3 illustrative case reports and narrative review of the literature

OBJECTIVES

Systemic autoimmune rheumatic diseases can occur as paraneoplastic phenomena in the context of underlying malignancies. We present three illustrative clinical cases and a narrative literature review focusing on systemic sclerosis, dermatomyositis and palmar fasciitis and polyarthritis syndrome.

METHODS

Medical data of three patients from the University Hospitals Leuven were retrospectively and anonymously obtained and reviewed. A narrative review was performed, searching the databases of PubMed, Embase and Cochrane Library.

RESULTS

Systemic sclerosis, dermatomyositis and palmar fasciitis and polyarthritis syndrome are systemic autoimmune rheumatic diseases that can present as paraneoplastic phenomena. Systemic autoimmune rheumatic diseases are often associated with the presence of specific autoantibodies, some associated with a high likelihood of underlying malignancy. The presence of anti-ribonucleic acid polymerase III antibodies and anti-transcription intermediary factor 1 gamma antibodies indicates an increased risk of underlying cancer in systemic sclerosis and dermatomyositis, respectively. Individual patient prognosis can be improved through early detection of underlying malignancy, hence the importance of adequate cancer screening.

CONCLUSION

Some systemic autoimmune rheumatic diseases can appear as paraneoplastic phenomena, whereby the presence of specific autoantibodies is known to be related to the likelihood of underlying malignancy. We highlight the importance of clinician's knowledge of these distinct features, as it facilitates early detection and treatment of underlying malignancy, thereby improving individual patient prognosis.

Functional autoantibodies: Definition, mechanisms, origin and contributions to autoimmune and non-autoimmune disorders

A growing body of evidence underscores the relevance of functional autoantibodies in the development of various pathogenic conditions but also in the regulation of homeostasis. However, the definition of functional autoantibodies varies among studies and a comprehensive overview on this emerging topic is missing. Here, we do not only explain functional autoantibodies but also summarize the mechanisms underlying the effect of such autoantibodies including receptor activation or blockade, induction of receptor internalization, neutralization of ligands or other soluble extracellular antigens, and disruption of protein-protein interactions. In addition, in this review article we discuss potential triggers of production of functional autoantibodies, including infections, immune deficiency and tumor development. Finally, we describe the contribution of functional autoantibodies to autoimmune diseases including autoimmune thyroid diseases, myasthenia gravis, autoimmune pulmonary alveolar proteinosis, autoimmune autonomic ganglionopathy, pure red cell aplasia, autoimmune encephalitis, pemphigus, acquired thrombotic thrombocytopenic purpura, idiopathic dilated cardiomyopathy and systemic sclerosis, as well as non-autoimmune disorders such as allograft rejection, infectious diseases and asthma.

Association between multiple sclerosis and cancer risk: An extensive review/meta and Mendelian randomization analyses

BACKGROUND

Observational investigations examining cancer risk among multiple sclerosis (MS) patients have produced contradictory findings. Herein, we performed an extensive review and meta-analysis to evaluate the correlation and causation between MS and cancer incidence.

METHODS

We systematically screened for published articles examining cancer incidences among MS patients within the Cochrane Library, PubMed, and Embase databases. Next, we employed STATA v.16.0 for data analysis. Following meta-analysis, we performed a two-sample Mendelian randomization (MR) analysis to uncover the underlying mechanism behind the MS-mediated regulation of certain cancers.

RESULTS

Overall, we selected 18 articles encompassing 14 individual cancers incidences and a total of 368,952 patients for meta-analysis. Based on our analysis, there was reduced pancreatic (ES = 0.68; 95% CI: 0.49-0.93; I 2 = 0%) and ovarian cancer (ES = 0.65; 95% CI: 0.53-0.80; I 2 = 86.7%) co-occurrences among MS patients. Meanwhile, the incidences of breast (ES = 1.10; 95% CI: 1.01-1.21; I 2 = 60.9%) and brain cancers (ES = 1.94; 95% CI: 1.12-3.37; I 2 = 56.1%) were elevated among the same population. However, MR analysis revealed the opposite relation between MS and breast cancer risk (OR = 0.94392; 95% CI: 0.91011-0.97900, P = 0.002). Moreover, it revealed strong incidence of lung cancer (OR = 1.0004; 95% CI: 1.0001-1.0083, P = 0.001) among MS patients, as evidenced by the inverse variance weighting estimator. Lastly, MR found that other forms of cancers were not significantly related to MS.

CONCLUSIONS

Using meta-analysis, we demonstrated that MS patients exhibited enhanced pancreatic and ovarian cancer risk, and diminished breast and brain cancer risk. However, using MR analysis, we discovered an inverse relation between MS and breast cancer risk, and additionally saw an uptick in lung cancer co-occurrence among MS patients.

Glial cells and neurologic autoimmune disorders

Neurologic autoimmune disorders affect people's physical and mental health seriously. Glial cells, as an important part of the nervous system, play a vital role in the occurrence of neurologic autoimmune disorders. Glial cells can be hyperactivated in the presence of autoantibodies or pathological changes, to influence neurologic autoimmune disorders. This review is mainly focused on the roles of glial cells in neurologic autoimmune disorders and the influence of autoantibodies produced by autoimmune disorders on glial cells. We speculate that the possibility of glial cells might be a novel way for the investigation and therapy of neurologic autoimmune disorders.

The role of [18F]FDG PET/CT in paraneoplastic autoimmune disorders: an umbrella review

Paraneoplastic autoimmune disorders (PAD) are a group of autoimmune diseases associated with neoplasms. Several evidence-based articles (systematic reviews and meta-analyses) have reported data about the role of positron emission tomography (PET) and related hybrid modalities (e.g., PET/CT) using 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) in patients with PAD. We performed an umbrella review of published systematic reviews and meta-analyses in this setting to provide an evidence-based summary and suggestions for further studies. Several databases were searched to find systematic reviews and meta-analysis on [18F]FDG PET/CT in PAD. Evidence-based data support the use of [18F]FDG PET/CT in patients with suspected PAD for investigating an underlying malignancy even if it is still unclear whether [18F]FDG PET/CT should be performed after negative/inconclusive conventional imaging or as part of the initial workup of PAD.

The Autoantibodies against Tumor-Associated Antigens as Potential Blood-Based Biomarkers in Thyroid Neoplasia: Rationales, Opportunities and Challenges

The Autoantibodies targeting Tumor-Associated Antigens (TAA-AAbs) emerge as a result of a variety of tumor-related immunogenic stimuli and may be regarded as the eyewitnesses to the anti-tumor immune response. TAA-AAbs may be readily detected in peripheral blood to unveil the presence of a particular TAA-expressing tumor, and a fair number of TAAs eliciting the tumor-associated autoantibody response have been identified. The potential of TAA-AAbs as tumor biomarkers has been extensively studied in many human malignancies with a major influence on public health; however, tumors of the endocrine system, and, in particular, the well-differentiated follicular cell-derived thyroid neoplasms, remain understudied in this context. This review provides a detailed perspective on and legitimate rationales for the potential use of TAA-AAbs in thyroid neoplasia, with particular reference to the already established diagnostic implications of the TAA-AAbs in human cancer, to the windows for improvement and diagnostic niches in the current workup strategies in nodular thyroid disease and differentiated thyroid cancer that TAA-AAbs may successfully occupy, as well as to the proof-of-concept studies demonstrating the usefulness of TAA-AAbs in thyroid oncology, particularly for the pre-surgical discrimination between tumors of different malignant potential in the context of the indeterminate results of the fine-needle aspiration cytology.

Infiltration of plasma cells in colorectal adenocarcinoma associated with autoimmune encephalitis

Paraneoplastic autoimmune encephalitis (PAE) represents a group of rare neurological syndromes associated with neoplastic diseases. Here, we report a case that multiple anti‐neuronal antibodies were present in a patient with PAE who developed both small cell lung cancer and colorectal adenocarcinoma. Furthermore, the immunopathological investigation of the colorectal adenocarcinoma revealed the formation of abnormal neuronal antigens and a massive infiltration of plasma cells in the tumor tissue. These findings support the hypothesis that expression of neuronal antigens in neoplasm initiates autoimmune responses in PAE.

An updated advance of autoantibodies in autoimmune diseases

Autoantibodies are abnormal antibodies which are generated by pathogenic B cells when targeting an individual's own tissue. Autoantibodies have been identified as a symbol of autoimmune disorders and are frequently considered a clinical marker of these disorders. Autoimmune diseases, including system lupus erythematosus and rheumatoid arthritis, consist of a series of disorders that share some similarities and differences. They are characterized by chronic, systemic, excessive immune activation and inflammation and involve in almost all body tissues. Autoimmune diseases occur more frequently in women than men due to hormonal impacts. In this review we systemically introduce and summarize the latest advances of various autoantibodies in multiple autoimmune diseases.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is associated with IRF7, BANK1 and TBX21 polymorphisms in two populations

BACKGROUND AND PURPOSE

Autoantibodies targeting the GluN1(NR1) subunit of the anti-N-methyl-D-aspartate receptor (NMDAR) cause encephalitis. Although it has been shown that anti-NMDAR encephalitis is associated with human leukocyte antigen (HLA) loci, susceptibility genes for the disease outside the HLA loci remain unidentified. In this study, we aimed to explore the association of anti-NMDAR encephalitis with non-HLA genes.

METHODS

Two Chinese anti-NMDAR encephalitis cohorts from Han populations were recruited for this study. The North Chinese case-control set consisted of 98 patients and 460 controls, while the South Chinese case-control set included 78 patients and 541 controls. All participants were genotyped for 28 single nucleotide polymorphisms that are associated with autoimmune disorders or infectious diseases.

RESULTS

In two independent case-control sets, we identified significant associations of anti-NMDAR encephalitis with IRF7 rs1131665 (odds ratio [OR] 3.34, 95% confidence interval [CI] 1.99-5.63; P < 0.000001, P^adjusted  = 0.00004), BANK1 rs4522865 (OR 1.44, 95% CI 1.15-1.82; P = 0.0017, P^adjusted  = 0.0149), and TBX21 rs17244587 (OR 2.03, 95% CI 1.35-3.05; P = 0.00051, P^adjusted  = 0.0066). Furthermore, analysis of the three polymorphisms with clinical features of the disease revealed that the IRF7 rs1131665 was associated with tumor status.

CONCLUSION

The present study has for the first time identified non-HLA susceptibility genes for anti-NMDAR encephalitis. The association of IRF7, BANK1 and TBX21 with anti-NMDAR encephalitis suggests that B-cell activation, Th1 responses, virus infection and the type I interferon signaling pathway are involved in the pathogenesis of the disease.

Eight pillars of oncorheumatology: Crossroads between malignancies and musculoskeletal diseases

ONCORHEUMATOLOGY

RELATIONSHIP BETWEEN MALIGNANCIES AND MUSCULOSKELETAL DISEASES: Oncorheumatology is the meeting point of tumor formation and rheumatic musculoskeletal diseases (RMD). Multiple interactions exist between these two medical specialties. One major field is the topic of malignancies associated with rheumatic diseases, while the other topic covers the development of musculoskeletal disease in cancer patients. Within the first group, secondary malignancies may be associated with rheumatic diseases. Mostly sustained inflammation is responsible for transition into cancer. Tumor-associated antigens (TAA) with adhesive properties are present on tumor cells. These molecules may also be expressed by inflammatory leukocytes and soluble TAA levels may be elevated in RMDs. There has been continuous debate with respect to the possible carcinogenicity of conventional and targeted antirheumatic drugs. Very recent data from registries suggest that neither biologics, nor JAK inhibitors increase cancer risk in arthritis patients. The issue of physiotherapy in rheumatic patients with recent or current cancer has also been controversial. Some modalities, primarily exercise, may be safely applied to patients with RMD and cancer. The second large topic includes paraneoplastic syndromes. Musculoskeletal paraneoplasias are triggered by tumor-derived mediators. These syndromes are sometimes slightly different from the classical RMDs. Various chemotherapies may also be associated with autoimmune side effects. Recently, these immune-related complications have also been observed in cancer patients treated with immune-checkpoint inhibitors. Sex hormone-deprivation therapies, such as aromatase inhibitors and anti-androgens are widely used for the treatment of breast and prostate cancer, respectively. These compounds may induce bone loss and lead to osteoporosis. Finally, primary and secondary malignancies of the musculoskeletal system may also interest rheumatologists. In this review, the clinical, practical aspects of these eight pillars of oncorheumatology will be discussed.

Risk of cancer in multiple sclerosis (MS): A systematic review and meta-analysis

OBJECTIVE

To assess the pooled risk of cancer in patients with multiple sclerosis.

METHODS

We searched PubMed, Scopus, EMBASE, Web of Science, Ovid, google scholar and gray literature (references of studies, conference abstracts) which were published up to September 2019. The search strategy included the MeSH and text words as ((cancer) OR tumor) OR neoplasm) OR "malignant neoplasm) OR "benign neoplasm) AND (Multiple Sclerosis OR Sclerosis, Multiple) OR Sclerosis, Disseminated) OR Disseminated Sclerosis) OR MS (Multiple Sclerosis)) OR Multiple Sclerosis, Acute Fulminating).

RESULTS

The first literature search revealed 18,996 articles. After deletion of duplicate articles, finally, 264 articles remained. Excluding non-relevant articles, resulted in including 5 articles which met inclusion criteria. The RR estimated between 0.7 and 1.67 in included articles. The pooled RR estimated as 0.83 (95% CI:0.73-0.96) (I² = 90%, P < 0.001). Two studies provided prevalence of different cancers. The pooled prevalence of breast cancer in two studies was 2% (95%CI:2%-2%) (I² = 0%). The pooled prevalence of digestive system cancer in two studies was 2% (95%CI:1%-2%) (I² = 0%). The pooled prevalence of skin cancer in two studies was 1% (95%CI:0%-1%) (I² = 0).

CONCLUSION

The result of this systematic review showed that the risk of cancer in patients with MS is less than the general population.