Cerebrospinal fluid B-cell activating factor levels as a novel biomarker in patients with neurosarcoidosis

Diagnostic Biomarkers for Uveitis: Serum BAFF and CXCL9 in Differentiating Ocular Sarcoidosis, Tuberculosis and Other Entities with Implication for QuantiFERON-Positive Uveitis

PURPOSE

To evaluate serum B cell activating factor (BAFF) and CXCL9 as diagnostic biomarkers for ocular sarcoidosis and ocular tuberculosis (TB). We also explore their role in the stratification of patients with QuantiFERON (QFT)-positive uveitis without another identifiable cause.

METHODS

Eighty uveitis patients with various entities were included: 10 with ocular sarcoidosis, 35 with TB-related uveitis (including 11 confirmed (ocular TB) and 24 QFT-positive uveitis of unknown cause) and 35 with other uveitis entities. Levels of serum BAFF and CXCL9 were measured.

RESULTS

Serum BAFF was higher in ocular sarcoidosis compared to other groups (area under the curve (AUC) = 0.74; 95% CI: 0.53-0.96, p = 0.017). At an optimal serum BAFF cut-off point of 772.3 pg/ml, the sensitivity was 70.0% (95% CI: 39.7-89.2) and the specificity was 89.1% (95% CI: 77.0-95.3). Serum CXCL9 was comparable between ocular sarcoidosis and confirmed ocular TB but was significantly higher in these groups compared to other uveitis entities (AUC = 0.71, 95% CI: 0.57-0.86, p = 0.011). To differentiate ocular sarcoidosis and TB from other uveitis entities, CXCL9 (cutoff: 105.5 pg/ml) showed a sensitivity of 88.9% (95% CI: 67.2-98.0) and a specificity of 54.3% (95% CI: 38.2-69.5). High CXCL9 TB-related uveitis patients demonstrated a higher proportion of uveitis resolution when fully treated with antitubercular treatment (ATT) (p = 0.027).

CONCLUSIONS

Serum BAFF and CXCL9 serve as potential diagnostic biomarkers for differentiating ocular sarcoidosis, ocular TB and other uveitis entities. These might identify QFT-positive uveitis who are most in need of ATT.

Cerebrospinal Fluid Cytokine and Chemokine Profiles in Central Nervous System Sarcoidosis: Diagnostic and Immunopathologic Insights

OBJECTIVE

To evaluate the cerebrospinal fluid (CSF) cytokine/chemokine profile of central nervous system (CNS) neurosarcoidosis (NS), and its utility in differential diagnosis, treatment, and prognostication.

METHODS

In this case-control study, we validated 17 cytokines/chemokines (interleukin [IL]-1-beta, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, IL-17A, BAFF, IL-8/CXCL8, CXCL9, CXCL10, CXCL13, GM-CSF, interferon-gamma, and tumor necrosis factor [TNF]-alpha) in a multiplexed automated immunoassay system (ELLA; Bio-Techne, Minneapolis, MN, USA), and assessed them in CSF and serum of symptomatic patients with probable or definite CNS NS (01/2011-02/2023) with gadolinium enhancement and/or CSF pleocytosis. Patients with multiple sclerosis, primary CNS lymphoma, aquaporin-4 immunoglobulin G positivity, non-inflammatory disorders, and healthy individuals were used as controls.

RESULTS

A total of 32 NS patients (59% women; median age, 59 years [19-81]) were included; concurrent sera were available in 12. CSF controls consisted of 26 multiple sclerosis, 8 primary CNS lymphoma, 84 aquaporin-4 immunoglobulin G positive, and 34 patients with non-inflammatory disorders. Gadolinium enhancement was present in 31 of 32 NS patients, and CSF pleocytosis in 27 of 32 (84%). CSF IL-2, IL-6, IL-10, IL-13, BAFF, IL-8/CXCL8, CXCL9, CXCL10, CXCL13, GM-CSF, interferon-gamma, and TNF-alpha levels were significantly higher in NS patients compared with non-inflammatory controls (p ≤ 0.02); elevations were more common in CSF than serum. Concurrent elevation of IL-6, CXCL9, CXCL10, GM-CSF, interferon-gamma, and TNF-alpha was present in 18 of 32 NS patients, but only in 1 control. Elevated IL-6, IL-10, IL-13, CXCL9, CXL10, GM-CSF, and TNF-alpha associated with measures of disease activity.

INTERPRETATION

NS CSF cytokine/chemokine profiles suggest T cell (mainly T helper cell type 1), macrophage, and B-cell involvement. These signatures aid in NS diagnosis, indicate disease activity, and suggest therapeutic avenues. ANN NEUROL 2024;96:704-714.

Diagnostic value of soluble Interleukin-2 receptor in patients suffering neurosarcoidosis: A systematic review

Background

Neurosarcoidosis is an inflammatory granulomatous disease. Up to 25% of occult sarcoidosis affecting the nervous system are only detected by autopsy. In addition, in recent years the suspicion arose that the soluble Interleukin-2 Receptor (sIL-2R) might be useful in differentiating between neurosarcoidosis and neurosarcoidosis-like diseases such as neurotuberculosis, multiple sclerosis, or cerebral lymphoma.

Objectives

Therefore, we aimed to systematically review randomized controlled trials (RCT), observational studies, and case-control studies evaluating sIL-2R levels in neurosarcoidosis patients.

Design

For this systematic review, a comprehensive literature search of electronic databases including EMBASE, The Web Of Science, The Cochrane Library, MEDLINE, and Google Scholar was conducted. The search was limited to the English language and publication date up to January 08th, 2024.

Data Sources and Methods

As part of the search strategy conducted, 6 articles met the inclusion criteria. Two independent reviewers extracted the relevant data from each article. In addition, 2 independent reviewers assessed the quality of each study using the Newcastle-Ottawa Scale (NOS).

Results

We included 6 studies comprising 98 patients suffering from neurosarcoidosis, 525 non-sarcoidosis patients, and 118 healthy controls. Included studies were published between 2010 and 2023. Cerebrospinal fluid (CSF) sIL-2R levels differed significantly between neurosarcoidosis patients and multiple sclerosis, vasculitis, and healthy controls whereas serum sIL-2R levels did not reveal sufficient discriminative power. sIL-2R index was able to discriminate neurosarcoidosis from neurotuberculosis, bacterial/viral meningitis, and healthy controls.

Conclusions

In this systematic review, we found indications that sIL-2R may be a useful biomarker for the diagnosis of neurosarcoidosis. To determine an additional diagnostic value of sIL-2R, large prospective studies are needed that not only examine absolute sIL-2R levels in serum or CSF but also the dynamic changes as well as the implications of renal function on sIL-2R levels.

Neurologic Manifestations of Rheumatologic Disorders

OBJECTIVE

This article provides an overview of the neurologic manifestations of sarcoidosis and select rheumatologic disorders. An approach to the assessment and differential diagnosis of characteristic clinical presentations, including meningitis and vasculitis, is also reviewed. A review of treatment options is included as well as discussion of distinct areas of overlap, including rheumatologic disease in the setting of neuromyelitis spectrum disorder and demyelinating disease in the setting of tumor necrosis factor-α inhibitors.

LATEST DEVELOPMENTS

An increased understanding of the immune mechanisms involved in sarcoidosis and rheumatologic diseases has resulted in a greater diversity of therapeutic options for their treatment. Evidence directing the treatment of the central nervous system (CNS) manifestations of these same diseases is lacking, with a paucity of controlled trials.

ESSENTIAL POINTS

It is important to have a basic knowledge of the common CNS manifestations of rheumatologic diseases and sarcoidosis so that they can be recognized when encountered. In the context of many systemic inflammatory diseases, including systemic lupus erythematosus, IgG4-related disease, and sarcoidosis, CNS disease may be a presenting feature or occur without systemic manifestations of the disease, making familiarity with these diseases even more important.

Biomarkers and molecular endotypes of sarcoidosis: lessons from omics and non-omics studies

Sarcoidosis is a chronic granulomatous disorder characterized by unknown etiology, undetermined mechanisms, and non-specific therapies except TNF blockade. To improve our understanding of the pathogenicity and to predict the outcomes of the disease, the identification of new biomarkers and molecular endotypes is sorely needed. In this study, we systematically evaluate the biomarkers identified through Omics and non-Omics approaches in sarcoidosis. Most of the currently documented biomarkers for sarcoidosis are mainly identified through conventional "one-for-all" non-Omics targeted studies. Although the application of machine learning algorithms to identify biomarkers and endotypes from unbiased comprehensive Omics studies is still in its infancy, a series of biomarkers, overwhelmingly for diagnosis to differentiate sarcoidosis from healthy controls have been reported. In view of the fact that current biomarker profiles in sarcoidosis are scarce, fragmented and mostly not validated, there is an urgent need to identify novel sarcoidosis biomarkers and molecular endotypes using more advanced Omics approaches to facilitate disease diagnosis and prognosis, resolve disease heterogeneity, and facilitate personalized medicine.