Diagnostic reliability of magnetic resonance imaging for central nervous system syndromes in systemic lupus erythematosus: a prospective cohort study

Quinolinic acid, a kynurenine/tryptophan pathway metabolite, associates with impaired cognitive test performance in systemic lupus erythematosus

OBJECTIVES

Interferon-alpha, an important contributor to SLE pathogenesis, induces the enzyme indoleamine 2,3-dioxygenase in the kynurenine/tryptophan (KYN/TRP) pathway. This leads to a potentially neurotoxic imbalance in the KYN/TRP pathway metabolites, quinolinic acid (QA), an N-methyl D-aspartate glutamatergic receptor (NMDAR) agonist, and kynurenic acid (KA), an NMDAR antagonist. We determined whether QA/KA ratios associate with cognitive dysfunction (CD) and depression in SLE.

METHODS

This cross-sectional study included 74 subjects with SLE and 74 healthy control (HC) subjects; all without history of neuropsychiatric disorders. Serum metabolite levels (KYN, TRP, QA, KA) were measured concurrently with assessments of cognition (Automated Neuropsychological Assessment Metrics (ANAM), 2×2 array), mood and pain, and compared between SLE and HC. Multivariable modelling in SLE was used to evaluate associations of metabolites with cognitive performance and depression.

RESULTS

Serum KYN/TRP and QA/KA ratios were elevated in SLE versus HC (p<0.0001). SLE performed worse than HC on four of five ANAM tests (all p≤0.02) and the 2×2 array (p<0.01), and had higher depression scores (p<0.01). In SLE, elevated QA/KA ratios correlated with poor performance on Match to Sample (MTS), a working memory and visuospatial processing task (p<0.05). Subjects with SLE with elevated QA/KA ratios also had slightly higher odds of depression, but this did not reach significance (p=0.09). Multivariable modelling in SLE confirmed an association between QA/KA ratios and poor MTS performance when considering potentially confounding factors (p<0.05).

CONCLUSIONS

Elevated serum KYN/TRP and QA/KA ratios confirm KYN/TRP pathway activation in SLE. The novel association between increased QA/KA ratios and poor cognitive performance supports further study of this pathway as a potential biomarker or therapeutic target for SLE-mediated CD.

Relevant domains and outcome measurement instruments in Neuropsychiatric Systemic Lupus Erythematosus: a systematic literature review

OBJECTIVES

Although neuropsychiatric involvement in Systemic Lupus Erythematosus (NPSLE) is one of the most complex and troubling manifestations of the disease, validated outcome instruments to be used as sensitive endpoints in controlled clinical trials are lacking. We set out a systematic literature review (SLR) to identify outcome measurement instruments and domains used to assess NPSLE.

METHODS

The Preferred Reporting Items for systematic reviews and Meta-analysis (PRISMA) guidelines were used. Articles available in English (1967-2020), listed in PubMed, EMBASE, PsycINFO, Cochrane Library and EULAR outcome measures library were screened. All domains and outcome measurement instruments were characterized according to the OMERACT Filter 2.1, considering core areas (manifestations/abnormalities, life impact, death/lifespan, societal/resource use) and contextual factors.

RESULTS

Of 3,392 abstracts evaluated, 83 studies were included in the SLR (15,974 patients, females 89.9%). Eligible studies included domains and instruments pertinent to all core areas defined by OMERACT, except for "societal/resource use". The most common core areas were "manifestations/abnormalities", covering 10 domains pertinent to laboratory and instrumental markers, indexes and neuropsychiatric dimension (cognitive, neurologic and psychiatric field), and "life impact", covering 7 domains related to physical function (from both the perspective of the patient and the physician), pain and quality of life.

CONCLUSION

Our study revealed great heterogeneity in the instruments derived from populations with NPSLE and none of these had high-quality evidence. This supports the need to develop and further validate a core domain set and outcome measurement instruments to promote clinical research in this field, enhancing comparability across studies.

A comparison of the performance of the 2019 European League Against Rheumatism/American College of Rheumatology criteria and the 2012 Systemic Lupus International Collaborating Clinics criteria with the 1997 American College of Rheumatology classification criteria for systemic lupus erythematous in new-onset Chinese patients

Background

New criteria published by the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) use a point system that gives varying weight to each of 22 criteria. The aim of this study was to compare the performance of the 2019 EULAR/ACR criteria and the 2012 Systemic Lupus International Collaborating Clinics (SLICC) criteria with the 1997 ACR criteria in a Chinese cohort.

Methods

A cross-sectional observation study of patients with a clinical diagnosis of SLE was performed. We collected 199 new-onset SLE patients and 175 control subjects. The data were retrospectively collected to establish the patients who fulfilled the 1997 ACR, 2012 SLICC and 2019 EULAR/ACR criteria. The sensitivity and specificity of the three classification criteria were compared using McNemar’s test.

Results

The sensitivity and specificity of the 2019 EULAR/ACR criteria were 96.5% and 90.3%, respectively. For the 2012 SLICC criteria, the sensitivity and specificity were 92.0% and 84.0%, respectively, while for the 1997 ACR criteria, these two values were 75.4% and 96.0%. Leucopaenia (62%), arthritis (54%) and autoimmune haemolysis (45%) were the most frequently observed clinical manifestations in the group that fulfilled the 2019 EULAR/ACR criteria. Fever was reported by 39% of participants.

Conclusion

Compared with the 1997 ACR and 2012 SLICC criteria, the 2019 EULAR/ACR criteria performed best in terms of sensitivity but less well in terms of specificity in Chinese new-onset lupus patients.

Combined Brain/Heart Magnetic Resonance Imaging in Systemic Lupus Erythematosus

Cardiovascular Disease (CVD) in Systemic Lupus Erythematosus (SLE) and Neuropsychiatric SLE (NPSLE) has an estimated prevalence of 50% and 40%, respectively and both constitute major causes of death among SLE patients. In this review, a combined brain/heart Magnetic Resonance Imaging (MRI) for SLE risk stratification has been proposed. The pathophysiologic background of NPSLE includes microangiopathy, macroscopic infarcts and accelerated atherosclerosis. Classic brain MRI findings demonstrate lesions suggestive of NPSLE in 50% of the NPSLE cases, while advanced MRI indices can detect pre-clinical lesions in the majority of them, but their clinical impact still remains unknown. Cardiac involvement in SLE includes myo-pericarditis, valvular disease/endocarditis, Heart Failure (HF), coronary macro-microvascular disease, vasculitis and pulmonary hypertension. Classic and advanced Cardiovascular Magnetic Resonance (CMR) indices allow function and tissue characterization for early diagnosis and treatment follow-up of CVD in SLE. Although currently, there are no clinical data supporting the combined use of brain/heart MRI in asymptomatic SLE, it may have a place in cases with clinical suspicion of brain/heart involvement, especially in patients at high risk for CVD/stroke such as SLE with antiphospholipid syndrome (SLE/APS), in whom concurrent cardiac and brain lesions have been identified. Furthermore, it may be of value in SLE with multi-organ involvement, NPSLE with concurrent cardiac involvement, and recent onset of arrhythmia and/or heart failure.

Central nervous system manifestation of lupus erythematosus resembling brain abscess

Manifestations of central nervous system involvement are one of the leading causes of morbidity and mortality in patients suffering from systemic lupus erythematosus. It frequently involves the central nervous system and sometimes need to be differentiated from lesions of infectious etiology, thus representing a major diagnostic dilemma. We present the case of a male adolescent with a known history of idiopathic thrombocytopenic purpura who presented with a seizure ictus and a space-occupying lesion, which posed significant diagnostic challenges to specify its characteristics.

Clinical, neuroimaging and immunological phenotype of South African neuropsychiatric systemic lupus erythematosus patients

Neuropsychiatric systemic lupus erythematosus (NPSLE) is an important cause of morbidity and mortality. We undertook this observational retrospective study of patients with NPSLE who had brain magnetic resonance imaging (MRI) to determine the indications for MRI and the correlation of clinical and laboratory findings with MRI. We identified 83 NPSLE patients (84.3% women) seen at Inkosi Albert Luthuli Central Hospital in Durban, South Africa, between June 2003 and May 2017. The mean age at SLE diagnosis was 26.24 ± 12.81 years and the median interval to NPSLE was 11.0 (interquartile range, 4.0-39.0) months. The most common indications for MRI were seizures (45.8%), psychosis (18.1%) and cerebrovascular disease (18.1%). The MRI was abnormal in 68 (81.9%) with small-vessel disease in 65 (78.3%) and large-vessel disease in eight (9.6%). The small-vessel abnormalities were white-matter hyperintensities (WMH) (59.0%), atrophy (55.4%) and lacunae (4.6%). Our patients had high disease activity at NPSLE. Cerebrovascular disease was associated with an abnormal MRI ( p = 0.018) and large-vessel disease ( p = 0.014) on MRI. Our NPSLE patients were younger and had high disease activity, and seizures were more common compared with other studies. The most common MRI abnormalities were WMH and cortical atrophy, in agreement with other studies.

Silent cerebral MRI findings in lupus nephritis patients: Is it clinically significant?

Lupus nephritis (LN) carries high morbidity and mortality and whenever added to neuropsychiatric manifestations lead to more unfavorable prognosis. Though silent brain MRI findings in systemic lupus erythematosus (SLE) had been widely studied, the current work focused on LN patients comparing them to those without kidney affection, studying their cerebral MRI and its correlation with the histopathological classes of LN and disease activity. This may enable us to know more about early brain affection in LN patients for better follow up, management, and prognosis of this serious comorbidity. Cerebral MRI and MRA were studied in 40 SLE patients without neuropsychiatric manifestations; 20 LN patients with different histopathological classes and 20 patients without kidney affection. Disease activity was assessed for all patients using SLE disease activity index (SLEDAI). Abnormal MRI brain findings were more common in LN patients “though non significant” (P = 0.9). The most common lesions were white matter hyperintense lesions (WMHLs). Number and size of such lesions were significantly higher in LN patients (1.8 fold that of non nephritis, P = 0.003 and 0.03, respectively) and positively correlated with urea, creatinine, urinary albumin/creatinine ratio, SLEDAI, ESR, CRP, and grades of renal biopsy and negatively correlated with C3 and C4. Cortical atrophy and prepontine space dilatation were also significantly higher in LN patients (P = 0.01). Asymptomatic MRI brain lesions whenever present in LN patients, they are usually clinically significant and well correlate to laboratory parameters of LN, grades of renal biopsy, and disease activity independent to age, sex and hypertension.

Relationship Between Clinical and Immunological Features with Magnetic Resonance Imaging Abnormalities in Female Patients with Neuropsychiatric Systemic Lupus Erythematosus

BACKGROUND

Conventional magnetic resonance imaging (MRI) is the preferred neuroimaging method in the evaluation of neuropsychiatric systemic lupus erythematosus (NPSLE). The purpose of this study was to investigate the association between clinical and immunological features with MRI abnormalities in female patients with NPSLE, to screen for the value of conventional MRI in NPSLE.

METHODS

A total of 59 female NPSLE patients with conventional MRI examinations were enrolled in this retrospective study. All patients were classified into different groups according to MRI abnormalities. Both clinical and immunological features were compared between MRI abnormal and normal groups. One-way analysis of variance was used to compare the systemic lupus erythematosus disease activity index (SLEDAI) score for MRI abnormalities. Multivariate logistic regression analysis investigated the correlation between immunological features, neuropsychiatric manifestations, and MRI abnormalities.

RESULTS

Thirty-six NPSLE patients (61%) showed a variety of MRI abnormalities. There were statistically significant differences in SLEDAI scores (P < 0.001), incidence of neurologic disorders (P = 0.001), levels of 24-h proteinuria (P = 0.001) and immunoglobulin M (P = 0.004), and incidence of acute confusional state (P = 0.002), cerebrovascular disease (P = 0.004), and seizure disorder (P = 0.028) between MRI abnormal and normal groups. In the MRI abnormal group, SLEDAI scores for cerebral atrophy (CA), cortex involvement, and restricted diffusion (RD) were much higher than in the MRI normal group (P < 0.001, P = 0.002, P = 0.038, respectively). Statistically significant positive correlations between seizure disorder and cortex involvement (odds ratio [OR] = 14.90; 95% confidence interval [CI], 1.50-151.70; P = 0.023) and cerebrovascular disease and infratentorial involvement (OR = 10.00; 95% CI, 1.70-60.00; P = 0.012) were found.

CONCLUSIONS

MRI abnormalities in NPSLE, especially CA, cortex involvement, and RD might be markers of high systemic lupus erythematosus activity. Some MRI abnormalities might correspond to neuropsychiatric manifestations and might be helpful in understanding the pathophysiology of NPSLE.

Advanced and Conventional Magnetic Resonance Imaging in Neuropsychiatric Lupus

Neuropsychiatric lupus is a major diagnostic challenge, and a main cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Magnetic resonance imaging (MRI) is, by far, the main tool for assessing the brain in this disease. Conventional and advanced MRI techniques are used to help establishing the diagnosis, to rule out alternative diagnoses, and recently, to monitor the evolution of the disease. This review explores the neuroimaging findings in SLE, including the recent advances in new MRI methods.

Neuropsychiatric systemic lupus erythematosus: magnetic resonance imaging findings and correlation with clinical and immunological features

Neuropsychiatric (NP) syndromes are a major cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). The aims of this work were to describe the brain abnormalities in a group of SLE patients during their first episode of NP manifestations using a conventional magnetic resonance imaging (MRI) technique and to investigate the possible correlation between these findings and the clinical and immunological characteristics of these patients. We performed an observational retrospective cross-sectional study that included all patients with NP symptoms who underwent MRI at the Hospital Clinic of Barcelona between the years 2003 and 2012 because of suspecting NP syndromes due to SLE (NPSLE). We studied 43 patients in which 11 types of NPSLE were present, being headache the most frequent, followed by cerebrovascular disease, epileptic crises and cranial neuropathy. A statistically significant association was found between myelopathy and low complement (C4) levels (p=0.035) and disease activity measured as SLE Disease Activity Index (SLEDAI) >4 (p=0.00006). Eighteen (41.9%) patients presented MRI abnormalities. We found an association between myelopathy and the presence of inflammatory or mixed (vascular and inflammatory) type lesions (p=0.003). This pattern was also associated with a high SLEDAI score (p=0.002) and low complement (CH50) levels (p=0.032). We found no relationship between MRI changes and age, time of evolution, or the presence of antiphospholipid or anti-dsDNA antibodies. These results suggest that MRI, although it is the imaging modality of choice in the present moment, by itself does not establish or exclude the diagnosis of NPSLE. In addition, the presence of certain disease activity features (SLEDAI and low complement levels) seems to be associated with the presence of an inflammatory pattern on MRI.

[An acute psychotic episode revealing neuropsychiatric lupus with atypical brain MRI]

INTRODUCTION

The frequency of neuropsychiatric symptoms in systemic lupus varies between 14 and 75%. Their mechanisms are multiple and their non-specificity makes the etiological diagnosis more difficult. The MRI lesions are dominated by small white matter hyperintensities.

CASE REPORT

We report a case of 17-year-old girl without medical, surgical or familial past, who presented an acute psychotic episode with fever. The neurological examination showed a pyramidal syndrome. The brain MRI objectified diffuse, bilateral and symmetrical white and gray matter hyperintensities. The diagnosis of neuropsychiatric lupus was retained with association of more than four criteria among the 11 ARA revised criteria: pleural effusion, neuropsychiatric manifestations, anemia, lymphopenia and positive ANA. The treatment was based on corticosteroids. The evolution was fatal.

DISCUSSION

Psychiatric disorders are polymorphic and appear during the course of the disease or at diagnosis; they can be seen in 20% of cases and are a sign of a poor prognosis. Most often these disorders are a non-specific reaction, but severe clinical forms can be observed as suicidal risk or mood disorders (depression, mania...), or acute psychotic episode.

CONCLUSION

The diagnosis of neuropsychiatric lupus must be evoked systematically in atypical neuropsychiatric disorders especially when confronted with minimal biological and brain imaging abnormalities.

Serum antibodies against the 70k polypeptides of the U1 ribonucleoprotein complex are associated with psychiatric syndromes in systemic lupus erythematosus: a retrospective study

OBJECTIVES

We assessed the association between serum autoantibodies against the 70-kDa polypeptide of the U1-ribonucleoprotein (RNP) complex (U1-70k) and the central nervous system (CNS) syndromes in systemic lupus erythematosus (SLE) patients.

METHODS

We studied 106 hospitalized patients with active SLE, comparing those with (n = 32) and without (n = 74) CNS syndromes. CNS syndromes were further classified into neurologic (n = 21) and psychiatric (n = 15) disorders. Immunoglobulin G (IgG) anti-U1-70k antibodies were measured by enzyme-linked immunosorbent assay (ELISA) using recombinant antigens. IgG antibodies against whole U1-RNP were measured using commercial ELISA kits.

RESULTS

Although there was no significant difference in the levels of serum anti-U1-70k antibodies in SLE patients with or without CNS syndromes (p = 0.83), the levels were significantly elevated in SLE patients compared with patients without psychiatric syndromes (p = 0.030). In contrast, no significant difference was observed in the levels of serum anti-U1-RNP antibodies in SLE patients with or without psychiatric syndromes (p = 0.555).

CONCLUSIONS

These results indicate that serum anti-U1-70k antibodies are associated with psychiatric syndromes in SLE but that they are not associated with CNS syndromes as a whole or with neurologic syndromes. The anti-U1-70k antibodies might be involved in the pathological mechanisms of psychiatric syndromes in SLE.

Semiquantitative measurement of aquaporin-4 antibodies as a possible surrogate marker of neuromyelitis optica spectrum disorders with systemic autoimmune diseases

OBJECTIVES

To assess the association between serum aquaporin-4 (AQP4) autoantibodies and neuromyelitis optica spectrum disorders (NMOSDs) associated with systemic autoimmune diseases.

METHODS

We retrospectively studied 626 hospitalized patients with systemic lupus erythematosus (SLE) or Sjögren's syndrome (SS). We collected serum samples from those patients with suspected NMOSDs (i.e., myelitis or optic neuritis) at the time of onset and thereafter. AQP4 antibodies were measured by a cell-based indirect immunofluorescence assay using AQP4-transfected HEK-293 cells in a semi-quantitative manner.

RESULTS

Sera from 6 patients with suspected NMOSDs and SLE (n = 3) or SS (n = 3) were evaluated. Among these, 2 patients' sera samples, i.e., 1 with SLE and 1 with SS, were positive for AQP4 antibodies. There was an inverse relationship between disease amelioration and antibody titer in one NMOSD patient, whereas the antibody titer remained high in the other NMOSD patient, whose clinical manifestations of NMOSDs did not improve despite intensive immunosuppressive treatments.

CONCLUSIONS

These results indicate that serum AQP4 antibodies are present in some SLE/SS patients with myelitis/optic neuritis and might be associated with clinical outcomes. The semi-quantitative measurement of the AQP4 antibody might be a possible surrogate marker in patients with NMOSDs associated with systemic autoimmune diseases.

Secondary neuropsychiatric manifestations caused by Epstein-Barr virus encephalitis in a new onset systemic lupus erythematosus patient

Abnormal manifestations of central nervous system in system lupus erythematosus (SLE) patients are mainly caused by primary neuropsychiatric SLE (NP-SLE). We reported a new onset SLE patient who had secondary neuropsychiatric manifestations caused by Epstein-Barr virus (EBV) encephalitis. Although EBV has an uncertain association with SLE, Epstein-Barr virus encephalitis occurred in active SLE patients was not reported previously. Our report may be the first case about EBV encephalitis occurred in active SLE.

Identification of three new autoantibodies associated with systemic lupus erythematosus using two proteomic approaches

Our objective was to identify new serum autoantibodies associated with systemic lupus erythematosus (SLE), focusing on those found in patients with central nervous system (CNS) syndromes. Autoantigens in human brain proteins were screened by multiple proteomic analyses: two-dimensional polyacrylamide gel electrophoresis/Western blots followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis and immunoprecipitation followed by liquid chromatography-tandem mass spectrometry shotgun analysis. The presence of serum IgG autoantibodies against 11 selected recombinant antigens was assessed by Western blot and enzyme-linked immunosorbent assay (ELISA) in the sera of 106 SLE patients and 100 normal healthy controls. The O.D. values in sera from SLE patients were significantly higher than those of controls for the antigens crystallin αB (p = 0.0002), esterase D (p = 0.0002), APEX nuclease 1 (p < 0.0001), ribosomal protein P0 (p < 0.0001), and PA28γ (p = 0.0005); the first three are newly reported. The anti-esterase D antibody levels were significantly higher in the CNS group than in the non-CNS group (p = 0.016). Moreover, when the SLE patients were categorized using CNS manifestations indicating neurologic or psychiatric disorders, the anti-APEX nuclease 1 antibody levels were significantly elevated in SLE patients with psychiatric disorders (p = 0.037). In conclusion, the association of SLE with several new and previously reported autoantibodies has been demonstrated. Statistically significant associations between anti-esterase D antibodies and CNS syndromes as well as between anti-APEX nuclease 1 antibodies and psychiatric disorders in SLE were also demonstrated. The combined immunoproteomic approaches used in this study are reliable and effective methods for identifying SLE autoantigens.