Metrics and definitions used in the assessment of cognitive impairment in systemic lupus erythematosus: A systematic review

Outcome clusters and their stability over 1 year in patients with SLE: self-reported and performance-based cognitive function, disease activity, mood and health-related quality of life

OBJECTIVE

To determine if self-reported fatigue, anxiety, depression, cognitive difficulties, health-related quality of life, disease activity scores and neuropsychological battery (NB) cluster into distinct groups in patients with SLE based on symptom intensity and if they change at 1-year follow-up.

METHODS

This is a retrospective analysis of consecutive consenting patients, followed at a single centre. Patients completed a comprehensive NB, the Beck Anxiety Inventory, Beck Depression Inventory, Fatigue Severity Scale, Short-Form Health Survey Physical Component Summary and Mental Component Summary scores and the Perceived Deficits Questionnaire. Disease activity was assessed by Systemic Lupus Erythematosus Disease Activity Index 2000. Ward's method was used for clustering and principal component analysis was used to visualise the number of clusters. Stability at 1 year was assessed with kappa statistic.

RESULTS

Among 142 patients, three clusters were found: cluster 1 had mild symptom intensity, cluster 2 had moderate symptom intensity and cluster 3 had severe symptom intensity. At 1-year follow-up, 49% of patients remained in their baseline cluster. The mild cluster had the highest stability (77% of patients stayed in the same cluster), followed by the severe cluster (51%), and moderate cluster had the lowest stability (3%). A minority of patients from mild cluster moved to severe cluster (19%). In severe cluster, a larger number moved to moderate cluster (40%) and fewer to mild cluster (9%).

CONCLUSION

Three distinct clusters of symptom intensity were documented in patients with SLE in association with cognitive function. There was a lower tendency for patients in the mild and severe clusters to move but not moderate cluster over the course of a year. This may demonstrate an opportunity for intervention to have moderate cluster patients move to mild cluster instead of moving to severe cluster. Further studies are necessary to assess factors that affect movement into moderate cluster.

Comparison of cognitive performance measures in individuals with systemic lupus erythematosus

OBJECTIVE

Cognitive impairment is a common complaint in SLE, but approaches to measuring cognitive performance objectively vary. Leveraging data collected in a population-based cohort of individuals with validated SLE, we compared performance and potential impairment across multiple measures of cognition.

METHODS

During a single study visit (October 2019-May 2022), times to complete the Trail Making Test B (TMTB; N=423) were recorded; potential impairment was defined as an age-corrected and education-corrected T-score <35 (>1.5 SD longer than the normative time). A clock drawing assessment (CLOX; N=435) with two parts (free clock draw (CLOX1) and copy (CLOX2)) was also performed (score range: 0-15; higher scores=better performance); potential impairment was defined as CLOX1 <10 or CLOX2 <12. Fluid cognition (N=199; in-person visits only) was measured via the National Institutes of Health (NIH) Toolbox Fluid Cognition Battery and expressed as age-corrected standard scores; potential impairment was defined by a score <77.5 (>1.5 SD lower the normative score).

RESULTS

Participants (mean age 46 years; 92% female; 82% black) had a median (IQR) TMTB time of 96 (76-130) s; median (IQR) CLOX1 and CLOX2 scores of 12 (10-13) and 14 (13-15); and a mean (SD) fluid cognition standard score of 87.2 (15.6). TMTB time and fluid cognition score (ρ=-0.53, p<0.001) were the most highly intercorrelated measures. Overall, 65%, 55% and 28% were potentially impaired by the TMTB test, CLOX task and NIH Toolbox Fluid Cognition Battery, respectively. While there was overlap in potential impairment between TMTB and CLOX, more than half (58%) had impairment by only one of these assessments. Few (2%) had impairment in fluid cognition only.

CONCLUSION

The TMTB, CLOX and NIH Fluid Cognition Battery each provided unique and potentially important information about cognitive performance in our SLE cohort. Future studies are needed to validate these measures in SLE and explore interventions that maintain or improve cognitive performance in this population.

Juvenile neuropsychiatric systemic lupus erythematosus: A specific clinical phenotype and proposal of a probability score

OBJECTIVE

Juvenile systemic lupus erythematosus (j-SLE) is a rare chronic auto-immune disease involving several organs. Neuropsychiatric (NP) SLE (NPSLE) is frequent in j-SLE and associated with increased morbidity/mortality. Although NPSLE classification criteria exist, attributing NP features to j-SLE remains a major challenge. The study objective is to thoroughly describe j-NPSLE patients and assist in their diagnosis.

METHODS

This is a 4-year retrospective monocentric study of j-SLE patients. NP events were attributed to j-SLE using standardised diagnostic criteria and multidisciplinary paediatric clinical expertise. Clinical features, brain magnetic resonance imaging (MRI)s and samples analysis including cerebrospinal fluid were assessed. A risk of j-NPSLE score was developed based on multivariable logistic regression analysis.

RESULTS

Of 39 patients included, 44% were identified as having j-NPSLE. J-NPSLE diagnosis was established at the onset of j-SLE in 59% of patients. In addition to frequent kidney involvement (76%) and chilblains (65%), all j-NPSLE patients displayed psychiatric features: cognitive symptoms (82%), hallucinations (76%), depressed mood (35%), acute confused state (18%) and catatonia (12%). Neurological involvement was often mild and nonspecific, with headache (53%) in about half of the patients. The main features reported on brain MRI were nonspecific T2/FLAIR white matter hyperintensities (65%), and cerebral atrophy (88%). Upon immunosuppressive treatment, clinical improvement of NP features was observed in all j-NPSLE patients. The score developed to attribute j-NPSLE probability, guide further investigations and appropriate treatments is based on hallucinations, memory, sleep and renal involvement (Sensitivity: 0.95 Specificity: 0.85). Cerebrospinal fluid (CSF) neopterin assessment increases the score sensitivity and specificity.

CONCLUSION

Physicians should carefully and systematically assess the presence of NP features at diagnosis and early stages of j-SLE. For j-NPSLE patients with predominant psychiatric features, a multidisciplinary collaboration, including psychiatrists, is essential for the diagnosis, management and follow-up.

Fluid Cognition Among Individuals With Systemic Lupus Erythematosus

OBJECTIVE

We sought to describe fluid cognition and its correlates among individuals with systemic lupus erythematosus (SLE).

METHODS

Participants (n = 199) were recruited from a population-based cohort for a single study visit (October 2019 to May 2022). Fluid cognition was measured via the National Institutes of Health Toolbox Fluid Cognition Battery (including episodic memory, working memory, attention and inhibitory control, processing speed, and cognitive flexibility domains) and expressed as age-corrected standard scores (mean 100, SD 15). Potential impairment was defined as a standard score >1.5 SD below the mean. Descriptive statistics were calculated and associations of various participant characteristics with the potential fluid cognition impairment were assessed with multivariable logistic regression.

RESULTS

Participants' mean age was 46.1 years; most were female (87.4%), Black (86.4%), and non-Hispanic (95.0%). The mean overall fluid cognition score was 87.2; of the individual domains, the participants' mean score was lowest on attention and inhibitory control (82.0). Working status (odds ratio [OR] 0.30, 95% confidence interval [CI] 0.14-0.64) and higher self-reported physical functioning (OR 0.46, 95% CI 0.28-0.75) and physical performance (OR 0.72, 95% CI 0.59-0.87) were associated with lower odds of fluid cognition impairment; lower educational attainment was associated with higher odds (OR 3.82, 95% CI 1.67-8.75). Self-reported forgetfulness, neuropsychiatric damage, and depressive symptoms were not statistically significantly associated with potential impairment.

CONCLUSION

Fluid cognition and, particularly, attention and inhibitory control were low in those with SLE relative to the general US population. Working status, higher physical functioning and performance, and higher educational attainment were associated with lower prevalence of potential impairment. Future work is needed to develop and implement interventions to help support cognition in individuals with SLE.

Systemic lupus erythematosus and damage: What has changed over the past 20 years?

The young age of onset and chronic/relapsing nature of systemic lupus erythematosus (SLE) make SLE patients prone to develop and accrue organ damage as a result of long-standing disease activity and side effects of treatment. There is a growing interest in objectifying damage and identifying its risk factors. Still, the lack of therapeutic alternatives has led to difficulties in avoiding immunosuppressives particularly corticosteroids, which have been implicated in a large spectrum of organ damage in SLE patients. Moreover, it continues to be very challenging to determine what actually causes damage in different organ-systems. Cardiovascular disease continues to be one of the leading types of damage in patients with SLE, reported as early as 1976. Since then, many researchers have focused on identifying SLE or treatment-related and traditional risk factors. The same considerations are valid for other conditions, such as the occurrence of metabolic syndrome, osteoporosis, avascular necrosis, susceptibility to infections, etc. On the other hand, diverse risk factors contribute to the development of chronic kidney disease (CKD) in SLE. Most evidence suggests that high initial levels of serum creatinine, hypocomplementemia, nephrotic range proteinuria, concomitant uncontrolled hypertension, Black and Hispanic ancestry, non-adherence to treatment, and biopsy findings such as diffuse proliferative lupus nephritis (LN), a high chronicity index, tubular atrophy, and tubulointerstitial inflammation are risk factors for progression to end stage renal disease (ESRD) in LN. While cardiovascular disease, CKD and infections are leading causes of mortality in patients with SLE, hospitalizations are caused mostly by SLE disease flares and infections. Cognitive impairment and mood disorders are common in SLE but continue to impose a challenge on how to measure, manage and decipher the underlying pathogenesis. Nevertheless, they have a great impact on SLE patients' health-related quality of life (HRQoL) and social functioning. Also, skin manifestations, such as alopecia and scaring, cataracts, and sicca symptoms result in a significant decrease in HRQoL. In light of recent developments in SLE treatment, we can expect to enter a period of new-age targeted therapies that will enable us to reduce disease activity and glucocorticoid usage further and positively alter the trajectory of damage development and accrual in SLE.

Systemic lupus erythematosus phenotypes formed from machine learning with a specific focus on cognitive impairment

OBJECTIVE

To phenotype SLE based on symptom burden (disease damage, system involvement and patient reported outcomes), with a specific focus on objective and subjective cognitive function.

METHODS

SLE patients ages 18-65 years underwent objective cognitive assessment using the ACR Neuropsychological Battery (ACR-NB) and data were collected on demographic and clinical variables, disease burden/activity, health-related quality of life (HRQoL), depression, anxiety, fatigue and perceived cognitive deficits. Similarity network fusion (SNF) was used to identify patient subtypes. Differences between the subtypes were evaluated using Kruskal-Wallis and χ2 tests.

RESULTS

Of the 238 patients, 90% were female, with a mean age of 41 years (s.d. 12) and a disease duration of 14 years (s.d. 10) at the study visit. The SNF analysis defined two subtypes (A and B) with distinct patterns in objective and subjective cognitive function, disease burden/damage, HRQoL, anxiety and depression. Subtype A performed worst on all significantly different tests of objective cognitive function (P < 0.03) compared with subtype B. Subtype A also had greater levels of subjective cognitive function (P < 0.001), disease burden/damage (P < 0.04), HRQoL (P < 0.001) and psychiatric measures (P < 0.001) compared with subtype B.

CONCLUSION

This study demonstrates the complexity of cognitive impairment (CI) in SLE and that individual, multifactorial phenotypes exist. Those with greater disease burden, from SLE-specific factors or other factors associated with chronic conditions, report poorer cognitive functioning and perform worse on objective cognitive measures. By exploring different ways of phenotyping SLE we may better define CI in SLE. Ultimately this will aid our understanding of personalized CI trajectories and identification of appropriate treatments.

Centrally acting ACE inhibitor (cACEi) and angiotensin receptor blocker (cARB) use and cognitive dysfunction in patients with SLE

OBJECTIVE

Cognitive dysfunction (CD) is detectable in approximately 40% of patients with SLE. Despite this high prevalence, there are no approved pharmacological treatment options for this detrimental condition. Preliminary murine studies show potential for targeting microglial activation as a treatment of SLE-CD, which may be ameliorated with centrally acting ACE inhibitor (cACEi) and angiotensin receptor blocker (cARB) use. The aim of this study is to determine if there is an association of cACEi/cARB use with cognitive function in a human SLE cohort.

METHODS

The American College of Rheumatology neuropsychological battery was administered to patients with consecutive SLE at a single academic health centre at baseline, 6 and 12 months. Scores were compared with sex-matched and age-matched control subjects. Clinical and demographic data were gathered at each visit. The primary outcome was CD defined as dysfunction in two or more cognitive domains. The primary predictor was a total cumulative dose of cACEi/cARB in milligrams per kilogram, recorded as an equivalent ramipril dose. Odds of CD with respect to cACEi/cARB use were determined through generalised linear mixed modelling.

RESULTS

A total of 300 patients, representing 676 visits, completed this study. One hundred sixteen (39%) met the criteria for CD. Fifty-three participants (18%) were treated with a cACEi or cARB. Mean cumulative dose was 236 mg/kg (calculated as equivalent ramipril dose). Cumulative cACEi/cARB dose was not protective against SLE-CD. Caucasian ethnicity, current employment status and azathioprine cumulative dose were each associated with reduced odds of SLE-CD. Increasing Fatigue Severity Scale score was associated with increased odds of CD.

CONCLUSIONS

In a single-centre SLE cohort, cACEi/cARB use was not associated with absence of CD. Many important confounders may have influenced the results of this retrospective study. A randomised trial is required to accurately determine if cACEi/cARB is a potential treatment for SLE-CD.

Assessing the Utility of the Montreal Cognitive Assessment in Screening for Cognitive Impairment in Patients With Systemic Lupus Erythematosus

OBJECTIVE

Screening for cognitive impairment (CI) in systemic lupus erythematosus (SLE) relies on the American College of Rheumatology (ACR) neuropsychological battery (NB). By studying the concurrent criterion validity, our goal was to assess the Montreal Cognitive Assessment (MoCA) as a screening tool for CI compared to the ACR-NB and to evaluate the added value of the MoCA to the Automated Neuropsychological Assessment Metrics (ANAM).

METHODS

A total of 285 adult SLE patients were administered the ACR-NB, MoCA, and ANAM. For the ACR-NB, patients were classified as having CI if there was a Z score of ≤-1.5 in ≥2 domains. The area under the curve (AUC) and sensitivities/specificities were determined. A discriminant function analysis was applied to assess the ability of the MoCA to differentiate between CI, undetermined CI, and non-CI patients.

RESULTS

CI was not accurately identified by the MoCA compared to the ACR-NB (AUC of 0.66). Sensitivity and specificity were poor at 50% and 69%, respectively, for the cutoff of 26, and 80% and 45%, respectively, for the cutoff of 28. The MoCA had a low ability to identify CI status. The addition of the MoCA to the ANAM led to improvement on the AUC by only 2.5%.

CONCLUSION

The MoCA does not have adequate concurrent criterion validity to accurately identify CI in patients with SLE. The low specificity of the MoCA may lead to overdiagnosis and concern among patients. Adding the MoCA to the ANAM does not substantially improve the accuracy of the ANAM. These results do not support using the MoCA as a screening tool for CI in patients with SLE.

Intraindividual Change in Cognitive Function Among Adults With Systemic Lupus Erythematosus: A Markov Analysis Over 7 Years

OBJECTIVE

Cognitive impairment is prevalent in systemic lupus erythematosus (SLE). There remain gaps in understanding cognition and SLE longitudinally. We studied intraindividual change in cognition in SLE over time.

METHODS

Data were from the University of California, San Francisco Lupus Outcome Study, which included 1281 adults with SLE. The Hopkins Verbal Learning Test-Revised (HVLT-R) and the Controlled Oral Word Association Test (COWAT) were administered annually over 7 years. A two-state Markov analysis was used to model transition intensities for probabilities of change in cognition. Logistic regression examined the association between clinical variables and cognitive change.

RESULTS

Minimal transition between cognitive states was observed in the Markov analysis. Using the COWAT, higher levels of self-reported depression were associated with decreased likelihood of cognitive improvement (Relative Risk [RR]: 0.98; 95% confidence interval [CI]: 0.96-0.99), and higher self-reported disease severity was associated with cognitive decline (RR: 1.05; 95% CI: 1.02-1.09). Using the HVLT-R, increasing age (RR: 1.02; 95% CI: 1.01-1.03) and higher education level (RR: 1.82; 95% CI: 1.28-2.58) were associated with cognitive improvement, and higher self-reported disease severity (RR: 1.02; 95% CI: 1.01-1.03) and depression (RR: 1.05; 95% CI: 1.03-1.07) were associated with cognitive decline.

CONCLUSION

Most individuals with SLE did not transition between states of high (Z score ≥ -1.5) or low (Z score < -1.5) cognition in a Markov analysis over a 7-year assessment period, highlighting a degree of relative stability in cognition over time. Increasing age and higher education levels were associated with greater likelihood of cognitive improvement. Greater self-reported SLE disease severity and depression were associated with cognitive decline.

Cognitive dysfunction in SLE: An understudied clinical manifestation

Neuropsychiatric lupus (NPSLE) is a debilitating manifestation of SLE which occurs in a majority of SLE patients and has a variety of clinical manifestations. In the central nervous system, NPSLE may result from ischemia or penetration of inflammatory mediators and neurotoxic antibodies through the blood brain barrier (BBB). Here we focus on cognitive dysfunction (CD) as an NPSLE manifestation; it is common, underdiagnosed, and without specific therapy. For a very long time, clinicians ignored cognitive dysfunction and researchers who might be interested in the question struggled to find an approach to understanding mechanisms for this manifestation. Recent years, however, propelled by a more patient-centric approach to disease, have seen remarkable progress in our understanding of CD pathogenesis. This has been enabled through the use of novel imaging modalities and numerous mouse models. Overall, these studies point to a pivotal role of an impaired BBB and microglial activation in leading to neuronal injury. These insights suggest potential therapeutic modalities and make possible clinical trials for cognitive impairment.

Cross-cultural adaptation and initial validation of the Brazilian-Portuguese version of the pediatric automated neuropsychological assessment metrics

Automated neuropsychiatric batteries have been used in research and clinical practice, including for chronic diseases, such as Systemic Lupus Erythematosus. The Pediatric Automated Neuropsychological Assessment Metrics battery (Ped-ANAM), originally developed for use in American-English speaking individuals, allows tracking of cognitive functions. It can be applied to people over 9 years old. The aim of this study was to translate and present initial validation data from the Ped-ANAM into Brazilian-Portuguese. We translated the battery according to Beaton’s guidelines. Psychometric properties were tested, internal consistency was analyzed by Cronbach’s alpha coefficient, test-retest reliability by the intraclass correlation coefficient (ICC). Further, we measured the test execution speed at both times as a temporal stability. Principal component analysis (PCA) was used for structural validity. Evidence of construct validity was assessed through assessment of the relationships with the Wechsler Intelligence Scales. All participants prior to the start of study related activities signed an informed consent form approved by the local ethics committee. A sample of 230 individuals [mean (range) of age: 23 (9 to 60) years; 65% females] was included; a subset of 51 individuals [mean (range) of age: 18 (9 to 57) years, 59% female] completed the Ped-ANAM twice to assess test-retest reliability, and another subset of 54 individuals [mean (range) of age: 20.4 (7 to 62) years; 67% female] completed the Wechsler Intelligence Scales for Children and Adult for assessment of the Ped-ANAM’s construct validity. Our results suggest that the internal consistency of the Ped-ANAM (Cronbach’s α = 0.890) and its subtest test-retest reliability were excellent (ICC: 0.59 to 0.94). There was no clustering in the Principal Components Analysis, suggestive of non-grouping of the evaluated variables. Construct validity assessment to the Wechsler Scales showed expected ranges of low to strong correlations (Spearman correlations: ρ = 0.40 to ρ = 0.69). We concluded that, based on the results of this study, a cross-culturally validated Brazilian-Portuguese version of the Ped-ANAM has been developed and it is a reliable tool for the screening cognitive function.