Background/Purpose: Anti-NR2, a subclass of anti-NMDA receptor antibodies, is reportedly associated with NPSLE syndromes. However, its diagnostic accuracy is inconsistent across prior studies. Hence, we aimed to quantitatively synthesize the data regarding the sensitivity and specificity of anti-NR2 in diagnosing NPSLE.

Methods: We searched PubMed, Embase, CINAHL and the Web of Knowledge. We included the studies of the diagnostic test accuracy of anti-NR2 for diagnosing NPSLE among patients with SLE, in which they used the ACR case definitions or other validated tools as their reference standards. Two investigators (SFA, GZ) independently replicated data extraction by using a standard form, which included an assessment of study quality as well as participant-level data to populate 2×2 contingency tables. For meta-analysis, we used the Hierarchical Summary Receiver Operating Characteristic (HSROC) model by Rutter & Gatsonis (2001) in Stata 13.0.

Results: We screened 1583 records and eventually included the data from 8 studies with a collective sample of 984 patients (Figure 1). The pooled data represented a wide range of NPSLE manifestations including acute confusional state, seizure disorders, cerebrovascular disease, aseptic meningitis, headaches, cognitive dysfunction, psychoses, mood disorders, movement disorders (chorea), myasthenia gravis, demyelinating syndromes, myelopathy, plexopathy, and mono, poly, and cranial neuropathies. The reported sensitivities fell within a wider range (5% to 100%) compared to the specificities range (64% to 92%) (Figure 2). Meta-analysis of the results yielded the following pooled results with their 95% confidence intervals: Sensitivity 53% (24-80%), Specificity 77% (69-83%), -Likelihood ratio (LR) 0.61 (0.30-1.25), and +LR 2.26 (1.07-4.76) (Figure 3).

Conclusion: Serum anti-NR2 Ab has non-significant sensitivity and -LR, but it has statistically significant specificity and +LR in diagnosing NPSLE. Thus, patients with suspected NPSLE may benefit from checking their anti-NR2 levels. Nevertheless, further analyses are needed before recommending anti-NR2 for routine clinical use.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/serum-anti-nr2-has-a-better-specificity-than-sensitivity-in-diagnosing-neuropsychiatric-systemic-lupus-erythematosus-npsle/