To the Editor:
We thank Dr. Abud-Mendoza and colleagues1 for their interest in our report2. The suggestion of additional biomarkers as an aid in the diagnostic process of neuropsychiatric systemic lupus erythematosus (NPSLE) and its phenotypes is excellent and we plan to report on that in the near future. In daily practice the analysis of cerebrospinal fluid is mandatory if infections are in the differential diagnosis, but to the best of our knowledge the discriminative value of slight abnormalities in cerebrospinal fluid is insufficient to diagnose NPSLE or to discriminate between an inflammatory or ischemic etiology. Indeed the 100% sensitivity of an abnormality on MRI was only found in ischemic NPSLE, whereas more than a quarter of patients with inflammatory NPSLE had an unremarkable MRI. Since we recognize the limitations of the standard clinical sequences of MRI, we are currently in the process of analyzing whether more sophisticated imaging modalities can contribute to the accuracy of the diagnostic process in NPSLE.