To the Editor:

We apologize for this awful mistake on our part. Indeed, the correct reference is the report by Hirohata and Miyamoto (Hirohata S, Miyamoto T. Elevated levels of interleukin-6 in cerebrospinal fluid from patients with systemic lupus erythematosus and central nervous system involvement. Arthritis Rheum 1990;33:644–9), which was the first demonstration of elevated levels of IL-6 in CSF from NPSLE patients. They even showed that CSF IL-6 levels decreased when the central nervous system manifestations in the SLE patients resolved after treatment. Since publication of that report, the presence of IL-6 in the CSF has been a commonly described feature of NPSLE.

Our study results confirmed Hirohata and Miyamoto's observations and provided an extended profile of cytokines and chemokines in the CSF of NPSLE patients. We also showed that the levels of IL-6 and chemokines declined significantly after the NP manifestations had resolved.

We thank Dr. Hirohata for his comments and for providing us the opportunity to correct this error.

Hilda Fragoso-Loyo MD*, Luis Llorente MD*, Jorge Sánchez-Guerrero MD, MS*, * Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.