ro-16-0154 and Lupus-Erythematosus--Systemic

Gamma-aminobutyric acid-A (GABA-A) receptors play a crucial role in regulating neuronal excitability and cognitive functions. Single-photon emission computerized tomography (SPECT) analysis of GABA-A receptors binding by (123)I-labelled Iomazenil ((123)I-IMZ) has been applied in some neuropsychiatric disorders to investigate conditions where GABA-A receptor density can be detected in several pathophysiological conditions. In this study we investigate cerebral GABA-A receptor density in a small series of patients with systemic lupus erythematosus (SLE) and cognitive impairment characterized by recurrent, episodic memory loss. Nine female patients with SLE and cognitive alterations underwent to a clinical neuropsychiatric evaluation including digital video-EEG, brain MRI, (99m)Tc-ECD brain SPECT and (123)I-IMZ brain SPECT. All patients tested showed diffuse or focal GABA-A receptor density reduction. This is, to our knowledge, the first report on GABA-A receptor density abnormalities associated with cognitive defects in SLE patients. We hypothesize that in our series a decrease in GABA-A receptor density might be related to the neurological manifestations. Further studies are needed to clarify this aspect and the possible mechanisms. GABA-A receptor density impairment might be due to the SLE-related cerebral vasculopathy, or to neuronal-reacting auto-antibodies or drugs which could interfere with GABA-A receptors expression/binding. This study may support the concept that cognitive impairment in systemic lupus erythematosus could be the outcome of fine-tuned neurotransmission alterations.

Topics: Adult; Central Nervous System; Cerebral Cortex; Cerebrovascular Circulation; Cognition Disorders; Electroencephalography; Female; Flumazenil; Humans; Iodine Radioisotopes; Lupus Erythematosus, Systemic; Magnetic Resonance Imaging; Middle Aged; Pregnancy; Radiopharmaceuticals; Receptors, GABA-A; Tomography, Emission-Computed, Single-Photon