The effectiveness of very slow switching to aripiprazole in schizophrenia patients with dopamine supersensitivity psychosis: a case series from an open study.

Dopamine supersensitivity psychosis (DSP) in patients with schizophrenia is induced by treatment with a high dosage of antipsychotics for a long time period, and it is characterized by unstable psychotic symptoms. The upregulation of dopamine D2 receptor (DRD2) provoked by antipsychotics underlies DSP. Aripiprazole does not cause an excessive blockade of DRD2 and is less likely to upregulate DRD2 by aripiprazole's dopamine partial agonistic profile. Aripiprazole; however, has a potential risk of inducing severe rebound psychosis in patients who have already developed dopamine supersensitivity. Recently, an animal model study suggested that aripiprazole could attenuate established dopamine supersensitivity. The present study was conducted to examine whether very slowly switching to aripiprazole could help patients with schizophrenia with dopamine supersensitivity while avoiding rebound psychosis. This study was a single-armed and open-labeled study in which patients were observed over a period of 2 years. Only 11 patients were ultimately recruited. Five patients were successfully switched to a sufficient dose of aripiprazole and completed the study protocol. These five patients did not present with severe DSP over the study period, but only one patient showed a large improvement in psychopathology. Five patients dropped out of the study, and one of these five showed a severe worsening of psychosis. The present study indicated that the introduction of aripiprazole in patients with DSP was difficult, but suggested that aripiprazole could contribute to attaining a stable state in psychosis if it was applied with careful observation.

Lipoteichoic acid improves the capability of mast cells in the host defense system against bacteria.

OBJECTIVES AND DESIGN: We investigated the effects of microbial components on the uptake of microbes by mast cells (MCs), and studied the change in cytokine production in MCs after bacterial uptake. MATERIAL OR SUBJECTS: LAD2 human mast cells, cord-blood and peripheral-blood derived MCs were employed to analyze their surface molecule expression and cytokine generation by flow cytometry. Bacterial internalization in these MCs was observed by confocal microscopy and flow cytometry. RESULTS: Complement receptor 3 expression was augmented by LTA but not by PGN or 3CpG-oligodeoxynucleotide. LTA also enhanced the uptake of opsonized bacteria (over twofold augmentation). After bacterial uptake, MCs augmented the production of chemoattractant cytokines for neutrophils, while Th1 and Th2 cytokine production showed little or no change. CONCLUSIONS: LTA increases the capability of the MC as a sentinel in the host immune response, and some bacterial components direct human MC function towards innate immunity after pathogen infection.