Clozapine-related Immunodeficiency in Parkinsons Disease

Inclusion criteria

• Patient ≥ 18 years old with Parkinson's disease according to MDS 2015 criteria
• Psychotic symptoms requiring treatment with Clozapine
• Patients with initially a normal leukocyte count (number of white blood cells

≥ 3500/mm3 [3.5 x 109/l] and an absolute neutrophil count PNN ≥ 2000/mm3 [2 x 109/l])

• patients in whom the number of white blood cells (WBC) and the absolute number of neutrophils (PNN) may be determined regularly at the following intervals: once a week during the first 18 weeks of treatment and, thereafter, at least every 4 weeks for the duration of the treatment. This monitoring must be continued throughout the treatment and for 4 weeks who follow the complete cessation of CLOZAPINE
• Informed and written consent.
• Affiliation to a social security system

Exclusion criteria

• Patients with a contraindication to the use of Clozapine according to the summary of product characteristics (SPC)
• Hypersensitivity to the active substance or to any of the excipients.
• Patients who cannot receive regular blood tests.
• History of granulopenia or toxic or idiosyncratic agranulocytosis (unless it results from previous chemotherapy).
• History of agranulocytosis induced by CLOZAPINE
• Treatment with CLOZAPINE should not be started at the same time as substances known to have a high potential for inducing agranulocytosis; The concomitant administration of depot antipsychotics is not recommended.
• Functional bone marrow failure.
• Uncontrolled epilepsy.
• Alcoholic or induced psychosis, drug intoxication, comatose states.
• Circulatory collapse and / or CNS depression regardless of the aetiology.
• Severe renal or cardiac disorders (eg: myocarditis).
• Active liver disease with nausea, anorexia or jaundice; progressive liver disease, liver failure.
• Paralytic ileus.
• Patient with another potential cause of immunosuppression
• Immunosuppressive or immune modulatory treatment active or stopped for less than 5 years
• Anti-epileptic treatment active or stopped for less than 5 years
• Chemotherapy active or stopped for less than 5 years
• Solid or hematologic cancer active or treated for less than 5 years
• Human immunodeficiency virus infection
• Already known constitutional immune deficiency
• Nephrotic syndrome
• Protein-losing enteropathy
• A history of radiotherapy
• Long-term use of corticosteroids
• Patient with potentially major cognitive disorders defined by a MoCA score less than or equal to 23
• Pregnant or breastfeeding women
• Patient under guardianship/curatorship or deprived of liberty