The Predictive Factors of Good Clinical Response to Cholinesterase Inhibitors in Alzheimer Disease and Mixed Dementia

Study Overview
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Brief Summary
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Background and objectives: The aims of this naturalistic study were: to analyze factors which could be predictive of good response to cholinesterase inhibitors (ChEI), such as: age, sex, schooling, mild (CDR 1) or moderate Alzheimer's disease (AD),(CDR 2), Apoliprotein epsilon 4 (APOE Ɛ4), among others, in their cognitive and clinical response. We also classified patients according to their response to Mini mental State of Examination (MMSE). Finally we saw the polymorphisms of APO E and cytochrome P450 2D6 (CYP2D6) and tried to correlate the response with different allelic forms of Apo E and among others with wild type homozygotes (wt/wt) and their polymorphisms (CYP2D6*3,*4, *5, *6 and 10) of CYP 2D6. Patients and Methods: 129 patients were diagnosed as AD or AD+cerebrovascular disease (CVD) mild or moderate. After 12 month-treatment, 97 patients completed the study. They were assessed (four) times. In the first visit, without taking ChEI, after 3, 6 and 12 month-treatment, they were taking donepezil or rivastigmine or galantamine. We also extracted 5 mL of blood sample to genotype the DNA. In each visit, we applied cognitive, functional, mood and behavior scales. Good responders were defined as those who scored > 2 in MMSE. Results and Conclusion: In longitudinal analysis, patients with mild AD and good responders at 3 months were considered good responders at 12 months. We obtained a higher rate of good responders comparing with other researches (27.8%). There was no correlation between dose, APOE and CYP 2D6 polymorphisms, although we already obtained clinical results with the dose dosage of 5mg.

Detailed Description
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Genomic DNA for genotyping was extracted from total blood samples collected in ethylenediaminetetraacetic acid (EDTA) (Wizard Genomic DNA Purification Kit: Promega®, USA) and kept frozen at seventy degrees Celsius negative (-70ºC) until analysis. For APOE genotyping (alleles Ɛ2, Ɛ3 and Ɛ4), DNA samples were amplified by polymerase chain reaction (PCR), followed by digestion with Haemophilus haemolyticus restriction endonuclease I (HhaI) and restriction fragment length polymorphism (RFLP) analysis, as previously described by Hixson and Vernier. The CYP2D6*3, CYP2D6*4 and CYP2D6*6 alleles were investigated by tetra-primer PCR and the CYP2D6*5 allele, which presents the entire CYP2D6 gene deletion, was identified by long PCR reaction, according to the method described by Hersberger et al. The CYP2D6*10 allele was amplified by PCR following Baclig et al. and the RFLP analysis was performed with Type II restriction enzyme (HphI). For all analysis a positive and negative controls were included. Subjects carrying Epsilon 3, Epsilon 3 (Ɛ3Ɛ3), CYP2D6*3/4/5/6/10-nor specific mutations are classified as wild-type and functional allele carriers. The subjects carrying two defective alleles were classified as poor metabolizers (PM) and those heterozygous were classified as extensive metabolizers (EM).

Official Title
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The Predictive Factors of Good Clinical Response to Cholinesterase Inhibitors in Mild and Moderate Alzheimer Disease and Mixed Dementia: a Naturalistic Study

Conditions
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Alzheimer Disease, Late Onset

Intervention / Treatment
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* Drug: cholinesterase inhibitors


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - AD diagnosis or AD with CVD according the criteria of National Institute on Aging and the Alzheimer's Association workgroup and the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) Exclusion Criteria: Patients with mild cognitive impairment; Other types of dementia, such as pure vascular dementia, frontotemporal dementia, dementia with Lewy bodies, corticobasal degeneration; Severe dementia (CDR 3) Those who were already taking ChEI, If there have not been agreement between the first researcher and the treating physician.

Ages Eligible for Study
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Minimum Age: 59 Years
Maximum Age: 92 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Alzheimer disease or mixed dementia<br>Patients were evaluated four times. In the first consultation, without taking cholinesterase inhibitors (ChEI), after three, six and 12 months taking ChEI. | Drug: cholinesterase inhibitors<br>* The first group received donepezil (5 or 10 mg) the second group received galantamine (16 or 24 mg) The third group received rivastigmine (3 or 4,5 or 6 mg BID) according to the treating physician.<br>* Other names: No applicable;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cognitive results | Clinical assessment: The clinical domains examined and the respective evaluation tools were: global cognition - MMSE, clock drawing test score and Mattis Dementia Rating Scale - DRS). Patients were seen between 06/2009 to 03/2013. Good clinical responders were those who scored ≥ 2 on the MMSE after 12 month-treatment, the neutrals had the scores between -1 and +1, and bad responders scored ≤ -2 at the same period. A subgroup who scored > 2 on the MMSE were defined as very good responders. Patients were seen for four times: at the first consultation (n=129), at three (n=114), six (n=105) and twelve months of treatment (n=97). | Patients were evaluated from 06/2009 to 03/2013 for four times - first visit ( without taking medication), after three, six and 12 months of treatment with cholinesterase inhibitors (up to 12 months) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Genetic and biochemical analyzes | Genomic DNA for genotyping was extracted from total blood samples collected in EDTA (Wizard Genomic DNA Purification Kit: Promega®, USA) and kept frozen at -70ºC until analysis. For APOE genotyping (alleles Ɛ2, Ɛ3 and Ɛ4), DNA samples were amplified by polymerase chain reaction (PCR), followed by digestion with HhaI and restriction fragment length polymorphism (RFLP) analysis, as previously described by Subjects carrying Ɛ3Ɛ3, CYP2D6*3/4/5/6/10-nor specific mutations are classified as wild-type and functional allele carriers.Patients were seen four times (see Primary outcome). | To correlate allelic forms of APOE and CYP 2D6 polymorphisms with the response (up to 12 months) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Predictive factors of response, mild and moderate, Alzheimer disease, mixed dementia, APOE, polymorphisms of CYP 2D6