Maria Urbano

The APOE polymorphism in Alzheimer's disease patients with neuropsychiatric symptoms and syndromes

Neuropsychiatric symptoms (NPS) are a common feature of Alzheimers disease (AD), resulting in particular AD endophenotypes. The common AD genetic risk factor apolipoprotein E (APOE) has been suggested underlying these AD endophenotypes.

Klotho Gene and Selective Serotonin Reuptake Inhibitors: Response to Treatment in Late-Life Major Depressive Disorder

Klotho protein, encoded by the Klotho gene (KL) at locus 13q12, is an antiaging hormone-like protein playing a pivotal role in cell metabolism homeostasis and associated to longevity and age-related diseases. In particular, altered cell metabolism in central nervous system may influence the behavior of serotoninergic neurons. The role of KL in the response to treatment with selective serotonin reuptake inhibitors (SSRIs) in late-life depressive syndromes and late-life major depressive disorder (MDD) is unclear. We genotyped three single-nucleotide polymorphisms (SNPs) of KL in 329 older patients with diagnosis of late-life MDD, treated with SSRIs and evaluated with the Hamilton Rating Scale for Depression 21-items (HRSD-21) at baseline and after 6xa0months. A reduction ≥50 and <10xa0% in HDRS-21 score was considered as response or nonresponse to therapy, respectively, and the values of reduction between 10 and 49xa0% as poor responders. After 6xa0months of SSRI treatment, 176 patients responded, 54 patients did not respond and 99 patients showed a poor response. Ordinal logistic models showed a significant association between mutation of SNP rs1207568 and responders and, similarly, for each unitary risk allele increase overlapping results were found. Conversely, a significantly higher frequency of the minor genotype of SNP rs9536314 was found in nonresponders. Considering the pre-post differences of HRSD-21 scores as a continue variable, we confirmed a significant improvement of depressive symptoms after treatment in patients carrying at least one minor allele at rs1207568 and a worse response in patients homozygous for the minor allele at rs9536314. Our results were the first that suggested a possible role of KL in the complex pathway of SSRI response in late-life MDD.

Pharmacogenetics in older people: what we know and what we need to know

The prevalence of therapeutic failures (TFs) and adverse drug reactions (ADRs) markedly increased in older subjects. However, both TFs and ADRs did not always appear related to the presence of multiple pharmacologic treatments, a common status in subjects aged 65 and over. Instead, they seem more related to variations in the genes encoding protein metabolizing and transporting drugs. Thus, variations in these proteins may account for the inter-individual differences observed in drug efficacy, including the most severe clinical consequences TFs and ADRs. The genetics of drug metabolizing enzymes (DMEs) and drug transporters (DTs) is a very active area of multidisciplinary research, overlapping the fields of medicine, biology, pharmacology, and genetics. These proteins are virtually responsible for metabolism and disposition, and thus the efficacy, of a number of drugs currently used in clinical practice. This article explored some basic concepts of the pharmacogenetics of DMEs and DTs. We also focused current knowledge of the genetic basis of TFs and ADRs of the most common drugs currently used in geriatric clinics. The knowledge of what we know and what we need to know is needed to advance the application of pharmacogenetics in clinical practice, in order to introduce personalized treatments for elderly people.

Psychiatry meets pharmacogenetics for the treatment of revolving door patients with psychiatric disorders

ABSTRACT Introduction: Therapeutic failures (TFs) and adverse drug reactions (ADRs), together with the recurring nature of the clinical course of psychiatric disorders, mainly bipolar disorders (BDs), strongly contributed to the prevalence and frequency of hospital readmissions observed in these patients. This is the revolving door (RD) condition, dramatically rising costs for the management of these patients in psychiatric settings. Areas covered: We searched in the medical literature until May 2016 to review the role of functional variants in the cytochrome P450 (CYP) 2D6 gene on observed ADRs and TFs in RD patients with BDs, conferring a different capacity to metabolize psychotropic drugs. Expert commentary: CYP2D6 functional polymorphisms might directly contributed to the prevalence and frequency of the RD condition, commonly observed in BD patients. Although several environmental and socio-demographic/diagnostic variables such as alcohol/drug abuse, and medication non-compliance accounted for a significant proportion of the ability to predict RD prevalence and frequency, the pharmacogenetics of CYP, particularly CYP2D6, may help to identify BD patients at risk for ADRs and TFs. These patients may be addressed towards alternative treatments, thus improving their quality of life, and reducing RD prevalence and frequency and the overall costs for their management.

Role of the serotonin transporter gene locus in the response to SSRI treatment of major depressive disorder in late life

It has been suggested that the serotonin or 5-hydroxytriptamine (5-HT) transporter (5-HTT) and its gene-linked polymorphic region (5-HTTLPR) are selective serotonin reuptake inhibitor (SSRI) response modulators in late-life depression (LLD), and particularly in late-life major depressive disorder (MDD). Previous studies differed in design and results. Our study aimed to investigate the solute carrier family 6 (neurotransmitter transporter and serotonin) member 4 (SLC6A4) gene locus, encoding 5-HTT and SSRI treatment response in late-life MDD. For a prospective cohort study, we enrolled 234 patients with late-life MDD to be treated with escitalopram, sertraline, paroxetine or citalopram for 6 months. The SLC6A4 polymorphisms rs4795541 (5-HTTLPR), rs140701 and rs3813034 genotypes spanning the SLC6A4 locus were investigated in blinded fashion. No placebo group was included. We assessed responder or non-responder phenotypes according to a reduction in the 21-item version of the Hamilton Depression Rating Scale (HDRS-21) score of ⩾ 50%. At follow-up, 30% of the late-life MDD patients were non-responders to SSRI treatment. No time-course of symptoms and responses was made. A poor response was associated with a higher baseline HDRS-21 score. We observed a significant over-representation of the rs4795541-S allele in the responder patients (0.436 versus 0.321; p = 0.023). The single S-allele dose-additive effect had OR = 1.74 (95% CI 1.12–2.69) in the additive regression model. Our findings suggested a possible influence of 5-HTTLPR on the SSRI response in patients with late-life MDD, which is potentially useful in identifying the subgroups of LLD patients whom need a different pharmacological approach.

Angiotensin-converting enzyme (ACE) genotypes and disability in hospitalized older patients

The association between angiotensin-converting enzyme (ACE) genotypes and functional decline in older adults remains controversial. To assess if ACE gene variations influences functional abilities at older age, the present study explored the association between the common ACE insertion/deletion (I/D) polymorphism and disability measured with activities of daily living (ADL) in hospitalized older patients. We analyzed the frequency of the ACE genotypes (I/I, I/D, and D/D) in a population of 2,128 hospitalized older patients divided according to presence or absence of ADL disability. Logistic regression analysis adjusted for possible confounding factors, identified an association between the I/I genotype with ADL disability (ORu2009=u20091.54, 95% CI 1.04–2.29). This association was significant in men (ORu2009=u20092.01, 95% CI 1.07–3.78), but not in women (ORu2009=u20091.36, 95% CI 0.82–2.25). These results suggested a possible role of the ACE polymorphism as a genetic marker for ADL disability in hospitalized older patients.

Erythrocyte Associated Amyloid-β as Potential Biomarker to Diagnose Dementia

BACKGROUNDnAlthough it is known that Alzheimers disease (AD) is associated with the progressive accumulation of amyloid β-peptide (Aβ) in the human brain, its pathogenic role has to be completely clarified. Aβ moves from the bloodbrain barrier to the plasma and an increased Aβ production in brain could be associated with higher Aβ concentrations in blood. A recent study has evaluated Aβ40 and Aβ42 levels in human red blood cells (RBCs) with evidence of agedependent higher Aβ concentration in RBCs.nnnOBJECTIVEnThe aim of the study was to investigate if erythrocyte associated Aβ (iAβ) levels could be different in subjects affected by dementia in comparison with controls and according to the patients cognitive impairment or different dementia subtypes.nnnMETHODnTo answer these questions we assessed iAβ40 and iAβ42 levels in 116 patients: 32 healthy controls, 39 with diagnosis of vascular dementia (VaD), 14 mild cognitive impairment (MCI) and 31 AD.nnnRESULTSnIn this population we found significant differences in iAβ42 between controls and cognitive impaired patients. Moreover, iAβ42 significantly differed between dementia vs MCI. AD also showed different iAβ42 levels as compared to VaD. Conversely, no differences were found for iAβ40. All the analyses were adjusted for potential confounders like age, gender and Hb concentration. A direct correlation between increasing iAβ42 concentration and the progression of the cognitive decline using the MMSE score as continuous variable was also found.nnnCONCLUSIONnOur findings support the evidence that iAβ42 could be an instrument to early recognize dementia and predict cognitive impairment.

Role of the APOE polymorphism in carotid and lower limb revascularization: A prospective study from Southern Italy

Background Atherosclerosis is a complex multifactorial disease and the apolipoprotein E (APOE) polymorphism has been associated to vascular complications of atherosclerosis. Objectives To investigate the relationship between the APOE genotypes and advanced peripheral vascular disease. Materials and methods 258 consecutive patients (201 males and 57 females, mean age 70.83 ± 7.89 years) with severe PVD were enrolled in a 42-months longitudinal study (mean 31.65 ± 21.11 months) for major adverse cardiovascular events. At follow-up genotypes of the APOE polymorphism were investigated in blinded fashion. Results As compared with ε3/ε3, in ε4-carriers a significant higher incidence of major adverse cardiovascular events (35.58% vs. 20.79%; p = 0.025) and total peripheral revascularization (22.64% vs. 5.06%; p < 0.001) was observed. Prospective analysis, showed that ε4-carriers have an increased hazard ratio for major adverse cardiovascular events (adjusted HR 1.829, 95% CI 1.017–3.287; p = 0.044) and total peripheral revascularization (adjusted HR = 5.916, 95% CI 2.405–14.554, p <0.001). Conclusions The ε4 allele seems to be risk factor for major adverse cardiovascular events, and in particular for total peripheral revascularization in patients with advanced atherosclerotic vascular disease.

Role of CLU, PICALM, and TNK1 Genotypes in Aging With and Without Alzheimer’s Disease

Healthy and impaired cognitive aging may be associated to different prevalences of single-nucleotide polymorphisms (SNPs). In a multicenter case-control association study, we studied the SNPs rs11136000 (clusterin, CLU), rs541458 (phosphatidylinositol binding clatrin assembly protein, PICALM), and rs1554948 (transcription factor A, and tyrosine kinase, non-receptor, 1, TNK1) according to the three age groups 50–65xa0years (group 1), 66–80xa0years (group 2), and 80+ years (group 3) in 569 older subjects without cognitive impairment (NoCI) and 520 Alzheimer’s disease (AD) patients. In NoCI subjects, a regression analysis suggested a relationship between age and TNK1 genotypes, with the TNK1-A/A genotype frequency that increased with higher age, and resulting in a different distribution of the TNK1-A allele. In AD patients, a regression analysis suggested a relationship between age and PICALM genotypes and TNK1 genotypes, with the PICALM-T/C and TNK1-A/A genotype frequencies that decreased with increasing age. A resulting difference in the distribution of PICALM-C allele and TNK1-A allele was also observed. The TNK1-A allele was overrepresented in NoCI subjects than in AD patients in age groups 2 and 3. These results confirmed after adjustment for apolipoprotein E polymorphism, which suggested a different role of PICALM and TNK1 in healthy and impaired cognitive aging. More studies, however, are needed to confirm the observed associations.

Psychotropic drugs and CYP2D6 in late-life psychiatric and neurological disorders. What do we know?

ABSTRACT Introduction: Late-life psychiatric and neurological disorders (LLPND) are interesting models to understand the potential role of pharmacogenetics in drug management, since several pharmacological approaches for treating LLPND have proven to be ineffective or deleterious, thus resulting in therapeutic failures (TF) and adverse drug reactions (ADR). Common variants in the genes encoding the cytochrome P450 (CYP) enzyme system, the ‘engine room’ of drug metabolism, together with well-known age-related increased polypharmacy also contributed to the prevalence of TF and ADR observed in these patients, also rising number and time of hospital readmissions and rate of institutionalizations. Areas covered: The genetics of CYP and how it may be used for the management of the outcomes of the most frequent drugs (antidepressants, antipsychotics, anticholinesterase inhibitors, and anxiolytics) used in LLPND. Expert opinion: Tailored CYP-based pharmacological treatments of LLPND will reduce TFs and ADRs, improving patient’s life, reducing number and dosage of administered drugs, and the number and duration of hospital readmissions, saving costs for clinical management of LLPND. Pharmacokinetic interactions are less predictable than pharmacodynamic ones and several requests are made to regulatory organisms for the pharmacological management of frail older patients affected by LLPND.