Investigation of the role of rare TREM2 variants in frontotemporal dementia subtypes

Frontotemporal dementia (FTD) is a clinically and genetically heterogeneous disorder. Rare TREM2 variants have been recently identified in families affected by FTD-like phenotype. However, genetic studies of the role of rare TREM2 variants in FTD have generated conflicting results possibly because of difficulties on diagnostic accuracy. The aim of the present study was to investigate associations between rare TREM2 variants and specific FTD subtypes (FTD-S). The entire coding sequence of TREM2 was sequenced in FTD-S patients of Spanish (n = 539) and German (n = 63) origin. Genetic association was calculated using Fisher exact test. The minor allele frequency for controls was derived from in-house genotyping data and publicly available databases. Seven previously reported rare coding variants (p.A28V, p.W44X, p.R47H, p.R62H, p.T66M, p.T96K, and p.L211P) and 1 novel missense variant (p.A105T) were identified. The p.R47H variant was found in 4 patients with FTD-S. Two of these patients showed cerebrospinal fluid pattern of amyloid beta, tau, and phosphorylated-tau suggesting underlying Alzheimer's disease (AD) pathology. No association was found between p.R47H and FTD-S. A genetic association was found between p.T96K and FTD-S (p = 0.013, odds ratio = 4.23, 95% Confidence Interval [1.17-14.77]). All 6 p.T96K patients also carried the TREM2 variant p.L211P, suggesting linkage disequilibrium. The remaining TREM2 variants were found in 1 patient, respectively, and were absent in controls. The present findings provide evidence that p.T96K is associated with FTD-S and that p.L211P may contribute to its pathogenic effect. The data also suggest that p.R47H is associated with an FTD phenotype that is characterized by the presence of underlying AD pathology.

APOE-dependent phenotypes in subjects with mild cognitive impairment converting to Alzheimer's disease

BACKGROUND

The E4 isoform of the APOE genotype is the most significant genetic risk factor for sporadic Alzheimer's disease (AD) and has recently been found to modulate disease expression in patients with AD.

OBJECTIVE

To investigate APOE-dependent cognitive and structural phenotypes in subjects with mild cognitive impairment who converted to AD within the following three years.

METHODS

Subjects converting to AD (n = 63) were compared to a control group with stable mild cognitive impairment (n = 131). Clinical, neuropsychological, and MRI data were obtained by the German Dementia Competence Network. Subgroups of converting and stable APOE E4 carriers and non-carriers were investigated longitudinally with MRI to examine structural correlates of conversion. Voxel-based morphometry was applied to investigate gray matter distribution.

RESULTS

At baseline, executive performance correlated with global and bilateral prefrontal gray matter volume and predicted conversion only among non-carriers. Converting carriers and non-carriers presented distinct patterns of brain atrophy on longitudinal analysis, in line with a dissociation between more pronounced occipital atrophy in carriers and more frontoparietal volume loss in non-carriers at follow-up.

CONCLUSIONS

The current findings suggest that in APOE E4 non-carriers with AD, executive dysfunction is closely linked to frontal gray matter atrophy and predictive of progression to dementia. The results are consistent with APOE genotype-dependent profiles of structural damage and cognitive decline in patients with imminent conversion to AD.

Genetic interaction of PICALM and APOE is associated with brain atrophy and cognitive impairment in Alzheimer's disease

BACKGROUND

Evidence has emerged indicating that the ε4 allele of APOE and PICALM interact in conferring risk of Alzheimer's disease (AD). The biologic basis of this interaction is unclear, but it is likely to have phenotypic relevance and contribute to the structural and clinical heterogeneity of AD.

METHODS

The aim of this study was to investigate interaction effects of the APOE ε4 allele and the alleles at the single-nucleotide polymorphism rs3851179 located in the PICALM locus. We analyzed brain volumes and cognitive phenotypes of 165 patients with early AD dementia.

RESULTS

There was a synergistic adverse effect of homozygosity for the PICALM risk allele G in rs3851179 and APOE ε4 on volume in prefrontal and performance on the Trail Making Test A, which is sensitive to processing speed and working memory function.

CONCLUSIONS

The data suggest a neural mechanism for APOE-PICALM interactions in patients with manifest AD and indicate that the PICALM genotype modulates both brain atrophy and cognitive performance in APOE ε4 carriers.

Flupentixol use and adverse reactions in comparison with other common first- and second-generation antipsychotics: data from the AMSP study

This study compares the first-generation antipsychotic (FGA) flupentixol to haloperidol and common second-generation antipsychotics (SGAs) as to drug utilization and severe adverse drug reactions (ADRs) in clinical treatment of schizophrenia inpatients using data from the drug safety program Arzneimittelsicherheit in der Psychiatrie (AMSP). AMSP drug utilization and reported ADR data were analyzed. Type and frequency of severe ADRs attributed to flupentixol were compared with haloperidol, clozapine, olanzapine, quetiapine, risperidone and amisulpride in a total of 56,861 schizophrenia inpatients exposed to these drugs. In spite of increasing prescription of SGAs, flupentixol was consistently used in schizophrenic inpatients (about 5 %) over time. Reporting rates of severe ADR ranged from 0.38 to 1.20 % for the individual antipsychotics (drugs imputed alone); flupentixol ranked lowest. The type of ADR differed considerably; as to severe EPMS, flupentixol (0.27 %), such as risperidone (0.28 %), held an intermediate position between haloperidol/amisulpride (0.55/0.52 %) and olanzapine/quetiapine (<0.1 %). The study is a heuristic approach, not a confirmatory test. Flupentixol has a stable place in the treatment of schizophrenia in spite of the introduction of different SGAs. Comparative ADR profiles suggest an intermediate position between FGAs and SGAs for flupentixol in clinical practice.

Seizures during antidepressant treatment in psychiatric inpatients--results from the transnational pharmacovigilance project "Arzneimittelsicherheit in der Psychiatrie" (AMSP) 1993-2008

RATIONALE

There is little clinical data available about seizure rates in psychiatric inpatients, and there are no studies with reference data to the frequencies of antidepressant (AD) use for this important clinical population.

OBJECTIVE

This study investigates seizure rates during AD treatment in psychiatric inpatient settings, drawn from the transnational pharmacovigilance programme Arzneimittelsicherheit in der Psychiatrie (AMSP) in relation to the known frequencies of ADs used in the participating clinics. Comparisons are made to former publications and their limitations.

RESULTS

Seventy-seven cases were identified with grand mal seizures (GMS) during AD treatment between 1993 and 2008, with a total number of 142,090 inpatients under surveillance treated with ADs in the participating hospitals. The calculated overall rate of reported seizures of patients during AD treatment in this collective is 0.05 % for ADs imputed alone or in combination with other psychotropic drug groups and 0.02 % when only ADs were given and held responsible for GMS. The patients receiving tri- or tetracyclic ADs (TCAs) had a 2-fold risk to develop a seizure as compared to the overall average rate in this sample. In 11 cases, there was only one AD imputed--the majority of these cases (9/11) were TCA. Monotherapy with selective serotonin reuptake inhibitors (SSRI) or dual serotonin and noradrenaline reuptake inhibitors (SNRI) were never imputed alone in this sample.

CONCLUSIONS

The results of the study favour the assumption that SSRIs, noradrenergic and specific serotonergic antidepressants (NaSSA) and dual SNRI might be more appropriate than TCAs for the treatment of psychiatric patients with an enhanced seizure risk.

[Assessment of benefits of drug therapies: memantine for Alzheimer's disease as an example]

After the approval of a drug, which represents a first assessment, independent institutions and medical professional associations provide further evaluations. Here, the question is to be asked whether common or diverging evaluation methods exist that can have an impact on the result. In principle, two methods are used: meta-analyses and responder analyses. Meta-analyses and the resulting effect sizes have to be interpreted according to the field of application (for example, the type and severity degree of a disease) with medical expertise. Omitting this can lead to incorrect evaluations and to a discrepancy of evaluation results. In the case of memantine, the merely biometric evaluation of meta-analyses performed by the IQWiG led to a denial of the benefit, while the same data, considering clinical routine, led professional associations to recommend memantine for moderate to severe Alzheimer´s disease. In contrast to meta-analyses, responder analyses directly show the benefit of a therapy option in the presence of significant group differences, as the selected responder criteria are based on the indication. The corresponding results of the responder analyses on memantine were also acknowledged by the IQWiG and led to a positive evaluation of memantine. This discrepancy of evaluation results illustrates the fact that statistical procedures are necessary when evaluating drug and non-drug therapy options but, that the interpretation of the results with medical expertise is essential.

Response trajectories in "real-world" naturalistically treated schizophrenia patients

BACKGROUND

To date, research has identified distinct antipsychotic response trajectories yet focussing on data from randomized-controlled trials (RCTs). Therefore, the heterogeneity of response in "real-world" schizophrenia patients is still unknown.

METHODS

Antipsychotic response was evaluated in 399 patients suffering from a schizophrenia spectrum disorder within a naturalistic multicenter study of the Competence Network on Schizophrenia using latent class regression. Baseline and illness-related variables were compared between the different trajectory classes as well as currently proposed outcome definitions (early improvement, response, remission) using univariate tests. In order to predict the trajectory group membership classification and regression tree analysis were furthermore performed.

RESULTS

Five distinct trajectories of antipsychotic response were identified: Class 1 (15%) showing an early and considerable improvement, Class 2 (14%) incorporating patients with the greatest response to treatment, Class 3 (34%) again showing an early improvement to treatment yet with a slightly lower degree of improvement, Class 4 (22%) featuring patients gradually responding to treatment, and Class 5 (15%) with the poorest antipsychotic response. Fewer depressive symptoms at admission, better functioning, a shorter duration of illness and less previous hospitalizations were found to be significant predictors of good response. No considerable differences were found comparing the present results to the previous trajectory analyses deriving from RCTs.

CONCLUSION

Our results underline the heterogeneous course of response independent of the study or treatment design suggesting that the diversity in schizophrenia response and outcome is determined primarily by different pathophysiological underpinnings.

Insight in schizophrenia-course and predictors during the acute treatment phase of patients suffering from a schizophrenia spectrum disorder

BACKGROUND

To analyse insight of illness during the course of inpatient treatment, and to identify influencing factors and predictors of insight.

METHODS

Insight into illness was examined in 399 patients using the item G12 of the Positive and Negative Syndrome Scale ("lack of insight and judgement"). Ratings of the PANSS, HAMD, UKU, GAF, SOFAS, SWN-K and Kemp's compliance scale were performed and examined regarding their potential association with insight. The item G12 was kept as an ordinal variable to compare insight between subgroups of patients.

RESULTS

Almost 70% of patients had deficits in their insight into illness at admission. A significant improvement of impairments of insight during the treatment (p<0.0001) was observed. At admission more severe positive and negative symptoms, worse functioning and worse adherence were significantly associated with poorer insight. Less depressive symptoms (p=0.0004), less suicidality (p=0.0218), suffering from multiple illness-episodes (p<0.0001) and worse adherence (p=0.0012) at admission were identified to be significant predictors of poor insight at discharge.

CONCLUSION

The revealed predictors might function as treatment targets in order to improve insight and with it outcome of schizophrenia.

Cerebrospinal fluid amyloid-β 2-42 is decreased in Alzheimer's, but not in frontotemporal dementia

Alzheimer’s dementia (AD) and frontotemporal dementias (FTD) are common and their clinical differential diagnosis may be complicated by overlapping symptoms, which is why biomarkers may have an important role to play. Cerebrospinal fluids (CSF) Aβ2-42 and 1-42 have been shown to be similarly decreased in AD, but 1-42 did not display sufficient specificity for exclusion of other dementias from AD. The objective of the present study was to clarify the diagnostic value of Aβ2-42 peptides for the differential diagnosis of AD from FTD. For this purpose, 20 non-demented disease controls (NDC), 22 patients with AD and 17 with FTD were comparatively analysed by a novel sequential aminoterminally and carboxyterminally specific immunoprecipitation protocol with subsequent Aβ-SDS-PAGE/immunoblot, allowing the quantification of peptides 1-38^ox, 2-40 and 2-42 along with Aβ 1-37, 1-38, 1-39, 1-40, 1-40^ox and 1-42. CSF Aβ1-42 was decreased in AD as compared to NDC, but not to FTD. In a subgroup of the patients analyzed, the decrease of Abeta2-42 in AD was evident as compared to both NDC and FTD. Aβ1-38 was decreased in FTD as compared to NDC and AD. For differentiating AD from FTD, Aβ1-42 demonstrated sufficient diagnostic accuracies only when combined with Aβ1-38. Aβ2-42 yielded diagnostic accuracies of over 85 % as a single marker. These accuracy figures could be improved by combining Aβ2-42 to Aβ1-38. Aβ2-42 seems to be a promising biomarker for differentiating AD from other degenerative dementias, such as FTD.

Evaluating depressive symptoms in schizophrenia: a psychometric comparison of the Calgary Depression Scale for Schizophrenia and the Hamilton Depression Rating Scale

BACKGROUND

The aim of this study was to compare two measures of depression in patients with schizophrenia and schizophrenia spectrum disorder, including patients with delusional and schizoaffective disorder, to conclude implications for their application.

SAMPLING AND METHODS

A total of 278 patients were assessed using the Calgary Depression Scale for Schizophrenia (CDSS) and the Hamilton Depression Rating Scale (HAMD-17). The Positive and Negative Syndrome Scale (PANSS) was also applied. At admission and discharge, a principal component analysis was performed with each depression scale. The two depression rating scales were furthermore compared using correlation and regression analyses.

RESULTS

Three factors were revealed for the CDSS and HAMD-17 factor component analysis. A very similar item loading was found for the CDSS at admission and discharge, whereas results of the loadings of the HAMD-17 items were less stable. The first two factors of the CDSS revealed correlations with positive, negative and general psychopathology. In contrast, multiple significant correlations were found for the HAMD-17 factors and the PANSS subscores. Multiple regression analyses demonstrated that the HAMD-17 accounted more for the positive and negative symptom domains than the CDSS.

CONCLUSIONS

The present results suggest that compared to the HAMD-17, the CDSS is a more specific instrument to measure depressive symptoms in schizophrenia and schizophrenia spectrum disorder, especially in acutely ill patients.

Predictors of relapse in the year after hospital discharge among patients with schizophrenia

OBJECTIVE

Relapse and its predictors were examined among patients with schizophrenia in the year after hospital discharge.

METHODS

The sample included 200 patients with schizophrenia participating in a German multicenter study. Relapse was defined as a worsening of psychopathological symptoms or rehospitalization in the year after hospital discharge. Predictors examined were variables related to course of illness and to response and remission at discharge.

RESULTS

Fifty-two percent of participants had a relapse. Patients whose symptoms were not in remission at discharge were more likely to have a relapse, as were those who had more severe symptoms and more side effects at discharge. Those who experienced a relapse were less likely to be taking a second-generation antipsychotic at discharge, less likely to have a positive attitude toward treatment adherence, and less likely to be employed.

CONCLUSIONS

The high rate of relapse among patients with schizophrenia highlights the need to improve current treatment strategies.

A combination of galantamine and memantine modifies cognitive function in subjects with amnestic MCI

OBJECTIVES

Mild cognitive impairment (MCI) is etiologically heterogeneous, and a substantial proportion of MCI subjects will develop different dementia disorders. One subtype of this syndrome, amnestic MCI, occurs preferentially but not exclusively in prodromal AD and is characterized by defined deficits of episodic memory.

DESIGN, SETTING AND PARTICIPANTS

For a 2-year, double-blinded, placebo-controlled study MCI patients, presenting with an amnestic syndrome but not necessarily based on presumed prodromal AD were randomized.

INTERVENTION

Patients received (a) a combination of 16 mg galantamine plus 20 mg memantine, or (b) 16 mg galantamine alone or (c) placebo.

MEASUREMENTS

The primary objective was to explore the differential impact of these interventions on the progression to dementia and on cognitive changes as measured by the ADAScog.

RESULTS

After recruitment of 232 subjects, the trial was halted before reaching the planned sample size, because safety concerns arose in other studies with galantamine in MCI. This resulted in a variable treatment duration of 2-52 weeks. The statistical analysis plan was amended for studying cognitive effects of discontinuing the study medication, which was done separately for galantamine and memantine, and under double-blind conditions. There was one death, no unexpected severe adverse events, and no differences of severe adverse events between the treatment arms. The cognitive changes on the ADAScog were not different among the groups. Only for the subgroup of amnestic MCI with presumed AD etiology, a significant improvement of ADAScog score over placebo before the discontinuation of medication was observed, while amnestic MCI presumably due to other etiologies showed no cognitive changes with broad variation. Cognitive improvement was numerically larger in the combination treatment group than under galantamine alone. Patients who received placebo declined as expected. Discontinuation of galantamine, either as part of the combination regimen or as mono treatment, resulted in a transient decline of the ADAScog score in amnestic MCI of presumed AD etiology, while discontinuation of Memantine did not change the cognitive status.

CONCLUSION

In an interrupted trial with amnestic MCI subjects the combination of galantamine plus memantine were generally well tolerated. In the subgroup of MCI subjects with presumed AD etiology, a cognitive benefit of a short-term combination treatment of galantamine plus memantine was observed, and cognitive decline occurred after discontinuation of galantamine.

Genome-wide association study of vascular dementia

BACKGROUND AND PURPOSE

Most studies investigating the genetics of dementia have focused on Alzheimer disease, but little is known about the genetics of vascular dementia. The aim of our study was to identify new loci associated with vascular dementia.

METHODS

We performed a genome-wide association study in the Rotterdam Study, a large prospective population-based cohort study in the Netherlands. We sought to replicate genome-wide significant loci in 2 independent replication samples.

RESULTS

In the discovery analysis of 5700 dementia-free individuals, 67 patients developed incident vascular dementia over a mean follow-up time of 9.3 ± 3.2 years. We showed genome-wide significance for rs12007229, which is located on the X chromosome near the androgen receptor gene (OR, 3.7; 95% CI, 2.3-5.8, per copy of the minor allele; P=1.3 × 10(-8)). This association was further confirmed in 2 independent populations (probability value of combined replication samples=0.024).

CONCLUSIONS

Our study shows a novel genetic locus for vascular dementia on the X chromosome. Further replication of this finding is required.

Cerebrospinal fluid tau, p-tau 181 and amyloid-β38/40/42 in frontotemporal dementias and primary progressive aphasias

BACKGROUND/AIMS

We determined cerebrospinal fluid (CSF) concentrations of amyloid-β (Aβ)(1-38), Aβ(1-40), Aβ(1-42), total tau and phospho-tau (p-tau) in order to study their differential expression in frontotemporal dementia (FTD, n = 25) and primary progressive aphasia (PPA, n = 12) as compared to Alzheimer's dementia (AD, n = 25) and nondemented controls (n = 20).

METHODS

Commercially available ELISA and electrochemiluminescence methods were applied.

RESULTS

High CSF p-tau and low ratios of Aβ(1-42)/Aβ(1-40) and Aβ(1-42)/Aβ(1-38), respectively, were specific for AD. CSF Aβ(1-38) was reduced in FTD as compared to each of the other diagnostic groups, including PPA. CSF tau and p-tau levels were elevated in PPA as compared to FTD.

CONCLUSION

This is the first detailed report on biomarker patterns in PPA, indicating distinct CSF biomarker patterns in FTD and PPA as major subgroups of frontotemporal lobar degeneration. The diagnostic and pathophysiological implications of our results warrant further studies on larger and neuropathologically diagnosed patient populations.

Common variants at ABCA7, MS4A6A/MS4A4E, EPHA1, CD33 and CD2AP are associated with Alzheimer's disease

We sought to identify new susceptibility loci for Alzheimer's disease through a staged association study (GERAD+) and by testing suggestive loci reported by the Alzheimer's Disease Genetic Consortium (ADGC) in a companion paper. We undertook a combined analysis of four genome-wide association datasets (stage 1) and identified ten newly associated variants with P ≤ 1 × 10(-5). We tested these variants for association in an independent sample (stage 2). Three SNPs at two loci replicated and showed evidence for association in a further sample (stage 3). Meta-analyses of all data provided compelling evidence that ABCA7 (rs3764650, meta P = 4.5 × 10(-17); including ADGC data, meta P = 5.0 × 10(-21)) and the MS4A gene cluster (rs610932, meta P = 1.8 × 10(-14); including ADGC data, meta P = 1.2 × 10(-16)) are new Alzheimer's disease susceptibility loci. We also found independent evidence for association for three loci reported by the ADGC, which, when combined, showed genome-wide significance: CD2AP (GERAD+, P = 8.0 × 10(-4); including ADGC data, meta P = 8.6 × 10(-9)), CD33 (GERAD+, P = 2.2 × 10(-4); including ADGC data, meta P = 1.6 × 10(-9)) and EPHA1 (GERAD+, P = 3.4 × 10(-4); including ADGC data, meta P = 6.0 × 10(-10)).

Evaluating depressive symptoms and their impact on outcome in schizophrenia applying the Calgary Depression Scale

OBJECTIVE

To examine depressive symptoms, their course during treatment, and influence on outcome.

METHOD

Weekly Calgary Depression Scale for Schizophrenia ratings were performed in 249 inpatients with schizophrenia. Early response was defined as a 20% reduction in the total score of the Positive and Negative Syndrome Scale for Schizophrenia from admission to week 2, response as a 50% reduction in the total score of the Positive and Negative Syndrome Scale for Schizophrenia (PANSS) from admission to discharge and remission according to the consensus criteria.

RESULTS

Thirty six per cent of the patients were depressed at admission, with 23% of them still being depressed at discharge. Depressed patients scored significantly higher on the PANSS negative and general psychopathology subscore, featured more impairments in subjective well-being (P < 0.0001) and functioning (P < 0.0001). They suffered from more suicidality (P = 0.0021), and had greater insight into their illness (P = 0.0105). No significant differences were found regarding early response, response, and remission.

CONCLUSION

Patients with depressive symptoms should be monitored closely, given the burden of negative symptoms, their impairments in well-being and functioning and the threat of suicidality.

A critical analysis and discussion of the appropriateness of the schizophrenia consensus remission criteria in clinical pharmaceutical trials

BACKGROUND

The aim of this paper is to apply the proposed consensus remission criteria to an acutely ill inpatient sample at admission and evaluate their adaptability in this patient population and pharmaceutical trials.

METHODS

The Remission in Schizophrenia Working Group's consensus criteria were applied to 272 acutely ill schizophrenia patients. Patients were examined using the PANSS, HAMD, UKU and SWN-K total scales at admission as well as the GAF, SOFAS and the Strauss-Carpenter Prognostic Scale. Sociodemographic and clinical baseline variables were assessed using a standardized documentation system.

RESULTS

33 patients (12%) fulfilled the symptom severity component of the proposed remission criteria already at baseline. Almost no significant differences were found when comparing patients with achieved and failed symptom severity component that would explain the hospitalization of the patients with achieved criteria despite their apparently mild psychopathological symptoms. The only explainable difference was that patients with an achieved symptom severity component had received significantly more antipsychotics and had suffered from significantly more life events before admission.

CONCLUSION

The present results raise the question whether the symptom severity threshold is adequate to identify patients in remission when applied in clinical trials.

Suicidality as rare adverse event of antidepressant medication: report from the AMSP multicenter drug safety surveillance project

OBJECTIVE

Since the advent of antidepressant drug treatment, the question of whether these substances induce suicidal ideation and behavior has not been satisfactorily answered. The aim of this study is to contribute to this ongoing discussion by taking a heuristic case-based approach to the question.

METHOD

A large data set from a European drug surveillance program (Arzneimittelsicherheit in der Psychiatrie; AMSP) performed in 85 psychiatric hospitals from 1993 until 2008 was analyzed. A series of single cases were carefully assessed. The observed frequencies of adverse drug reactions (ADRs) in this sample were related to the total AMSP population, who used the imputed medication.

RESULTS

A total of 142,090 adult patients taking antidepressant medication were observed. Thirty-three incidents of suicidality (12 cases of suicidal ideation, 18 attempts, and 3 completed suicides) were documented. Fourteen cases were assumed to be probably, and 19 to be possibly, related to the drug. Twenty-three cases judged as suicidal ADRs were associated with restlessness, 10 with ego-dystonia, 9 with impulsiveness, and 3 with psychosis. A higher incidence of suicidal ADRs was observed for selective serotonin reuptake inhibitors (0.034%; 95% CI, 0.020-0.054) and serotonin-norepinephrine reuptake inhibitors (0.034%; 95% CI, 0.015-0.068) compared to noradrenergic and specific serotonergic antidepressants (0.009%; 95% CI, 0.002-0.027) and tricyclic antidepressants (0.002%; 95% CI, 0.000-0.014).

CONCLUSION

Despite the methodological limitations of this study, the large AMSP data set supports the assumption that antidepressant drugs rarely trigger suicidality.