Triin Eller

Serotonin transporter promoter region polymorphisms do not influence treatment response to escitalopram in patients with major depression

Several studies and meta-analyses have implicated a polymorphism in the promoter region of the serotonin transporter (5-HTT) gene, 5-HTTLPR in treatment outcomes of selective serotonin re-uptake inhibitors in patients with major depression. In this study we investigated the impact of 5-HTTLPR and a functional SNP rs25531 on the treatment outcomes to escitalopram in depressive patients. The study sample consisted of 135 outpatients with major depressive disorder (mean age 31.1+/-11.6 years, 68% females) treated with escitalopram 10-20 mg/day for 12 weeks. There were no significant associations between 5-HTT promoter region polymorphisms and response rate or mean change of depressive symptoms during escitalopram treatment. However we showed that patients carrying S allele of 5-HTTLPR may have increased risk for some side effects, including headache, induced by escitalopram medication.

Polymorphisms in the interleukin-10 gene cluster are possibly involved in the increased risk for major depressive disorder

BackgroundInnate immune inflammatory response is suggested to have a role in the pathogenesis of major depressive disorder (MDD). Interleukin (IL)-10 family cytokines IL-10, IL-19, IL-20, and IL-24 are all implicated in the inflammatory processes and polymorphisms in respective genes have been associated with various immunopathological conditions. This study was carried out to investigate whether single-nucleotide polymorphisms (SNPs) in these genes are also associated with MDD.MethodsCase-control association study was performed with seven SNPs from the IL10 gene cluster. 153 patients with MDD and 277 healthy control individuals were recruited.ResultsNone of the selected SNPs were individually associated with MDD. The linkage disequilibrium (LD) analysis indicated the existence of two recombination sites in the IL10 gene cluster, thus confirming the formerly established LD pattern of this genomic region. This also created two haplotype blocks, both consisting of three SNPs. Additionally, the haplotype analysis detected a significantly higher frequency of block 2 (IL20 and IL24 genes) haplotype TGC in the patients group compared to healthy control individuals (P = 0.0097).ConclusionOur study established increased risk for MDD related to the IL20 and IL24 haplotype and suggests that cytokines may contribute to the pathogenesis of MDD. Since none of the block 2 SNPs were individually associated with MDD, it is possible that other polymorphisms linked to them contribute to the disease susceptibility. Future studies are needed to confirm the results and to find the possible functional explanation.

Associations between LSAMP gene polymorphisms and major depressive disorder and panic disorder.

The purpose of this case–control genetic association study was to explore potential relationships between polymorphisms in the limbic system-associated membrane protein (LSAMP) gene and mood and anxiety disorders. A total of 21 single-nucleotide polymorphisms (SNPs) from the LSAMP gene were analyzed in 591 unrelated patients with the diagnoses of major depressive disorder (MDD) or panic disorder (PD) and in 384 healthy control subjects. The results showed a strong association between LSAMP SNPs and MDD, and a suggestive association between LSAMP SNPs and PD. This is the first evidence of a possible role of LSAMP gene in mood and anxiety disorders in humans.

Effects of bupropion augmentation on pro-inflammatory cytokines in escitalopram-resistant patients with major depressive disorder

Abstract Studies so far have provided contradictory results on immune system markers during use of antidepressants. There are no data on changes in immune parameters after treatment augmentation. The present study aimed to clarify whether the addition of bupropion in escitalopram-resistant patients with major depression causes changes in the immune system and whether treatment response could be predicted by baseline levels of cytokines. We recruited 28 depressive patients (11 men and 17 women) who did not respond to 12-week treatment with escitalopram (20 mg/d) for an augmentation trial with bupropion (150–300 mg/day). The levels of soluble interleukin-2 receptor, interleukin-8 (IL-8) and tumor-necrosis factor-α were measured before and 6 weeks after addition of bupropion. For a control group, we recruited 45 healthy volunteers (19 men and 26 women). The results indicated that the baseline levels of studied cytokines did not predict treatment response to bupropion augmentation. Concentration of IL-8 increased during the treatment similarly in both responder and non-responder groups. Although bupropion augmentation had increased the response rate in escitalopram-resistant patients, this clinical improvement was not accompanied by specific changes in studied cytokine levels.

Whole-exome sequencing identifies a polymorphism in the BMP5 gene associated with SSRI treatment response in major depression

Although antidepressants are widely used in the pharmacotherapy of major depressive disorder (MDD), their efficacy is still insufficient as approximately one-third of the patients do not fully recover even after several treatment trials. Inter-individual genetic differences are thought to contribute to the variability in antidepressant response; however, current findings from pharmacogenetic studies are uncertain or not clearly replicated. Here we report the first application of full exome sequencing for the analysis of pharmacogenomics on antidepressant treatment. After 12 weeks of treatment with the selective serotonin re-uptake inhibitor escitalopram, we selected five clear responders and five clear non-responders for exome sequencing. By comparing the allele counts of previously known single nucleotide polymorphisms and novel polymorphisms we selected 38 markers for further genotyping in two independent patient samples treated with escitalopram (n=116 and n=394). The A allele, carried by approximately 30% of the patients with MDD, of rs41271330 in the bone morphogenetic protein (BMP5) gene showed strong association with worse treatment response in both sample sets (p=0.001), indicating that this is an promising pharmacogenetic marker for prediction of antidepressant therapeutic outcome.

Thyroid autoimmunity and treatment response to escitalopram in major depression.

Background: There is evidence that immune alterations play an important part in the pathogenesis of major depression. Thyroid autoimmunity has been found in association with major depression in several studies. Aim: 1) to examine whether the prevalence of anti-thyroid peroxidase autoantibodies (anti-TPO) in depressive patients differs from that in healthy controls; 2) to investigate the possible relationship between thyroid autoimmunity, total T3, free T3, free T4, thyroid-stimulating hormone (TSH), clinical status and treatment outcome in depression. Method: The study group consisted of 129 outpatients (69.8% female; mean age 31.7±12.0 years) with major depressive disorder with a Montgomery–Åzsberg Depression Rating Scale total score of 22 or higher and 72 healthy controls (62.5% female; mean age 31.7±13.1 years). The patients were treated with escitalopram 10–20 mg/day for 12 weeks using open-label placebo non-controlled design. Anti-TPO, total T3, free T3, free T4 and TSH were measured before the treatment. Results: The anti-TPO was found in eight (8.9%) depressive and two (4.8%) healthy females without statistical difference between these groups. Since anti-TPO was not seen in males, all further statistical analyses were carried out in females. At the end of week 12 of the treatment, 60 female patients (66.7%) were defined as responders and 30 depressive females (33.3%) showed insufficient response to treatment. Although there were no significant differences in the measurements between responders and non-responders, the last group showed a trend for a higher prevalence of anti-TPO compared with responders. Conclusion: Thyroid autoimmunity might be a factor predicting treatment response to antidepressants in depressive patients.

Interleukin 10 family gene polymorphisms are not associated with major depressive disorder and panic disorder phenotypes

Genetic regulation of immune system and inflammatory response may be related to the pathogenesis and manifestations of mood and anxiety disorders. In the present study we examined a range of single-nucleotide polymorphisms (SNP) in chromosomal region 1q32, the locus of interleukin 10 (IL10) gene, in patients with major depressive disorder (n=312) and panic disorder (n=210), and matched healthy controls (n=356). We found no significant associations of the SNPs in IL10 family genes with either diagnostic group. Haplotype analysis revealed seven haplotype blocks, but their frequencies did not differ between patients and controls. Significant associations were detected for SNP rs1539243 in IKBKE (inhibitor of kappa light polypeptide gene enhancer in B-cells, kinase epsilon) gene showing different allelic and genotypic distributions in the total as well as in separate diagnostic groups as compared to controls. IKBKE emerged as a candidate for further studies of genetic factors associated with panic disorder and major depressive disorder.

Whole-genome expression analysis reveals genes associated with treatment response to escitalopram in major depression

The reasons for variability in treatment response in major depressive disorder (MDD) are not fully understood, but there is accumulating evidence suggesting that therapeutic outcomes of antidepressants can be influenced by genetic factors. In the present study we applied the microarray Illumina platform for whole genome expression profiling in depressive patients treated with escitalopram medication in order to identify genes underlying response to antidepressant treatment. The initial study sample consisted of 135 outpatients with major depressive disorder (mean age 31.1±11.6 years, 68% females) treated with escitalopram 10-20mg/day for 12 weeks, from which 87 patients (55 females) were included in gene expression analyzing. The gene expression profiles were measured on peripheral blood cells at baseline, at week 4 and at the end of treatment (week 12) using BeadChips Illumina. The fold change was used to demonstrate rate of changes in average gene expressions between studied groups. Statistical analyses were performed using the false discovery rate (FDR). The most interesting gene, which showed the predictive effect on treatment outcome by delineating low dose responders and treatment-resistant patients at the beginning of medication, was NLGN2, belonging to a family of neuronal cell surface proteins and involving in synapse formation. In addition, the several gene clusters, related to immune response, signal transduction and neurotrophin pathway, have distinguished responders from non-responders at the week 4 of treatment. After 4 weeks of escitalopram treatment (10mg/day), the YWHAZ gene has showed the highest transcriptional change in responders as compared with non-responders. Finally, at the end of the treatment we noticed that at least three genes (NR2C2, ZNF641, FKBP1A) have been strongly associated with resistance to escitalopram. Thus the results of this study support that exploration of peripheral gene expression is a useful tool in the further identification of novel genetic biomarkers for antidepressant treatment response.

Obstructive sleep apnea syndrome (OSAS): Pathophysiology in Estonians

The aim of the study was to clarify the roles of age, obesity, smoking, alcohol, pathoanatomy and -physiology in Estonians OSAS. For this 164 randomly chosen such patients were selected in different regions of Estonia. They underwent naso-oropharyngeal examination, physical examination of craniofacial abnormalities, and polysomnography. They also completed a self-reported questionnaire about smoking, alcohol use, excessive daytime sleepiness, hypertension, cardiac disorders, headaches, concentration disorders, and recurrent upper-airway diseases. The patients (129 men; 35 women) aged between 19 and 75 years (mean 47+/-12), BMI between 21 and 49 (mean 30.5+/-5.15), AHI between 5 and 105 (33+/-22). The results showed that there was a high percentage of naso-oropharyngeal disorders, such as: recurrent upper-airway diseases (54.2%), nasal breathing disorders (63.5%), and hypertrophy of tonsils (57%). There was also a high percentage of general characteristics, such as alcohol use (64%), excessive daytime sleepiness (85.5%), overweight (63%), and hypertension (51.2%). The regression summary for the dependent variable AHI if p-level=0.0042 (R=0.63347013) included age, BMI, hypertension, cardiac disorders, headaches, nasal obstruction, hypertrophy of pharyngeal muscles, tongue level, submental fat and slow-wave sleep (S3+S4%). In conclusion recurrent upper-airway diseases, nasal obstruction, and hypertrophy of tonsils in combination with smoking and alcohol caused the changes in the pharyngeal and lingual muscles. The latter gives rise to such sleep apnea-related problems as heart complaints, hypertension, headache and shortage of slow-wave sleep (SWS).

Polymorphisms of IKBKE gene are associated with major depressive disorder and panic disorder.

The immune system has been increasingly implicated in the development of mood and anxiety disorders. Inhibitor of kappa light polypeptide gene enhancer in B cells, kinase epsilon (IKBKE) gene encodes IKKε protein that is involved in innate immunity, predominantly antiviral response generation. It also bears pro‐inflammatory properties that could affect psychiatric outcomes. In order to investigate the possible role of IKBKE gene in major depressive disorder (MDD) and panic disorder (PD), we conducted a case–control genetic association study concerning these disorders.