TNF-alpha polymorphisms are associated with obsessive-compulsive disorder

Multistrain probiotic rescinds quinpirole-induced obsessive-compulsive disorder phenotypes by reshaping of microbiota gut-brain axis in rats

Obsessive-compulsive disorder (OCD) is a disabling mental condition that poses recurring bothersome intrusive thoughts, obsessions, and compulsions. Considering the positive impact of probiotics on neuropsychiatric disorders, herein, we investigated the effect of multistrain probiotic (Bifidobacterium lactis UBBLa-70, Bacillus coagulans Unique IS-2, Lactobacillus rhamnosus UBLR-58, Lactobacillus plantarum UBLP-40, Bifidobacterium infantis UBBI-01, Bifidobacterium breve UBBr-01, and glutamine) in the management of OCD-like phenotype in rats. Rats injected with quinpirole for 5 weeks showed an increased number of marble burying and self-grooming episodes. Quinpirole-injected animals also did less head dipping in the hole board test and avoided exploration of open spaces in the elevated-plus maze. These repetitive, compulsive, self-directed, and anxiety-like phenotypes were abolished after 8-week of multistrain probiotic treatment. The probiotic formulation also prevented the elevated mRNA expression of interleukin-6, tumor-necrosis factor-α, and C-reactive protein in the amygdala and dysregulated levels of 5-hydroxytryptamine, dopamine, and noradrenaline in the frontal cortex of quinpirole-injected rats. The level of brain-derived neurotrophic factor in the frontal cortex remained unaffected across the groups. The altered levels of goblet cells and crypt-to-villi ratio in quinpirole rats were prevented by multistrain probiotic treatment. The results of 16S-rRNA gene-sequencing of gut microbiota from feces contents revealed an elevation in the abundance of Allobaculum and Bifidobacterium species (specifically Bifidobacterium animalis), while the presence of Lactobacillus species (including Lactobacillus reuteri and Lactobacillus vaginalis) exhibited a decline in quinpirole-induced rats. These results imply that modifying the gut-brain axis may be a possible mechanism by which selective multistrain probiotic therapy prevents OCD-like behaviors.

Peripheral control of psychiatric disorders: Focus on OCD. Are we there yet?

"We are all in this together" - we often hear this phrase when we want to flag up a problem that is not for a single individual but concerns us all. A similar reflection has been recently made in the field of mental disorders where brain-centric scientists have started to zoom out their brain-focused graphical representations of the mechanisms regulating psychiatric diseases to include other organs or mediators that did not belong historically to the world of neuroscience. The brain itself - that has long been seen as a master in command secluded in its fortress (the blood brain barrier), has now become a collection of Airbnb(s) where all sorts of cells come in and out and sometimes even rearrange the furniture! Under this new framework of reference, mental disorders have become multisystem pathologies where different biological systems - not just the CNS -contribute 'all together' to the development and severity of the disease. In this narrative review article, we will focus on one of the most popular biological systems that has been shown to influence the functioning of the CNS: the immune system. We will specifically highlight the two main features of the immune system and the CNS that we think are important in the context of mental disorders: plasticity and memory.

Obsessive-Compulsive Disorder Interactome Profile Analysis: A Perspective From Molecular Mechanism

Introduction:

Obsessive-Compulsive Disorder (OCD) is one of the complex neuropsychiatric conditions. This disorder disables individuals in many different aspects of their personal and social life. Interactome analysis may provide a better understanding of this disorder’s molecular origin and its underlying mechanisms.

Methods:

In this study, the OCD-associated genes were extracted from the literature. The criterion for gene selection was to choose genes with at least one significant report. Furthermore, by applying Cytoscape and its plugins, protein-protein interaction network, and gene ontology of the 31 candidate genes related to OCD from genetic association studies is examined. The cross-validation method was used for network centrality assessment.

Results:

A scale-free network, including 1940 nodes and 3269 edges for 31 genes, was constructed. According to the network centrality evaluation, ESR1, TNFα, DRD2, DRD4, HTR1B, HTR2A, and CDH2 showed the highest values and can be considered hub-bottlenecks elements. It is also confirmed by the number of 123 cross-validation tests that the frequency of these essential genes remains unaltered against the initial seed genes’ changes with the accuracy of 0.962. Besides, enrichment analysis identified four highlighted biological processes related to the 31 candidate genes. The top biological processes are determined as dopamine transport, learning, memory, and monoamine transport.

Conclusion:

Among 31 initial genes, 7 were introduced as crucial elements for onset and development in OCD and can be suggested for further investigations. Furthermore, the complex molecular origin of OCD requires high-throughput screening for diagnosis and treatment goals. The findings are a possible valuable source to establish molecular-based diagnostic tools for OCD.

Searching for host immune-microbiome mechanisms in obsessive-compulsive disorder: A narrative literature review and future directions

Obsessive-compulsive disorder (OCD) is disabling and often treatment-refractory. Host immunity and gut microbiota have bidirectional communication with each other and with the brain. Perturbations to this axis have been implicated in neuropsychiatric disorders, but immune-microbiome signaling in OCD is relatively underexplored. We review support for further pursuing such investigations in OCD, including: 1) gut microbiota has been associated with OCD, but causal pathogenic mechanisms remain unclear; 2) early environmental risk factors for OCD overlap with critical periods of immune-microbiome development; 3) OCD is associated with increased risk of immune-mediated disorders and changes in immune parameters, which are separately associated with the microbiome; and 4) gut microbiome manipulations in animal models are associated with changes in immunity and some obsessive-compulsive symptoms. Theoretical pathogenic mechanisms could include microbiota programming of cytokine production, promotion of expansion and trafficking of peripheral immune cells to the CNS, and regulation of microglial function. Immune-microbiome signaling in OCD requires further exploration, and may offer novel insights into pathogenic mechanisms and potential treatment targets for this disabling disorder.

Anti-inflammatory Augmentation Therapy in Obsessive-compulsive Disorder: A Review

Background:

Obsessive-Compulsive Disorder (OCD) is considered as a serious disabling psychiatric disorder, influencing 2-3% of the total general population, with an unknown etiology.

Methods:

A comprehensive literature search in electronic databases was performed to investigate treatments targeting inflammation in patients suffering from OCD.

Results:

Recent studies display that inflammation processes and the dysfunction of the immune system are likely to play a role in the pathophysiology of OCD, indicating that the disturbances in neurotransmitters such as serotonin and dopamine cannot be alone involved in the development of OCD. Therefore, it seems that medications with anti-inflammatory effects have the potential to be evaluated as a new therapeutic strategy for OCD. However, this issue can be studied closely if OCD etiological factors are thoroughly understood. The present review study aims at gathering all obtained results concerning new treatments targeting inflammation in OCD patients. Reviewing the conducted studies shows that the use of agents with anti-inflammatory properties, including some NSAIDs, Minocycline and Atorvastatin, could lead to promising and intriguing results in the treatment of OCD. Curcumin also showed good efficacy in the reduction of OCD-like behavior when it has been used in an animal model. However, there is still no definitive and conclusive evidence for any of the medications proposed.

Conclusion:

More future studies are needed to investigate anti-inflammatory treatment strategies for OCD and its other subtypes such as Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS), and Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal infection (PANDAS).

Corticostriatal circuit defects in Hoxb8 mutant mice

Hoxb8 mutant mice exhibit compulsive grooming and hair removal dysfunction similar to humans with the obsessive-compulsive disorder (OCD)-spectrum disorder, trichotillomania. As, in the mouse brain, the only detectable cells that label with Hoxb8 cell lineage appear to be microglia, we suggested that defective microglia cause the neuropsychiatric disorder. Does the Hoxb8 mutation in microglia lead to neural circuit dysfunctions? We demonstrate that Hoxb8 mutants contain corticostriatal circuit defects. Golgi staining, ultra-structural and electrophysiological studies of mutants reveal excess dendritic spines, pre- and postsynaptic structural defects, long-term potentiation and miniature postsynaptic current defects. Hoxb8 mutants also exhibit hyperanxiety and social behavioral deficits similar to mice with neuronal mutations in Sapap3, Slitrk5 and Shank3, reported models of OCD and autism spectrum disorders (ASDs). Long-term treatment of Hoxb8 mutants with fluoxetine, a serotonin reuptake inhibitor, reduces excessive grooming, hyperanxiety and social behavioral impairments. These studies provide linkage between the neuronal defects induced by defective Hoxb8-microglia and neuronal dysfunctions directly generated by mutations in synaptic components that result in mice, which display similar pathological grooming, hyperanxiety and social impairment deficits. Our results shed light on Hoxb8 microglia-driven circuit-specific defects and therapeutic approaches that will become essential to developing novel therapies for neuropsychiatric diseases such as OCD and ASDs with Hoxb8-microglia being the central target.

Individualized Immunological Data for Precise Classification of OCD Patients

Obsessive⁻compulsive disorder (OCD) affects about 2% of the general population, for which several etiological factors were identified. Important among these is immunological dysfunction. This review aims to show how immunology can inform specific etiological factors, and how distinguishing between these etiologies is important from a personalized treatment perspective. We found discrepancies concerning cytokines, raising the hypothesis of specific immunological etiological factors. Antibody studies support the existence of a potential autoimmune etiological factor. Infections may also provoke OCD symptoms, and therefore, could be considered as specific etiological factors with specific immunological impairments. Finally, we underline the importance of distinguishing between different etiological factors since some specific treatments already exist in the context of immunological factors for the improvement of classic treatments.

Two distinct ontogenies confer heterogeneity to mouse brain microglia

Hoxb8 mutant mice show compulsive behavior similar to trichotillomania, a human obsessive-compulsive-spectrum disorder. The only Hoxb8 lineage-labeled cells in the brains of mice are microglia, suggesting that defective Hoxb8 microglia caused the disorder. What is the source of the Hoxb8 microglia? It has been posited that all microglia progenitors arise at embryonic day (E) 7.5 during yolk sac hematopoiesis, and colonize the brain at E9.5. In contrast, we show the presence of two microglia subpopulations: canonical, non-Hoxb8 microglia and Hoxb8 microglia. Unlike non-Hoxb8 microglia, Hoxb8 microglia progenitors appear to be generated during the second wave of yolk sac hematopoiesis, then detected in the aorto-gonad-mesonephros (AGM) and fetal liver, where they are greatly expanded, prior to infiltrating the E12.5 brain. Further, we demonstrate that Hoxb8 hematopoietic progenitor cells taken from fetal liver are competent to give rise to microglia in vivo Although the two microglial subpopulations are very similar molecularly, and in their response to brain injury and participation in synaptic pruning, they show distinct brain distributions which might contribute to pathological specificity. Non-Hoxb8 microglia significantly outnumber Hoxb8 microglia, but they cannot compensate for the loss of Hoxb8 function in Hoxb8 microglia, suggesting further crucial differences between the two subpopulations.

The Effect of Atorvastatin on Obsessive-compulsive Symptoms of Refractory Obsessive-compulsive Disorder (Add-on Therapy)

Background

Considering the effect of statins on the regulation of dopamine neurotransmitters and glutamates and importance of the treatment of obsessive-compulsive disorder (OCD) due to its relatively high prevalence and disability of available drugs in treatment of many patients, we came to the point to examine effectiveness of statins in patients with OCD.

Materials and Methods

This study is a double-blind randomized clinical trial, which is done in OCD clinic of Isfahan Shariati in 2014 for 1 year. The target population consists of 64 patients with OCD; one group is given a daily 40 mg atorvastatin tablets and the other group receives placebo. At baseline, 4- and 8-week severities of obsessive-compulsive symptoms are measured using Yale-Brown scale and compared in the two groups.

Results

The study results show a statistically significant difference between the two groups of intervention and control (P < 0.001). Furthermore, the results show the intervention effect at the end of the 4^th week and 8^th week (P < 0.001) that this change is evident in the 4^th week but remained almost constant in the 8^th week.

Conclusion

Overall, the evidences obtained from the study declare the effects of adding statins to treat obsessive-compulsive symptoms.

Association between TNF-α-238G/A gene polymorphism and OCD susceptibility: A meta-analysis

BACKGROUND

Tumor necrosis factor-alpha (TNF-α) is an important cytokine and has been reported to be associated with the pathogenesis of many autoimmune and inflammatory diseases. TNF-α gene is located on a region that has been found to be associated with obsessive-compulsive disorder (OCD). We performed this meta-analysis to assess the relationship between susceptibility to OCD and the TNF-α-238G/A gene polymorphism.

METHODS

An extensive search of the available literature on the association between the susceptibility to OCD and the TNF gene polymorphism was conducted by searching PubMed, Web of Knowledge, Embase, Chinese Web of Knowledge, Wanfang, and Chongqing VIP database. The database was searched up to December 2016 and includes language of English and/or Chinese with the keywords of "obsessive-compulsive disorder" or "OCD," polymorphism or variant or mutation, "tumor necrosis factor" or "TNF" or "cytokine." The association between TNF-α-238G/A gene polymorphism and the susceptibility of OCD was anticipated by odds ratio (OR) with the corresponding 95% confidence interval (95% CI).

RESULTS

Four studies including 435 cases and 1073 controls were incorporated in our meta-analysis. In general, TNF-α-238G/A gene polymorphism might lead to a decreased risk of OCD susceptibility (G vs A genotype model: OR = 1.01, 95% CI = 0.37-2.77, P = .981; GG vs AA+AG model: OR = 0.93, 95% CI = 0.37-2.36, P = .879; GG+AG vs AA model: OR = 0.22, 95% CI = 0.06-0.73, P = .014; GG vs AA model: OR = 0.21, 95% CI = 0.06-0.71, P = .012; AG vs AA model: OR = 0.29, 95% CI = 0.07-1.16, P = .081; GG+AA vs AG model: OR = 1.17, 95% CI = 0.55-2.51, P = .683).

CONCLUSION

TNF-α-238G/A gene polymorphism might lead to a decreased risk of OCD susceptibility.

Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

OBJECTIVE

Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD).

METHODS

Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network.

RESULTS

The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics.

CONCLUSIONS

Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD.

Inflammation in children and adolescents with neuropsychiatric disorders: a systematic review

OBJECTIVE

There has been rapid growth in research regarding inflammation in neuropsychiatric disorders as it relates to youth. We therefore set out to systematically review the literature on inflammation and neuropsychiatric disorders in children and adolescents.

METHOD

A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies were included if proinflammatory markers (PIMs) in children and/or adolescents with neuropsychiatric disorders were measured.

RESULTS

Sixty-seven studies were included, involving 3,952 youth. Evidence for a proinflammatory state is strongest for autism spectrum disorders (ASD). PIMs are elevated in children and adolescents with major depressive disorder (MDD), bipolar disorder (BD), post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), Tourette's disorder (TD), attention-deficit/hyperactivity disorder (ADHD), and schizophrenia (SZ). However, the data are inconsistent. Evidence for specific PIMs is equivocal at this stage, although the findings in youth with MDD, BD, and PTSD converge with the extant adult literature in these areas. Definitive conclusions are limited by methodologic factors including cross-sectional and retrospective study design, between-study differences in specific markers and methods of analysis, small sample size, and other sources of heterogeneity.

CONCLUSION

The literature regarding inflammation among children and adolescents with neuropsychiatric disorders represents nearly 4,000 youth. There is preliminary evidence for elevated markers of inflammation in this population. Larger, prospective studies are needed to realize the goal of inflammatory markers informing clinical practice. In the interim, present findings suggest that further examination of this topic is warranted.

Searching for the immune basis of obsessive-compulsive disorder

The etiopathogenesis of obsessive-compulsive disorder (OCD) remains elusive. Clinical observation of the elevated frequency of obsessive-compulsive symptoms in patients with rheumatic fever, a post-streptococcal autoimmune disease, prompted the study of immune parameters in OCD. Anti-basal ganglia antibodies have been described in a subset of OCD patients. The assessment of circulating cytokines and immune cells confirmed unequivocal changes in at least some patients, although it is difficult to establish a particular immune profile in OCD. Several factors, including the use of psychotropic drugs and the presence of comorbid conditions, seem to influence these immune parameters.

Association between Obsessive Compulsive Disorder and Tumor Necrosis Factor-α Gene -308 (G>A) and -850 (C>T) Polymorphisms in Turkish Children

Obsessive compulsive disorder (OCD) is a neurobiological disease characterized with obsessions and compulsions. Obsessive compulsive disorder occurs with an autoimmune mechanism after Group A β hemolytic streptococcus (GABHS) infection. Tumor necrosis factor (TNF) is an important cytokine, as well as having an important role in the apoptosis mechanism of autoimmune diseases. It is expressed by the TNF-α gene. The aim of this study was to examine the relationship between the TNF-α gene promoter region −308 (G>A) and −850 (C>T) polymorphisms and OCD. In this study, ages of the OCD patients and the control group ranged between 4 and 12 years. We studied two patient groups, one included childhood onset OCD patients (n = 49) and the control group was composed of healthy children (n = 58). Patients were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorder (DSM-IV) criteria and with Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime (KSAD-S-PL) version. For identifying the polymorphisms, polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP) and polyacrylamide gel electrophoresis (PAGE) methods were used.

For the −308 polymorphism, 45 of 49 OCD patients’ results were completed, and for the −850 polymorphism, 47 of 49 OCD patients’ results were completed. According to our statistical results, there is a positive relationship between OCD and the −308 polymorphism (p <0.001) but no association between OCD and the −850 polymorphism (p = 0.053). There is no positive relationship between antistreptolysin O (ASO) titers and the −308 polymorphism (p = 0.953) but there is an important significance between the −850 polymorphism and ASO (p = 0.010). There is no positive relationship between gender of patients and OCD (p = 0.180) and no positive association between ASO and gender (p = 0.467). According to our results, we hypothesize that we can propose the mutant AA genotype for the −308 polymorphism, and that the mutant CT genotype for the −850 polymorphism may be used as molecular indicators for OCD.

Association between pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections disease and tumor necrosis factor-α gene-308 g/a, -850 c/t polymorphisms in 4-12-year-old children in Adana/Turkey

OBJECTIVES:

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) is a newly defined disease in neuropsychiatry and occurs with an autoimmune mechanism after Group A Beta Hemolytic Streptococcus (GABHS) infection. Tumor necrosis factor (TNF), encoded by TNF-α gene has an important role in the apoptotic mechanisms of autoimmune diseases. Recently, TNF-α polymorphisms and autoimmune/psychiatric disorders have been reported to be related. In this regard, we focused on to investigate a possible relation between the TNF-α gene promoter region−308 G/A and − 850 C/T polymorphisms and PANDAS.

MATERIALS AND METHODS:

In this study, ages of PANDAS patient and control groups were ranging from 4 years to 12-year-old. Patient group includes childhood onset PANDAS patients (n = 42) and control group includes healthy children (n = 58). Diagnoses have been carried out according to Diagnostic and Statistical Manual of Mental Disorder (DSM-IV) criteria with Affective Disorders and Schizophrenia-Present and Lifetime (KSAD-S-PL) and Children Yale-Brown Obsessive Compulsive Scale Moreover, PANDAS criteria established by the American National Psychiatry Institute have been employed for diagnoses. For identifying polymorphisms; Polymerase Chain Reaction, Restriction Fragment Length Polymorphism and Polyacrylamid Gel Electrophoresis were used.

RESULTS AND DISCUSSION:

For −308 polymorphism, 37 of 42 PANDAS patients’ results and for −850 C/T polymorphism, 38 of 42 PANDAS patients’ results were obtained. According to our statistical analysis there is a positive relationship between PANDAS patients for −308 G/A polymorphism but not for −850 C/T polymorphism. There is no positive relationship between −308 G/A polymorphism and antistrep-tolysin O (ASO) titers and no relationship between −850 C/T polymorphism and ASO titers. We found, however, positive relationship between genders of patients (boys) and the disease. According to our results, we propose that the AA polymorphism of −308 G/A polymorphism can be used as a molecular indicator for PANDAS.

A case-control association study between Obsessive-Compulsive Disorder (OCD) and the MCP-1 -2518G/A polymorphism in a Chinese sample

OBJECTIVE

To investigate the association between Obsessive-Compulsive Disorder (OCD) and a functional polymorphism of MCP-1 in the Chinese Han population.

METHOD

We genotyped and performed a case-control association analysis of the MCP-1 -2518G/A polymorphism in 200 OCD patients and 294 healthy control subjects.

RESULTS

There was no significant difference in MCP-1 -2518G/A genotypic and allelic frequencies between OCD cases and controls (x² = 1.123, df = 2, P = 0.57 by genotype; x² = 0.802, df = 1, P = 0.37 by allele).

CONCLUSIONS

Our results indicated that MCP-1 -2518G/A may not play a major role in the genetic predisposition of the Chinese Han population to OCD. However, further studies using a larger number of subjects are required to obtain a clear conclusion.

Association study between functional polymorphisms in the TNF-alpha gene and obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a prevalent psychiatric disorder of unknown etiology. However, there is some evidence that the immune system may play an important role in its pathogenesis. In the present study, two polymorphisms (rs1800795 and rs361525) in the promoter region of the cytokine tumor necrosis factor-alpha (TNFA) gene were genotyped in 183 OCD patients and in 249 healthy controls. The statistical tests were performed using the PLINK(®) software. We found that the A allele of the TNFA rs361525 polymorphism was significantly associated with OCD subjects, according to the allelic χ(2) association test (p=0.007). The presence of genetic markers, such as inflammatory cytokines genes linked to OCD, may represent additional evidence supporting the role of the immune system in its pathogenesis.

A cytokine study of adult patients with obsessive-compulsive disorder

OBJECTIVES

We aimed to determine the plasma levels of cytokines in patients with obsessive-compulsive disorder (OCD) as compared with healthy controls and to investigate whether there is any association between their concentrations and OCD clinical and therapeutic features.

METHODS

Forty patients with OCD and 40 healthy controls had their plasmas assessed for a range of cytokines (tumor necrosis factor-α, or TNF-α), chemokines (CCL2, CCL3, CCL11, CCL24, CXCL8, CXCL9, CXCL10), and other mediators (TNF soluble receptors sTNFR1 and sTNFR2 and interleukin-1 receptor antagonist) by enzyme-linked immunosorbent assay. Patients with OCD were further examined with the Mini-International Neuropsychiatric Interview, the Obsessive-Compulsive Inventory-Revised, and the Beck Depression Inventory.

RESULTS

Compared with healthy controls, patients with OCD exhibited significantly increased plasma levels of CCL3, CXCL8, sTNFR1, and sTNFR2. Among patients with OCD, there was a positive correlation between relative antidepressant dose and sTNFr2 levels. Furthermore, although the levels of sTNFR1 correlated positively with the severity of washing symptoms, CCL24 levels correlated negatively with the severity of hoarding.

CONCLUSIONS

The levels of certain immune markers are increased in adult patients with OCD and seem to vary according to predominant symptoms dimensions. Other studies are required to establish whether our findings truly reflect immunologic dysfunction in OCD or are the result of other hidden confounding factors.

Endophenotypes and serotonergic polymorphisms associated with treatment response in obsessive-compulsive disorder

OBJECTIVES

Approximately 40-60% of obsessive-compulsive disorder patients are nonresponsive to serotonin reuptake inhibitors. Genetic markers associated with treatment response remain largely unknown. We aimed (1) to investigate a possible association of serotonergic polymorphisms in obsessive-compulsive disorder patients and therapeutic response to selective serotonin reuptake inhibitors and (2) to examine the relationship between these polymorphisms and endocrine response to intravenous citalopram challenge in responders and non-responders to serotonin reuptake inhibitors and in healthy volunteers.

METHODS

Patients with obsessive-compulsive disorder were classified as either responders or non-responders after long-term treatment with serotonin reuptake inhibitors, and both groups were compared with a control group of healthy volunteers. The investigated genetic markers were the G861C polymorphism of the serotonin receptor 1Dβ gene and the T102C and C516T polymorphisms of the serotonin receptor subtype 2A gene.

RESULTS

The T allele of the serotonin receptor subtype 2A T102C polymorphism was more frequent among obsessive-compulsive disorder patients (responders and non-responders) than in the controls (p<0.01). The CC genotype of the serotonin receptor subtype 2A C516T polymorphism was more frequent among the non-responders than in the responders (p<0.01). The CC genotype of the serotonin receptor subtype 1Dβ G681C polymorphism was associated with higher cortisol and prolactin responses to citalopram (p<0.01 and p<0.001, respectively) and with a higher platelet-rich plasma serotonin concentration among the controls (p<0.05). However, this pattern was not observed in the non-responders with the same CC genotype after chronic treatment with serotonin reuptake inhibitors. This CC homozygosity was not observed in the responders.

A preliminary randomized double-blind clinical trial on the efficacy of celecoxib as an adjunct in the treatment of obsessive-compulsive disorder

Obsessive-compulsive disorder is a common neuropsychiatric condition. Although a variety of pharmaceutical agents is available for its treatment, psychiatrists have found that many patients cannot tolerate the side effects, do not respond to treatment adequately, and may finally discontinue their treatment. However, augmentation strategies have been shown to have some benefits in the treatment of OCD. These include reducing both the overall cost of treatment and the side effects. The purpose of this study was to assess the efficacy of celecoxib as an adjuvant agent in the treatment of OCD in an 8-week, double-blind, placebo controlled trial. To this end, 25 patients were assigned to a study group and were given fluoxetine 20mg/day plus celecoxib 400mg/day (200mg BID). The control group included 25 patients who were given fluoxetine 20mg/day plus placebo. Both protocols significantly lowered scores on the Yale-Brown Obsessive-Compulsive Scale over the trial period. The combination of fluoxetine and celecoxib decreased the symptoms of obsessions and compulsions significantly more than fluoxetine plus placebo. The results of this study suggest that celecoxib can be an effective adjuvant agent in the management of patients with OCD; therefore, anti-inflammatory therapies should be further investigated.

Understanding rheumatic fever

Through a comprehensive review of the recent findings on rheumatic fever, we intend to propose a new physiopathologic model for this disease. A Medline search was performed for all articles containing the terms rheumatic fever or rheumatic heart disease in title or abstract from 1970 to 2011. Best evidence qualitative technique was used to select the most relevant. The scientific interest on rheumatic fever has notably diminished throughout the twentieth century as evidenced by the comparison of the proportion of articles in which RF was a subject in 1950 (0.26%) and today (0.03%) [Pubmed]. However, RF remains a major medical and social problem in the developing world and in the so-called hotspots, where it still causes around 500.000 deaths each year, not too different from the pre-antibiotic era. The role of genetic factors in RF susceptibility is discussed. Familiar aggregation, similarity of disease patterns between siblings, identical twin, and HLA correlation studies are evidence for a genetic influence on RF susceptibility. The suspect-involved genes fall mainly into those capable of immunologic mediation. Molecular mimicry explains the triggering of RF, but an intense and sustained inflammation is needed to cause sequels. Also, RF patients vary greatly in terms of symptoms. It is likely that a genetic background directing immune response towards a predominantly Th1 or Th2 pattern contributes to these features. The recent findings on rheumatic fever provide important insight on its physiopathology that helps understanding this prototype post-infectious autoimmune disease giving insights on other autoimmune conditions.

Association study between the -62A/T NFKBIL1 polymorphism and obsessive-compulsive disorder

OBJECTIVE

Evidence from family and molecular genetic studies support the hypothesis of involvement of immunologic mechanisms in the pathophysiology of obsessive-compulsive disorder. The nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-like 1 (NFKBIL1) has been suggested as a modulator of the immunological system. Given the importance of NFKBIL1 in the immunological response, the present study investigated the -62A/T polymorphism (rs2071592), located in the promoter region of its gene (NFKBIL1), as a genetic risk factor for the development of obsessive-compulsive disorder.

METHOD

The -62A/T NFKBIL1 polymorphism was investigated in a sample of 111 patients who met DSM-IV criteria for obsessive-compulsive disorder and 272 healthy age- and gender-matched controls.

RESULTS

There were no differences in genotypic distributions between patients and controls (chi2 = 0.98; 2 d.f.; p = 0.61).

DISCUSSION

Despite these negative findings, more comprehensive polymorphism coverage within the NFKBIL1 is warranted in larger samples. Populations with different ethnic backgrounds should also be studied.

CONCLUSION

The results of the present investigation do not provide evidence for the association between the -62A/T NFKBIL1 polymorphism and obsessive-compulsive disorder in this Brazilian sample.

Obsessive-compulsive disorder and its related disorders: a reappraisal of obsessive-compulsive spectrum concepts

Obsessive-compulsive disorder (OCD) is a clinical syndrome whose hallmarks are excessive, anxiety-evoking thoughts and compulsive behaviors that are generally recognized as unreasonable, but which cause significant distress and impairment. When these are the exclusive symptoms, they constitute uncomplicated OCD. OCD may also occur in the context of other neuropsychiatric disorders, most commonly other anxiety and mood disorders. The question remains as to whether these combinations of disorders should be regarded as independent, cooccurring disorders or as different manifestations of an incompletely understood constellation of OCD spectrum disorders with a common etiology. Additional considerations are given here to two potential etiology-based subgroups: (i) an environmentally based group in which OCD occurs following apparent causal events such as streptococcal infections, brain injury, or atypical neuroleptic treatment; and (ii) a genomically based group in which OCD is related to chromosomal anomalies or specific genes. Considering the status of current research, the concept of OCD and OCD-related spectrum conditions seems fluid in 2010, and in need of ongoing reappraisal.

Hematopoietic origin of pathological grooming in Hoxb8 mutant mice

Mouse Hoxb8 mutants show unexpected behavior manifested by compulsive grooming and hair removal, similar to behavior in humans with the obsessive-compulsive disorder spectrum disorder trichotillomania. As Hox gene disruption often has pleiotropic effects, the root cause of this behavioral deficit was unclear. Here we report that, in the brain, Hoxb8 cell lineage exclusively labels bone marrow-derived microglia. Furthermore, transplantation of wild-type bone marrow into Hoxb8 mutant mice rescues their pathological phenotype. It has been suggested that the grooming dysfunction results from a nociceptive defect, also exhibited by Hoxb8 mutant mice. However, bone marrow transplant experiments and cell type-specific disruption of Hoxb8 reveal that these two phenotypes are separable, with the grooming phenotype derived from the hematopoietic lineage and the sensory defect derived from the spinal cord cells. Immunological dysfunctions have been associated with neuropsychiatric disorders, but the causative relationships are unclear. In this mouse, a distinct compulsive behavioral disorder is associated with mutant microglia.

The Genetics of Obsessive-Compulsive Disorder

OCD is a psychiatric disorder with a lifetime prevalence of 1-3% and is a significant cause of disability worldwide. Family studies indicate that OCD has a significant hereditable component, with relatives of OCD cases being 4 times more likely to develop the disorder than the general population. Linkage studies in OCD have generally been underpowered and have failed to reach the statistical threshold for genome-wide significance, but they have nevertheless been useful for revealing potential regions of interest for future candidate gene studies. Candidate gene studies in OCD have thus far focused on genes involved in the serotonergic, dopaminergic, and glutamatergic pathways. These studies have been for the most part inconclusive, and failures to replicate have been the norm until very recently. The only genetic association replicated by multiple groups was with a glutamate transporter gene (SLC1A1). Genome-wide association studies in OCD are in progress, but final results have not yet been reported. As with the study of many other psychiatric disorders, an improved understanding of OCD will only be achieved (1) with larger collaborative efforts involving more probands, (2) the use of probands and controls drawn from epidemiologically-based populations rather than clinical samples, (3) developing a more precise phenotypic description of OCD and (4) measuring important environmental influences that affect OCD pathogenesis and severity.

A review of psychiatric genetics research in the Brazilian population

OBJECTIVE AND METHOD: A large increase in the number of Brazilian studies on psychiatric genetics has been observed in the 1970's since the first publications conducted by a group of researchers in Brazil. Here we reviewed the literature and evaluated the advantages and difficulties of psychiatric genetic studies in the Brazilian population. CONCLUSION: The Brazilian population is one of the most heterogeneous populations in the world, formed mainly by the admixture between European, African and Native American populations. Although the admixture process is not a particularity of the Brazilian population, much of the history and social development in Brazil underlies the ethnic melting pot we observe nowadays. Such ethnical heterogeneity of the Brazilian population obviously brings some problems when performing genetic studies. However, the Brazilian population offers a number of particular characteristics that are of major interest when genetic studies are carried out, such as the presence of isolated populations. Thus, differences in the genetic profile and in the exposure to environmental risks may result in different interactions and pathways to psychopathology.

Higher prevalence of obsessive-compulsive spectrum disorders in rheumatic fever

OBJECTIVE

This study aims to compare the prevalence of obsessive-compulsive spectrum disorders (OCSD) in psychiatric outpatients with and without a history of rheumatic fever (RF).

METHODS

An analytical cross-sectional study assessing a large sample of consecutive psychiatric outpatients at a Brazilian private practice was conducted during a 10-year period. Psychiatric diagnoses were made by a senior psychiatrist based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Best-estimate diagnosis procedure was also performed.

RESULTS

The total sample comprised 678 subjects, 13 of whom (1.92%) presented with a previous history of RF. This group showed a higher prevalence of subclinical obsessive-compulsive disorder (P=.025) and OCSD (P=.007) when compared to individuals with no such history.

CONCLUSIONS

A previous history of RF was associated with OCSD. These results suggest that clinicians should be encouraged to actively investigate obsessive-compulsive symptoms and related disorders in patients with a positive history of RF.