Autoimmune pathology accounts for common manifestations in a wide range of neuro-psychiatric disorders: the olfactory and immune system interrelationship. Clin Immunol. 2009;130:235-243. [PMID: 19097945 DOI: 10.1016/j.clim.2008.10.010]

Behavioural evidence for enhanced olfactory and trigeminal perception in congenital hearing loss

Sensory deprivation, especially hearing loss (HL), offers a valuable model for studying neuroplasticity in the human brain and adaptive behaviours that support the daily lives of those with limited or absent sensory input. The study of olfactory function is particularly important as it is an understudied aspect of sensory deprivation. This study aimed to compare the effects of congenital HL on olfactory capacity by using psychophysical tasks. Methodological concerns from previous studies regarding the onset of HL and cognitive assessments were addressed. We recruited 11 individuals with severe-to-profound sensorineural HL (SNHL) since birth and 11 age- and sex-matched typical hearing non-signers. We used standardized neuropsychological tests to assess typical cognition among participants with SNHL. We evaluated olfactory functions by assessing olfactory detection threshold, odour discrimination and odour identification. Hearing-impaired participants outperformed their typical hearing counterparts in olfactory tasks. We further evaluated the accuracy and response time in identifying and localizing odours to disentangle olfactory sensitivity from trigeminal system sensitivity. Participants with SNHL demonstrated higher sensitivity to both the identification and localization tasks. These findings suggest that congenital SNHL is associated with enhanced higher-level olfactory processing and increased trigeminal sensitivity.

Association between cognitive impairment and olfactory deficits in systemic lupus erythematosus without major neuropsychiatric syndromes

OBJECTIVE

The aim of the study was to investigate the utility of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), evaluate cognitive deficits in systemic lupus erythematosus (SLE) patients and examine the relationship between cognitive and olfactory functions.

METHODS

55 SLE patients and 50 healthy controls were administered by RBANS including five indexes: immediate memory (IMME), visuospatial/constructional (Vis/Con), language (LANG), attention (ATT), and delayed memory (DEME). Olfactory functions were evaluated by computerized testing including three stages of smell: threshold (THR), identification (ID), and memory (ME) of different odors. The disease activity and cumulative damage were assessed by the SLE Disease Activity Index 2000 (SLEDAI-2K) and the Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index (SDI).

RESULTS

SLE patients exhibited significant lower total RBANS scores, IMME, Vis/Con, ATT, and DEME index scores than healthy controls (p < 0.01 for all and p = 0.027 for attention). Reduced RBANS scores were associated with several organ involvement and autoantibodies. SLE patients with higher SLEDAI-2K scores or with accumulated damage (SDI≥1) showed decreased RBANS scores. All the olfactory scores in SLE patients were significantly decreased than controls (p = 0.001). Patients had higher proportion of anosmia (8.57% vs 0%) and hyposmia (28.58% vs 5.72%) than controls (χ2 = 10.533, p = 0.015). Multivariable regression analysis revealed that olfactory functions had a positive effect on RBANS index scores. Olfactory memory and total scores were significantly correlated with the DEME (r = 0.393, p = 0.021) and total scores (r = 0.429, p = 0.011).

CONCLUSION

This study indicates that significantly cognitive and olfactory functions are impaired in SLE patients. The RBANS is a potentially useful instrument for evaluating neuropsychological status in SLE. Physicians are encouraged to perform routine screening in SLE patients to detect subtle cognitive dysfunction.

Oxidative stress and neuroimmune proteins in a mouse model of autism

Oxidative stress including decreased antioxidant enzyme activities, elevated lipid peroxidation, and accumulation of advanced glycation end products in the blood from children with autism spectrum disorders (ASD) has been reported. The mechanisms affecting the development of ASD remain unclear; however, toxic environmental exposures leading to oxidative stress have been proposed to play a significant role. The BTBRT+Itpr3tf/J (BTBR) strain provides a model to investigate the markers of oxidation in a mouse strain exhibiting ASD-like behavioral phenotypes. In the present study, we investigated the level of oxidative stress and its effects on immune cell populations, specifically oxidative stress affecting surface thiols (R-SH), intracellular glutathione (iGSH), and expression of brain biomarkers that may contribute to the development of the ASD-like phenotypes that have been observed and reported in BTBR mice. Lower levels of cell surface R-SH were detected on multiple immune cell subpopulations from blood, spleens, and lymph nodes and for sera R-SH levels of BTBR mice compared to C57BL/6 J (B6) mice. The iGSH levels of immune cell populations were also lower in the BTBR mice. Elevated protein expression of GATA3, TGM2, AhR, EPHX2, TSLP, PTEN, IRE1α, GDF15, and metallothionein in BTBR mice is supportive of an increased level of oxidative stress in BTBR mice and may underpin the pro-inflammatory immune state that has been reported in the BTBR strain. Results of a decreased antioxidant system suggest an important oxidative stress role in the development of the BTBR ASD-like phenotype.

Epilepsy, Immunity and Neuropsychiatric Disorders

Several studies have focused on the emerging role of immunity and inflammation in a wide range of neurological disorders. Autoimmune diseases involving central nervous system share well defined clinical features including epileptic seizures and additional neuropsychiatric symptoms, like cognitive and psychiatric disturbances. The growing evidence about the role of immunity in the pathophysiologic mechanisms underlying these conditions lead to the concept of autoimmune epilepsy. This relatively-new term has been introduced to highlight the etiological and prognostic implications of immunity in epileptogenesis. In this review, we aim to discuss the role of autoimmunity in epileptogenesis and its clinical, neurophysiological, neuroimaging and therapeutic implications. Moreover, we wish to address the close relationship between immunity and additional symptoms, particularly cognitive and psychiatric features, which deeply impact clinical outcomes in these patients. To assess these aspects, we first analyzed Rasmussen's encephalitis. Subsequently, we have covered autoimmune encephalitis, particularly those associated with autoantibodies against surface neuronal antigens, as these autoantibodies express a direct immune-mediated mechanism, different from those against intracellular antigens. Then, we discussed the connection between systemic immune disorders and neurological manifestations. This review aims to highlight the need to expand knowledge about the role of inflammation and autoimmunity in the pathophysiology of neurological disorders and the importance to early recognize these clinical entities. Indeed, early identification may result in faster recovery and a better prognosis.

Assessment of Hearing and Vestibular Functions in a Post-COVID-19 Patient: A Clinical Case Study

SARS-CoV-2 infection may cause such complications as post-COVID-19 syndrome, which includes chronic fatigue, myalgia, arthralgia, as well as a variety of neurological manifestations, e.g., neuropathy of small fibers, hearing and vestibular dysfunction, and cognitive impairment. This clinical case describes a 41-year-old patient suffering from post-COVID-19 syndrome and chronic fatigue syndrome. A detailed examination was performed, including an in-depth study of peripheral and central hearing and vestibular functions, as well as small nerve fibers length and density in the skin and cornea of the eye. Contrary to expectations, no peripheral nervous system dysfunction was detected, despite the presence of dizziness and gait instability in the patient. Hearing tests (gap detection test and dichotic test) showed central auditory processing disorders. The evaluated lesion in the processing of temporal and verbal auditory information can be a significant factor contributing to additional overload of the neural activity and leading to chronic fatigue when performing daily activities in patients with CFS and post-COVID-19 complications.

Neuropsychiatric lupus erythematosus: Focusing on autoantibodies

Patients with systemic lupus erythematosus (SLE) frequently suffer from nervous system complications, termed neuropsychiatric lupus erythematosus (NPLE). NPLE accounts for the poor prognosis of SLE. Correct attribution of NP events to SLE is the primary principle in managing NPLE. The vascular injuries and neuroinflammation are the fundamental neuropathologic changes in NPLE. Specific autoantibody-mediated central nerve system (CNS) damages distinguish NPLE from other CNS disorders. Though the central antibodies in NPLE are generally thought to be raised from the periphery immune system, they may be produced in the meninges and choroid plexus. On this basis, abnormal activation of microglia and disease-associated microglia (DAM) should be the common mechanisms of NPLE and other CNS disturbances. Improved understanding of both characteristic and sharing features of NPLE might yield further options for managing this disease.

A cross-sectional healthy-control study of serum inflammatory biomarkers interleukin (IL)-1B and IL-2R in panic disorder patients and their offspring

Alterations in the immune system have been associated with a variety of mental illnesses. An increase in circulating inflammatory cytokines is observed not only in people with mental disorders but also in their first-degree relatives. A considerable amount of data support the link between immune system activation and panic disorder (PD) pathogenesis, while it is still unclear whether differential immunological reactivity represents a propensity, a measure of disease activity, or both. To better understand the role of cytokines in PD pathophysiology, we compared the levels of serum inflammatory biomarkers interleukin (IL)-1B and IL-2R among PD patients, offspring of PD patients and healthy controls. The offspring of PD patients were evaluated by a psychiatrist and were considered unaffected by any mental disorder at the time of the evaluation. Concentrations of the cytokines IL-1B and IL-2R were assessed using the Immulite System (Diagnostic Products Corporation). The levels of proinflammatory markers IL-1B and IL-2R were increased in PD patients compared to those of controls, but offspring of PD patients and healthy controls demonstrated no differences regarding peripheral interleukin levels. Our findings suggest that interleukins might represent a disease-dependent marker in PD.

Not Only COVID-19: Involvement of Multiple Chemosensory Systems in Human Diseases

Chemosensory systems are deemed marginal in human pathology. In appraising their role, we aim at suggesting a paradigm shift based on the available clinical and experimental data that will be discussed. Taste and olfaction are polymodal sensory systems, providing inputs to many brain structures that regulate crucial visceral functions, including metabolism but also endocrine, cardiovascular, respiratory, and immune systems. Moreover, other visceral chemosensory systems monitor different essential chemical parameters of “milieu intérieur,” transmitting their data to the brain areas receiving taste and olfactory inputs; hence, they participate in regulating the same vital functions. These chemosensory cells share many molecular features with olfactory or taste receptor cells, thus they may be affected by the same pathological events. In most COVID-19 patients, taste and olfaction are disturbed. This may represent only a small portion of a broadly diffuse chemosensory incapacitation. Indeed, many COVID-19 peculiar symptoms may be explained by the impairment of visceral chemosensory systems, for example, silent hypoxia, diarrhea, and the “cytokine storm”. Dysregulation of chemosensory systems may underlie the much higher mortality rate of COVID-19 Acute Respiratory Distress Syndrome (ARDS) compared to ARDSs of different origins. In chronic non-infectious diseases like hypertension, diabetes, or cancer, the impairment of taste and/or olfaction has been consistently reported. This may signal diffuse chemosensory failure, possibly worsening the prognosis of these patients. Incapacitation of one or few chemosensory systems has negligible effects on survival under ordinary life conditions but, under stress, like metabolic imbalance or COVID-19 pneumonia, the impairment of multiple chemosensory systems may lead to dire consequences during the course of the disease.

Olfactory threshold predicts treatment response in relapsing multiple sclerosis

Background:

Olfactory threshold (OT) is associated with short-term inflammatory activity in relapsing multiple sclerosis (RMS).

Objective:

We aimed to investigate OT for prediction of treatment response in RMS.

Methods:

In this 5-year prospective study on 123 RMS patients, OT was measured at disease-modifying treatment (DMT) initiation (M0), after 3 months (M3), and 12 months (M12) by Sniffin’ Sticks test. Primary endpoint was defined as an absence of relapse during the observation period, with Expanded Disability Status Scale (EDSS) progression and magnetic resonance imaging (MRI) activity being the secondary endpoints. Optimal cutoff values were determined by receiver operating characteristic analyses and their predictive value assessed by multivariable Cox regression models.

Results:

Higher OT scores at M0, M3, and M12 were independently associated with decreased relapse probability with the strongest risk reduction at M3 (hazard ratio (HR) = 0.44, p < 0.001). Improvement of OT scores from M0 to M3 (ΔOTM3) was also associated with reduced relapse risk (HR = 0.12, p < 0.001). OT score > 6.5 at M3 was the strongest predictor of relapse freedom (HR = 0.10, p < 0.001) with high diagnostic accuracy (positive predictive value (PPV) = 87%), closely followed by ΔOTM3 ⩾ 0.5 (HR = 0.12, p < 0.001, PPV = 86%).

Conclusions:

OT is an independent predictor of freedom of disease activity upon DMT initiation within 5 years and may be a useful biomarker of treatment response.

MOSES: A New Approach to Integrate Interactome Topology and Functional Features for Disease Gene Prediction

Disease gene prediction is to date one of the main computational challenges of precision medicine. It is still uncertain if disease genes have unique functional properties that distinguish them from other non-disease genes or, from a network perspective, if they are located randomly in the interactome or show specific patterns in the network topology. In this study, we propose a new method for disease gene prediction based on the use of biological knowledge-bases (gene-disease associations, genes functional annotations, etc.) and interactome network topology. The proposed algorithm called MOSES is based on the definition of two somewhat opposing sets of genes both disease-specific from different perspectives: warm seeds (i.e., disease genes obtained from databases) and cold seeds (genes far from the disease genes on the interactome and not involved in their biological functions). The application of MOSES to a set of 40 diseases showed that the suggested putative disease genes are significantly enriched in their reference disease. Reassuringly, known and predicted disease genes together, tend to form a connected network module on the human interactome, mitigating the scattered distribution of disease genes which is probably due to both the paucity of disease-gene associations and the incompleteness of the interactome.

Seizures in systemic lupus erythematosus: A scoping review

Systemic lupus erythematosus is a systemic autoimmune disease that affects the central nervous system, either by direct neuronal damage, injury to brain vessels, or by pathogenic mechanisms indirectly induced by immune mechanisms related to the production and deposition of immune complexes. The prevalence of explicit episodes of seizures among SLE patients, varies from 2 to 8%. In some cases, patients with positivity for antiphospholipid or anti-β2 glycoprotein antibodies are found to be more prone to exhibit seizures compared to seronegative patients, other subjects at risk are carries of gene abnormalities codifying for ion channels. The exclusion of vasculitis or thrombosis is required for accurate treatment, imaging studies and alternative sequences are mandatory in patients with known SLE who present with a seizure. Several statements regarding SLE-related seizure remain to be decoded. In this scoping review we analyzed published information about prevalence, pathogenesis, clinical characteristics, diagnostic and therapeutic SLE patients that manifest a seizure, our objective is to provide with useful information for prompt diagnosis and individualized treatment.

Development of the Spanish Version of Sniffin's Sticks Olfactory Identification Test: Normative Data and Validity of Parallel Measures

The Sniffin' Sticks Olfactory Identification Test is a tool for measurement of olfactory performance developed in Germany and validated in several countries. This research aims to develop the Spanish version of the Sniffin' Sticks Olfactory Identification Test and obtain normative values for the Spanish population. The parameters are free recall and subjective intensity of odorants are included. The influence of possible demographic covariates such as sex, age, smoking, or educational level are analyzed, and the items that best discriminate are studied. In addition, the internal structure validity of the blue and purple versions is studied as a parallel measure, and a cultural adaptation of the purple version is carried out. For this, three independent samples of normosmic healthy volunteers were studied. To obtain normative values, the sample was of 417 participants (18-89 years). For the internal structure validity study of both versions, the sample was 226 (18-70 years), and for familiarity of the purple version, the sample was 75 participants (21-79 years). Results indicated that men and women and smokers and non-smokers perform equally. However, differences were found as age progresses, being more pronounced after 60 years old in all three measurements of the identification test. This research also provides the items that best discriminate in the blue version and a cultural adaptation for the purple version. In conclusion, the Sniffin' Sticks Odor Identification Test is a suitable tool for olfactory assessment in the Spanish population. The instrument has been expanded with two new scores, and normative data as a function of age are provided. Its parallel version also seems appropriate for testing, as items have been culturally adapted and evidence of internal structure validity for both versions is reported.

Inner nuclear layer and olfactory threshold are interlinked and reflect inflammatory activity in multiple sclerosis

Background

Retinal inner nuclear layer (INL) and olfactory threshold (OT) are associated with inflammatory activity in multiple sclerosis (MS).

Objective

The study aims to investigate (a) whether there is an association of INL and OT in MS and (b) if changes in INL and OT follow a time pattern in relation to MS relapse.

Methods

We assessed INL by optical coherence tomography and OT by Sniffin' Sticks in three different cohorts: a cross-sectional MS cohort (n = 260), a longitudinal, 3-year cohort of MS (n = 141) and healthy controls (n = 30), and a longitudinal, 24-weeks cohort with acute MS relapse (n = 28) and stable MS controls (n = 27).

Results

Cross-sectionally, INL and OT were strongly correlated with number but not localization of relapse in the previous 12 months and INL correlated with OT. Longitudinally, INL was thicker and OT score was lower short term in times of relapse activity, but not long term and independent of relapse localization. In acute MS relapse, INL and OT were altered compared with stable MS, again, independent of relapse localization resolving over 12-24 weeks with faster approximation to stable MS after escalation of disease-modifying treatment.

Conclusions

INL and OT are interlinked markers of short-term inflammatory activity, following a nearly congruent time pattern and independent of relapse localization, possibly reflecting a proinflammatory state within the central nervous system.

Neurobiology of sensory processing in autism spectrum disorder

Altered sensory processing and perception has been one of the characteristics of autism spectrum disorder (ASD). In this chapter, we review the neural underpinnings of sensory abnormalities of ASD by examining the literature on clinical, behavioral and neurobiological evidence that underlies the main patterns of sensory integration function and dysfunction. Furthermore, neural differences in anatomy, function and connectivity of different regions underlying sensory processing are also discussed. We conclude that sensory integration intervention is built on the premise of neuroplasticity to improve function and behavior for individuals with ASD.

Immunity and autoantibodies of a mouse strain with autistic-like behavior

Female and male mice of the BTBR T ⁺ Itpr3 ^tf /J (BTBR) strain have behaviors that resemble autism spectrum disorder. In comparison to C57BL/6 (B6) mice, BTBR mice have elevated humoral immunity, in that they have naturally high serum IgG levels and generate high levels of IgG antibodies, including autoantibodies to brain antigens. This study focused on the specificities of autoantibodies and the immune cells and their transcription factors that might be responsible for the autoantibodies. BTBR IgG autoantibodies bind to neurons better than microglia and with highest titer to nuclear antigens. Two of the antigens identified were alpha-enolase (ENO1) and dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex, mitochondrial (DLST). Surprisingly based on IgG levels, the blood and spleens of BTBR mice have more CD4⁺ and CD8⁺ T cells, but fewer B cells than B6 mice. The high levels of autoantibodies in BTBR relates to their splenic T follicular helper (Tfh) cell levels, which likely are responsible for the higher number of plasma cells in BTBR mice than B6 mice. BTBR mice have increased gene expression of interleukin-21 receptor (I l -21 r) and Paired Box 5 (Pax5), which are known to aid B cell differentiation to plasma cells, and an increased Lysine Demethylase 6B (Kdm6b)/DNA Methyltransferase 1 (Dnmt1) ratio, which increases gene expression. Identification of gene expression and immune activities of BTBR mice may aid understanding of mechanisms associated with autism since neuroimmune network interactions have been posited and induction of autoantibodies may drive the neuroinflammation associated with autism.

Neuropsychiatric lupus: new mechanistic insights and future treatment directions

Patients with systemic lupus erythematosus (SLE) frequently show symptoms of central nervous system (CNS) involvement, termed neuropsychiatric SLE (NPSLE). The CNS manifestations of SLE are diverse and have a broad spectrum of severity and prognostic implications. Patients with NPSLE typically present with nonspecific symptoms, such as headache and cognitive impairment, but might also experience devastating features, such as memory loss, seizures and stroke. Some features of NPSLE, in particular those related to coagulopathy, have been characterized and an evidence-based treatment algorithm is available. The cognitive and affective manifestations of NPSLE, however, remain poorly understood. Various immune effectors have been evaluated as contributors to its pathogenesis, including brain-reactive autoantibodies, cytokines and cell-mediated inflammation. Additional brain-intrinsic elements (such as resident microglia, the blood-brain barrier and other neurovascular interfaces) are important facilitators of NPSLE. As yet, however, no unifying model has been found to underlie the pathogenesis of NPSLE, suggesting that this disease has multiple contributors and perhaps several distinct aetiologies. This heterogeneity presents a challenge for clinicians who have traditionally relied on empirical judgement in choosing treatment modalities for patients with NPSLE. Improved understanding of this manifestation of SLE might yield further options for managing this disease.

Audio-visual and olfactory-visual integration in healthy participants and subjects with autism spectrum disorder

The human capacity to integrate sensory signals has been investigated with respect to different sensory modalities. A common denominator of the neural network underlying the integration of sensory clues has yet to be identified. Additionally, brain imaging data from patients with autism spectrum disorder (ASD) do not cover disparities in neuronal sensory processing. In this fMRI study, we compared the underlying neural networks of both olfactory-visual and auditory-visual integration in patients with ASD and a group of matched healthy participants. The aim was to disentangle sensory-specific networks so as to derive a potential (amodal) common source of multisensory integration (MSI) and to investigate differences in brain networks with sensory processing in individuals with ASD. In both groups, similar neural networks were found to be involved in the olfactory-visual and auditory-visual integration processes, including the primary visual cortex, the inferior parietal sulcus (IPS), and the medial and inferior frontal cortices. Amygdala activation was observed specifically during olfactory-visual integration, with superior temporal activation having been seen during auditory-visual integration. A dynamic causal modeling analysis revealed a nonlinear top-down IPS modulation of the connection between the respective primary sensory regions in both experimental conditions and in both groups. Thus, we demonstrate that MSI has shared neural sources across olfactory-visual and audio-visual stimulation in patients and controls. The enhanced recruitment of the IPS to modulate changes between areas is relevant to sensory perception. Our results also indicate that, with respect to MSI processing, adults with ASD do not significantly differ from their healthy counterparts.

Mysterious effects of olfactory pathway lesions on intestinal immunodeficiency targeting Peyer's patches: The first experimental study

BACKGROUND

Although olfaction has been considered as important neuroimmunomodulatory foundation, there is no satisfying analytical information between neurohistomorphological features olfactory networks and intestinal immune system hardwares. We studied if the olfactory bulb lesions (OBL) may rely on histopathological features of intestinal lymphatic Peyer's patches in an animal model.

METHODS

Thirty-two rats were grouped as control (Group I, n = 8), SHAM (Group II, n = 7) and OBL (Group III, n = 17) respectively; and followed eight weeks and animals were decapitated. The olfactory bulbs and intestines were extracted. Specimens stained with hematoxylin/eosin and GFAP methods and analyzed Stereologically to evaluate volume loss of olfactory bulbs and Peyer's patches volumes (PV) of intestines per cubic millimeter and compared with each other's statistically.

RESULTS

The mean olfactory bulbs volumes were estimated as 3.65 ± 0.32/mm³ in group I, 3.12 ± 0.20/mm³ in group II and 2.21 ± 0.15/mm³ in group III (p < 0.0005 Group III vs. I and II). The mean of PV were estimated as; (9 ± 2) × 10⁶ µm³/cm³ in Group-I, (12 ± 3) × 10⁶ µm³/cm³ in Group-II; and (23 ± 4) × 10⁶ µm³/cm³ in group-III (p < 0.005 Group II vs. I, p < 0.0005 Group III vs. I-II).

CONCLUSIONS

OBL could rely on intestinal immunodeficiency causing by olfaction loss induced denervation injury of Peyer's patches.

Smelling multiple sclerosis: Different qualities of olfactory function reflect either inflammatory activity or neurodegeneration

Background:

Peripapillary retinal nerve fiber layer (pRNFL) thickness and olfactory function are both emerging biomarkers in multiple sclerosis (MS). Impairment of odor identification and discrimination is an irreversible feature of more advanced MS suggested to be associated with neurodegeneration, while olfactory threshold is a transient feature of early, active MS possibly associated with short-term inflammatory disease activity.

Objective:

The aim of this study was to validate the association of olfactory (dys)function and parameters of MS disease course in a large cohort of MS patients and to correlate olfactory function with pRNFL thickness as a surrogate biomarker of neurodegeneration.

Methods:

In a cross-sectional design, olfactory function was assessed using the Sniffin’ Sticks test, which quantifies three different qualities of olfactory function (threshold, discrimination, and identification). pRNFL thickness was measured by spectral-domain optical coherence tomography (OCT). Results were correlated with age, sex, disease duration, relapses, Expanded Disability Status Scale (EDSS), cognitive function, depression, smoking, and pRNFL thickness by multivariable linear regression models.

Results:

We included 260 MS patients (mean age of 35.9 years, 68.7% female). Olfactory threshold correlated significantly with number of relapses in the year prior to assessment and shorter disease duration. Odor discrimination, identification, and their sum score were significantly correlated with longer disease duration, higher EDSS, and reduced cognitive function. pRNFL thickness was associated with identification and discrimination, but not with threshold.

Conclusion:

Olfactory threshold is a marker of short-term inflammatory relapse activity unrelated to parameters of neurodegeneration, while odor identification and discrimination are markers of neurodegeneration mostly independent of relapse activity. Assessment of olfactory function provides an opportunity to stratify MS patients with regard to inflammation and neurodegeneration.

Change of olfactory function as a marker of inflammatory activity and disability progression in MS

BACKGROUND

Impaired olfactory threshold has been reported in early inflammatory phases of MS, while impaired odor identification was associated with more widespread disability.

OBJECTIVE

To prospectively assess the development of olfactory function and its correlation with relapse and disability progression.

METHODS

In this prospective, 3-year longitudinal study on 151 MS patients and 30 healthy controls, three different qualities of olfactory function (threshold, discrimination, and identification) were quantified using the Sniffin' Sticks test. The influence of relapses and disability on olfactory function was analyzed at different time points and in a multivariate model.

RESULTS

Discrimination and identification capability significantly worsened over 3 years, while threshold did not. Threshold was markedly impaired in patients with relapse activity within 12 months, recovered in the absence of relapse, and was associated with a 2.5-fold increased risk of relapse. Deterioration of discrimination and identification was irreversible and both strongly associated with and predictive of EDSS progression.

CONCLUSION

Olfactory function changes over time in MS. Threshold impairment is transient and predicts inflammatory disease activity, while odor identification and discrimination are associated with disability progression. Olfactory dysfunction might be a useful and easily obtainable parameter to monitor patients with regard to inflammation and neurodegeneration in MS.

Neuropsychiatric SLE: from animal model to human

Animal models are a key element in disease research and treatment. In the field of neuropsychiatric lupus research, inbred, transgenic and disease-induced mice provide an opportunity to study the pathogenic routes of this multifactorial illness. In addition to achieving a better understanding of the immune mechanisms underlying the disease onset, supplementary metabolic and endocrine influences have been discovered and investigated. The ever-expanding knowledge about the pathologic events that occur at disease inception enables us to explore new drugs and therapeutic approaches further and to test them using the same animal models. Discovery of the molecular targets that constitute the pathogenic basis of the disease along with scientific advancements allow us to target these molecules with monoclonal antibodies and other specific approaches directly. This novel therapy, termed "targeted biological medication" is a promising endeavor towards producing drugs that are more effective and less toxic. Further work to discover additional molecular targets in lupus' pathogenic mechanism and to produce drugs that neutralize their activity is needed to provide patients with safe and efficient methods of controlling and treating the disease.

Infectious, atopic and inflammatory diseases, childhood adversities and familial aggregation are independently associated with the risk for mental disorders: Results from a large Swiss epidemiological study

AIM

To examine the associations between mental disorders and infectious, atopic, inflammatory diseases while adjusting for other risk factors.

METHODS

We used data from PsyCoLaus, a large Swiss Population Cohort Study (n = 3720; age range 35-66). Lifetime diagnoses of mental disorders were grouped into the following categories: Neurodevelopmental, anxiety (early and late onset), mood and substance disorders. They were regressed on infectious, atopic and other inflammatory diseases adjusting for sex, educational level, familial aggregation, childhood adversities and traumatic experiences in childhood. A multivariate logistic regression was applied to each group of disorders. In a complementary analysis interactions with sex were introduced via nested effects.

RESULTS

Associations with infectious, atopic and other chronic inflammatory diseases were observable together with consistent effects of childhood adversities and familial aggregation, and less consistent effects of trauma in each group of mental disorders. Streptococcal infections were associated with neurodevelopmental disorders (men), and measles/mumps/rubella-infections with early and late anxiety disorders (women). Gastric inflammatory diseases took effect in mood disorders (both sexes) and in early disorders (men). Similarly, irritable bowel syndrome was prominent in a sex-specific way in mood disorders in women, and, moreover, was associated with early and late anxiety disorders. Atopic diseases were associated with late anxiety disorders. Acne (associations with mood disorders in men) and psoriasis (associations with early anxiety disorders in men and mood disorders in women) contributed sex-specific results. Urinary tract infections were associated with mood disorders and, in addition, in a sex-specific way with late anxiety disorders (men), and neurodevelopmental and early anxiety disorders (women).

CONCLUSION

Infectious, atopic and inflammatory diseases are important risk factors for all groups of mental disorders. The sexual dimorphism of the associations is pronounced.

Integrative analysis of genetic data sets reveals a shared innate immune component in autism spectrum disorder and its co-morbidities

BACKGROUND

Autism spectrum disorder (ASD) is a common neurodevelopmental disorder that tends to co-occur with other diseases, including asthma, inflammatory bowel disease, infections, cerebral palsy, dilated cardiomyopathy, muscular dystrophy, and schizophrenia. However, the molecular basis of this co-occurrence, and whether it is due to a shared component that influences both pathophysiology and environmental triggering of illness, has not been elucidated. To address this, we deploy a three-tiered transcriptomic meta-analysis that functions at the gene, pathway, and disease levels across ASD and its co-morbidities.

RESULTS

Our analysis reveals a novel shared innate immune component between ASD and all but three of its co-morbidities that were examined. In particular, we find that the Toll-like receptor signaling and the chemokine signaling pathways, which are key pathways in the innate immune response, have the highest shared statistical significance. Moreover, the disease genes that overlap these two innate immunity pathways can be used to classify the cases of ASD and its co-morbidities vs. controls with at least 70 % accuracy.

CONCLUSIONS

This finding suggests that a neuropsychiatric condition and the majority of its non-brain-related co-morbidities share a dysregulated signal that serves as not only a common genetic basis for the diseases but also as a link to environmental triggers. It also raises the possibility that treatment and/or prophylaxis used for disorders of innate immunity may be successfully used for ASD patients with immune-related phenotypes.

Olfactory dysfunction in Multiple Sclerosis: A scoping review of the literature

OBJECTIVE

Olfactory dysfunction in Multiple Sclerosis (MS) has been reported, but results have been inconsistent. In this review we describe, synthesize, and interpret the existing literature on olfactory dysfunction in Multiple Sclerosis and identify gaps in the current level of knowledge.

METHODS

The study design was a scoping review of the literature covering several study designs. Systematic Searches of the PubMed, CINAHL, Cochrane Library, Web of Science, PsycARTICLES, PsycINFO and Google Scholar databases were conducted that included key words related to Multiple Sclerosis and Olfaction Disorders. Literature that met the criteria of pertaining to both Multiple Sclerosis and olfactory dysfunction was identified, with the aim of providing an overview of the extent and types of research available in this area.

RESULTS

Sixty-one reports were identified in the initial search, with 40 meeting the study criteria. Twenty-five clinical studies were included. Among them, 23 studies measured for olfactory dysfunction in MS patients, ten evaluated MRI correlates of olfactory dysfunction, and five evaluated neurophysiology correlates of olfactory dysfunction. Six of the included studies were abstracts. In addition, thirteen reviews/commentaries and two case studies were included. The majority of the studies identified some degree of olfactory dysfunction in MS patients, and various aspects and correlations with olfactory impairment were observed.

CONCLUSIONS

The overall weight of the literature suggests that olfactory dysfunction may occur in MS. Although there is variability in reported frequency, the more robust studies suggest the prevalence is significant, ranging from 20% to 45% in the MS population. Despite this, the mechanisms are unknown and the clinical relevance of this association has not been well explored. Interesting findings relating mood disorders, cognition, and olfactory dysfunction in MS are also suggested but remain poorly developed and require further investigation. Future studies are also warranted to understand the dynamic changes in olfactory function during the course of MS, and to correlate olfactory function with relapses/disease activity.

Olfactory impairment in patients with the fibromyalgia syndrome and systemic sclerosis

Patients with autoimmune diseases often present with olfactory impairment. The aim of the study was to assess the olfactory functions of female patients with fibromyalgia (FM) compared with patients with systemic sclerosis (SSc) and with healthy female controls. Olfactory functions were assessed in 24 patients with FM, 20 patients with SSc and 21 age-matched healthy controls. The sense of smell was evaluated using the Sniffin' Sticks test including the three stages of smell: threshold, discrimination, and identification (TDI) of the different odors. The severity of fibromyalgia was assessed using the fibromyalgia impact questionnaire (FIQ). The short form 36 (SF-36) questionnaire was also completed in order to seek a relationship between the patients perception of quality of life and the different aspects of the smell sense. Depression was evaluated in both FM and SSc patients utilizing the Beck depression inventory-II (BDI-II) questionnaire. Patients with FM had significantly lower TDI smell scores compared with both SSc patients and healthy controls (p < 0.005, One-Way ANOVA). Hyposmia (defined as TDI scores below 30) were observed in 14 of 24 (42 %) patients with FM compared to 3 of 20 (15 %) patients with SSc and 1 of the healthy controls (4.3 %) (p < 0.02). FM patients had significantly lower thresholds of smell compared to both healthy controls and patients with SSc (p < 0.001), whereas for patients with SSc only the ability to discriminate between odors was impaired (p < 0.006). We could not detect any statistical correlation between smell abilities and clinical manifestation of SSc or the FIQ and SF-36 scores among FM patients. However the correlation between depression, defined by the BDI-II score, and the sense of smell differed between patients with FM and patients with SSc. As only among SSc patients a lower sense of smell correlated with a higher BDI-II score (p = 0.02). Our findings suggest that there is a decrease in the sense of smell both in FM and SSc patients compared with healthy controls. However these impairments differ between patients group and might represent different mechanisms that affect the sense of smell.

The optimal evaluation and management of patients with a gradual onset of olfactory loss

PURPOSE OF REVIEW

The aim of this review is to provide an overview of the causes of olfactory dysfunction, their evaluation and management, with a main focus on the gradual/progressive loss of smell.

RECENT FINDINGS

As the sense of smell gives us essential information about our environment, its loss can cause nutritional and social problems while threatening an individual's safety. Recent surveys have shown quite a substantial prevalence of hyposmia (one out of four people) and anosmia (one out of 200 people) in a variety of populations.

SUMMARY

Nasal inflammatory diseases such as allergic rhinitis and predominantly chronic rhinosinusitis account for the major and common causes of gradual/progressive loss of smell. However, they are also among the most successfully treated forms of olfactory dysfunction. The management of gradual/progressive smell deficit must always address its etiological causes. In most cases, a detailed medical history and nasal examination, smell testing, and imaging will help to establish an appropriate diagnosis. In addition to anti-inflammatory therapy, mainly nasal and systemic corticosteroids, recent investigations on smell training suggest that the controlled exposure to selected odors may increase olfactory performance.

VIDEO ABSTRACT AVAILABLE

See the Video Supplementary Digital Content 1 (http://links.lww.com/COOH/A8).

Fox smell abrogates the effect of herbal odor to prolong mouse cardiac allograft survival

Background

Herbal medicines have unique odors, and the act of smelling may have modulatory effects on the immune system. We investigated the effect of olfactory exposure to Tokishakuyaku-san (TJ-23), a Japanese herbal medicine, on alloimmune responses in a murine model of cardiac allograft transplantation.

Methods

Naïve or olfactory-dysfunctional CBA mice underwent transplantation of a C57BL/6 heart and were exposed to the odor of TJ-23 until rejection. Some naïve CBA recipients of an allograft were given olfactory exposure to Sairei-to (TJ-114), trimethylthiazoline (TMT), individual components of TJ-23, or a TJ-23 preparation lacking one component. Adoptive transfer studies were performed to determine whether regulatory cells were generated.

Results

Untreated CBA mice rejected their C57BL/6 allografts acutely, as did olfactory-dysfunctional CBA mice exposed to the odor of TJ-23. CBA recipients of a C57BL/6 heart given olfactory exposure to TJ-23 had significantly prolonged allograft survival, whereas those exposed to the odor of TJ-114, TMT, one component of TJ-23, or TJ-23 lacking a component did not. Secondary allograft recipients that were given, at 30 days after transplantation, either whole splenocytes, CD4⁺ cells, or CD4⁺CD25⁺ cells from primary recipients exposed to the odor of TJ-23 had indefinitely prolonged allograft survival.

Conclusions

Prolonged survival of cardiac allografts and generation of regulatory cells was associated with exposure to the odor of TJ-23 in our model. The olfactory area of the brain may have a role in the modulation of immune responses.

Possible link between Toxoplasma gondii and the anosmia associated with neurodegenerative diseases

Toxoplasma gondii is an intracellular protozoan infecting 30% to 50% of global human population. Recently, it was suggested that chronic latent neuroinflammation caused by the parasite may be responsible for the development of several neurodegenerative diseases manifesting with the loss of smell. Studies in animals inoculated with the parasite revealed cysts in various regions of the brain, including olfactory bulb. Development of behavioral changes was paralleled by the preferential persistence of cysts in defined anatomic structures of the brain, depending on the host, strain of the parasite, its virulence, and route of inoculation. Olfactory dysfunction reported in Alzheimer's disease, multiple sclerosis, and schizophrenia was frequently associated with the significantly increased serum anti-T gondii immunoglobulin G antibody levels. Damage of the olfactory system may be also at least in part responsible for the development of depression because T gondii infection worsened mood in such patients, and the olfactory bulbectomized rat serves as a model of depression.

Autoantibodies against neuronal progenitors in sera from children with autism

The pathological role of autoantibodies in development of CNS disorders is a new idea with growing interest among neuroscientists. The involvement of autoimmune response in the pathogenesis of autism spectrum disorders (ASD) has been suggested by the presence of multiple brain-specific autoantibodies in children with ASD and in their mothers. The possibility of the effect of autoimmunity on neurogenesis and postnatal brain plasticity has not been determined. The presence of autoantibodies against human neuronal progenitor cells (NPCs) stimulated for neuronal differentiation in culture was tested in sera from children with autism (n=20) and age-matched controls (n=18) by immunoblotting and immunocytochemistry. Immunoreactivity against multiple NPCs proteins of molecular sizes of approximately 55 kDa, 105 kDa, 150 kDa, and 210 kDa in sera from individuals with autism had a higher incidence and was stronger than in control sera which immunoreacted mainly with a 150 kDa protein. The sera from children with autism immunoreacted the strongest with NPCs expressing neuronal markers Tuj1 and doublecortin, but not astrocyte marker GFAP. The epitopes recognized by antibodies from sera were not human-specific because they detected also NPCs in situ in murine hippocampus. The autoimmune reactions against NPCs suggest an impaired tolerance to neural antigens in autism. These autoantibodies may be symptomatic for autism and furthermore, their presence suggests that autoimmunity may affect postnatal neuronal plasticity particularly after impairment of blood-brain barrier. Future studies will determine the diagnostic value of the presence of autoantibodies in autism and the therapeutic value of prevention of autoimmunity in autism.

Chapter 13: Olfactory disorders

Decreased sense of smell can lead to significant impairment of quality of life, including taste disturbance and loss of pleasure from eating with resulting changes in weight, and difficulty in avoiding health risks such as spoiled food or leaking natural gas. Recent epidemiological reports have shown that despite fairly low self-reported prevalence of these disorders in large population studies, when validated smell identification or threshold tests are used they reveal quite a high prevalence of hyposmia and anosmia in certain groups, especially the elderly. Several different pathophysiological processes, such as head trauma, aging, autoimmunity, and toxic exposures, can contribute to smell impairment, with distinct implications concerning prognosis and possible treatment. Otolaryngologists are most likely to see this symptom in patients with chronic rhinosinusitis, and this now appears to be caused more by the mucosal inflammation than by physical airway obstruction.

Immune dysregulation and autoimmunity in bipolar disorder: Synthesis of the evidence and its clinical application

OBJECTIVE

Increasing evidence suggests that inflammation and immune dysregulation play an important role in the pathogenesis of bipolar disorder. Because the brain can be affected by various autoimmune processes, it is possible that some psychiatric disorders may have an autoimmune basis.

METHOD

This article reviews the literature on peripheral and central immune dysregulation and autoimmunity in bipolar disorder. The mechanisms of the innate and adaptive immune systems in the pathophysiology of bipolar disorder are explored. The clinical features and pathogenesis of neuropsychiatric systemic lupus erythematosus, anti-NMDA encephalitis, and Hashimoto's encephalopathy are summarized.

RESULTS

Neuroinflammation and peripheral immune dysregulation may play a role in the pathophysiology of bipolar disorder. This involves a complex interaction between immune cells of the central nervous system and periphery resulting in cellular damage through mechanisms involving excitotoxicity, oxidative stress, and mitochondrial dysfunction. Neuropsychiatric systemic lupus erythematosus, anti-NMDA encephalitis, and Hashimoto's encephalopathy are important differentials for a psychiatrist to consider when suspecting autoimmune encephalopathy.

CONCLUSIONS

The link between immune dysregulation, autoimmunity, and bipolar disorder may be closer than previously thought. Psychiatrists should be vigilant for autoimmunity in presentations of bipolar disorder due to its high morbidity and therapeutic implications. Advances in neuroimaging and biomarker identification related to immune dysregulation and neuroinflammation will contribute to our knowledge of the pathophysiology of bipolar disorder.

Association between antibodies to multiple infectious and food antigens and new onset schizophrenia among US military personnel

INTRODUCTION

Multiple studies have documented immune activation in many individuals with schizophrenia suggesting that antigens capable of generating a prolonged immune response may be important environmental factors in many cases of this disorder. While existing studies have found single-agent associations of antibodies to food and neurotropic infectious agents with schizophrenia, a simultaneous examination of multiple agents may shed light on agent interactions or possible etiopathogenic pathways.

METHODS

We used traditional regression and novel statistical techniques to examine associations of single and combined infectious and food antigens with schizophrenia. We tested 6106 serum samples from 855 cases and 1165 matched controls.

RESULTS

Higher antibody levels to casein were borderline significant in the prediction of schizophrenia (HR=1.08, p=0.06). Study participants with higher cytomegalovirus (CMV) IgG antibody levels had a reduced risk of developing schizophrenia (HR=0.90; p=0.02). While IgG antibodies to gliadin, Toxoplasma gondii, vaccinia, measles, and human herpesvirus-6 (HHV-6) showed no significant independent associations with schizophrenia, the increase in antibody levels to several combinations of agents, to include casein, measles, CMV, T. gondii and vaccinia, was predictive of an 18-34% increase in the risk of developing schizophrenia.

CONCLUSION

Certain patterns of antibodies, involving some agents, were predictive of developing schizophrenia, with the magnitude of association rising when the level of antibodies increased to two or more agents. A heightened antibody response to a combination of several infectious/food antigens might be an indicator of an altered immune response to antigenic stimuli.

The smell of Tokishakuyaku-san (TJ-23) induces generation of regulatory T cells and prolongation of survival of fully allogeneic cardiac grafts in mice

Oral administration of Tokishakuyaku-san (TJ-23), a Japanese herbal medicine, induces prolongation of cardiac allograft survival and generates regulatory cells in mice. Because herbal medicines usually have unique odor, and because smell is supposed to modulate the immune system, we examined whether the odor of TJ-23 induced prolonged allograft survival and regulatory cell generation. Naïve CBA mice (H2(k)) and olfactory-dysfunctional CBA mice after a stereotaxic operation underwent transplantation of C57BL/6 (B6, H2(b)) hearts, receiving fumigated water only or TJ-23 until rejection. Untreated or treated with water fumigation CBA mice rejected B6 cardiac grafts acutely (median survival times [MSTs], 7 and 8.5 days). When CBA mice were treated with fumigation of TJ-23, allograft survival was significantly prolonged (MST, 48 days). Olfactory-dysfunctional CBA mice treated with fumigation of TJ-23 rejected grafts acutely (MST, 7 days). Treatment with fumigation of TJ-23 also suppressed splenocytes proliferation and interferon-γ production. Secondary CBA recipients of whole splenocytes or CD4(+) cells from primary TJ-23-treated CBA recipients of B6 cardiac allografts at 30 days after grafting showed prolonged survival of B6 hearts (MST, >60 days). Flow cytometry studies showed increased CD4(+)CD25(+)Foxp3(+) regulatory cells in recipients given fumigation of TJ-23. In conclusion naïve but not olfactory-dysfunctional CBA mice treated with fumigation of TJ-23 displayed prolonged survival of fully allogeneic cardiac allografts and generation of regulatory cells.

An automated framework for hypotheses generation using literature

Background

In bio-medicine, exploratory studies and hypothesis generation often begin with researching existing literature to identify a set of factors and their association with diseases, phenotypes, or biological processes. Many scientists are overwhelmed by the sheer volume of literature on a disease when they plan to generate a new hypothesis or study a biological phenomenon. The situation is even worse for junior investigators who often find it difficult to formulate new hypotheses or, more importantly, corroborate if their hypothesis is consistent with existing literature. It is a daunting task to be abreast with so much being published and also remember all combinations of direct and indirect associations. Fortunately there is a growing trend of using literature mining and knowledge discovery tools in biomedical research. However, there is still a large gap between the huge amount of effort and resources invested in disease research and the little effort in harvesting the published knowledge. The proposed hypothesis generation framework (HGF) finds “crisp semantic associations” among entities of interest - that is a step towards bridging such gaps.

Methodology

The proposed HGF shares similar end goals like the SWAN but are more holistic in nature and was designed and implemented using scalable and efficient computational models of disease-disease interaction. The integration of mapping ontologies with latent semantic analysis is critical in capturing domain specific direct and indirect “crisp” associations, and making assertions about entities (such as disease X is associated with a set of factors Z).

Results

Pilot studies were performed using two diseases. A comparative analysis of the computed “associations” and “assertions” with curated expert knowledge was performed to validate the results. It was observed that the HGF is able to capture “crisp” direct and indirect associations, and provide knowledge discovery on demand.

Conclusions

The proposed framework is fast, efficient, and robust in generating new hypotheses to identify factors associated with a disease. A full integrated Web service application is being developed for wide dissemination of the HGF. A large-scale study by the domain experts and associated researchers is underway to validate the associations and assertions computed by the HGF.

Immunology, autoimmunity, and autoantibodies in Parkinson's disease

Recent revelations of immune alterations in Parkinson's disease have led to the convergence that an autoimmune mechanism may play a role in the etiopathogenesis of this neurodegenerative disease. In the current study, 77 Parkinson's disease patients and 77 matched healthy controls were analyzed for the presence of seven autoantibodies previously found to be associated with central nervous system manifestations namely: antineuronal-cells, anti-brain lysate, anti-dsDNA, anti-phosphatidylserine, anti-cardiolipin, anti-serotonin, and anti-melanocytes antibodies. Patients underwent systematic assessments of demographics, clinical, and biochemical manifestations. Three autoantibodies were found to be more prevalent among Parkinson's disease patients (antineuronal cells10.3% vs. 1.3%, p = 0.017; anti-brain lysate 9.1% vs. 1.3%, p = 0.032; anti-dsDNA 10.3% vs. 2.6%, p = 0.049). Clinical manifestations of Parkinson's disease, particularly dyskinesia and depression, were found to be associated with the presence of these autoantibodies.

Altered olfactory function in the MRL model of CNS lupus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that damages several bodily systems, including the CNS. Brain atrophy and diverse neuropsychiatric manifestations are common and serious complications of SLE. Recently, it has been reported that many patients with CNS involvement also present with olfactory deficits of unknown etiology. Similar to CNS SLE, spontaneous development of lupus-like disease in MRL/lpr mice is accompanied by neurodegeneration in periventricular regions and a constellation of behavioral deficits dependent on olfaction. To test the possibility that olfactory dysfunction also occurs in autoimmune mice, we presently examine odor-guided behaviors using a battery of paradigms. Indeed, lupus-prone males spent less time exploring unfamiliar conspecifics and demonstrated age-dependant performance deficits when exposed to low concentrations of attractant and repellant odors. The emergence of olfactory changes was associated with a skewed distribution of DCX(+) cells in the proximal portion of the rostral migratory stream (RMS). The present results are consistent with the hypothesis that the onset of a SLE-like condition affects periventricular regions, including the RMS, as evidenced by disrupted migration of neuronal precursor cells toward the olfactory bulb. If so, ensuing hyposmia and/or olfactory memory deficit may contribute to altered performance in other behavioral tasks and reflect a prodrome of brain damage induced by chronic autoimmune disease.

Prevalence and clinical significance of anti-ribosomal P antibody in childhood-onset systemic lupus erythematosus

Objective: To investigate the prevalence of the anti-ribosomal P (anti-P) antibodies in childhood-onset systemic lupus erythematosus patients (cSLE), healthy controls and first degree relatives. To elucidate the association between anti-P and disease activity, laboratory and treatment features in cSLE patients. Methods: We included consecutive SLE patients with disease onset before 16 years. Controls were age- and sex-matched. SLE patients were assessed for clinical and laboratory SLE manifestations, disease activity (SLE Disease Activity Index (SLEDAI)), damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI)) and current drug exposures. Mood disorders were determined through Becks Depression and Becks Anxiety Inventory. Anti-P measured by enzyme-linked immunosorbent assay. Results: We included 50 consecutive cSLE patients (mean age of 16.82 ± 3.46 years), 35 first degree relatives (mean age of 38.73 ± 3.89 years) and 20 health control (mean age of 18.3 ± 4.97 years). Anti-P was observed in 13 (26%) cSLE patients and in no first-degree relative ( p < 0.01) or control ( p < 0.01). Anti-P was more frequently observed in patients with anxiety ( p < 0.002). No other clinical, laboratory or treatment features, including SLEDAI and SDI scores were associated with the presence of anti-P in cSLE patients. Conclusion: Anti-P is frequently observed in cSLE patients and was associated with the presence of anxiety in this cohort of cSLE.

Olfactory dysfunction in Parkinson disease

Olfactory dysfunction is among the earliest nonmotor features of Parkinson disease (PD). Such dysfunction is present in approximately 90% of early-stage PD cases and can precede the onset of motor symptoms by years. The mechanisms responsible for olfactory dysfunction are currently unknown. As equivalent deficits are observed in Alzheimer disease, Down syndrome, and the Parkinson-dementia complex of Guam, a common pathological substrate may be involved. Given that olfactory loss occurs to a lesser extent or is absent in disorders such as multiple system atrophy, corticobasal degeneration, and progressive supranuclear palsy, olfactory testing can be useful in differential diagnosis. The olfactory dysfunction in PD and a number of related diseases with smell loss correlates with decreased numbers of neurons in structures such as the locus coeruleus, the raphe nuclei, and the nucleus basalis of Meynart. These neuroanatomical findings, together with evidence for involvement of the autonomic nervous system in numerous PD-related symptoms, suggest that deficits in cholinergic, noradrenergic and serotonergic function may contribute to the olfactory loss. This Review discusses the current understanding of olfactory dysfunction in PD, including factors that may be related to its cause.

Low serum IgA and increased expression of CD23 on B lymphocytes in peripheral blood in children with regressive autism aged 3-6 years old

INTRODUCTION

Immune system dysfunction is considered to be one of many medical disorders found in children with autism. The primary objective of the study was to assess if blood tests reflecting humoral immunity (IgA, IgG, IgM, IgE) are useful in identifying children with regressive autism. The secondary objective was to evaluate a part of the cellular arm of immunity (CD4/CD25 Tregs, CD4/CD23 cells) in those children.

MATERIAL AND METHODS

Using a clinical case-control design, the systemic levels of immunoglobulins and lymphocyte subpopulations analysed by flow cytometry were compared in children aged 3-6 years old with a new diagnosis of regressive autism (n = 24; mean age: 4.25 ±1.70 years; male 23/24) and in sex- and age-matched healthy children (n = 24; aged 4.25 ±2.20 years; male 23/24).

RESULTS

The humoral immunity profile, described by three binary variables, IgA < 0.97 g/l, IgE > 36 IU/ml, and IgG > 6.3 g/l, with a sensitivity of 79% and a specificity of 83% (p < 0.0001), was able to identify children with autism. The highest risk of autism diagnosis was associated with IgA < 0.97g/l (OR - 23.0; p < 0.001). A higher number of CD19/CD23 was found in children diagnosed with autism than in the control group (36.82 ±6.72% vs. 18.20 ±3.95%; p < 0.02). No correlation between the number of CD23-positive cells and serum IgE levels was observed.

CONCLUSIONS

A subtle shift of serum immunoglobulins consisting of low-normal IgA and B cell activation expressed by an increase of CD23-positive cells may characterize children with regressive autism aged 3-6 years old.

Neuromelanin is an immune stimulator for dendritic cells in vitro

Background

Parkinson's disease (PD) is characterized at the cellular level by a destruction of neuromelanin (NM)-containing dopaminergic cells and a profound reduction in striatal dopamine. It has been shown recently that anti-melanin antibodies are increased in sera of Parkinson patients, suggesting that NM may act as an autoantigen. In this study we tested whether NM is being recognized by dendritic cells (DCs), the major cell type for inducing T- and B-cell responses in vivo. This recognition of NM by DCs is a prerequisite to trigger an adaptive autoimmune response directed against NM-associated structures.

Results

Murine DCs were treated with NM of substantia nigra (SN) from human subjects or with synthetic dopamine melanin (DAM). DCs effectively phagocytized NM and subsequently developed a mature phenotype (CD86^high/MHCII^high). NM-activated DCs secreted the proinflammatory cytokines IL-6 and TNF-α. In addition, they potently triggered T cell proliferation in a mixed lymphocyte reaction, showing that DC activation was functional to induce a primary T cell response. In contrast, DAM, which lacks the protein and lipid components of NM but mimics the dopamine-melanin backbone of NM, had only very little effect on DC phenotype and function.

Conclusions

NM is recognized by DCs in vitro and triggers their maturation. If operative in vivo, this would allow the DC-mediated transport and presentation of SN antigens to the adaptive immune system, leading to autoimmmunity in susceptible individuals. Our data provide a rationale for an autoimmune-based pathomechanism of PD with NM as the initial trigger.

Aberrant immune responses in a mouse with behavioral disorders

BTBR T+tf/J (BTBR) mice have recently been reported to have behaviors that resemble those of autistic individuals, in that this strain has impairments in social interactions and a restricted repetitive and stereotyped pattern of behaviors. Since immune responses, including autoimmune responses, are known to affect behavior, and individuals with autism have aberrant immune activities, we evaluated the immune system of BTBR mice, and compared their immunity and degree of neuroinflammation with that of C57BL/6 (B6) mice, a highly social control strain, and with F1 offspring. Mice were assessed at postnatal day (pnd) 21 and after behavioral analysis at pnd70. BTBR mice had significantly higher amounts of serum IgG and IgE, of IgG anti-brain antibodies (Abs), and of IgG and IgE deposited in the brain, elevated expression of cytokines, especially IL-33 IL-18, and IL-1β in the brain, and an increased proportion of MHC class II-expressing microglia compared to B6 mice. The F1 mice had intermediate levels of Abs and cytokines as well as social activity. The high Ab levels of BTBR mice are in agreement with their increased numbers of CD40(hi)/I-A(hi) B cells and IgG-secreting B cells. Upon immunization with KLH, the BTBR mice produced 2-3 times more anti-KLH Abs than B6 mice. In contrast to humoral immunity, BTBR mice are significantly more susceptible to listeriosis than B6 or BALB/c mice. The Th2-like immune profile of the BTBR mice and their constitutive neuroinflammation suggests that an autoimmune profile is implicated in their aberrant behaviors, as has been suggested for some humans with autism.

Association between bovine casein antibody and new onset schizophrenia among US military personnel

Schizophrenia is a pervasive neuropsychiatric disorder of uncertain etiology. Multiple studies have documented immune activation in individuals with schizophrenia. One antigen capable of inducing a prolonged immune response is bovine casein derived from ingested milk products. Increased levels of casein antibodies have been found in individuals with schizophrenia after diagnosis. This study was directed at determining the potential association between schizophrenia and pre-illness onset levels of immunoglobulin G (IgG) antibodies to bovine casein. Parallel analyses for casein antibody levels with bipolar disorder were included as comparison. Cases were service members who received medical discharges from the military with a schizophrenia diagnosis from 1992 to 2005. Serum specimens were selected for 855 cases and 1165 matched healthy controls. IgG antibodies to bovine whole-casein were measured by solid phase enzyme-linked immunosorbent assays (ELISAs). Hazard ratios (HR) were calculated to examine the associations of casein IgG level with risk of schizophrenia by time to diagnosis and by subjects' initial level. Increasing casein IgG antibody levels among those with a high initial level, drawn before diagnosis, was associated with an 18% increase in the hazard risk of schizophrenia per unit increase (value of low-positive standard) in IgG antibody levels (HR=1.18; 95% CI 1.04, 1.34). This is the first report to identify an association between the risk of schizophrenia and elevated antibodies to bovine casein prior to disease onset. Additional research is required to elucidate the complex genetic environmental interactions involved in the pathogenesis of schizophrenia and to identify potentially modifiable risk factors.

Olfactory threshold is impaired in early, active multiple sclerosis

Background: Olfactory dysfunction has been reported in multiple sclerosis (MS). However, to date no data are available on different qualities of olfactory function, namely odour identification, odour discrimination and odour perception threshold.

Objective: To assess different qualities of olfactory function in patients with MS and correlate these with demographic data, clinical data, depression, quality of life and cognitive functions.

Methods: In this cross-sectional study, 50 patients with MS or clinically isolated syndrome and 30 healthy controls were included. Olfactory function was measured using the Sniffin’ Sticks test.

Results: The scores for odour identification ( p = 0.001), odour perception threshold ( p = 0.037) and the combined score of odour identification, discrimination and perception threshold (TDI, p = 0.002) were significantly lower in MS. Hyposmia for identification ( p = 0.0017), threshold ( p = 0.017) and TDI score ( p = 0.0014) was more frequent in MS. Olfactory threshold was impaired in patients who were clinically active in the previous year ( p = 0.026) and in patients with a disease duration less than 2 years ( p = 0.0093). Identification score was negatively correlated with disease duration ( p = 0.0017). Olfactory function was not associated with disability, depression or quality of life.

Conclusions: We report evidence for qualitatively distinct hyposmia in MS, with increased smell threshold in the early inflammatory phases of the disease and impaired identification with a more widespread chronic disease.

Evidence of impaired sense of smell in hereditary angioedema

BACKGROUND

Hereditary angioedema (HAE) is an autosomal-dominant disorder resulting from C1-inhibitor (C1INH) deficiency. Smell impairments were found in patients affected with systemic lupus erythematosus, that, similarly to HAE, is characterized by the activation of the classical complement pathway with C4 consumption. In this study, we aimed at evaluating the sense of smell in patients with HAE.

METHODS

Thirty patients with HAE and 30 healthy age- and sex-matched controls were evaluated for olfactory functions using the 3-stages Sniffin'-Sticks kit (threshold, discrimination, and identification [TDI]). TDI scores were analyzed according to complement levels (C1INH, C3, C4 and CH50), Beck depression inventory (BDI-II) and danazol treatment.

RESULTS

A significant decrease in olfactory function was observed in patients affected with HAE compared with controls in total TDI score (P < 0.001), and in the discrimination (P < 0.001) and identification scores (P = 0.012). Anosmia was present only in patients with HAE (3.3%) who also exhibited more frequently hyposmia (53.3%vs 3.3%, P < 0.0001). Complement levels were reduced in patients with HAE. C4 serum levels showed positive correlation with total TDI score (P < 0.001), and with discrimination (P = 0.002) and identification (P = 0.011) scores. CH50 complement levels showed positive correlation with total TDI score (P < 0.001), and with threshold (P = 0.002) and discrimination (P = 0.011) scores. Sex, age, danazol treatment, BDI-II scores were not different between the patients and controls and did not influence TDI scores significantly.

CONCLUSION

Evidence for an impaired sense of smell was found in patients with HAE. The reduction in olfactory function in these cases seems to correlate with complement C4 and CH50 levels. Immune and genetic mechanisms might play a role in this defect.