Immune Dysfunction in Schizophrenia Spectrum Disorders.

Evidence from epidemiological, clinical, and biological research resulted in the immune hypothesis: the hypothesis that immune system dysfunction is involved in the pathophysiology of schizophrenia spectrum disorders (SSD). The promising implication of this hypothesis is the potential to use existing immunomodulatory treatment for innovative interventions for SSD. Here, we provide a selective historical review of important discoveries that have shaped our understanding of immune dysfunction in SSD. We first explain the basic principles of immune dysfunction, after which we travel more than a century back in time. Starting our journey with neurosyphilis-associated psychosis in the nineteenth century, we continue by evaluating the role of infections and autoimmunity in SSD and findings from assessment of immune function using new techniques, such as cytokine levels, microglia density, neuroimaging, and gene expression. Drawing from these findings, we discuss anti-inflammatory interventions for SSD, and we conclude with a look into the future.

Diagnostic role of CXCL13 and CSF serology in patients with neurosyphilis.

BACKGROUND: Considering the unknown prevalence of neurosyphilis in West China, and the confusing diagnosis of neurosyphilis, the role of CSF_CXCL13 and syphilis serology was studied to provide a more accurate reference for the clinical detection and diagnosis of neurosyphilis. METHODS: A retrospective data set I was used to investigate the prevalence of neurosyphilis, as well as the laboratory characteristics of 244 patients. Besides, to explore the diagnostic value of CSF_CXCL13 and syphilis serology for neurosyphilis, another 116 CSF_serum paired samples (data set II) were collected from 44 neurosyphilis and 72 non-neurosyphilis/syphilis patients. RESULTS: About 6.25% (156 out of 2494) syphilis was neurosyphilis. When Treponema pallidum infection occurs, syphilis serology (sero_TRUST ≥1:16 and sero_TPPA titre ≥1:10240) can be good predictors of neurosyphilis, as well as syphilis CSF serology (CSF_TPPA ≥1:320, CSF_TRUST and venereal disease research laboratory). The sensitivity of serology in neurosyphilis can be complemented by CSF_CXCL13, which could be the therapy monitor of neurosyphilis. CONCLUSION: Due to the lack of ideal biomarkers for neurosyphilis, the importance of syphilis serology cannot be ignored, and their combination with CSF_CXCL13 or other biomarkers should be further investigated.

Cytokine and immune cell profiling in the cerebrospinal fluid of patients with neuro-inflammatory diseases.

BACKGROUND: Cytokines play multiple roles during neuro-inflammatory processes and several cytokines have been studied in the context of specific diseases. This study provides a comprehensive picture of cerebrospinal fluid (CSF) changes during neuro-inflammation by analyzing multiple cytokines in combination with immune cell subsets and standard CSF parameters. METHODS: Using multiplex assays, we simultaneously measured 36 cytokines (CCL1-3, CCL7, CCL8, CCL11, CCL13, CCL19, CCL20, CCL22-27, CXCL1, CXCL2, CXCL5, CXCL6, CXCL8, CXCL9, CXCL11-13, CXCL16, CX3CL1, IL2, IL4, IL6, IL10, IL16, GM-CSF, IFNγ, MIF, TNFα, and MIB1ß) in the CSF and serum of 75 subjects. Diagnoses included clinically isolated syndrome and relapsing-remitting multiple sclerosis (MS, n = 18), secondary progressive MS (n = 8), neuro-syphilis (n = 6), Lyme neuro-borreliosis (n = 13), bacterial and viral meningitis (n = 20), and patients with non-inflammatory neurological diseases (NIND, n = 10). Cytokine concentrations were correlated with CSF standard parameters and CSF immune cell subsets (CD4 and CD8 T cells, B cells, plasmablasts, monocytes, and NK cells) quantified by flow cytometry. RESULTS: We observed increased levels of multiple cytokines (26/36) in patients with neuro-inflammatory diseases when compared to NIND that consistently correlated with CSF cell count and QAlbumin. Most CSF cytokine concentrations correlated with each other, but correlations between CSF and serum values were scarce (3/36). Within the CSF compartment, CXCL13 showed a strong association with B cells when analyzing all patients, as well as patients with an intact blood-brain barrier (BBB). NK cells positively correlated with CSF concentrations of multiple cytokines (22/36) when analyzing all patients. These correlations were maintained when looking at patients with a disrupted BBB but not detectable in patients with an intact BBB. CONCLUSIONS: Under conditions of neuro-inflammation, multiple CSF cytokines are regulated in parallel and most likely produced locally. A combined increase of CSF CXCL13 levels and B cells occurs under conditions of an intact BBB. Under conditions of a disrupted BBB, CSF NK cells show significantly increased values and seem to have a major contribution to overall inflammatory processes, reflected by a strong correlation with multiple cytokines. Future studies are necessary to address the exact kinetics of these cytokines during neuro-inflammation and their relation to specific diseases phenotypes.

Risk of neurosyphilis in HIV-infected persons with syphilis lacking signs or symptoms of central nervous system infection.

OBJECTIVES: People living with HIV (PLWH) are at increased risk of asymptomatic neurosyphilis; thus, it has been common practice to perform a lumbar puncture (LP) in all PLWH presenting with syphilis regardless of stage, signs or symptoms. However, this practice varies widely among clinicians. Our objective was to elucidate the number of LPs required to diagnose a single case of asymptomatic neurosyphilis. METHODS: We performed an electronic health record (EHR) review of PLWH who were diagnosed with syphilis of any stage over a 10-year period. EHRs were reviewed to determine the number of subjects who had an LP performed, what proportion had neurological signs or symptoms, and whether a diagnosis of neurosyphilis was made at presentation or follow-up. RESULTS: In 261 separate episodes of syphilis in 230 subjects, we found the major risk factors for asymptomatic neurosyphilis to be low CD4 T-cell count (P = 0.0007), high rapid plasma reagin (RPR) titre (P = 0.019) and lack of HIV virological suppression (P = 0.003). The majority of our subjects (78%) with neurosyphilis presented with central nervous system (CNS) symptoms. We estimate, if standard practice is to perform LP in all patients, that the number needed to test (NNTT) = 38. CONCLUSIONS: This large number of potentially unnecessary LPs, along with heterogeneity of presentation, and the never-nil risk of asymptomatic neurosyphilis should be incorporated into clinical decision-making. The majority of PLWH presenting with a serological diagnosis of syphilis, but no neurological signs or symptoms, do not necessarily require an LP for an evaluation of asymptomatic neurosyphilis.

[Immunological markers of defeat of nervous tissue as an element of predictive model of damage of nervous system at syphilis.]

To develop predictive model of damage of nervous system on the basis of definition of concentration of interleukins-23, 12p40 and also a glial fibrillar acid protein (GFAP) in liquor of patients with various forms of syphilis. Comprehensive laboratory examination of patients with neurosyphilis and syphilis without specific damage of nervous system who were observed in venereologic office of BOUZAS of OO «Clinical Dermatovenerologic Clinic¼ of Omsk is conducted. To all patients were carried out: a serological blood analysis, serological and clinical trial of liquor, and also immunological research of liquor (interleukins - 23, 12p40, and also GFAP). On the basis of the research IL-23, SILT-12p40, GFAP, the level of protein and a pleocytosis in liquor the predictive model of development of neurosyphilis in patients with syphilis without specific damage of nervous system is offered. The analysis of immunological changes in liquor of patients showed that the research of a number of cytokines and markers of damage of nervous tissue to liquor as the most specific and reliable, especially in the absence of clinical symptomatology from central nervous system can be an integral part of diagnostics of neurosyphilis also.

Reported Cases of Neurosyphilis Among Early Syphilis Cases-United States, 2009 to 2015.

The surveillance of neurosyphilis, an uncommon but severe consequence of syphilis, is complex; surveillance classification of neurosyphilis requires a lumbar puncture and cerebrospinal fluid analysis. We examined the prevalence of reported neurosyphilis among primary, secondary, and early latent syphilis cases reported in the United States from 2009 to 2015. Overall, the prevalence of reported neurosyphilis from 2009 to 2015 was low (0.84%); however, this is likely an underestimate of the true burden in the United States.

Neurosyphilis and ophthalmic syphilis in persons with negative rapid plasma reagin and positive treponemal antibody test results.

The detection of serodiscordant syphilis test results raises several important clinical and public health questions. Based on our retrospective review, the probability of neurosyphilis in persons with serodiscordant serologies is low. The probability of ophthalmic syphilis may be higher, but we lack objective measures for that diagnosis.

Prevalence Estimates of Complicated Syphilis.

We reviewed 68 cases of possible neurosyphilis among 573 syphilis cases in King County, WA, from 3rd January 2012 to 30th September 2013; 7.9% (95% confidence interval, 5.8%-10.5%) had vision or hearing changes, and 3.5% (95% confidence interval, 2.2%-5.4%) had both symptoms and objective confirmation of complicated syphilis with either abnormal cerebrospinal fluid or an abnormal ophthalmologic examination.

Refining a non-invasive prediction model for neurosyphilis diagnosis by using immunoassay to detect serum anti-TP0435 (TP17) and TP0574 (TP47) IgG antibodies: two-centre cross-sectional retrospective study in China.

OBJECTIVES: Invasive lumbar puncture is the conventional method for diagnosing neurosyphilis (NS). We investigated a non-invasive alternative method to detect serum Treponema pallidum-specific antibodies against highly immunogenic antigens TP0171 (TP15), TP0435 (TP17), and TP0574 (TP47) by using luciferase immunosorbent assay. METHODS: A total of 816 HIV-negative patients suspected of NS from the Beijing and Guangzhou cohorts were retrospectively selected and tested for serum anti-TP15, TP17, and TP47 IgG antibodies. Two diagnostic prediction models were developed using stepwise logistic regression in the Beijing cohort, and evaluated in the Guangzhou cohort for external validation. RESULTS: Serum antibodies against TP15, TP17, and TP47 showed moderate capability for NS diagnosis in the Beijing cohort and the corresponding area under the receiver operating characteristic curves (AUCs) were 0.722 [95% confidence interval (CI): 0.680-0.762)], 0.780 (95% CI: 0.741-0.817), and 0.774 (95% CI: 0.734-0.811), respectively. An expanded NS prediction model integrated with anti-TP17 and anti-TP47 antibodies showed better performance than the base NS diagnostic model without anti-TP17 and anti-TP47 antibodies with the AUC of 0.874 (95% CI: 0.841-0.906) vs. 0.845 (95% CI: 0.809-0.881) (p = 0.007) in the development cohort, and 0.934 (95% CI: 0.909-0.960) vs. 0.877 (95% CI: 0.840-0.914) (p < 0.001) in validation cohort, respectively. Decision curve analysis revealed that the net benefit of the expanded model exceeded that of the base model when the threshold probability was between 0.10 and 0.95 in both the development and external validation cohorts. DISCUSSION: Serum antibodies against TP17 and TP47 exhibited promising diagnostic capability for NS and significantly enhanced the predictive accuracy of model for NS diagnosis. Our study highlights the potential of serum treponemal antibody detection as a non-invasive method for NS diagnosis to substitute invasive lumbar puncture in NS diagnosis.

Elevated cerebrospinal fluid interleukin-17A and interferon-γ levels in early asymptomatic neurosyphilis.

BACKGROUND: The mechanisms underlying the process of Treponema pallidum clearance from the central nervous system have not yet been established. Considering that neurosyphilis is associated with mild cerebrospinal fluid (CSF) pleocytosis with a lymphocytic predominance, it has been suggested that cells involved in the adaptive immune response may play a role in this process. In the current study, we assessed the cytokine production profile of T-helper cells in the serum and CSF of patients with early syphilis, with and without CSF abnormalities. METHODS: Cerebrospinal fluid and blood samples were collected from 33 patients with secondary and early latent syphilis. Five patients (15%) had a reactive CSF Venereal Disease Research Laboratory test without any accompanying neurological symptoms. According to the Centers of Disease Control and Prevention classification, they were diagnosed with asymptomatic neurosyphilis. Serum and CSF levels of interferon-γ (IFN-γ; Th1-type cytokine), interleukin-4 (IL-4; Th2-type cytokine), and interleukin-17A (IL-17A; Th17-type cytokine) were determined by enzyme-linked immunosorbent assay. RESULTS: Patients with asymptomatic neurosyphilis had significantly higher levels of IL-17A (8-fold) and IFN-γ (7.8-fold) in the CSF compared with patients in the no-neurosyphilis group. Six individuals had CSF pleocytosis but a negative CSF Venereal Disease Research Laboratory test result (presumptive neurosyphilis group). In this group, CSF IFN-γ and CSF IL-17A levels were also significantly elevated when compared with no-neurosyphilis group. There was no correlation between serum and CSF concentrations of IL-17A. However, CSF pleocytosis correlated positively with both CSF IL-17A (r = 0.4, P = 0.01) and IFN-γ (r = 0.42, P = 0.01). CONCLUSIONS: Increased CSF levels of IFN-γ and IL-17A in syphilitic patients with CSF abnormalities suggest that cells of adaptive immunity (probably T-helper cells producing IFN-γ and IL-17) may contribute to the inflammatory response associated with neurosyphilis. In addition, the lack of correlation between serum and CSF IL-17A levels suggests intrathecal production of this cytokine. Further studies are needed to establish the exact nature of the immune response accompanying neurosyphilis and its clinical significance.

Criteria for the diagnosis of neurosyphilis in cerebrospinal fluid: relationships with intrathecal immunoglobulin synthesis and blood-cerebrospinal fluid barrier dysfunction.

BACKGROUND: The origin of cerebrospinal fluid (CSF) syphilis antibodies (intrathecal or blood-derived) is in doubt. Little is known about CSF test behavior under the condition of physiological or disturbed functioning of blood-CSF barrier (BCB) and intrathecal immunoglobulin (Ig) production. METHODS: We collected 126 serum/CSF pairs from patients with serological evidence of syphilis. We explored the relationships between the established facts of intrathecal Ig synthesis and/or BCB dysfunction and the results of CSF diagnostic tests: the Treponema pallidum hemagglutination (TPHA) test, the fluorescent treponemal antibody absorption (FTA-Abs) test, the Venereal Disease Research Laboratory (VDRL) test, and white blood cell counts. We checked the criteria used either to support or refute the diagnosis of neurosyphilis. RESULTS: Reactive CSF-VDRL tests, elevated CSF-white blood cell counts, and elevated CSF-TPHA titers/indices were associated with the signs of intrathecal Ig synthesis, whereas nonreactive CSF-fluorescent treponemal antibody absorption, nonreactive CSF-TPHA tests, and CSF-TPHA titers from 1:4 to 1:160 were associated with cases where the intrathecal synthesis was not detected. There were some peculiarities of the tests toward BCB dysfunction.Most of reactive CSF-VDRL test samples and CSF samples with pleocytosis were also meeting at least 1 of the CSF-TPHA titer/indices-based criteria. T. pallidum hemagglutination indices were in no better conformity with the facts of intrathecal immune response than CSF-TPHA titers. CONCLUSIONS: Our findings have shown that all the examined criteria for the diagnosis of neurosyphilis in CSF are different assessment tools of intrathecal humoral immune activity and support the hypothesis that high CSF treponemal-specific antibody titers are a consequence of inflammatory pathology of the central nervous system.

Clinical spectrum of neurosyphilis among HIV-negative patients in the modern era.

BACKGROUND: The clinical spectrum of neurosyphilis (NS) has changed over time. OBJECTIVE: To describe the clinical spectrum and characteristics of NS in HIV-negative patients. METHODS: A retrospective chart review was performed for 149 in patients with NS. RESULT: All patients were >25 years old, including 16.8% asymptomatic for NS, 15.4% with syphilitic meningitis, 24.2% with meningovascular NS, 38.9% with general paresis, 4.0% with tabes dorsalis and 0.7% with gummatous NS. The original misdiagnosis rate was 84.6%. All 149 patients had positive serum Treponema pallidum particle agglutination (TPPA) and rapid plasma reagin (RPR). The overall positive rates of cerebrospinal fluid RPR (CSF-RPR) and CSF-TPPA were 57.0 and 89.9%, respectively. CSF pleocytosis and elevated CSF protein were found in 40.3% of patients. Nonspecific abnormal brain magnetic resonance imaging and electroencephalography findings were present in 60.4 and 54.8% of NS patients, respectively. CONCLUSIONS: NS has various clinical manifestations, laboratory findings and magnetic resonance imaging and electroencephalography findings, but all studies lack specificity. Every patient with neurological or psychiatric symptoms that are without unambiguous causes should have blood tests for syphilis. When serology proves positive, patients should undergo CSF examination.

The performance of cerebrospinal fluid treponemal-specific antibody tests in neurosyphilis: a systematic review.

BACKGROUND: No single laboratory test is both sensitive and specific to diagnose neurosyphilis. Several major clinical guidelines suggest that negative cerebrospinal fluid (CSF) treponemal-specific antibody tests rule out the diagnosis of neurosyphilis. Our aim was to systematically review the literature and describe the performance of treponemal-specific CSF antibody tests when diagnosing neurosyphilis. METHODS: Two reviewers independently assessed studies published in electronic databases, trial registries, and bibliographies for content and quality. Entry criteria included the assessment of treponemal-specific CSF tests currently used in clinical practice, and the use of standard criteria for both diagnosis and exclusion of neurosyphilis. The primary outcomes were sensitivity, specificity, and negative predictive values of treponemal-specific CSF antibody tests. RESULTS: Of 141 unique citations, 18 studies were included in the systematic review. Due to significant heterogeneity among studies, we were unable to generate pooled summary statistics. Seven different treponemal-specific tests were assessed. Of those, 13 studies evaluated the CSF FTA-ABS (fluorescent treponemal antibody-absorbed) and 9 evaluated the CSF fluorescent treponemal antibody. The performance estimates of these tests were highly variable and depended on the choice of negative and positive controls. No single test had perfect sensitivity, thus the negative predictive value was dependant on the specificity of the test and the prevalence (i.e., pretest probability) of neurosyphilis: the higher the prevalence, the lower the negative predictive value. Few studies included HIV-infected persons. CONCLUSIONS: A negative CSF-treponemal-specific antibody test may not exclude the diagnosis of neurosyphilis when the clinical suspicion for neurosyphilis is high.

[Western blot as a confirming test in the laboratory diagnosis of syphilis].

Two hundred and ninety-five patients who had been found to have Treponema pallidum antibodies detected by enzyme immunoassay were additionally studied by a Western blot test to confirm their presence. Every four cases were ascertained to be false-positive, false seropositivity being more frequent in the presence of IgM antibody against T. palladium. Spinal fluid analysis provided evidence for the course of neurosyphilis in 5 cases. The diagnosis of congenital syphilis was verified in 2 children who had p15, p17, p45, and 47. The findings demonstrate it necessary to extensively use a Western blot in the health care system.

Cerebrospinal fluid human immunodeficiency virus viral load in patients with neurosyphilis.

Syphilis is a frequent coinfection with human immunodeficiency virus (HIV). Whereas systemic syphilis infection increases plasma HIV RNA levels (viral load; VL), effects of syphilis on cerebrospinal fluid (CSF) VL are unknown. We hypothesized that intrathecal immune activation in neurosyphilis would selectively increase CSF VL in coinfected patients. In this study, HIV-infected research subjects (N = 225) were categorized into three groups based on serum rapid plasma reagin (RPR), microhemaglutination for Treponema pallidum (MHA-TP) MHA-TP, and CSF VDRL: 23 with neurosyphilis (NS+; reactive serum RPR and MHA-TP and positive CSF VDRL); 42 with systemic syphilis but not neurosyphilis (Syph+; reactive serum RPR and MHA-TP; negative CSF VDRL), and 160 without syphilis (Syph-; nonreactive serum RPR). Plasma and CSF HIV VL were quantified by reverse transcriptase-ploymerase chain reaction (RT-PCR) (Amplicor, Roche) in log(10) copies/ml. To adjust for covariates previously shown to influence CSF HIV VL (i.e., plasma VL, CD4, pleocytosis, and highly active antiretroviral therapy [HAART]), multivariable linear regression was used. Lumbar punctures (LP) done for research purposes diagnosed 23 with neurosyphilis; most (83%) of these reported prior syphilis treatment. Among subjects with detectable plasma VL, CSF VL was highest in NS+, followed by Syph+ and Syph- (P =.006). This relationship was independent of the level of plasma VL or CSF pleocytosis. By contrast, among subjects with undetectable plasma HIV VL, CSF VLs were similar in the three syphilis subgroups (P = .50). Neurosyphilis may amplify intrathecal HIV replication, possibly through immune activation that persists even after syphilis treatment. Because elevated CSF VL is associated with subsequent neurocognitive decline, future studies should evaluate the impact of neurosyphilis on the course of central nervous system (CNS) HIV infection.

Relevance in biology and mechanisms of immune and treatment evasion of Treponema pallidum.

INTRODUCTION: During syphilis a compelling fight is engaged between the host's humoral and cellular immune responses that work to eliminate the infection and Treponema pallidum (T. pallidum) that manages to evade eradication and cause chronic infection. Different mechanisms are utilized by treponemes to overcome immunological response. Although penicillin (BPG) proved to be effective in quelling the early manifestations of the disease and consequently its contagiousness, questions remain about its ability to prevent the late complications and to provide a microbiological eradication in vivo. In fact, both serological and microbiological failures have been reported following conventional treatment. EVIDENCE ACQUISITION: We reviewed some biologic properties of T. pallidum in order to establish a relationship with the persistence of the infection and the alleged treatment resistance. EVIDENCE SYNTHESIS: The host humoral response, sometimes, may not protect completely against T. pallidum and accounts for the persistent infection and tertiary damages. In fact, the cell mediated response during infection may be downregulate in response to pathogen-derived molecules, or indirectly by generating Treg cells. It is also possible that there are strain types of T. pallidum with higher ability of evasion determining neurosyphilis. In addition, apart the impressive results that BPG has made on the syphilis cutaneous lesions, concerns still remain on its efficacy in preventing late complications. CONCLUSIONS: Understanding the biology of the T. pallidum may help researchers in this field to develop future target therapies in order to prevent persistent infection and progression of the disease.

A comparison of nontreponemal tests in cerebrospinal fluid for neurosyphilis diagnosis: equivalent detection of specific antibodies.

BACKGROUND: Syphilis is a re-emerging sexually-transmitted infection, caused by the spirochete Treponema pallidum, that may penetrate early into the central nervous system. The venereal disease research laboratory test (VDRL) on the cerebrospinal fluid (CSF) is the most widely used for neurosyphilis diagnosis. We evaluated the performance of two other nontreponemal tests (rapid plasma reagin [RPR] and unheated serum reagin [USR] tests) in comparison with the VDRL in CSF. METHODS: We analyzed CSF samples from 120 individuals based on VDRL reactivity in the CSF and the clinical picture of neurosyphilis. RESULTS: High inter-rater reliability was found among all three tests, with equivalent sensitivity and specificity. Intraclass correlation coefficient for absolute agreement was 1 for VDRL versus USR, 0.99 for VDRL versus RPR, and 0.99 for RPR versus USR. CONCLUSIONS: Rapid plasma reagin and unheated serum reagin tests were identified as excellent alternatives for neurosyphilis diagnosis.

Concurrent aquaporin-4-positive NMOSD and neurosyphilis: A case report.

Neuromyelitis optica spectrum disorder (NMOSD) is a common neuroinflammatory demyelinating disease associated with aquaporin-4 (AQP4) antibody in the central nervous system. Neurosyphilis is a neurological disease caused by Treponema pallidum infection. NMOSD commonly occurs concurrently with autoimmune diseases. However, they have rarely been associated with infectious diseases. In this report we describe a rare case of concurrent AQP4-positive NMOSD and neurosyphilis. A 60-year-old man was admitted to our hospital with a complaint of progressive weakness in his legs for one month. T2-weighted magnetic resonance images of the spinal cord showed longitudinal extensive lesions at C7-T7. The rapid plasma reagin test and T. pallidum particle agglutination assay performed using patient serum and cerebrospinal fluid (CSF) were positive. Additionally, the AQP4-immunoglobulin (Ig) G was detected in the serum and CSF. The patient's symptom gradually improved after penicillin and methylprednisolone treatment. This case report highlights the possibility of the presence of an infectious disease in patients with NMOSD.