Canadian Public Health Laboratory Network laboratory guidelines for the diagnosis of neurosyphilis in Canada

Diagnosis of neurosyphilis in HIV-negative patients with syphilis: development, validation, and clinical utility of a suite of machine learning models

Background

The ability to accurately identify the absolute risk of neurosyphilis diagnosis for patients with syphilis would allow preventative and therapeutic interventions to be delivered to patients at high-risk, sparing patients at low-risk from unnecessary care. We aimed to develop, validate, and evaluate the clinical utility of simplified clinical diagnostic models for neurosyphilis diagnosis in HIV-negative patients with syphilis.

Methods

We searched PubMed, China National Knowledge Infrastructure and UpToDate for publications about neurosyphilis diagnostic guidelines in English or Chinese from database inception until March 15, 2023. We developed and validated machine learning models with a uniform set of predictors based on six authoritative diagnostic guidelines across four continents to predict neurosyphilis using routinely collected data from real-world clinical practice in China and the United States (through the Dermatology Hospital of Southern Medical University in Guangzhou [659 recruited between August 2012 and March 2022, treated as Development cohort], the Beijing Youan Hospital of Capital Medical University in Beijng [480 recruited between December 2013 and April 2021, treated as External cohort 1], the Zhongshan Hospital of Xiamen University in Xiamen [493 recruited between November 2005 and November 2021, treated as External cohort 2] from China, and University of Washington School of Medicine in Seattle [16 recruited between September 2002 and April 2014, treated as External cohort 3] from United States). We included all these patients with syphilis into our analysis, and no patients were further excluded. We trained eXtreme gradient boosting (XGBoost) models to predict the diagnostic outcome of neurosyphilis according to each diagnostic guideline in two scenarios, respectively. Model performance was measured through both internal and external validation in terms of discrimination and calibration, and clinical utility was evaluated using decision curve analysis.

Findings

The final simplified clinical diagnostic models included neurological symptoms, cerebrospinal fluid (CSF) protein, CSF white blood cell, and CSF venereal disease research laboratory test/rapid plasma reagin. The models showed good calibration with rescaled Brier score of 0.99 (95% CI 0.98-1.00) and excellent discrimination (the minimum value of area under the receiver operating characteristic curve, 0.84; 95% CI 0.81-0.88) when externally validated. Decision curve analysis demonstrated that the models were useful across a range of neurosyphilis probability thresholds between 0.33 and 0.66 compared to the alternatives of managing all patients with syphilis as if they do or do not have neurosyphilis.

Interpretation

The simplified clinical diagnostic models comprised of readily available data show good performance, are generalisable across clinical settings, and have clinical utility over a broad range of probability thresholds. The models with a uniform set of predictors can simplify the sophisticated clinical diagnosis of neurosyphilis, and guide decisions on delivery of neurosyphilis health-care, ultimately, support accurate diagnosis and necessary treatment.

Funding

The Natural Science Foundation of China General Program, Health Appropriate Technology Promotion Project of Guangdong Medical Research Foundation, Department of Science and technology of Guangdong Province Xinjiang Rural Science and Technology（Special Commissioner）Project, Southern Medical University Clinical Research Nursery Garden Project, Beijing Municipal Administration of Hospitals Incubating Program.

The optimum condition of the toluidine red unheated serum test for the replacement of the venereal disease research laboratory test in cerebrospinal fluid for neurosyphilis diagnosis

Background

The cerebrospinal fluid (CSF) venereal disease research laboratory (VDRL) test remains the standard for the laboratory diagnosis of neurosyphilis. The toluidine red unheated serum test (TRUST) is an alternative to the VDRL test as a serological test for syphilis, but it lacks guidelines for its use in CSF for neurosyphilis diagnosis.

Methods

A total of 210 suspected neurosyphilis patients were included, consisting of 124 neurosyphilis patients and 86 syphilis/non-neurosyphilis patients. The TRUST was modified into the CSF-TRUST-10 test with 10 μL of antigen by referring to the CSF-VDRL test, and the CSF-TRUST-17 test with 17 μL of antigen by referring to its procedures in serum. The diagnostic performance of the CSF-TRUST-10 and CSF-TRUST-17 tests and the concordance between them and the CSF-VDRL test were evaluated.

Results

The diagnostic performance of the CSF-TRUST-10 and CSF-TRUST-17 tests for diagnosing neurosyphilis were comparable to the CSF-VDRL test, as well as the positive rate. The agreement rate was 98.7% between the qualitative CSF-TRUST-10 and CSF-VDRL tests. A total of 91.4% of the quantitative CSF-TRUST-10 results were consistent with the CSF-VDRL test, and the discordant results were no more than two titres. The agreement rate was 98.1% between the qualitative CSF-TRUST-17 and CSF-VDRL tests and 87.6% between the quantitative CSF-TRUST-17 and CSF-VDRL tests.

Conclusions

The CSF-TRUST with 10 μL of antigen could be an alternative for the CSF-VDRL test for neurosyphilis diagnosis. Our results provide a basis for using the TRUST to guide the diagnosis of neurosyphilis.

Advances in laboratory diagnostic methods for cerebrospinal fluid testing for neurosyphilis

Neurosyphilis is a chronic infectious disease caused by the invasion of Treponema pallidum into the central nervous system. In recent years, with the increase in the latent syphilis infection rate, the incidence of neurosyphilis has gradually increased, the typical symptoms of neurosyphilis have decreased, atypical manifestations have increased, and the clinical manifestations have become increasingly diverse. Cerebrospinal fluid testing plays an important role in the diagnosis of neurosyphilis. In recent years, there have been many advances in cerebrospinal fluid testing. This review focuses on the current and potential laboratory indicators of neurosyphilis in cerebrospinal fluid, aiming to provide a reference for clinical application and ideas for future experimental research of neurosyphilis.

Intrathecal immunoglobin synthesis and its role in patients with neurosyphilis

Background

Intrathecal protein synthesis (ITS) occurs in various central nervous system disorders, but few quantitative studies have focused on ITS for neurosyphilis (NS) in southwestern China. We made a study to quantitatively assess the ITS in patients with NS and to investigate the association between ITS and the stages of NS.

Methods

CSF-serum specimen pairs from 142 patients (66 NS and 76 non-NS/syphilis) were collected for routine CSF and serum tests. The NS group was divided into slight and severe subgroups according to the NS stages. Three formulas for the quantitative determination of the intrathecal synthesis were calculated to characterize the specimens, including the Ig index (Q_Ig/Q_alb), Ig extended index (Ig_EI), and intrathecally synthesized fraction (IgIF) using the hyperbolic function. The role of QTPPA/QIgG as an antibody index (AI = Q specific Ig/QIgG) was also explored.

Results

Sero_TRUST titres (1:16, 1:1-1:256), sero_TPPA titres (1:163840, 1:1280-1:1310720), total protein (MTP), and CSF_Igs (p < 0.05) were found to be significantly elevated in the NS group. Intrathecal Ig synthesis can be identified using all three formulas in the NS group. The pattern of Ig intrathecal synthesis was IgIF-G (48.62%) > IgIF-A = IgIF-M (p < 0.05), with the dominant intrathecal fraction being IgG (median, 48.62%), which was also verified by Q_IgG> Q_alb> Q_IgM = Q_IgA. In the slight NS group, the intrathecal fractions of IgM (>0 in 4 out of 20 cases) and IgG (>0 in 16 out of 20) were lower than the intrathecal fractions of IgM (>0 in 19 out of 35 cases) and IgG (>0 in 33 out of 38) in the severe group (p < 0.05). The area under the curve (AUC) of the CSF_TPPA antibody index was 0.867 (0.792, 0.922), with an optimal cutoff point of 0.81, providing a sensitivity of 88.91% and specificity of 84.62%.

Conclusion

Although the intrathecal synthesis pattern is IgG dominant in patients with NS, brain-derived IgM and IgA can also be found. Moreover, intrathecal IgM and IgG were associated with a parenchymatous type of neurosyphilis. Syphilis-specific antibodies are a new potential tool for NS diagnosis.

Serum Interleukin-26 is a Potential Biomarker for the Differential Diagnosis of Neurosyphilis and Syphilis at Other Stages

Background

Interleukin-26 (IL-26) is an atypical proinflammatory cytokine due to its binding to circulating double-stranded DNA and direct antibacterial activity. Although IL-26 has been confirmed to be involved in the pathophysiology of cancer, chronic inflammatory diseases and infections, the diagnostic and prognostic values of IL-26 levels in syphilis patients are not clear. This study aimed to investigate IL-26 levels in different stages of syphilis progression.

Methods

A total of 30 healthy controls and 166 patients with syphilis at different stages of disease progression were enrolled. Serum IL-26 levels were quantified in accordance with the protocols of RayBio^® Human Interleukin-26 Enzyme Linked Immunosorbent Assay (ELISA) kits. Clinical laboratory diagnostic parameters and blood analysis data were detected and collected according to clinical medical laboratory standards.

Results

The levels of serum IL-26 were significantly higher in neurosyphilis patients than in healthy subjects (6.87 (4.36, 12.14) and 1.67 (0.09, 4.89) pg/μL, respectively; ****p < 0.0001), latent syphilis (1.48 (0.40, 2.05) pg/μL, ****p < 0.0001), seroresistant syphilis (0.81 (0.20, 2.91) pg/μL, ****p < 0.0001) and secondary syphilis (1.66 (0.41, 4.25) pg/μL, ****p < 0.0001) with data presented as the median with interquartile range. The concentration of serum IL-26 was most sensitive to serum low-density lipoprotein concentration (r = -0.438, **p = 0.004) in latent syphilis, urine epithelial cells (r = 0.459, **p = 0.003) in seroresistant syphilis, and serum creatinine levels (r = 0.463, **p = 0.004) and urea creatinine ratio levels (r = 0.500, **p = 0.008) in secondary syphilis patients. There was no significant correlation with the concentration of IL-26 and toluidine red unheated serum test (TRUST) titers in each type of syphilis patient.

Conclusion

Circulating IL-26 in serum displays diagnostic potential in the progression of neurosyphilis and warrants further evaluation in clinical trials.

Which Is the Optimum Antigen Concentration for the Venereal Disease Research Laboratory Test of Cerebrospinal Fluid for Neurosyphilis Diagnosis: 10 or 17 μL?

The manufacturer's instructions for the venereal disease research laboratory (VDRL) antigen test for diagnosing neurosyphilis describe testing of serum samples and do not include procedures for cerebrospinal fluid (CSF) testing. This study compared the CSF-VDRL test with 10 μL of antigen (CSF-VDRL-10) according to the American Public Health Association to the CSF-VDRL test with 17 μL of antigen (CSF-VDRL-17) according to the VDRL serum procedure. A total of 121 neurosyphilis patients and 86 syphilis/non-neurosyphilis patients were included. The sensitivities of the CSF-VDRL-10 and CSF-VDRL-17 tests were comparable for neurosyphilis diagnosis. The positive rate of the CSF-VDRL-17 test was higher than that of the CSF-VDRL-10 test. In all, 78.3% of the quantitative CSF-VDRL-17 results were consistent with those of the CSF-VDRL-10 test, 18.4% exhibited one-titer higher results than those of the CSF-VDRL-10 test, and 3.4% had positive CSF-VDRL-17 results but negative CSF-VDRL-10 results. The CSF-VDRL test with 17 μL of antigen was more sensitive, and it is worth performing longitudinal studies to understand its practical implications.

Clinical features associated with neurosyphilis in people living with HIV and late latent syphilis

Background

The diagnosis of neurosyphilis is a challenge, and the criteria for deciding when to perform a lumbar puncture are still controversial, especially in people living with HIV with a late latent syphilis diagnosis.

Methods

Retrospective analysis of demographic, clinical, and laboratory data of people with HIV and documented late latent syphilis or syphilis of unknown duration with a cerebrospinal fluid VDRL test.

Results

122 patients were evaluated, of whom 52 had the diagnosis of neurosyphilis. Patients with and without neurosyphilis presented a similar viral load and lymphocyte CD4⁺ T-cell count. Neurological symptoms (OR 6.4, 95% CI 2.1–22.4; p < 0.01), serum VDRL titers of 1:32 (p<0.01), 1:64 (p = 0.055), and ≥1:128 (p < 0.001) were associated with neurosyphilis. Furthermore, serum VDRL ≥1:32 were associated with (OR 24.9, 95% CI 5.45–154.9; p < 0.001) or without (OR 6.5, 95% CI 2.0–29.2; p = 0.004) neurological symptoms with neurosyphilis; however, VDRL ≤1:16 with neurological symptoms can be associated with neurosyphilis (OR 7.6, 95% CI 1.03–64.3; p = 0.046).

Conclusion

Neurological symptoms, particularly headache, were predictors of neurosyphilis in people with HIV irrespective of their viral load and lymphocyte CD4⁺ T-cell count in late latent syphilis. A serum VDRL ≥1:32 increased the risk of neurosyphilis in patients with or without any symptoms.

Predicting asymptomatic neurosyphilis using peripheral blood indicators

Background

The high misdiagnosis rate of asymptomatic neurosyphilis (ANS) has long challenged infectious disease clinicians. We aim to develop a model for diagnosing ANS in asymptomatic syphilis (AS) patients without CSF indicators.

Results

277 AS patients with HIV-negative and underwent lumbar puncture were enrolled in this horizontal study.The area under the curve for predicting ANS by CSF leukocytes and protein was 0.643 and 0.675 [95% CI, 0.583–0.699VS.0.616–0.729]. Through LRM, the AUC increased to 0.806 [95% CI, 0.732–0.832], and the Youden's index was 0.430. If the score is ≤ 0.159, ANS can be excluded with a predictive value of 92.9%; we can identify ANS while the score is over 0.819, with a predictive value of 91.7% and a specificity of 99.25%. This study showed that the LRM can diagnose ANS in AS patients effectively.

Conclusion

Given a large number of misdiagnosis ANS patients and CSF results' insufficiency, the model is more practical. Our research will help clinicians track suspected syphilis, especially those who cannot accept the CSF test.

Clinical characteristics, diagnosis, and predictors of neurosyphilis patients with human immunodeficiency virus co-infection: A retrospective study at infectious diseases hospitals in two cities of China

ABSTRACT

This study aimed to compare between the clinical and laboratory characteristics of neurosyphilis and those of syphilis in human immunodeficiency virus (HIV) positive and explore the risk factors associated with the occurrence of neurosyphilis in the HIV infected.In-patients diagnosed with HIV and syphilis co-infection who underwent a lumbar puncture and completed cerebrospinal fluid (CSF) examination were divided into neurosyphilis group and syphilis group. The demographic characteristics, symptoms and signs, and laboratory tests of the 2 groups were comparatively analyzed. Logistic regression analysis was used to explore the risk factors associated with the occurrence of neurosyphilis.Among 81 patients, 33 patients were assigned to the neurosyphilis group, and 48 to the syphilis group. There were no significant differences in the age, gender, marital status, acquired immunodeficiency syndrome course, opportunistic infections, serum HIV viral load, and history of syphilis treatment. The difference in HIV transmission route between the 2 groups was statistically significant (P = .010), and the patients from the neurosyphilis group were mainly infected via heterosexual contact. The proportion of serum toludine red unheated serum test (TRUST) titer ≥1:16 in the neurosyphilis group were 78.8%, which was significantly higher compared to the syphilis group (48.9%). The level of CSF white blood cell count, CSF protein, and CSF HIV viral load in the neurosyphilis group were significantly higher than those of the syphilis group. The proportion of patients with neurological symptoms and signs in the neurosyphilis group was significantly higher compared to the syphilis group (P < .001). Multivariate logistic regression analysis showed that heterosexual contact transmission route, not received antiretroviral therapy, lower CD4 cell count and higher serum TRUST titer, untreated with syphilis, and neurological symptoms and signs were risk factors associated with the occurrence of neurosyphilis.The serum TRUST titer, CSF white blood cell count, CSF protein level, CSF HIV viral load, and the percentage of neurological symptoms and signs in the neurosyphilis group were higher. Heterosexual transmission route, not received antiretroviral therapy, and untreated with syphilis prompted the possibility of neurosyphilis occurrence.

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.

Combination of the neutrophil to lymphocyte ratio and serum toluidine red unheated serum test titer as a predictor of neurosyphilis in HIV-negative patients

The present study explored the associations of the neutrophil to lymphocyte ratio (NLR) and the serum toluidine red unheated serum test (TRUST) titer with neurosyphilis (NS). The present retrospective study examined 87 NS patients and 80 Non-NS patients from an HIV-negative cohort and 1:1 age- and gender-matched healthy controls. The results demonstrated that the NLR was increased in both NS and Non-NS groups compared with that in the healthy controls (P<0.001 and P=0.01, respectively). The NLR and serum TRUST titer in the NS group were significantly higher than those in the Non-NS group (P=0.004 and P<0.001, respectively). The NLR was positively correlated with the serum TRUST titer (r=0.298, P<0.001). Age, elevated NLR and serum TRUST titer were distinctly associated with NS by binomial logistic regression analysis [odds ratio (OR)=1.10, P<0.001; OR=1.36, P=0.028; OR=3.07, P<0.001; respectively]. The cut-off values for the NLR and serum TRUST titer were 1.97 and 1:8, respectively. A significantly higher sensitivity of 90.8% was obtained for screening out NS with a combination of the NLR and serum TRUST titer compared with each test alone. Age, elevated NLR and serum TRUST titer were associated with NS. The combination of NLR and serum TRUST titer is a potential predictor for NS, and the reduced NLR and serum TRUST titer at the 6-month follow up suggested that the NLR and serum TRUST titer were biomarkers for monitoring the disease course.

Early symptomatic neurosyphilis and ocular syphilis: A comparative study between HIV-positive and HIV-negative patients

OBJECTIVES

Since the 2000s, there has been an increase in prevalence of neurosyphilis (NS) and ocular syphilis (OS). As data about symptomatic NS/OS is limited, this study aims to assess the characteristics of symptomatic NS/OS, according to HIV status.

METHODS

We compared the clinical and biological presentation of early symptomatic NS/OS and its outcome in HIV-positive and HIV-negative patients.

RESULTS

Ninety-six patients (93% men, 49% HIV-positive) were included from 2000 to 2016 in two centers, with 67 (69%) having OS, 15 (16%) NS, and 14 (14%) both. HIV-positive patients were younger (P=0.006) and more likely to be males having sex with males (P=0.00048) or to have a history of syphilis (P=0.01). Among 81 OS, there were 43 posterior uveitis (57%), and bilateral involvement was more common in HIV-positive patients (62% versus 38%, P=0.045). Among 29 NS there were 21 cases of cranial nerve involvement (72%), seven meningitis (24%) and 11 paresthesia (38%). Involvement of the VIII^th cranial nerve was the most common (16 cases). Treponemal tests were more commonly found positive in cerebrospinal fluid in HIV-positive patients (88% versus 76%, P=0.04). Visual acuity (VA) always improved after treatment (initial VA logMAR 0.8±0.8 versus 0.1±0.1 at 3 months), but 32% and 18% of the patients still had neurological or ocular impairment respectively six and 12 months after treatment. Non-treponemal serological reversion was observed in 43/50 patients (88%) at six months.

CONCLUSION

HIV infection has no consequence on the outcome of NS and OS. Sequelae are common, emphasizing the importance of prevention, and screening, and questioning enhanced treatment.

Dynamic changes in peripheral blood lymphocyte subsets in adult patients with COVID-19

INTRODUCTION

Coronavirus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread widely. The aim of this study was to investigate the dynamic changes in peripheral blood lymphocyte subsets in adult patients with COVID-19.

METHODS

The electronic medical records were reviewed. Data including demographic characteristics, clinical manifestations, comorbidities, laboratory data, and radiological examinations of 435 hospitalized COVID-19 patients with a confirmed SARS-CoV-2 viral infection were extracted and analyzed retrospectively. Lymphocyte subset counts at each week after the onset of the illness were compared with those of the other weeks of illness and with those of control individuals.

RESULTS

The various lymphocyte subsets (CD3+, CD4+, CD8+, CD19+, and CD16/56+) were below the normal ranges at 1 week after the onset of illness, reaching a nadir during the second week. They increased gradually during the third week and returned to normal levels in the fifth week, but were still lower than those of the healthy controls. The CD3+, CD4+, and CD8+ counts were significantly lower in patients with severe disease compared to those with non-severe disease, and in patients who died compared to those who recovered.

DISCUSSION

This research indicates that the levels of peripheral blood lymphocyte subsets (CD3+, CD4+, and CD8+) are associated with disease progression and severity, and with the prognosis in patients with COVID-19. Dynamic monitoring of human immune function is one of the indicators for evaluating the severity of disease and the prognosis of COVID-19 patients, and is useful for formulating appropriate treatment strategies.

Predictors of unfavorable outcome in neurosyphilis: Multicenter ID-IRI Study

Neurosyphilis (NS) has different clinical manifestations and can appear during any stage of syphilis. We aimed to identify the factors affecting poor outcome in NS patients. Patients with positive cerebrospinal fluid Venereal Disease Research Laboratory test, and positive serological serum treponemal or nontreponemal tests were classified as definite NS. The data of 141 patients with definite NS were submitted from 22 referral centers. Asymptomatic NS, syphilitic meningitis, meningovascular syphilis, tabes dorsalis, general paresis, and taboparesis were detected in 22 (15.6%), 67 (47.5%), 13 (9.2%), 10 (7%), 13 (9.2%), and 16 patients (11.3%), respectively. The number of HIV-positive patients was 43 (30.4%). The most common symptoms were headache (n = 55, 39%), fatigue (n = 52, 36.8%), and altered consciousness (50, 35.4%). Tabetic symptoms were detected in 28 (19.8%), paretic symptoms in 32 (22.6%), and vascular symptoms in 39 patients (27.6%). Eye involvement was detected in 19 of 80 patients (23.7%) who underwent eye examination and ear involvement was detected in eight of 25 patients (32%) who underwent ear examination. Crystallized penicillin was used in 109 (77.3%), procaine penicillin in seven (4.9%), ceftriaxone in 31 (21.9%), and doxycycline in five patients (3.5%). According to multivariate regression analysis, while headache was a protective factor in NS patients, double vision was significantly associated to poor outcome. We concluded that double vision indicated unfavorable outcome among NS patients. A high clinical suspicion is needed for the diagnosis NS. As determined in our study, the presence of headache in syphilitic patients can help in early diagnosis of central nervous system disease.

Biological false-positive venereal disease research laboratory test in cerebrospinal fluid in the diagnosis of neurosyphilis - a case-control study

BACKGROUND

There is no clear consensus on the diagnosis of neurosyphilis. The Venereal Disease Research Laboratory (VDRL) test from cerebrospinal fluid (CSF) has traditionally been considered the gold standard for diagnosing neurosyphilis but is widely known to be insensitive.

OBJECTIVE

In this study, we compared the clinical and laboratory characteristics of true-positive VDRL-CSF cases with biological false-positive VDRL-CSF cases.

METHODS

We retrospectively identified cases of true and false-positive VDRL-CSF across a 3-year period received by the Immunology and Serology Laboratory, Singapore General Hospital. A biological false-positive VDRL-CSF is defined as a reactive VDRL-CSF with a non-reactive Treponema pallidum particle agglutination (TPPA)-CSF and/or negative Line Immuno Assay (LIA)-CSF IgG. A true-positive VDRL-CSF is a reactive VDRL-CSF with a concordant reactive TPPA-CSF and/or positive LIA-CSF IgG.

RESULTS

During the study period, a total of 1254 specimens underwent VDRL-CSF examination. Amongst these, 60 specimens from 53 patients tested positive for VDRL-CSF. Of the 53 patients, 42 (79.2%) were true-positive cases and 11 (20.8%) were false-positive cases. In our setting, a positive non-treponemal serology has 97.6% sensitivity, 100% specificity, 100% positive predictive value and 91.7% negative predictive value for a true-positive VDRL-CSF based on our laboratory definition. HIV seropositivity was an independent predictor of a true-positive VDRL-CSF.

CONCLUSION

Biological false-positive VDRL-CSF is common in a setting where patients are tested without first establishing a serological diagnosis of syphilis. Serological testing should be performed prior to CSF evaluation for neurosyphilis.

The big imitator strikes again: a case report of neurosyphilis in a patient with newly diagnosed HIV

BACKGROUND

Neurosyphilis is the result of an infection of the central nervous system caused by the spirochete Treponema pallidum. Its clinical presentation includes meningovascular syphilis, tabes dorsalis, and dementia paralytica, resulting in a wide range of symptoms such as psychosis, Parkinsonism, and depression.

CASE REPORT

A 49-year-old male was admitted to a psychiatric hospital because of social withdrawal and self-neglect, indicative of a major depression. A routine HIV-test was positive and resulted in an admission to the Antwerp University Hospital. Clinical examination showed Argyll Robertson pupils, a wide-based gait, absence of vibration sense in the lower limbs, and a MMSE-score of 25/30. Blood analysis revealed a CD4+ count of 99 cells/μL and a HIV viral load of 2,13 × 10⁵ copies/mL plasma. A serum TPHA (T. pallidum hemagglutination assay) titre of 1/20480 and RPR (rapid plasma reagin) titre of 1/128 were detected. TPHA and RPR titre in the cerebrospinal fluid were, respectively, 1/10240 and 1/4. A brain MRI showed diffuse cortical atrophy and lesions in the white matter compatible with HIV-encephalopathy. The diagnoses of advanced HIV-infection and late neurosyphilis were made. HAART (highly active antiretroviral therapy) and high-dose IV penicillin G were started.

CONCLUSION

In all patients with new-onset dementia or untreatable psychosis, neurosyphilis should always be considered. Argyll Robertson pupils are regarded as pathognomonic of neurosyphilis. The management of neurosyphilis includes high-dose IV benzyl penicillin for 10 to 14 days. Close follow-up including a lumbar puncture after 6 months is warranted to ensure treatment recovery.

Central Nervous System Infections

This chapter provides an overview of infectious syndromes, pathogens, and diagnostic testing modalities for central nervous system infections in the immunocompromised host.

Novel predictors of neurosyphilis among HIV-negative syphilis patients with neurological symptoms: an observational study

Background

Known predictors of neurosyphilis were mainly drawn from human immunodeficiency virus (HIV)-infected syphilis patients, which may not be applicable to HIV-negative populations as they have different characteristics, particularly those with neurological symptoms. This study aimed to identify novel predictors of HIV-negative symptomatic neurosyphilis (S-NS).

Methods

From June 2005 to June 2015, 370 HIV-negative syphilis patients with neurological symptoms were recruited, consisting of 191 S-NS patients (including 123 confirmed neurosyphilis and 68 probable neurosyphilis patients) and 179 syphilis/non-neurosyphilis (N-NS) patients. Clinical and laboratory characteristics of S-NS were compared with N-NS to identify factors predictive of S-NS. Serum rapid plasma reagin (RPR), Treponema pallidum particle agglutination (TPPA), and their parallel testing format for screening S-NS were evaluated.

Results

The likelihood of S-NS was positively associated with the serum RPR and TPPA titers. The serum TPPA titers performed better than the serum RPR titers in screening S-NS. The optimal cut-off points to recognize S-NS were serum RPR titer ≥1:4 and serum TPPA titer ≥1:2560 respectively. A parallel testing format of a serum RPR titer ≥1:2 and serum TPPA titer ≥1:1280 screened out 95.8% of S-NS and all confirmed cases of neurosyphilis. S-NS was independently associated with male sex, serum RPR titer ≥1:4, serum TPPA titer ≥1:2560, and elevated serum creatine kinase. Concurrence of these factors increased the likelihood of S-NS.

Conclusions

Quantitation of serum TPPA is worthwhile and performs better than serum RPR in screening S-NS. Serum RPR, serum TPPA, male sex, and serum creatine kinase can predict S-NS. Moreover, patients with both a serum RPR titer <1:2 and a serum TPPA titer <1:1280 have a low probability of S-NS, suggesting that it is reasonable to reduce lumbar punctures in such individuals.

Multifocal neuropathic arthropathy in patient with undiagnosed neurosyphilis: A case report

Although the prevalence of syphilis has decreased significantly, syphilis is still a common cause of neuropathic arthropathy. Tabetic arthropathy means progressive painless joint destruction that is related to neurosensory deficits caused by syphilis. In general, lower limb joints are involved and gradual swelling and instability of the involved joints are observed. Diagnosis of tabetic arthropathy is difficult as its clinical presentation is not specific and differential diagnosis is wide ranging. Hence, diagnosis of tabetic arthropathy requires clinical suspicion and an appropriate serological test. Laboratory tests for the diagnosis of syphilis include nontreponemal tests and treponemal tests. Conventionally, a nontreponemal test such as the Venereal Disease Research Laboratory test or the Rapid Plasma Reagin test is performed first as a screening test for syphilis, followed by a treponemal test to confirm the positive response found in the screening test. However, the sensitivity and specificity of the serum nontreponemal and treponemal tests for the diagnosis of syphilis are different based on the test type and the syphilis stages. We herein report a case of multifocal neuropathic arthropathy found in a patient whose syphilis was not diagnosed due to a nonreactive screening test result.

Macrophage migration inhibitory factor as a novel cerebrospinal fluid marker for neurosyphilis among HIV-negative patients

BACKGROUND

Neurosyphilis (NS) is difficult to diagnose, especially in syphilis patients with negative cerebrospinal fluid (CSF) rapid plasma reagin (RPR) or Venereal Disease Research Laboratory (VDRL) tests.

METHODS

We conducted a cross-sectional study and an analysis of macrophage migration inhibitory factor (MIF) in syphilitic patients to identify a novel marker for the diagnosis of NS, with a focus on probable NS (NS with negative VDRL/RPR tests). For this purpose, CSF and serum MIF concentrations were determined in 43 NS and 43 syphilis/non-NS (N-NS) patients at the Zhongshan Hospital of the Medical College of Xiamen University from July 2014 to June 2015. Sixty-three blood donors were used as healthy controls.

RESULTS

NS patients had higher CSF (median [IQR]: 8.77ng/ml [4.76-19.13]) and serum (52.58ng/ml [28.31-95.94]) MIF concentrations than N-NS patients did (4.08 [2.21-9.68] and 34.30 [19.77-59.75], respectively). Using a cut-off point of 6.63ng/ml, CSF MIF had a sensitivity of 74.42% and a specificity of 67.74% for the diagnosis of NS. The sensitivity was higher than that of CSF RPR (39.53%) and increased protein (48.84%) tests and similar to that of CSF pleocytosis (67.44%). Additionally, the sensitivity of CSF MIF, which was 92.31% for the diagnosis of probable NS, was higher than that of CSF pleocytosis (65.38%) and increased protein (53.85%) tests. By integrating all CSF parameters (pleocytosis, increased protein and MIF), the sensitivity would be improved to 100% by parallel testing, which would avoid missed diagnoses. Moreover, the specificity would be improved to 100% by the serial testing algorithm, which would again avoid misdiagnosis.

CONCLUSIONS

CSF MIF concentrations can be used as a novel CSF marker to establish or exclude a diagnosis of NS.

Neurobehavioral Manifestations of Human Immunodeficiency Virus/AIDS: Diagnosis and Treatment

Behavioral disorders are common in persons infected with human immunodeficiency virus (HIV). The differential includes preexisting psychiatric diseases, substance abuse, direct effects of HIV infection, opportunistic infection, and the adverse effects of medical therapies. Many patients have more than one contributing or comorbid problem to explain these behavioral changes. The differential should always include consideration of psychosocial, genetic, and medical causes of disease. Treatment strategies must take into account the coadministration of antiretroviral therapy and the specific neurologic problems common in patients infected with HIV.

Serum TRSUT Titer ≥1: 16 Is a Predictor for Neurosyphilis Among HIV-Infected Patients With Concurrent Syphilis and No Neurological Symptoms

Investigating the predictors for lumbar puncture to diagnose the asymptomatic neurosyphilis among HIV and syphilis co-infected patients in Shanghai, China. Respectively, screening the medical records from August 1, 2009 to June 30, 2015. Those HIV-infected patients with concurrent syphilis who had received lumbar puncture were selected and their clinical and demographic data were recorded. Participants comprised symptomatic and asymptomatic patients. The latter ones could be further divided into 3 groups: late syphilis, early syphilis with anti-syphilis treatment failure, and early syphilis with serum toludine red unheated serum test (TRUST) ≥1:32. Both syphilis stage and anti-syphilis treatment effect were defined by common criteria, and syphilis of unknown duration was considered as late syphilis. Asymptomatic neurosyphilis was defined as neurosyphilis without neurological symptoms such as headache, cognitive dysfunction, motor deficits, auditory or ophthalmic abnormalities, and stroke. Neurosyphilis was defined as reactive cerebrospinal fluid (CSF) TRUST and/or CSF white blood cell >20 cells/μL without other reasons. Mann-Whitney test and Fisher's exact test were used for analyzing the difference between neurosyphilis and non-neurosyphilis group. Logistic regression test was performed to analyze the risk factors for neurosyphilis. In total, 170 participants were collected, and the rate of neurosyphilis was 32.35%. Among all the 105 participants without neurological symptoms, 80 patients were with late syphilis and 25 were with early syphilis. Among the early syphilis patients, 23 had a TRUST ≥1:32 and the other 2 experienced an anti-syphilis treatment failure. The differences of clinical and demographic variables between neurosyphilis and non-neurosyphilis group were not statistically significant except the serum TRUST titer (P < 0.01). From HIV/syphilis co-infected patients with or without neurological symptom, those who had neurological symptoms, CD4 <350 per μL and serological TRUST titer ≥1:16 were 4.9-fold (95% confidence interval [CI]: 2.37-10.31), 4.3-fold (95% CI: 1.17-15.78), and 4.1-fold (95% CI: 1.58-10.76), respectively, more likely to be diagnosed with neurosyphilis. Asymptomatic patients whose serum TRUST titer ≥1:16 were 8.48-fold (95% CI: 1.08-66.63) more likely to have asymptomatic neurosyphilis. Among asymptomatic HIV-infected patients with late syphilis or early syphilis experienced an anti-syphilis treatment failure, those who have a serum TRUST titer ≥1:16 are suggested to perform lumbar puncture in order to avoid delayed diagnosis and the occurrence of severe sequelae of syphilis.