Clinical and Laboratory Characteristics of Symptomatic and Asymptomatic Neurosyphilis in HIV-Negative Patients: A Retrospective Study of 264 Cases

Cerebrospinal Fluid Biomarkers of Symptomatic Neurosyphilis in People With HIV Compared with Uninfected Individuals

We evaluated the diagnostic clinical performance characteristics (DCPC) of cerebrospinal fluid (CSF) total protein (TP), white blood cell count (WBC), and lactate (LA) with different cutoff points as adjunct biomarkers of confirmed or presumptive symptomatic neurosyphilis (NS) and the impact of HIV infection. From 5,640 participants who underwent lumbar punctures, 236 participants were included, and classified as either people with HIV (PWH) or people without HIV (PWoH) according to the CDC criteria for confirmed NS (n = 42), presumptive NS (n = 74), systemic syphilis (SS) (n = 38), serological diagnosis of syphilis (n = 18), PWH without SS and NS (n = 10), and negative control (n = 72). In PWoH, for presumptive NS, the combination of CSF TP > 45 mg/dL and/or WBC > 5.0 cells/mm3 is valuable for screening, whereas in PWH, it is not recommended for either screening or case-finding NS, however the DCPC were better in the suppressed group. In PWoH, the value of CSF TP > 45 mg/dL is adequate for both screening and confirmation of presumptive NS, subject to prevalence. For WBC count > 20 cell/mm3, the positive predictive value (PPV) of the test is almost perfect, suggesting a confirmatory test. In PWH, CSF TP is an inadequate marker of NS. The WBC count, with cutoffs of > 10 or > 20 cells/mm3, was moderately applicable for screening.As conclusions: CSF WBC count and TP showed distinct DCPC in confirmed or presumptive NS, better in the former. These biomarkers could be included for presumptive NS diagnosis. DCPC of these biomarkers for the diagnosis of NS is greatly affected by HIV co-infection.

Serological testing for syphilis in the differential diagnosis of cognitive decline and polyneuropathy in geriatric patients

BACKGROUND

In the 19th century, neurosyphilis was the most frequent cause of dementia in Western Europe. Now dementia caused by syphilis has become rare in Germany. We studied whether routine testing of patients with cognitive abnormalities or neuropathy for antibodies against Treponema pallidum has therapeutic consequences in geriatric patients.

METHODS

A Treponema pallidum electrochemiluminescence immunoassay (TP-ECLIA) is routinely performed in all in-patients treated at our institution with cognitve decline or neuropathy and no or insufficient previous diagnostic workup. Patients with a positive TP-ECLIA treated from October 2015 to January 2022 (76 months) were retrospectively evaluated. In cases of positive TP-ECLIA, further specific laboratory investigations were performed to assess whether antibiotic therapy was indicated.

RESULTS

In 42 of 4116 patients (1.0%), TP-ECLIA detected antibodies directed against Treponema in serum. Specifity of these antibodies was ensured by immunoblot in 22 patients (11 × positiv, 11 × borderline values). Treponema-specific IgM was detectable in the serum of one patient, in 3 patients the Rapid Plasma Reagin (RPR) test, a modified Venereal Disease Research Laboratory test (VDRL), in serum was positiv. CSF analysis was performed in 10 patients. One patient had CSF pleocytosis. In 2 other patients, the Treponema-specific IgG antibody index was elevated. 5 patients received antibiotic therapy (4 × ceftriaxone 2 g/d i.v., 1 × doxycycline 300 mg/d p.o.).

CONCLUSION

In approx. 1‰ of patients with previously undiagnosed or not sufficiently diagnosed cognitive decline or neuropathy, the diagnostic workup for active syphilis resulted in a course of antibiotic treatment.

CARE-NS, a research strategy for neurosyphilis

Neurosyphilis is a major clinical manifestation of syphilis. In recent years, an increase in neurosyphilis cases has been reported in many countries. The overall incidence of neurosyphilis remains unknown, and there is a lack of understanding of the disease pathogenesis, which hampers clinical management, development of prevention strategies, and control. This article proposes the CARE-NS research strategy to enhance the clinical management of neurosyphilis, which consists of six key features: comprehensive management including multidisciplinary treatment (C), alleviating neurological impairment and sequelae (A), risk factors and clinical epidemiology (R), etiology and pathogenesis (E), new diagnostic indicators and strategies (N), and social impact and cost-effectiveness analysis (S).

Neuropsychological Features in Patients with General Paresis of the Insane at an Early Stage

BACKGROUND This study aimed to explore the features of cognitive impairment in patients with neurosyphilis at the early stage of mild cognitive impairment (MCI). MATERIAL AND METHODS A total of 18 patients with asymptomatic neurosyphilis (ANS), 19 patients with neurosyphilis at the MCI stage (neurosyphilis-MCI), and 15 patients with neurosyphilis at the dementia stage (neurosyphilis-dementia) were enrolled. Cognitive function was evaluated using comprehensive rating scales. Tests of syphilis in blood and cerebrospinal fluid (CSF) were conducted, and white blood cell (WBC) counts and protein levels in CSF were measured. RESULTS Overall cognitive function and individual cognitive domains, including memory, language, visuospatial skill, and attention/executive function, were all significantly impaired in the neurosyphilis-MCI group compared with the ANS group, and were further impaired in the neurosyphilis-dementia group. Although there was no difference in serum rapid plasma regain (RPR) titer among the 3 groups, the number of patients with serum RPR titer ≥1: 32 in the neurosyphilis-MCI group was much higher than that in the ANS group. CSF RPR positive rate in the neurosyphilis-MCI group was significantly higher than that in the ANS group. The WBC count, protein level, and the rate of elevated protein level or increased WBC count in CSF did not differ among the 3 groups. CONCLUSIONS The feature of cognitive impairment of neurosyphilis-MCI patients displayed multiple-domain amnestic MCI. Perhaps there were extensive brain areas involved at the early stage, and a continuous neuroinflammatory process was through the different stages of neurosyphilis. Early diagnosis and treatment are very important for preventing the progression of general paresis of the insane.

Ceftriaxone compared with penicillin G for the treatment of neurosyphilis: study protocol for a multicenter randomized controlled trial

BACKGROUND

Neurosyphilis may cause irreversible neurological sequelae. First-line treatment consists of penicillin G, with ceftriaxone being an alternative treatment in patients allergic to penicillin. The lack of clinical data comparing the efficacy of these two drugs indicated the need for comparative clinical trials to improve national treatment guidelines in China.

METHODS/DESIGN

In this multicenter randomized controlled clinical trial, 290 patients newly diagnosed with neurosyphilis will be randomized 1:1 to treatment with aqueous crystalline penicillin G (ACPG) or ceftriaxone. Patients will be treated with standard regimens of ACPG or ceftriaxone according to Chinese National Guidelines and will be followed up for 12 months. All clinical parameters will be assessed at baseline and at follow-up 3, 6, 9, and 12 months later. The primary outcomes will include cerebrospinal fluid (CSF) white blood cell (WBC) count, serological efficacy, and clinical efficacy. The secondary outcomes will include CSF protein concentrations, Mini-Mental State Examination (MMSE) scores, imaging results, recurrence, and time to recovery from neurosyphilis. Adverse events will be monitored and recorded during the trial.

DISCUSSION

This trial will provide clinical data to determine whether ceftriaxone is non inferior to ACPG in treating neurosyphilis and will provide evidence for the improvement of treatment guidelines.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100047164. Registered on 9 June 2021 and updated on 23 November 2021.

An Updated Review of Recent Advances in Neurosyphilis

Neurosyphilis is caused by Treponema pallidum invading the central nervous system, of which the incidence is increasing worldwide. Due to its variable clinical manifestations, diagnosis of neurosyphilis remains challenging, especially the asymptomatic form. This review focuses on recent advances in neurosyphilis, including epidemiology, clinical manifestations, laboratory findings, comorbidities, diagnosis, treatment, prognosis, and basic research. The expansion of men who have sex with men and the infection of human immunodeficiency virus mainly accounted for the increasing incidence of neurosyphilis. The rate of some historically described forms of neurosyphilis in the pre-antibiotic era declined significantly; atypical features are more prevalent. Neurosyphilis, regarded as a great mimicker for neuro-ophthalmic, audio-vestibular, and psychiatric disorders, often presents concomitantly with other diseases, including metabolic disorders. Studies on long non-coding RNAs, miRNAs, chemokines, and metabolites in peripheral blood and cerebrospinal fluid may facilitate exploring the pathogenesis and identifying novel biomarkers of neurosyphilis. The drug resistance of Treponema pallidum to penicillin has not been reported; ceftriaxone was proposed to be more effective than penicillin, whereas few randomized controlled trials supported this view. This study may pave the way for further research, especially the diagnosis and treatment of neurosyphilis.

Neurosyphilis Presenting as an Atypical Case of Posterior Placoid Chorioretinitis in a Young, HIV-Negative Male

Ocular syphilis can occur at any time after initial infection and most commonly presents as posterior uveitis or panuveitis, although many other ocular findings have been documented. We present the case of a young, otherwise healthy Caucasian HIV-negative male who presented with acute onset of photopsias, floaters, and a rapidly progressive unilateral scotoma who was originally diagnosed with acute zonal occult outer retinopathy (AZOOR) and started on a high dose prednisone taper. Although his clinical symptoms improved on corticosteroids, he was later switched to Penicillin G treatment when his blood and cerebrospinal fluid (CSF) testing demonstrated syphilis as his underlying diagnosis. Given his ocular findings on the exam and reactive syphilitic testing, he was ultimately diagnosed with acute syphilitic posterior placoid chorioretinitis (ASPPC). Our patient's clinical improvement after a high-dose prednisone trial offers further evidence of an autoimmune component to the pathophysiology of ASPPC.

Clinical Manifestations, Fluid Changes and Neuroimaging Alterations in Patients with General Paresis of the Insane

PURPOSE

We aim to study the clinical manifestations, fluid changes and neuroimaging alterations in patients with general paresis of the insane (GPI).

METHODS

A total of 119 patients suffering from GPI recruited in Beijing Ditan Hospital, Capital Medical University from 2010 to 2020 were retrospectively analyzed.

RESULTS

In 119 GPI patients, 103 cases (86.6%) were male. Misdiagnosed rate was up to 83.2%, schizophrenia and mood disorders were the most common misdiagnosed diseases. Duration from symptom onset to the final confirmed diagnosis was 10.4±12.9 months. The main clinical manifestations included cognitive impairment (114 cases, 95.8%) and neuropsychiatric symptoms (107 cases, 90.0%). The cognitive domains including the delayed recall, visuospatial/executive function and language ability indicated by MoCA score were damaged severely. Rapid plasma regain (RPR) of all GPI patients was 100% positive in serum and 89.9% positive in cerebral spinal fluid (CSF). The white blood cell (WBC) number in CSF was between 6 and 50/μL in 73 GPI patients (61.3%). The protein level was between 45.1 and 70mg/dL in 47 cases (39.5%). In the 110 cases, 96 cases (87.3%) were abnormal indicated by cerebral atrophy mostly located in the anterior brain and abnormal signals distributed in various regions of the brain mostly in the frontal lobe and temporal lobe.

CONCLUSION

The symptoms of GPI were complex and easy to misdiagnose. The clinicians were still short of vigilance for neurosyphilis. We should expand serologic testing for syphilis especially in patients with cognitive impairment and neuropsychiatric symptoms. We suggest syphilis curricula in the training program of the clinicians especially for neurologist and psychiatrist.

German guidelines on the diagnosis and treatment of neurosyphilis

Introduction

In view of the importance of neurosyphilis and the difficulties encountered in diagnosing it, the S1 guideline "Neurosyphilis" has been published by the German Society for Neurology (DGN) in accordance with the stipulations of the Association of the Scientific Medical Societies in Germany (AWMF). The present article is an abridged translation of that German guideline.

Main recommendations

(a) Neurosyphilis can manifest as early neurosyphilis (meningitis, meningovascular neurosyphilis or syphilitic gummas) or late neurosyphilis (tabes dorsalis, general paresis). (b) The following diagnostic criteria help to establish the presence of probable neurosyphilis (always point iv, accompanied by any two of points i to iii): (i) subacute or chronic neuro-psychiatric symptoms; (ii) increased cerebrospinal fluid (CSF) cell count or signs of blood-CSF barrier disruption; (iii) positive effect of anti-neurosyphilis antibiotic therapy on clinical course and CSF findings; (iv) positive TPHA/TPPA or FTA test in serum. (c) The diagnosis of neurosyphilis is confirmed by the subsequent detection of intrathecal production of antibodies against Treponema pallidum. (d) In neurosyphilis, treatment with intravenous penicillin or ceftriaxone for 14 days is recommended. (e) The following parameters can be used to assess a therapeutic effect: clinical findings, serum VDRL, and CSF cell count.

Conclusion

The German guideline on the diagnosis and treatment of neurosyphilis is a practical tool to support clinicians in diagnosing and treating patients with neurosyphilis. This article is an abridged translation of this guideline (Klein MW, J.; Angstwurm, K.; Esser, S.; Hahn, K.; Matschke, M.; Scheithauer, S.; Schoefer, H.; Sturzenegger, M.; Wildemann, B. Neurosyphilis, S1-Leitlinie. Deutsche Gesellschaft für Neurologie, Leitlinien für Diagnostik und Thearpie in der Neurologie 2020).

Cerebrospinal Fluid Cytokines in Patients with Neurosyphilis: The Significance of Interleukin-10 for the Disease

The aim of this study was to examine the cerebrospinal fluid (CSF) concentrations of proinflammatory and anti-inflammatory cytokines in neurosyphilis (NS), analyze the differences between asymptomatic NS (ANS) and symptomatic NS (SNS), and explore the diagnostic value of these cytokines. We enrolled 45 patients with a diagnosis of NS, including 18 patients with ANS and 27 patients with SNS, whose cerebrospinal fluid (CSF) samples were collected before penicillin therapy. Twelve patients with syphilis but non-NS (NNS) were also included. We measured the CSF levels of interleukin- (IL-) 1β, IL-4, IL-6, IL-10, IL-17A, IL-21, and tumor necrosis factor- (TNF-) α; the CSF levels of the microglial activation marker soluble triggering receptor expressed on myeloid cells 2 (sTREM2); and the CSF levels of the neuronal injury marker neurofilament light proteins (NFL) using the human cytokine multiplex assay or ELISA. Of the measured cytokines in the CSF, only IL-10 levels were significantly increased in NS patients compared to NNS patients (p < 0.001). In a subgroup analysis, the CSF levels of IL-10 were significantly elevated in SNS patients compared to ANS and NNS patients (p = 0.024 and p < 0.001, respectively). The CSF IL-10 levels had a significant correlation with the markers of microglial activation and neuronal injury, and they also correlated with CSF rapid plasma reagin (RPR) titer, CSF white blood cell (WBC) count, and CSF protein concentration. The areas under the ROC curve (AUC) of CSF IL-10 in the diagnosis of NS and ANS were 0.920 and 0.891, respectively. The corresponding sensitivities/specificities were 86.7%/91.7% and 83.3%/91.7%, respectively. Therefore, the excessive production of IL-10 might facilitate bacterial persistent infection, play an important role in the pathogenesis of NS, and associate with the progression of the disease. CSF IL-10 concentration had a useful value in the diagnosis of NS, especially in ANS.

Chemokine Ligand 13 (CXCL13) in Neuroborreliosis and Neurosyphilis as Selected Spirochetal Neurological Diseases: A Review of Its Diagnostic Significance

Neuroborreliosis (NB) and neurosyphilis (NS) are abnormal conditions caused by spirochetal bacteria which affect the nervous system. Diagnosis of neuroborreliosis and neurosyphilis is determined by clinical examination of visible symptoms, serum and cerebrospinal fluid (CSF) analysis, and serological detection of antibodies against Borrelia burgdorferi sensu lato and Treponema pallidum, respectively. Establishing a diagnosis may sometimes pose a number of diagnostic difficulties. A potential role of chemokine ligand 13 (CXCL13) as an accurate diagnostic biomarker of intrathecal inflammation has been suggested. In this review, we focused on changes in serum and cerebrospinal fluid concentration of chemokine ligand 13 in selected spirochetal neurological diseases neuroborreliosis and neurosyphilis reported in the available literature. We performed an extensive search of the literature relevant to our investigation via the MEDLINE/PubMed database. It has been proven that CXCL13 determination can provide rapid information regarding central nervous system inflammation in patients with selected spirochetosis. We described that neuroborreliosis and neurosyphilis are associated with an elevated CXCL13 concentration, mainly in the cerebrospinal fluid. Moreover, literature data suggest that CXCL13 determination is the most interesting additional marker for diagnosis and monitoring of neuroborreliosis and neurosyphilis thanks to its high sensitivity. Based on these published findings, we suggest that CXCL13 has high diagnostic utility and may be applied in laboratory diagnostics as a potential diagnostic marker in human spirochetal neurologic diseases.

Neuroimaging Features, Follow-Up Analyses, and Comparisons Between Asymptomatic and Symptomatic Neurosyphilis

Introduction

Many studies have explored the imaging characteristics of patients with neurosyphilis, but no systematic study has been made on the neuroimaging changes after anti-syphilitic treatment. The purpose of this study was to examine neuroimaging differences before and after treatment, comparing patients with asymptomatic and symptomatic neurosyphilis.

Methods

A total of 102 patients with neurosyphilis, including 60 cases of symptomatic neurosyphilis and 42 cases of asymptomatic neurosyphilis, were identified between December 2012 and June 2019. Their demographics, medical histories, serological tests of peripheral blood and cerebrospinal fluid, and especially neuroimaging features before and after anti-syphilitic treatment were collected and analyzed.

Results

The patients presented with variable clinical and neuroimaging features, including cerebral infarction or hemorrhage, atrophy, demyelination, arteritis, encephalitis, and hippocampal sclerosis. A total of 29 neuroradiological re-examinations were performed in 19 patients treated with anti-syphilitic medicine. The results indicated that some patients still presented neuroradiological progression after treatment, including 42.1% showing infarction lesions, 47.4% mild to severe brain atrophy, and 15.8% white matter demyelination.

Conclusion

The clinical and neuroimaging features of neurosyphilis patients are diverse, and their follow-up neuroimaging continued to show progression even with standardized treatment.

Electronic supplementary material

The online version of this article (10.1007/s13555-020-00361-3) contains supplementary material, which is available to authorized users.

Increased CSF Soluble TREM2 Concentration in Patients With Neurosyphilis

Objective: To explore cerebrospinal fluid (CSF) levels of soluble triggering receptor expressed on myeloid cells 2 (sTREM2) and neurofilament light proteins (NFL) in patients with neurosyphilis (NS).

Methods: We enrolled 71 NS patients (41 early-NS and 30 late-NS patients) and 20 syphilis but non-NS patients whose CSF samples were collected. The CSF levels of the microglial activation biomarker sTREM2 and neuronal injury biomarker NFL were measured using ELISA.

Results: CSF sTREM2 levels were significantly higher in NS patients compared to those in syphilis/non-NS patients (p < 0.001). In a subgroup analysis, the CSF sTREM2 levels elevated significantly in late-NS patients than those in early-NS patients (p < 0.001). The CSF sTREM2 levels in early-NS group were also significantly higher than those in syphilis/non-NS group (p = 0.024). Like CSF sTREM2, similar differences between groups were also found in CSF NFL. There was a moderate correlation between CSF sTREM2 and CSF NFL (r = 0.406, p < 0.001) in NS group.

Conclusions: CSF sTREM2 levels elevated in NS and peaked at the late stage, suggesting that CSF sTREM2 may be a useful marker to quantify microglia activation in NS and may play a role in the progression of NS. The positive correlation between CSF sTREM2 and CSF NFL indicates a linkage between microglial activation and neuronal injury in NS.

Diagnostic Issues of Asymptomatic Neurosyphilis in HIV-Positive Patients: A Retrospective Study

Introduction: Asymptomatic neurosyphilis (ANS) is a disease that is difficult to diagnose in people living with HIV (PLWH). The European Guidelines on the management of syphilis suggest that ANS should be suspected and thus the lumbar puncture (LP) should be performed in cases of (1) late syphilis (acquired >2 years previously), (2) CD4⁺ cells ≤ 350/mm³ and/or a serum Venereal Disease Research Laboratory/Rapid Plasma Reagin (VDRL/RPR) title > 1:32, (3) “serological failure” after syphilis therapy, and (4) the use of alternative treatment for syphilis. In the present study, we aimed to verify the accuracy of the guideline’s criteria for the indication of LP in the suspicion of ANS in a cohort of PLWH. Methods: This retrospective study was carried out in a cohort of PLWH referred at a single medical center of a large academic hospital in Italy. Clinical and laboratory data of patients diagnosed with late syphilis were extracted from the cohort and analyzed. The European Guidelines of syphilis were adopted for patient management. Results: Out of a cohort of 713 PLWH, only 51 (7%) had a diagnosis of late syphilis and were therefore included in the study. Thirty-one subjects (61%) met one or more diagnostic criteria to perform LP: 39% (12/31) of patients undergoing LP had a diagnosis of ANS. The accuracy of predictive criteria for ANS, suggested by the guidelines, was 62% for RPR > 1:32 and 74% for CD4⁺ ≤ 350 cc/µL. The simultaneous occurrence of both criteria (RPR > 1:32 plus CD4⁺ ≤ 350 cc/µL) achieved a diagnostic accuracy of 59%. Interestingly, only 17% of patients who underwent LP for serological failure were eventually diagnosed positive for ANS. Conclusion: Asymptomatic neurosyphilis represents a challenging, but not uncommon, diagnosis. Therefore, it requires a careful investigation. Low CD4⁺ cell count and RPR > 1:32 remain excellent predictors of neurosyphilis, but have become the only acceptable predictors of ANS in PLWH. “Serologic failure” should be regarded with caution as a criterion to perform LP in order to investigate possible ANS in HIV-syphilis coinfected patients asymptomatic for neurological disorders. The retrospective nature of this single-site study may represent a limit to the interpretation of the data. Thus, larger clinical studies on the topic are warranted.