Finding neurosyphilis without the Venereal Disease Research Laboratory test

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.

Clinical presentation and outcomes of syphilitic meningitis among hospitalized adults in lusaka, Zambia

Background

Few studies exist to describe the characteristics of symptomatic syphilitic meningitis, particularly in sub-Saharan Africa, despite a global resurgence.

Methods

We conducted a retrospective analysis of a cohort of adults with meningitis presenting to Zambia’s largest referral hospital between April 2014 and December 2017. Individuals with pyogenic bacterial and cryptococcal meningitis were excluded from this cohort. We calculated the prevalence of syphilitic meningitis in the cohort and described the demographic, clinical and laboratory characteristics and outcomes.

Results

Of 512 participants, 273 were male, mean age was 37 ± 11 years and 84% were people living with HIV. The prevalence of syphilitic meningitis was 5% with in-hospital and 1-year mortality of 17% and 53%, respectively. Participants with syphilitic meningitis had lower Glasgow Coma Scores than those with other forms of meningitis. Among people living with HIV, those with syphilitic meningitis were less likely to have meningismus and had higher CSF white cell counts.

Conclusions

Syphilitic meningitis was found in 5% of Zambian adults presenting with non-pyogenic bacterial meningitis and non-cryptococcal meningitis, and one-year mortality was high. A high degree of clinical suspicion for syphilitic meningitis in all individuals with meningitis in Zambia is recommended, especially in people living with HIV.

Neurosyphilis in HIV-infected patients

A review article is addressed the issue of the diagnosis and treatment of neurosyphilis that is developing against the background of HIV-infection. HIV-infected patients are at higher risk of neurologic, ocular and auricular manifestation of syphilis as well as treatment failures and relapses. Diagnosis of neurosyphilis in HIV-positive patients is complicated because both infections cause similar changes in the cerebrospinal fluid (CSF). The effectiveness of neurosyphilis treatment in patients with HIV co-infection is difficult to estimate, since the normalization of their CSF goes slower comparing to HIV-negatives. The increase in incidence of syphilis and HIV co-infection is anticipated in the coming years. This necessitates a comprehensive study of the problem and requires the development of new approaches to neurosyphilis diagnosis and treatment in co-infected patients.

Evaluation of treponemal serum tests performed on cerebrospinal fluid for diagnosis of neurosyphilis

OBJECTIVES

We evaluated the use of treponemal serum tests in cerebrospinal fluid (CSF) to diagnose neurosyphilis since CSF-Venereal Disease Research Laboratory (VDRL) is specific but lacks sensitivity.

METHODS

We tested CSF specimens using the following treponemal serum tests: INNO-LIA, Treponema pallidum particle agglutination (TP-PA), Trep-Sure, and Maxi-Syph. The reference standard to calculate sensitivity and specificity was having two or more reactive/positive tests on CSF.

RESULTS

The reference standard group included 11 cases that fulfilled the definition of neurosyphilis (reactive CSF-VDRL plus symptoms) and three cases that did not fulfill the definition: two cases had neurologic symptoms but a nonreactive CSF-VDRL, and one had several positive CSF syphilis tests (reactive VDRL and positive treponemal and syphilis polymerase chain reaction) but no history (referred sample). Controls included 18 patients in whom a CSF-VDRL was performed the same week as patients in the reference group. The sensitivity was 85.7% (12/14) for CSF-VDRL, 92.9% (13/14) for Trep-Sure, 100% (10/10) for Maxi-Syph, 92.3% (12/13) for INNO-LIA, and 83.3% (10/12) for TP-PA. Specificity was 100% for all tests.

CONCLUSIONS

Treponemal serum tests performed on CSF were useful in identifying two patients with nonreactive CSF-VDRL.

Experience of meningovascular syphilis in human immunodeficiency virus infected patient

Since the start of the antibiotic era, syphilis has become rare. However, in recent times, it has tended to be prevalent concomitantly with human immunodeficiency virus (HIV) infection and coinfection in North America and Europe. Now, such cases are expected to increase in elsewhere including Korea. A 40-year-old male patient visited hospital complaining of a headache for about one month. Brain computed tomography and magnetic resonance imaging, showed leptomeninged enhancing mass with edema an right porisylvian region, which was suspected to be glioma. Patient underwent a blood test and was diagnosed with syphilis and acquired immune deficiency syndrome. Partial cortical and subcortical resection were performed after small craniotomy. The dura was thick, adhered to the brain cortex, and was accompanied by hyperemic change of the cortex. The pathologic diagnosis was meningovascular syphilis (MS) in HIV infection. After the operation, the patient was treated with aqueous penicillin G. Thereafter, he had no neurological deficit except intermittent headache. At first, this case was suspected to be glioma, but it was eventually diagnosed as MS in HIV coinfection. At this point the case was judged to be worth reporting.

A review of pediatric uveitis: Part I. Infectious causes and the masquerade syndromes

Uveitis is a manifestation of complex processes that can represent an infectious or a purely immune system modulated condition and may have grave effects on the eye. Much of the morbidity in these conditions is the result of the immune response to these stimuli. These infectious diseases may be successfully treated by addressing the inciting organism with recognized interventions. Treatment of the immune response to the organism often must be pursued simultaneously to minimize long-term complications caused by structural changes within the eye. Assisting the individual's immune response to eliminate the organism while minimizing the immune response's damaging effects remains a unique challenge drawing on both the science and the art of medicine. Several non-infectious conditions that are not autoimmune diseases may commonly masquerade as uveitis, leading to delays in appropriate treatment.

Syphilis management and treatment

Syphilis poses a serious health problem in many developing countries and in some areas of North America and Europe, especially Eastern Europe. This article initially addresses the state of the art regarding the interaction between syphilis and HIV infection and its consequences for management and treatment. Further attention is given to laboratory diagnosis of syphilis and false-positive and false-negative serologic reactions. The diagnosis and management of neurosyphilis, ocular, cardiovascular, and congenital syphilis are addressed, as well as management of syphilis patients allergic to penicillin and the Jarisch-Herxheimer reaction. Finally, the role of partner(s) and contact tracing is discussed.

Syphilis. Serology

Microbiologic tests are essential in the diagnosis and management of patients with syphilis. Apart from the very early stage of disease (when T. pallidum may be detected in the lesions of primary syphilis before an antibody response is detectable) serology is the mainstay of laboratory testing. The performance of cardiolipin antigen ("reagin") and treponemal antigen (native and recombinant) tests is discussed in relation to the stage of syphilis, treatment status, and interactions between syphilis and HIV infection. Screening with cardiolipin antigen tests detects early stage disease, but treponemal antigen tests are required for the reliable detection of late-stage infection and the exclusion of syphilis in HIV-infected patients. EIA tests using treponemal antigen are sensitive and specific and fit well into current laboratory practices. Although the FTA-abs test is often considered the "gold standard" confirmatory test, its sensitivity is slightly lower than that of certain other treponemal antigen tests. A reactive antitreponemal IgM test correlates well with untreated or recently treated early infection, but specific IgM tests are often negative in untreated late-stage disease. Serial quantitative cardiolipin antigen tests remain the method of choice for monitoring the efficacy of treatment. The role of the laboratory in aiding a diagnosis of neurosyphilis and congenital infection is discussed briefly, as is the current status of newer technologies, such as PCR and immunoblotting.