Clare L. Maxwell

Cerebrospinal Fluid Abnormalities in Patients with Syphilis: Association with Clinical and Laboratory Features

OBJECTIVE To define clinical and laboratory features that identify patients with neurosyphilis. METHODS Subjects (n=326) with syphilis but no previous neurosyphilis who met 1993 Centers for Disease Control and Prevention criteria for lumbar puncture underwent standardized history, neurological examination, venipuncture, and lumbar puncture. Neurosyphilis was defined as a cerebrospinal fluid (CSF) white blood cell count >20 cells/ microL or reactive CSF Venereal Disease Research Laboratory (VDRL) test result. RESULTS Sixty-five subjects (20.1%) had neurosyphilis. Early syphilis increased the odds of neurosyphilis in univariate but not multivariate analyses. In multivariate analyses, serum rapid plasma reagin (RPR) titer > or =1 : 32 increased the odds of neurosyphilis 10.85-fold in human immunodeficiency virus (HIV)-uninfected subjects and 5.98-fold in HIV-infected subjects. A peripheral blood CD4+ T cell count < or =350 cells/ microL conferred 3.10-fold increased odds of neurosyphilis in HIV-infected subjects. Similar results were obtained when neurosyphilis was more stringently defined as a reactive CSF VDRL test result. CONCLUSION Serum RPR titer helps predict the likelihood of neurosyphilis. HIV-induced immune impairment may increase the risk of neurosyphilis.

Normalization of cerebrospinal fluid abnormalities after neurosyphilis therapy: does HIV status matter?

To identify factors that affect normalization of laboratory measures after treatment for neurosyphilis, 59 subjects with neurosyphilis underwent repeated lumbar punctures and venipunctures after completion of therapy. The median duration of follow-up was 6.9 months. Stepwise Cox regression models were used to determine the influence of clinical and laboratory features on normalization of cerebrospinal fluid (CSF), white blood cells (WBCs), CSF protein concentration, CSF Venereal Disease Research Laboratory (VDRL) reactivity, and serum rapid plasma reagin (RPR) titer. Human immunodeficiency virus (HIV)-infected subjects were 2.5 times less likely to normalize CSF-VDRL reactivity than were HIV-uninfected subjects. HIV-infected subjects with peripheral blood CD4+ T cell counts of < or =200 cells/ mu L were 3.7 times less likely to normalize CSF-VDRL reactivity than were those with CD4+ T cell counts of >200 cells/ mu L. CSF WBC count and serum RPR reactivity were more likely to normalize but CSF-VDRL reactivity was less likely to normalize with higher baseline values. Future studies should address whether more intensive therapy for neurosyphilis is warranted in HIV-infected individuals.

Normalization of Serum Rapid Plasma Reagin Titer Predicts Normalization of Cerebrospinal Fluid and Clinical Abnormalities after Treatment of Neurosyphilis

BACKGROUND Success of neurosyphilis treatment is defined by normalization of cerebrospinal fluid (CSF) and clinical abnormalities. The goal of this study was to determine whether normalization of serum rapid plasma reagin (RPR) titer could accurately predict treatment success. METHODS One hundred ten patients who were enrolled in a longitudinal study of CSF abnormalities in syphilis had asymptomatic syphilitic meningitis, symptomatic syphilitic meningitis, or syphilitic eye disease and were treated for neurosyphilis. At 4, 7, and 13 months after treatment, serum RPR titer and CSF and clinical abnormalities were analyzed for normalization. Odds ratios for normalization of each CSF and clinical abnormality when serum RPR titer had normalized and the positive predictive value of normalization of serum RPR titer for normalization of CSF and clinical abnormalities were determined. RESULTS Serum RPR titer had normalized in 63 patients (57%) by 4 months after treatment, in 94 (85%) by 7 months, and in 97 (88%) by 13 months. Except for CSF protein concentration, normalization of serum RPR titer predicted normalization of other CSF and clinical abnormalities in >80% of patients at 4 months, >85% at 7 months, and >90% at 13 months. The odds of normalization of CSF and clinical abnormalities were 28-57-fold higher when serum RPR titer had normalized, compared with when it had not. Normalization of serum RPR titer was consistently less accurate in predicting treatment success in human immunodeficiency virus-infected patients who were not receiving antiretroviral therapy, compared with those who were receiving such therapy. CONCLUSIONS In most instances, normalization of serum RPR titer correctly predicts success of treatment of neurosyphilis, and follow-up lumbar puncture can be avoided.

CXCL13 as a cerebrospinal fluid marker for neurosyphilis in HIV-infected patients with syphilis.

Background: Asymptomatic neurosyphilis is more difficult to diagnose in human immunodeficiency virus (HIV)-infected patients because HIV itself can cause cerebrospinal fluid (CSF) pleocytosis. The proportion of CSF lymphocytes that are B cells is elevated in neurosyphilis, suggesting that the CSF concentration of the B cell chemoattractant, chemokine (C-X-C motif) ligand 13 (CXCL13) concentration may also be elevated. Methods: CSF and blood were collected from 199 HIV-infected patients with syphilis and neurosyphilis. Serum and CSF CXCL13 concentrations were determined. Results: Patients with neurosyphilis had higher CSF and serum CXCL13 concentrations compared to patients with syphilis but not neurosyphilis. The odds of having symptomatic neurosyphilis were increased by 2.23-fold for every log increase in CSF CXCL13 concentration and were independent of CSF white blood cell and plasma HIV RNA concentrations, peripheral blood CD4+ T cell count and use of antiretroviral medications. A cut-off of 10 pg/mL CSF CXCL13 had high sensitivity and a cut-off of 250 pg/mL or evidence of intrathecal synthesis of CXCL13 had high specificity for diagnosis of both symptomatic and asymptomatic neurosyphilis. CSF concentrations of CXCL13 declined after treatment for neurosyphilis. Conclusions: CSF CXCL13 concentration may be particularly useful for diagnosis of neurosyphilis in HIV-infected patients because it is independent of CSF pleocytosis and markers of HIV disease.

Interpreting cerebrospinal fluid pleocytosis in HIV in the era of potent antiretroviral therapy

BackgroundCerebrospinal fluid (CSF) pleocytosis may be seen in asymptomatic HIV-infected individuals. This finding complicates interpretation of CSF abnormalities when such individuals are evaluated for other central nervous system infections. The goal of this study was to determine the relationship between CSF pleocytosis, central nervous system (CNS) antiretroviral penetration, adherence to antiretroviral medication regimens, neurological symptoms and performance on neuropsychological tests.MethodsClinically stable HIV-infected individuals at any peripheral blood CD4+ T cell count or any plasma viral load were asked to attend study visits at entry and every 6 months thereafter for at least one year. At each visit, they underwent a standardized neurological and medication history; neurological examination; a brief neuropsychological test battery: venipuncture; lumbar puncture; and assessment of medication adherence. Generalized estimating equations (GEE) were used to assess the relationships between CSF pleocytosis and other variables.ResultsCSF pleocytosis was independently and significantly related to lack of current antiretroviral use (OR 5.9, 95% CI 1.8–18.6, p = 0.003), CD4 count > 200/ul (OR 23.4, 95% CI 3.1–177.3, p = 0.002) and detectable plasma HIV RNA (OR 3.3, 95% CI 1.1–9.4, p = 0.03). At visits where antiretrovirals were used, and taking into account detectable plasma HIV RNA, an antiretroviral regimen that contained two or more agents with good CNS penetration conferred a trend toward lower odds of CSF pleocytosis (OR 0.45, 95% CI 0.18–1.12, p = 0.087).ConclusionCSF pleocytosis is a characteristic of HIV disease that varies significantly with easily identifiable clinical and laboratory features. Use of antiretroviral agents decreases the odds of pleocytosis. This association may be stronger when the regimen contains two or more agents with good CNS penetration.

Alternative cerebrospinal fluid tests to diagnose neurosyphilis in HIV-infected individuals.

Objective: To identify alternatives to the CSF-Venereal Disease Research Laboratory (VDRL) test for the diagnosis of neurosyphilis in HIV-infected individuals. Methods: CSF fluorescent treponemal antibody (FTA) reactivity and % CSF lymphocytes that were B cells in fresh and frozen samples were determined for 47 HIV-infected cases with syphilis and 26 HIV-infected controls. As for serum, CSF fluorescent treponemal antibody reactivity ≥2+ was considered positive. Based on the results in controls and cases with normal CSF measures, cut-offs for elevated CSF B cells were proposed to be ≥9% in fresh and ≥20% in frozen samples. Neurosyphilis was defined as a reactive CSF-VDRL. Results: CSF-FTA-ABS (absorbed) and CSF-FTA (unabsorbed and undiluted) were 100% sensitive for the diagnosis of neurosyphilis. Elevated % CSF B cells in fresh and cryopreserved samples was specific (100%) but not sensitive (40 and 43%) in post hoc analyses. The results of CSF-FTA and assessment of % CSF B cells together allowed 16% of cases with pleocytosis but nonreactive CSF-VDRL to be diagnosed with neurosyphilis and 26% to be diagnosed as not having neurosyphilis. Conclusion: When the CSF-VDRL is nonreactive, CSF-FTA and % CSF B cells may help exclude or establish the diagnosis of neurosyphilis.

Resolution of serum and cerebrospinal fluid abnormalities after treatment of neurosyphilis : Influence of concomitant human immunodeficiency virus infection

Background and Objectives: Little is known about resolution of serum and cerebrospinal fluid abnormalities after neurosyphilis treatment, especially in patients infected with human immunodeficiency virus (HIV). Goal: To examine the time course of resolution of these abnormalities. Study Design: Case series of 22 patients with neurosyphilis (13 infected with HIV) with reactive cerebrospinal fluid Venereal Disease Research Laboratory test who underwent at least one lumbar puncture after treatment. Results: Resolution of all serum and cerebrospinal fluid measures was slower in patients infected with HIV. Serum and cerebrospinal fluid abnormalities resolved in most patients not infected with HIV by 30 weeks, and all met Centers for Disease Control and Prevention criteria for cure. One patient infected with HIV failed therapy by Centers for Disease Control and Prevention criteria, and three others had persistent pleocytosis. Conclusions: HIV‐infected patients with neurosyphilis have slower resolution of serum and cerebrospinal fluid abnormalities after therapy. This observation may suggest impaired clearance of Treponema pallidum from the central nervous system.

The rapid plasma reagin test cannot replace the venereal disease research laboratory test for neurosyphilis diagnosis.

Background: The cerebrospinal fluid (CSF) Venereal Disease Research Laboratory (VDRL) test is a mainstay for neurosyphilis diagnosis, but it lacks diagnostic sensitivity and is logistically complicated. The rapid plasma reagin (RPR) test is easier to perform, but its appropriateness for use on CSF is controversial. Methods: RPR reactivity was determined for CSF from 149 individuals with syphilis using 2 methods. The CSF-RPR was performed according to the method for serum. The CSF-RPR-V was performed using the method recommended for the CSF-VDRL. Laboratory-defined neurosyphilis included reactive CSF-fluorescent treponemal antibody absorption test and CSF white blood cells >20/uL. Symptomatic neurosyphilis was defined as vision loss or hearing loss. Results: CSF-VDRL was reactive in 45 (30.2%) patients. Of these, 29 (64.4%) were CSF-RPR reactive and 37 (82.2%) were CSF-RPR-V reactive. There were no instances where the CSF-VDRL was nonreactive but the CSF-RPR or CSF-RPR-V was reactive. Among the 28 samples that were reactive in all 3 tests, CSF-VDRL titers (median [IQR], 1:4 [1:4–1:16]) were significantly higher than CSF-RPR (1:2 [1:1–1:4], P = 0.0002) and CSF-RPR-V titers (1:4 [1:2–1:8], P = 0.01). The CSF RPR and the CSF-RPR-V tests had lower sensitivities than the CSF-VDRL: 56.4% and 59.0% versus 71.8% for laboratory-diagnosed neurosyphilis and 51.5% and 57.6% versus 66.7% for symptomatic neurosyphilis. Conclusions: Compared with the CSF-VDRL, the CSF-RPR has a high false-negative rate, thus not improving upon this known limitation of the CSF-VDRL for neurosyphilis diagnosis. Adapting the RPR procedure to mimic the CSF-VDRL decreased, but did not eliminate, the number of false negatives and did not avoid all the logistical complications of the CSF-VDRL.

Cerebrospinal Fluid Treponema pallidum Particle Agglutination Assay for Neurosyphilis Diagnosis

ABSTRACT Limited data suggest that the cerebrospinal fluid Treponema pallidum particle agglutination assay (CSF-TPPA) is sensitive and a CSF Treponema pallidum hemagglutination assay (CSF-TPHA) titer of ≥1:640 is specific for neurosyphilis diagnosis. CSF-TPPA reactivity and titer were determined for a convenience sample of 191 CSF samples from individuals enrolled in a study of CSF abnormalities in syphilis (training data set). The sensitivity of a reactive test and the specificity for reactivity at serial higher CSF dilutions were determined. Subsequently, CSF-TPPA reactivity at a 1:640 dilution was determined for all available samples from study participants enrolled after the last training sample was collected (validation data set, n = 380). Neurosyphilis was defined as (i) a reactive CSF Venereal Disease Research Laboratory test (CSF-VDRL), (ii) detection of T. pallidum in CSF by reverse transcriptase PCR, or (iii) new vision loss or hearing loss. In the training data set, the diagnostic sensitivities of a reactive CSF fluorescent treponemal antibody absorption test (CSF-FTA-ABS) and a reactive CSF-TPPA did not differ significantly (67 to 98% versus 76 to 95%). The specificity of a CSF-TPPA titer of ≥1:640 was significantly higher than that of lower dilutions and was not significantly different from that of CSF-VDRL. In the validation data set, the diagnostic specificity of a CSF-TPPA titer of ≥1:640 was high and did not differ significantly from that of CSF-VDRL (93 to 94% versus 90 to 91%). Ten CSF samples with a nonreactive CSF-VDRL had a CSF-TPPA titer of ≥1:640. If a CSF-TPPA titer of ≥1:640 was used in addition to a reactive CSF-VDRL, the number of neurosyphilis diagnoses would have increased from 47 to 57 (21.3%). A CSF-TPPA titer cutoff of ≥1:640 may be useful in identifying patients with neurosyphilis when CSF-VDRL is nonreactive.

Neurosyphilis Increases Human Immunodeficiency Virus (HIV)-associated Central Nervous System Inflammation but Does Not Explain Cognitive Impairment in HIV-infected Individuals With Syphilis

Background Individuals infected with human immunodeficiency virus (HIV) who have previously had syphilis may have cognitive impairment. We tested the hypothesis that neurosyphilis causes cognitive impairment in HIV by amplifying HIV-related central nervous system (CNS) inflammation. Methods HIV-infected participants enrolled in a study of cerebrospinal fluid (CSF) abnormalities in syphilis underwent the mental alternation test (MAT), venipuncture, and lumbar puncture. CSF concentrations of chemokine (C-X-C motif) ligand 10 (CXCL10), chemokine (C-C motif) ligand 2 (CCL2), and neurofilament light (NFL) were determined by commercial assays. The proportion of peripheral blood mononuclear cells (PBMCs) and of CSF white blood cells (WBCs) that were activated monocytes (CD14+CD16+) was determined by flow cytometry. Neurosyphilis was defined as detection of Treponema pallidum 16S RNA in CSF or CSF white blood cells (WBCs) >20/uL or a reactive CSF-Venereal Disease Research Laboratory (VDRL) test; uncomplicated syphilis was defined as undetectable CSF T. pallidum, CSF WBCs ≤5/uL and nonreactive CSF-VDRL. MAT <18 was considered low. Results Median proportion of PBMCs that were activated monocytes (16.6 vs. 5.3), and median CSF CXCL10 (10658 vs. 2530 units), CCL2 (519 vs. 337 units) and HIV RNA (727 vs. 50 c/mL) were higher in neurosyphilis than in uncomplicated syphilis (P ≤ .001 for all comparisons). Neurosyphilis was not related to low MAT scores. Participants with low MAT scores had higher median CSF CXCL10 (10299 vs. 3650 units, P = .008) and CCL2 (519 vs. 365 units, P = .04) concentrations than those with high MAT scores. Conclusions Neurosyphilis may augment HIV-associated CNS inflammation, but it does not explain cognitive impairment in HIV-infected individuals with syphilis.