title: Has CXCL13 an added value in diagnosis of neurosyphilis?
abstract: In patients with syphilis, central nervous system (CNS) involvement is often difficult to determine. In patients who also are infected with human immunodeficiency virus (HIV), this is even more challenging, as cerebrospinal fluid (CSF) pleocytosis can be attributed to HIV, syphilis, or both. Hence, this study investigated (i) CSF chemokine (C-X-C motif) ligand 13 (CXCL13) as a potential marker to diagnose neurosyphilis in HIV-infected individuals and (ii) the added value of CSF CXCL13 to conventional CSF biomarkers, such as the rapid plasma reagin test (RPR), in diagnosing neurosyphilis. We included 103 syphilis patients from two centers in The Netherlands: 47 non-HIV-infected patients and 56 HIV-infected patients. A positive CSF-RPR was regarded as the gold standard for neurosyphilis. CSF CXCL13 levels were significantly higher in neurosyphilis patients when neurosyphilis was diagnosed by CSF-RPR (P = 0.0002) than in the syphilis control group. The sensitivity and specificity of CSF CXCL13 (cutoff of 76.3 pg/ml) to diagnose neurosyphilis by using positive CSF-RPR as the gold standard were 50% and 90%, respectively. CSF CXCL13 had an added value to CSF-RPR positivity in 70% of HIV-positive patients and in 33% of HIV-negative patients. Our data show that CSF CXCL13 might be a potential additional marker in neurosyphilis when other markers are not conclusive. The added value of CSF CXCL13 measurement to the current neurosyphilis gold standard appears to benefit HIV-positive patients more than HIV-negative patients.
authors: Department of Internal Medicine and Nijmegen Institute for Infection, Inflammation and Immunity, Division of Infectious Diseases, Radboud University Nijmegen Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands Khutso.Mothapo@radboudumc.nl.
authors: Khutso M
authors: KM
authors: Mothapo
authors: Departments of Neurology and Laboratory Medicine, Radboud University Nijmegen Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
authors: Marcel M
authors: MM
authors: Verbeek
authors: Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands PAMM (Laboratory for Pathology and Microbiology), Veldhoven, The Netherlands.
authors: Lieven B
authors: LB
authors: van der Velden
authors: Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands.
authors: C Wim
authors: CW
authors: Ang
authors: Department of Internal Medicine and Nijmegen Institute for Infection, Inflammation and Immunity, Division of Infectious Diseases, Radboud University Nijmegen Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
authors: Peter P
authors: PP
authors: Koopmans
authors: Department of Internal Medicine and Nijmegen Institute for Infection, Inflammation and Immunity, Division of Infectious Diseases, Radboud University Nijmegen Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
authors: Andre
authors: A
authors: van der Ven
authors: Department of Medical Microbiology, Radboud University Nijmegen Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
authors: Foekje
authors: F
authors: Stelma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000134:cerebrospinal fluid*; D054382:Chemokine CXCL13 / Q000134:cerebrospinal fluid*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D015658:HIV Infections / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D009494:Neurosyphilis / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers; C110663:CXCL13 protein, human; D054382:Chemokine CXCL13