title: Quantification of cerebrospinal fluid lactic acid in the differential diagnosis between HIV chronic meningitis and opportunistic meningitis.
abstract: BACKGROUND
  Approximately 40% of HIV infected patients have chronic meningitis at various stages during the infection, 59% are asymptomatic. This is a diagnosis of exclusion and a confounding factor in cerebrospinal fluid (CSF) analysis, any other causes of chronic meningitis by opportunistic or co-infection must be ruled out. The aim of this study was to analyze CSF lactic acid (LA) as an adjuvant biomarker in chronic meningitis due to HIV.
  
  
  METHODS
  CSF LA was quantified in 223 CSF samples by the Dimension AR (Dade Behring, Deerfield, IL, USA), distributed into nine groups: 1) HIV positive with an increase in CSF WBCs (n=17); 2) HIV positive with normal CSF (n=20); 3) enterovirus meningitis (n=33); 4) Herpesviridae meningoencephalitis (n=30); 5) fungal meningitis (n=25); 6) tuberculosis (TB) meningitis (n=17); 7) toxoplasmosis (n=18); 8) neurosyphilis (n=6); 9) control group (n=57).
  
  
  RESULTS
  CSF LA (median; IQR) was higher in samples with TB meningitis (5.5; 2.9-7.5 mmol/L) and Cryptococcus neoformans meningitis (3.9; 2.7-5.8 mmol/L) compated with samples with HIV chronic meningitis (1.7; 1.4-1.9 mmol/L) and other groups (p ≤ 0.0001). For the diagnosis of HIV chronic meningitis, using a cut-off of 3.5 mmol/L, CSF LA showed high sensitivity and negative predictive value, although low specificity.
  
  
  CONCLUSIONS
  CSF LA helps to discriminate between C. neoformans or TB meningitis and HIV chronic meningitis: CSF LA can be included with the methods currently used to identify these specific pathogens, though it does not replace them. It is rapid, inexpensive and easy to perform, and can be used in developing countries.
authors.affiliation: Virology Section, Clinical Pathology Laboratory, Hospital de Clínicas, Federal University of Paraná, Curitiba, Brazil. sergio.ma@pop.com.br
authors.forename: Sérgio Monteiro
authors.initials: SM
authors.lastname: de Almeida
authors.forename: Kátia
authors.initials: K
authors.lastname: Boritza
authors.forename: Laura Lucia
authors.initials: LL
authors.lastname: Cogo
authors.forename: Luis
authors.initials: L
authors.lastname: Pessa
authors.forename: João
authors.initials: J
authors.lastname: França
authors.forename: Indianara
authors.initials: I
authors.lastname: Rota
authors.forename: Marisol
authors.initials: M
authors.lastname: Muro
authors.forename: Cléa
authors.initials: C
authors.lastname: Ribeiro
authors.forename: Sonia Mara
authors.initials: SM
authors.lastname: Raboni
authors.forename: Luine Rosele
authors.initials: LR
authors.lastname: Vidal
authors.forename: Meri Bordignon
authors.initials: MB
authors.lastname: Nogueira
authors.forename: Ronald
authors.initials: R
authors.lastname: Ellis
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000134:cerebrospinal fluid* / Q000175:diagnosis*; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000134:cerebrospinal fluid; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D019344:Lactic Acid / Q000134:cerebrospinal fluid*; D008297:Male; D008587:Meningitis, Viral / Q000134:cerebrospinal fluid* / Q000150:complications / Q000175:diagnosis*; D008875:Middle Aged; D055815:Young Adult
chemical_list: D015415:Biomarkers; D019344:Lactic Acid