Publication Abstract Display | Type: Published Abstract | Title: Quantification of CSF lactic acid in chronic HIV meningitis: opportunistic CNS infection meningitis by Crytococcus neoformans, tuberculosis, and herpesviridae meningoencephalitis. | Authors: de Almeida S, Boritza K, Vidal L, Pessa L, Ribeiro C, Franca J, Rota I, Muro M, Rosario D, Ellis R | Year: 2009 | Publication: UCSD Center for AIDS Research | Volume: Issue: Pages: | Abstract:Background: 40% of HIV infected patients have chronic meningitis; 59% are
asymptomatic. This is an exclusion diagnosis and a confounding factor for cerebral
spinal fluid (CSF) analysis. Causes of chronic meningitis by opportunistic or coinfections
such as Cryptococcus neoformans, tuberculosis (Tb), or syphilis must be
ruled out. CSF concentration of lactic acid (LA) is directly dependent upon its central
nervous system (CNS) production rate. The aim of this study was to analyze CSF LA
levels in chronic meningitis (caused by HIV, C. neoformans, and tuberculosis) and
acute viral meningitis (by enterovirus and Herpesvidae) in order to identify a CSF
adjuvant biomarker that may assist in the differential diagnosis between increasing
number of CSF cells due to HIV or that due to an opportunistic infection.
Methods: In this retrospective, cross-sectional study CSF LA was quantified in 134
samples by Dimension AR. Samples were divided into seven groups: HIV positive with
increased CSF WBCs (n=11); HIV positive with normal CSF (n=15); Enterovirus
meningitis (n=26); Herpesviridae meningoencephalitis (n=18) HIV positive or negative;
C.neoformans meningitis (n=17) diagnosed by direct mycological examination, antigen
latex agglutination, culture; Suspicion of Tb meningitis (n=5); and control group: HIV
negative, no meningitis (n=42). Continuous variables were compared using nonparametric
tests Kruskal-Wallis and Mann-Whitney.
Results: CSF LA (mean+SD; median [IQR]) was higher in samples with C.neoformans
meningitis (4.3+2.3; 4.0 [2.5-6.1] mmol/L) and those with suspicion of Tb meningitis
(5.9+4.1; 5.5 [0.8-10] mmol/L) compared to samples with HIV chronic meningitis
(1.5+0.2; 1.6 [1.4-1.7] mmol/L) and other groups (KW, P<0.0001). There was no
difference between the HIV viral meningitis group and other groups. For diagnosis of
C.neoformans meningitis (cutoff: 3.5 mmol/L), the sensitivity is 71%, specificity 96%,
positive predictive factor (PPF) 75%, and negative predictive factor (NPF) 96%. For the
diagnosis of tuberculosis meningitis the sensitivity is 80%, specificity 96%, PPF 50%,
and NPF 96%.
Conclusions: CSF LA is a useful adjuvant biomarker for discriminating C.neoformans
or suspicion of Tb meningitis from HIV chronic meningitis. Although it does not
replace current methods used to identify these specific pathogens, it may be associated
with them. CSF LA quantification is a rapid, easy, and inexpensive tool that can be
employed in developing world settings. |
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