963. Routine CSF analysis based on coccidioidal CF antibody titers:  evidence based practice or dogma?
Session: Poster Abstract Session: Clinical Mycology
Saturday, October 22, 2011
Room: Poster Hall B1
Background: Coccidioidal complement fixation (CF) IgG antibody titers have been shown to correlate with patient symptoms.  Antibody titers exceeding 1:16 frequently prompt evaluation for evidence of disseminated infection.  Absent data regarding the likelihood of clinically silent CSF involvement, lumbar puncture (LP) with CSF analysis is often performed on patients with high CF titers even in the absence of CNS symptoms. Since this practice subjects patients to potentially harmful and unneeded diagnostic testing, the utility of this approach was evaluated.

Methods: As part of a multicenter collaborative group aimed at improving care in patients with coccidioidomycosis a retrospective analysis of all patients undergoing CSF examination for possible coccidioidal meningitis was performed.  Clinical variables including demographic data, patient symptoms and exam findings, serum coccidioidal CF antibody titers, and CSF results were collected.  Neurologic abnormalities were defined as headache, photophobia, focal deficits, seizures, neurologic abnormalities on examination or abnormal CNS radiographic studies.

Results: Eighty-eight patients with known coccidioidomycosis who underwent an LP were identified.  Seven patients (8%) were diagnosed with CNS coccidioidomycosis following CSF analysis, all of whom exhibited at least one sign or symptom of CNS infection before the LP.  Forty-two (47%) patients had no clinical signs or symptoms of CNS involvement and no patient in this group was ultimately found to have meningitis by LP (P=0.013).  However, while all patients diagnosed with CNS infection had at least one sign or symptom only 15% (7/46) of those with suggestive symptoms/signs were proven to have CNS infection. 

Conclusion: In patients with coccidioidomycosis without symptoms or signs of CNS infection LP is unhelpful and should not be recommended as part of the routine evaluation of patients with elevated coccidioidal CF antibody titers.  The absence of clinical signs and symptoms was highly sensitive (100%), and had a high negative predictive value (100%) for ruling out coccidioidal meningitis in this cohort.  In contrast, the specificity (52%) of clinical signs and symptoms was low, as was the positive predictive value (15%) in this cohort.


Subject Category: M. Mycology including clinical and basic studies of fungal infections

George R. Thompson III, MD1, Sharon Wang, DO2, Robert Bercovitch, MD3, Michael Bolaris, MD4, Addie Spier4, Rodrigo Lopez, MD5, Antonio Catanzaro3, Jose Cadena, MD6, Peter Chin-Hong, MD7 and Brad Spellberg, MD, FIDSA8, (1)Medical Microbiology and Immunology, University of California-Davis, Davis, CA, (2)University of California - Davis, Sacramento, CA, (3)University of California - San Diego, La Jolla, CA, (4)Harbor - UCLA Medical Center, Torrance, CA, (5)University of Texas Health Science Center - San Antonio, San Antonio, TX, (6)Dept. of Med, Infectious Diseases and Ctr for Patient Safety and Health Policy,Univ. of Texas Health Science Ctr at San Antonio., San Antonio, TX, (7)Internal Medicine, Division of Infectious Disease, UCSF, San Francisco, CA, (8)Harbor-UCLA Medical Center, Torrance, CA

Disclosures:

G. R. Thompson III, Pfizer: Investigator, Research support

S. Wang, None

R. Bercovitch, None

M. Bolaris, None

A. Spier, None

R. Lopez, None

A. Catanzaro, None

J. Cadena, None

P. Chin-Hong, None

B. Spellberg, None

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