1823. Elevation of AST to ALT Ratio in Disseminated Histoplasmosis as Compared to Local Disease and Other Endemic Fungi
Session: Oral Abstract Session: Fungal Infections
Saturday, October 5, 2013: 3:00 PM
Room: The Moscone Center: 300
Background: Histoplasma capsulatum is one of the most common causes of fungal infection in the United States.  Severe pulmonary or disseminated infection necessitates presumptive treatment while awaiting definitive tissue diagnosis. Histoplasma antigenemia/antigenuria assays have improved earlier detection but results may be delayed. In order to increase diagnostic certainty, “soft clues” may be looked for in laboratory data, such as elevated alkaline phosphatase or ferritin levels. At our institution, we observed an elevated AST/ALT ratio in patients with disseminated histoplasmosis. We sought to determine whether this finding is unique to histoplasmosis or a non-specific marker for disseminated fungal infection or sepsis in general.

Methods: We retrospectively examined electronic and microbiology records of all patients with tissue cultures positive for endemic fungi. We identified 90 cases of endemic fungal infections (EFIs) at our institution from 1997-2012 (Histoplasma 21, Blastomyces 56, Coccidioides 12, Paracoccidioides 1).  We also evaluated 9 patients that met 3 to 4 SIRS (systemic inflammatory response syndrome) criteria and had proven bacterial infection. We analyzed data based on type of fungal infection, underlying host immune status, and extent of disease.  The data was analyzed using one way and two way ANOVAs.

Results: The mean AST/ALT ratio in patients with disseminated histoplasmosis was 2.53 (range 0.85-5.7). For other EFIs, the mean ratio was 0.99 (range 0.11-1.63). The AST/ALT ratio was significantly higher in patients with disseminated histoplasmosis (p<0.0001). Although not as high as in disseminated histoplasmosis, patients with musculoskeletal blastomycosis had a higher AST/ALT ratio than other groups, likely from skeletal muscle inflammation.

Conclusion: We propose use of the AST/ALT ratio as a clinical “soft clue” suggestive of the diagnosis of disseminated histoplasmosis in the appropriate host.

Andrej Spec, MD1, Christopher Barrios, MD1, Usama Ahmad, MD1 and Laurie Proia, MD2, (1)Rush University Medical Center, Chicago, IL, (2)Infectious Disease, Rush University Medical Center, Chicago, IL

Disclosures:

A. Spec, None

C. Barrios, None

U. Ahmad, None

L. Proia, None

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