Coccidioides Antibodies (IgG, IgM), Immunodiffusion with Reflex to Complement Fixation

40299

Antibody to TP Antigen (IgM) and Antibody to F Antigen (IgG)

If either Antibody to TP Antigen or Antibody to F Antigen are positive, then Coccidioides Antibody, Complement Fixation, Serum will be performed at an additional charge (CPT Code(s): 86635).

1.5 mL serum

0.25 mL

Room temperature

Room temperature: 7 days
Refrigerated: 14 days
Frozen: 30 days

Gross hemolysis • Grossly lipemic • Grossly icteric

Set up: Mon, Wed, Fri, Sat; Report available: 3-6 days

This immunodiffusion-based test for antibodies to F antigen (IgG) and TP antigen (IgM) is used to diagnose coccidioidomycosis. This disease, also known as valley fever, is caused by Coccidioides, an environmental fungus in the southwestern United States, Central America, and South America. This test may be ordered when patients who have lived in or traveled to endemic areas have clinical suspicion of coccidioidomycosis [1].

Approximately 40% of people with Coccidioides infection present with acute pulmonary symptoms resembling community-based bacterial pneumonia; others are asymptomatic. A small number of individuals develop pulmonary sequelae, and some may develop disseminated disease. Severe complications are more common in Black and Filipino individuals. Coccidioidomycosis is a reportable disease in some states and is most common in Arizona and California [1].

Serologic tests are the most frequently used laboratory approach to diagnose coccidioidomycosis. Other tests include culture, histopathologic examination, and molecular assays [1]. If the IgG or IgM result is positive, a complement fixation test for Coccidioides antibodies will be performed at additional cost. A positive result for IgG, IgM, or any other laboratory component defined by the Council of State and Territorial Epidemiologists confirms coccidioidomycosis in Arizona and California; other states generally require both laboratory and clinical evidence for the diagnosis [1]. A negative result does not exclude the diagnosis of coccidioidomycosis.

The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.

Reference
1. Surveillance for coccidioidomycosis - United States, 2011-2017. Centers for Disease Control and Prevention. Updated September 19, 2019. Accessed December 8, 2021. https://www.cdc.gov/mmwr/volumes/68/ss/ss6807a1.htm