Test Catalog

Test ID: HICBL    
Histoplasma/Blastomyces Panel, Spinal Fluid

Useful For Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of Histoplasma meningitis


Detecting antibodies in patients having blastomycosis

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

See Meningitis/Encephalitis Panel Algorithm in Special Instructions.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test


Histoplasma capsulatum is a soil saprophyte that grows well in soil enriched with bird droppings. The usual disease is self-limited, affects the lungs, and is asymptomatic. Chronic cavitary pulmonary disease, disseminated disease, and meningitis may occur and can be fatal, especially in young children and immunosuppressed patients.



The dimorphic fungus, Blastomyces dermatitidis, causes blastomycosis. When the organism is inhaled, it causes pulmonary disease: cough, pain, and hemoptysis, along with fever and night sweats. It commonly spreads to the skin, bone, or internal genitalia where suppuration and granulomas are typical. Occasionally, primary cutaneous lesions after trauma are encountered; however, this type of infection is uncommon. Central nervous system disease is uncommon.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Histoplasma ANTIBODY

Mycelial by complement fixation: Negative

Yeast by complement fixation: Negative

Antibody by immunodiffusion: Negative




Interpretation Provides information to assist in interpretation of the test results


-Any positive serologic result in spinal fluid is significant.

-Simultaneous appearance of the H and M precipitin bands indicates active histoplasmosis.

-The M band alone indicates active or chronic disease or a recent skin test for histoplasmosis.



A positive result is suggestive of infection, but the results cannot distinguish between active disease and prior exposure. Furthermore, detection of antibodies in cerebrospinal fluid (CSF) may reflect intrathecal antibody production, or may occur due to passive transfer or introduction of antibodies from the blood during lumbar puncture.


Routine fungal culture of clinical specimens (eg, CSF) is recommended in cases of suspected blastomycosis involving the central nervous system.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances


-Antibody levels may be low in spinal fluid in cases of Histoplasma meningitis.

-Histoplasmin skin tests yield specific antibodies in titratable quantity, and may cause difficulties in interpretation.

-Cross-reacting antibodies with coccidioidomycosis or blastomycosis may cause false-positive results for histoplasmosis.



-A negative result does not rule out blastomycosis.

-Patients with histoplasmosis may have low-titered cross reactions.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Kaufman L, Kovacs JA, Reiss E: Clinical immunomycology. In: Rose NL, Conway-de Macario E, Folds JD, eds. Manual of Clinical and Laboratory Immunology. ASM Press; 1997:588-589

2. Gauthier GM, Klein BS: Blastomycosis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Elsevier; 2020:3177-3189

3. Deepe GS: Histoplasma capsulatum Histoplasmosis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Elsevier; 2020:3162-3176

Special Instructions Library of PDFs including pertinent information and forms related to the test