Comparison of macrocomplement and microcomplement fixation techniques used in fungus serology.

Area of Science:

• Medical Mycology
• Immunology
• Clinical Diagnostics

Background:

• Complement fixation (CF) tests are standard for diagnosing endemic mycoses.
• Micro- and macro- versions of the CF test are commonly employed.
• Standardization and comparison of these methods are crucial for reliable serodiagnosis.

Purpose of the Study:

• To comparatively evaluate the micro- and macro-complement fixation (CF) tests.
• To assess the reproducibility and diagnostic utility of the micro-CF test.
• To determine the suitability of the micro-CF test for endemic mycoses serodiagnosis.

Main Methods:

• Comparative analysis of micro- and macro-CF tests using 937 human sera.
• Testing against yeast-form antigens of *Blastomyces dermatitidis* and *Histoplasma capsulatum*.
• Utilizing coccidioidin and histoplasmin as soluble antigens for testing.

Main Results:

• Micro-CF test results correlated within +/- 1 dilution of macro-CF test results in 83-93% of sera.
• The micro-CF test demonstrated high reproducibility in quality control serum testing.
• Diagnostic and prognostic interpretations were similar between the micro- and macro-CF tests.

Conclusions:

• The micro-CF test is a sensitive, reproducible, economical, and easy-to-perform method.
• Micro-CF testing is highly recommended for routine use in fungus serology.
• This method offers reliable serodiagnosis for blastomycosis, coccidioidomycosis, and histoplasmosis.