Evaluation of cross-reactions in Histoplasma capsulatum serologic tests.
Cross-reactivity in Histoplasma serologic tests was evaluated by using sera from patients with histoplasmosis and other infections. Serum samples from 127 of 134 (95%) patients with histoplasmosis were judged positive by complement fixation tests, and 121 (90%) showed H bands, M bands, or both by immunodiffusion. Of these 134 patients, cross-reactions were seen to Blastomyces dermatitidis in 53 patients (40%), to Coccidioides immitis in 20 patients (16%), and to Aspergillus fumigatus in 3 patients (2%) by complement fixation. Serum samples from 5 of 99 patients (5%) with other fungal infections and from 5 of 46 patients (11%) with tuberculosis had M precipitin bands by the Histoplasma immunodiffusion test, whereas none of the 123 sera from patients with other bacterial, Mycoplasma, or viral infections showed H or M precipitin bands. In the complement fixation test, positive reactions were observed in 16 of 90 patients (18%) with other fungal infections, in 14 of 41 patients (34%) with tuberculosis, and in 18 of 105 patients (17%) with other bacterial, Mycoplasma, or viral infections. Positive reactions were seen by radioimmunoassay in 54 of 110 patients (49%) with other fungal infections, in 23 of 46 patients (50%) with tuberculosis, and in 35 of 123 patients (28%) with with other bacterial, Mycoplasma, or viral infections. These results demonstrate a wider range of cross-reactions in Histoplasma serology than has been previously recognized, and the cross-reactivity was greatest when observed by radioimmunoassay. Caution should be exercised in the interpretation of serologic data from patients with suspected fungal infections.
J
J
Wheat
M L
ML
French
S
S
Kamel
R P
RP
Tewari
D000908:Antibodies, Fungal / Q000032:analysis / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology; D000946:Antigens, Fungal / Q000276:immunology*; D001232:Aspergillus fumigatus / Q000276:immunology; D001758:Blastomyces / Q000276:immunology; D003045:Coccidioides / Q000276:immunology; D003168:Complement Fixation Tests; D003429:Cross Reactions; D000939:Epitopes; D005069:Evaluation Studies as Topic; D006658:Histoplasma / Q000276:immunology* / Q000302:isolation & purification; D006660:Histoplasmosis / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D006801:Humans; D005779:Immunodiffusion; D009174:Mycoplasma / Q000276:immunology; D011863:Radioimmunoassay
D000908:Antibodies, Fungal; D000942:Antigens, Bacterial; D000946:Antigens, Fungal; D000939:Epitopes