Abstract
The limulus factor G reacts with (1→3)‐β‐D‐glucan, a major structural component of fungal cell walls. The Fungitec G test is a colorimetric assay that measures the concentration of (1→3)‐β‐D‐glucan and is used as a serodiagnostic test for deep mycosis. Wako‐WB003 is another assay for (1→3)‐β‐D‐glucan that determines the change in turbidity of the gelatin reaction of limulus factor G with (1→3)‐β‐D‐glucan. In five rabbits inoculated intravenously with 1 × 107 CFU of Candida albicans, the concentration of (1→3)‐β‐D‐glucan measured by the fungitec G test increased gradually reaching a peak of 660.9 ± 427.9 pg/ml (mean ± SD) 4 days after inoculation, but to 42.225 ± 41.275 ng/ml on day 6 in the Wako‐WB003 test. In one rabbit challenged intravenously with 5 × 106 CFU of C. albicans, (1→3)‐β‐D‐glucan increased to 101.5 pg/ml on day 4 on the fungitec G test, whereas the level remained below the detection limit of the Wako‐WB003 test throughout the course of the disease. We also detected high concentrations of (1→3)‐β‐D‐glucan in 11 patients with candidemia, 4 with suspected candidemia, 1 with invasive pulmonary aspergillosis, and 12 patients with aspergilloma. The concentration of (1→3)‐β‐D‐glucan measured by the Fungitec G test was > 150, > 1006.8, 312.1, and 55.6 ± 37.4 pg/ml (range, 20.1–138.0 pg/ml), and by the Wako‐WB003 test > 153.000, > 17.70, 153.000 and 2.645 ± 7.248 ng/ml (range, < 25.20 ng/ml) in these patients, respectively. In contrast, the concentration of (1→3)‐β‐D‐glucan in 9 patients with pulmonary cryptococcosis and 6 with superficial candida colonization ranged from < 13.2 and < 15.3 pg/ml in the Fungitec G test and < 0.53 and < 0.12 ng/ml in Wako‐WB003 test. There was a weak relationship between the concentration of (1→3)‐β‐D‐glucan measured by the Fungitec G test and Wako‐WB003 test (r = 0.521). Our results indicate that the sensitivity of the Wako‐WB003 test is lower than that of the Fungitec G test. J. Clin. Lab. Anal. 11:73–77. © 1997 Wiley‐Liss, Inc.
Keywords: Fungitec G test, Wako‐WB003 test, (1→3)‐β‐D‐glucan, candidiasis, aspergillosis, diagnostic test
References
- 1. Kohno S: Development of diagnostic procedure for deep‐seated mycosis. Asian Med J 34: 665–671, 1991. [Google Scholar]
- 2. Nakamura A, Ishikawa N, Suzuki H: Diagnosis of invasive candidiasis by detection of mannan antigen by using the avidin‐biotin enzyme immunoassay. J Clin Microbiol 29: 2363–2367, 1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Kohno S, Mitsutake K, Maesaki S, Yasuoka A, Miyazaki T, Kaku M, Koga H, Hara K: An evaluation of serodiagnostic tests in patients with candidemia: (1→3)‐β‐D‐glucan, mannan, candida antigen by Cand‐Tec, and D‐arabinitol. Microbiol Immunol 37: 207–212, 1993. [DOI] [PubMed] [Google Scholar]
- 4. Ikegami K, Ikemura K, Shimazu T, Shibuya M, Sugimoto H, Yoshioka T, Sugimoto T: Early diagnosis of invasive candidiasis and rapid evaluation of antifungal therapy by combined use of conventional chromogenic limulus test and a newly developed endotoxin specific assay. J Trauma 28: 1118–1126, 1988. [DOI] [PubMed] [Google Scholar]
- 5. Obayashi T, Yoshida M, Tamura H, Aketagawa J, Tanaka S, Kawai T: Determination of plasma (1→3)‐β‐D‐glucan: A new diagnostic aid to deep mycosis. J Med Vet Mycol 30: 275–280, 1992. [DOI] [PubMed] [Google Scholar]
- 6. Miyazaki T, Kohno S, Koga H, Kaku M, Mitsutake K, Maesaki S, Yasuoka A, Hara K, Tanaka S, Tamura H: G test, a new direct method for diagnosis of Candida infection: Comparison with assays for betaglucan and mannan antigen in a rabbit model of systemic candidiasis. J Clin Lab Anal 6: 315–318, 1992. [DOI] [PubMed] [Google Scholar]
- 7. Kakinuma A, Asano T, Torii H, Sugino Y: Gelation of Limulus amoebocyte lysate by an antitumor (1→3)‐β‐D‐glucan. Biochem Biophys Res Commun 101: 434–439, 1981. [DOI] [PubMed] [Google Scholar]
- 8. Morita T, Tanaka S, Nakamura T, Iwanaga S: A new (1→3)‐β‐D‐glucan‐mediated coagulation pathway found in Limulus amebocytes. FEBS Lett 129: 318–321, 1981. [Google Scholar]
- 9. Iwanaga M, Miyata T, Tokunaga F, Muta T: Molecular mechanism of hemolymph clotting system in Limulus . Thromb Res 68: 1–32, 1992. [DOI] [PubMed] [Google Scholar]
- 10. Tanaka S, Aketagawa J, Takahashi S, Shibata Y, Tsumuraya Y, Hashimoto Y: Activation of a limulus coagulation factor G by (1→3)‐β‐D‐glucans. Carbohydr Res 218: 167–174, 1991. [DOI] [PubMed] [Google Scholar]
- 11. Obayashi T, Tamura H, Tanaka S, Ohki M, Takahashi S, Arai M, Masuda M, Kawai T: A new chromogenic endotoxin‐specific assay using recombined limulus coagulation enzymes and its clinical applications. Clin Chim Acta 149: 55–63, 1985. [DOI] [PubMed] [Google Scholar]
- 12. Miyazaki T, Kohno S, Mitsutake K, Yamada H, Yasuoka A, Maesaki S, Kaku M, Koga H, Hara K: Combination of conventional and endotoxin‐specific limulus tests for measurement of polysaccharides in sera of rabbits with experimental systemic candidiasis. Tohoku J Exp Med 168: 1–9, 1992. [DOI] [PubMed] [Google Scholar]
- 13. Miyazaki T, Kohno S, Mitsutake K, Maesaki S, Tanaka K, Ishikawa N, Hara K: Plasma (1→3)‐β‐D‐glucan and fungal antigenemia in patients with candidemia, aspergillosis, and cryptococcosis. J Clin Microbiol 33: 3115–3118, 1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14. Aketagawa J, Tanaka S, Tamura H, Shibata Y, Saito H: Activation of limulus coagulation factor G by several (1→3)‐β‐D‐glucan: Comparison of the potency of glucans with identical degree of polymerization but different conformations. J Biochem 113: 683–686, 1993. [DOI] [PubMed] [Google Scholar]
- 15. Zhang G, Baek L, Buchardt O, Koch C: Differential blocking of coagulation‐activating pathways of Limulus amebocyte lysate. J Clin Microbiol 32: 1537–1541, 1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16. Miyazaki T, Kohno S, Mitsutake K, Maesaki S, Hara K: (1→3)‐β‐D‐glucan in culture fluid of fungi activates factor G, a limulus coagulation factor. J Clin Lab Anal 9: 334–339, 1995. [DOI] [PubMed] [Google Scholar]
- 17. Mitsutake K, Kohno S, Miyazaki T, Yamamoto Y, Yanagihara K, Kakeya H, Hashimoto A, Koga H: Detection of (1→3)‐β‐D‐glucan in a rat model of aspergillosis. J Clin Lab Anal 9: 119–122, 1995. [DOI] [PubMed] [Google Scholar]