Cryptococcal Antigen
| Label Mnemonic: | CRYAG |
| Epic code: | LAB2233 |
| Order form: | Microbiology Laboratory Requisition |
| Supply order: | Supply Order Form |
| Billing: | Billing Policies |
| CPT code: | 87899 |
Specimen(s):
CSF, Serum
Collection Medium:
 |
| Red top tube 5 mL (Clot Activator) |
Minimum:
1 mL; CSF or serum (red top)
Testing
Schedule:
24 hrs/day, 7 days a week, including holidays. Results are available within 2 hours.
Comments:
Refrigerate if delayed.
Test
Limitations:
The presence of cryptococcal antigen is indicative of cryptococcosis.
Monitoring titers is not recommended as low-level titers may persist
for a year or more in the absence of active infection [3,4].
Samples that are positive by the cryptococcal antigen assay will automatically reflex to a titer.
Cryptococcal antigen titers obtained with this method (IMMY lateral flow) are usually higher than those obtained with latex agglutination, which is the method that most prior research and guidelines have used as a gold standard [1,2,5]. Titers acquired by different methods are not always interchangeable but the titers reported for the lateral flow assay at the University of Iowa have been calibrated to the most commonly used historical method (Meridian Bioscience CALAS latex agglutination) and should be considered comparable.
Hemolyzed samples may interfere with the lateral flow assay, causing a false-negative result. Other potential interferences such as Trichosporon spp. have not been evaluated.
[1] J. R. Perfect, W. E. Dismukes, F. Dromer, D. L. Goldman, J. R. Graybill, R. J. Hamill, T. S. Harrison, R. A. Larsen, O. Lortholary, M.- H. Nguyen, P. G. Pappas, W. G. Powderly, N. Singh, J. D. Sobel, and T. C. Sorrell, "Clinical Practice Guidelines for the Management of Cryptococcal Disease: 2010 Update by the Infectious Diseases Society of America," Clin Infect Dis., vol. 50, no. 3, pp. 291�322, Feb. 2010.
[2] O. Lortholary, G. Poizat, V. Zeller, S. Neuville, A. Boibieux, M. Alvarez, P. Dellamonica, F. Botterel, F. Dromer, and G. Ch�ne, "Long- term outcome of AIDS-associated cryptococcosis in the era of combination antiretroviral therapy:," AIDS, vol. 20, no. 17, pp. 2183� 2191, Nov. 2006.
[3] S. Antinori, A. Radice, L. Galimberti, C. Magni, M. Fasan, and C. Parravicini, "The Role of Cryptococcal Antigen Assay in Diagnosis and Monitoring of Cryptococcal Meningitis," J. Clin. Microbiol., vol. 43, no. 11, pp. 5828�5829, Nov. 2005.
[4] A. E. Brouwer, P. Teparrukkul, S. Pinpraphaporn, R. A. Larsen, W. Chierakul, S. Peacock, N. Day, N. J. White, and T. S. Harrison, "Baseline Correlation and Comparative Kinetics of Cerebrospinal Fluid Colony-Forming Unit Counts and Antigen Titers in Cryptococcal Meningitis," J Infect Dis., vol. 192, no. 4, pp. 681�684, Aug. 2005.
[5] T. Kabanda, M. J. Siedner, J. D. Klausner, C. Muzoora, and D. R. Boulware, "Point-of-Care Diagnosis and Prognostication of Cryptococcal Meningitis With the Cryptococcal Antigen Lateral Flow Assay on Cerebrospinal Fluid," Clin Infect Dis., vol. 58, no. 1, pp. 113�116, Jan. 2014.
Samples that are positive by the cryptococcal antigen assay will automatically reflex to a titer.
Cryptococcal antigen titers obtained with this method (IMMY lateral flow) are usually higher than those obtained with latex agglutination, which is the method that most prior research and guidelines have used as a gold standard [1,2,5]. Titers acquired by different methods are not always interchangeable but the titers reported for the lateral flow assay at the University of Iowa have been calibrated to the most commonly used historical method (Meridian Bioscience CALAS latex agglutination) and should be considered comparable.
Hemolyzed samples may interfere with the lateral flow assay, causing a false-negative result. Other potential interferences such as Trichosporon spp. have not been evaluated.
[1] J. R. Perfect, W. E. Dismukes, F. Dromer, D. L. Goldman, J. R. Graybill, R. J. Hamill, T. S. Harrison, R. A. Larsen, O. Lortholary, M.- H. Nguyen, P. G. Pappas, W. G. Powderly, N. Singh, J. D. Sobel, and T. C. Sorrell, "Clinical Practice Guidelines for the Management of Cryptococcal Disease: 2010 Update by the Infectious Diseases Society of America," Clin Infect Dis., vol. 50, no. 3, pp. 291�322, Feb. 2010.
[2] O. Lortholary, G. Poizat, V. Zeller, S. Neuville, A. Boibieux, M. Alvarez, P. Dellamonica, F. Botterel, F. Dromer, and G. Ch�ne, "Long- term outcome of AIDS-associated cryptococcosis in the era of combination antiretroviral therapy:," AIDS, vol. 20, no. 17, pp. 2183� 2191, Nov. 2006.
[3] S. Antinori, A. Radice, L. Galimberti, C. Magni, M. Fasan, and C. Parravicini, "The Role of Cryptococcal Antigen Assay in Diagnosis and Monitoring of Cryptococcal Meningitis," J. Clin. Microbiol., vol. 43, no. 11, pp. 5828�5829, Nov. 2005.
[4] A. E. Brouwer, P. Teparrukkul, S. Pinpraphaporn, R. A. Larsen, W. Chierakul, S. Peacock, N. Day, N. J. White, and T. S. Harrison, "Baseline Correlation and Comparative Kinetics of Cerebrospinal Fluid Colony-Forming Unit Counts and Antigen Titers in Cryptococcal Meningitis," J Infect Dis., vol. 192, no. 4, pp. 681�684, Aug. 2005.
[5] T. Kabanda, M. J. Siedner, J. D. Klausner, C. Muzoora, and D. R. Boulware, "Point-of-Care Diagnosis and Prognostication of Cryptococcal Meningitis With the Cryptococcal Antigen Lateral Flow Assay on Cerebrospinal Fluid," Clin Infect Dis., vol. 58, no. 1, pp. 113�116, Jan. 2014.
Methodology:
Laterial Flow Assay
Sample
Processing:
Label transport tube with two patient identifiers, date and time of collection.
Submit in sterile transport container.
Submit in sterile transport container.
Sample
Storage:
Refrigerate up to 24 hours.
Transport
Instructions:
Coolant packs up to 8 hours.
Place requisition into outside pocket of bag.
Place specimen into zip-lock type bag, seal bag.
Place requisition into outside pocket of bag.
Place specimen into zip-lock type bag, seal bag.
CPT Code:
87899