Aspergillus Real-time PCR Panel
Inhaled dormant Aspergillus spores (conidia) can germinate and cause invasive pulmonary aspergillosis, a disease with a mortality rate often exceeding 50%. Invasive pulmonary aspergillosis is seen primarily in the immunocompromised host. Standard laboratory techniques for the diagnosis of invasive pulmonary aspergillosis include direct examination, lung tissue histology and culture of respiratory secretions. Under the best of circumstances, bronchoalveolar lavage (BAL) fluid analysis yields a diagnosis by culture and direct exam in only approximately 50% of cases. However, some centers have shown that the rate of diagnosis is substantially lower using these techniques.
The Aspergillus PCR panel is comprised of 3 real-time PCR assays: a Pan-Aspergillus assay that detects all Aspergillus species, an A. fumigatus assay that detects the most common Aspergillus species, and an A. terreus assay that detects a clinically important Aspergillus species that is resistant to Amphotericin B. When used in conjunction with other diagnostic procedures, such as microbiological culture, Aspergillus Galactomannan EIA, Fungitell® ß-D Glucan, histological examination of biopsy specimens, and radiographic evidence, the Aspergillus PCR panel can be useful in the diagnosis of invasive pulmonary aspergillosis.
About Aspergillus
Invasive aspergillosis is a common opportunistic fungal infection in patients who are profoundly neutropenic, either as a result of chemotherapy or after having received hematopoietic stem cell or solid organ transplantation.1 Prevalence of invasive aspergillosis is 1–15% and mortality can exceed 90%.2 Early diagnosis of invasive aspergillosis remains a challenge, but screening of patients in the early stage of infection may be useful in establishing an early diagnosis and may result in improved outcomes.3
ProcedureExtraction of Aspergillus DNA from specimen followed by amplification and detection using real-time, qualitative PCR. An internal control is added to each clinical specimen in order to ensure the extraction was performed correctly and the PCR reaction was not inhibited. This test has not been cleared or approved for diagnostic use by the U.S. Food and Drug Administration.
SpecificityThe Aspergillus PCR panel is comprised of 3 real-time PCR assays: a Pan-Aspergillus assay that detects all Aspergillus species, an A. fumigatus assay that detects the most common Aspergillus species, and an A. terreus assay that detects a clinically important Aspergillus species that is resistant to Amphotericin B.
For Respiratory Sample Types (BAL and Bronch Wash): Same day (within 12 - 24 hours from receipt of specimen), Monday through Saturday.
For Tissue Sample Types (Formalin-Fixed Paraffin-Embedded and Fresh Frozen): 2- 5 business days from receipt of specimen.
| Specimen Type | Test Code | CPT Code | NY Approved | Volume | Assay Range | Special Instructions |
|---|---|---|---|---|---|---|
| BAL | 8909 | 87798 x3 | Yes | 2 mL (min. 0.5 mL) |
Qualitative results are independently resulted for Pan-Aspergillus, A. fumigatus and A. terreus and are reported as “Detected/Not Detected”. The lowest order of detection for the Aspergillus PCR Panel is 13 germinated conidia per mL BAL. |
|
| bronch wash | 8926 | 87798 x3 | Yes | 2 mL (min. 0.5 mL) |
Qualitative results are independently resulted for Pan-Aspergillus, A. fumigatus and A. terreus and are reported as “Detected/Not Detected”. The lowest order of detection for the Aspergillus PCR Panel is 13 germinated conidia per mL BAL. |
|
| Fresh Frozen Tissue [Qual] | 8905 | 87798 (x3) | Yes | 5 mg fresh tissue (approximately 1/2 of a pencil eraser size) |
Detected/ Not Detected |
|
| FFPE Tissue [Qual] | 8906 | 87798 (x3) | Yes | Two 10µm scrolls from the FFPE block |
Detected/ Not Detected |
|
Assay Limitations
A negative test result cannot rule out the diagnosis of invasive pulmonary aspergillosis.
The performance of the Aspergillus PCR Panel has not been evaluated outside of lung transplant patient populations (e.g. HSCT).
Formalin fixation dramatically reduces the sensitivity of the assays due to reduced template yield and quality. Fresh tissue is the optimal specimen of choice, as it reduces the chance of introducing exogenous DNA templates or microorganisms during embedding/fixation.
ShippingShip Monday through Friday. Friday shipments must be labeled for Saturday delivery. All specimens must be labeled with patient's name and collection date. A Eurofins Viracor test requisition form must accompany each specimen. Multiple tests can be run on one specimen. Ship specimens FedEx Priority Overnight® to: Eurofins Viracor, 18000 W 99th St. Ste, #10, Lenexa, KS 66219
Causes for RejectionSpecimens that have been stored at ambient temperature, specimens received in trap containers, Respiratory FFPE and/or FF specimens received outside stability, insufficient specimen volume, and specimens other than those listed. Specimens that have been stored at 2 to 8°C for >2 days. If storage longer than 2 days is needed, specimens should be frozen at -70°C. Unless indicated as stored frozen, the specimen will be rejected if the draw date is >2 days from receipt at Eurofins Viracor.
Specimens are approved for testing in New York only when indicated in the Specimen Information field above.
The CPT codes provided are based on Eurofins Viracor's interpretation of the American Medical Association's Current Procedural Terminology (CPT) codes and are provided for informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. Eurofins Viracor assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material.
References1 Ascioglu S, Rex JH, de Pauw B, et al. Defining opportunistic invasive fungal infections in immunocompromised patients with cancer and hematopoietic stem cell transplants: an international consensus. Clin Infect Dis. 2002;34:7–14.2.
2 Walsh TJ, Anaissie EJ, Denning DW, et al. Treatment of aspergillosis: clinical practice guidelines of the Infectious Diseases Society of America. Clin Infect Dis.2008;46:327–60.3.
3 Pfeiffer CD, Fine JP, Safdar N. Diagnosis of invasive aspergillosis using a galactomannan assay: a meta-analysis. Clin Infect Dis. 2006;42:1417–27.