Transcript Slide 1

Launching at MMC
- Aspergillus Galactomannan EIA “Galactomannan Screening for the Early
Diagnosis of Invasive Aspergillosis”
Dr. Vilma M. Co / Dr. Demetrio Valle
• Pledge of Support – Pfizer / Lifeline
• Message of Acceptance – Makati Medical Center
• Ceremonial MOA Signing
...........................Refreshments……………………….
Aspergillus
• fungus (or mold) that is
common in the environment
– soil
– plants and in decaying plant
matter
– household dust
– building materials
– spices & some food items.
Different types of Aspergillus
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Aspergillus fumigatus
Aspergillus flavus
Aspergillus terreus
Aspergillus nidulans
Aspergillus niger
Aspergillosis
1. allergic bronchopulmonary aspergillosis
(also called ABPA)
- a condition where the fungus causes
allergic respiratory symptoms, such as
wheezing and coughing, but does not
actually invade and destroy tissue.
Aspergillosis
2. Invasive Aspergillosis
- a disease that usually affects people with
immune system problems.
- the fungus invades and damages tissues
in the body.
- most commonly affects the lungs, but can
also cause infection in many other organs
& can spread throughout the body.
High-risk Patients
• Invasive aspergillosis generally affects
immunocompromised patients
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bone marrow transplant or solid organ transplant,
people who are taking high doses of corticosteroids,
people getting chemotherapy for cancers such as leukemia.
persons with advanced HIV infection
Mode of Transmission
• Inhalation of Aspergillus spores (i.e., in a
very dusty environment) can lead to
infection.
• Studies have shown that invasive
aspergillosis can occur during building
renovation or construction.
• Outbreaks of Aspergillus skin infections
have been traced to contaminated
biomedical devices.
Symptoms of Aspergillosis:
1. respiratory symptoms like wheezing,
coughing and even fever
2. allergic sinusitis/bloody sputum
3. aspergilloma, or a “fungus ball” in the lung or
other organs.
• Lung aspergillomas usually occur in people
with other forms of lung disease, like
emphysema or a history of TB.
Invasive Aspergillosis
• fever, chest pain, cough, and shortness of
breath.
• When invasive aspergillosis spreads
outside of the lungs, it can affect almost
any organ in the body, including the brain.
Incubation Period
• Incubation time varies depending on host
factors & exposure characteristics.
Diagnosis of Aspergillus infection
• risk factors, symptoms, & P.E. findings
• chest x-ray or CT scan of the lungs.
• fungal culture of samples of respiratory
secretions or affected tissues
• biopsies of affected tissue
• newer tests that can help monitor for invasive
aspergillosis in high-risk persons who are
severely immunocompromised
Aspergillus Galactomannan EIA
CLINICAL UTILITY
• used in conjunction with other diagnostic
procedures to aid in the diagnosis of
Invasive Aspergillosis.
– microbiological culture
– histological examination of biopsy specimens
– radiographic evidence
Screening & Diagnosing IA in High-Risk Patients
KEY BENEFITS :
Screening high-risk patients with PlateliaTM
Aspergillus EIA, twice-weekly, provides early
diagnosis of IA.
Recent publications:
 GM Ag was positive 6-10 days before onset of
clinical signs
 GM positivity preceded positivity of CT-Scan or
culture by >1 week
 PlateliaTM Aspergillus EIA was most sensitive
(compared to RT-PCR and -glucan) at predicting the
diagnosis of IA in patients with hematologic disorder.
Screening and Diagnosing IA in High-Risk patients
Comparison to Other Diagnostic Methods :
Diagnostic Method
Sensitivity
Specificity
Chest Radiograph
94%
60%
CT-Scan (any abnormality)
78%
7%
CT-Scan (halo sign)
28%
93%
Culture (BAL)
50%
92%
GM EIA :
Single sample  1.5
2 consecutive samples ≥ 1.5
94%
94%
85%
99%
J.Maertens JID 2002
Treatment of Invasive
Aspergillosis
• Voriconazole is currently first-line
treatment for invasive aspergillosis.
• itraconazole, lipid amphotericin
formulations, caspofungin, micafungin,
and posaconazole
• Whenever possible, immunosuppressive
medications should be discontinued or
decreased.
Prevention
• avoidance of dusty environments and activities
where dust exposure is likely (such as construction
zones)
• wearing N95 masks in dusty environments
• avoidance of activities such as gardening
• air quality improvement measures such as HEPA
filtration may be used in healthcare settings
• prophylactic antifungal medication in some
circumstances
Platelia Aspergillus EIA and Diagnosis of IA
ELISA SETUP
WASHER
INCUBATOR
READER
PLATELIATM Aspergillus EIA and
DIAGNOSIS of IA
PROCEDURE
• immunoenzymatic sandwich microplate
assay for the detection of Aspergillus
galactomannan antigen
• adult and pediatric serum samples
• uses EBA-2 monoclonal antibodies
which detect Aspergillus
galactomannan.
Screening & Diagnosing IA in High-Risk patients
For maximum sensitivity, the test should be
performed
at
least
twice-weekly
during
hospitalization. For all positive patients, it is
recommended that a new aliquot of the same sample
be repeated as well as collection of a new sample
from the patient.
According to the EORTC/MSG criteria, two consecutive
positive results are required for classification as true
positive. In daily practice, it is important that physicians
submit a follow-up specimen upon receipt of the initial
positive result, ideally before initiating antifungal
therapy to achieve the highest specificity using the test.
SPECIMEN TYPE &
SPECIMEN HANDLING
• Serum:
• Collect 3 to 5 ml blood specimen in a serum
separator tube (SST) without anti-coagulants.
• Allow specimen to clot, then centrifuge specimen
within 2 hours of draw to pellet cells below the gel.
• Minimum volume of 1.0 ml serum following
centrifugation is required.
• Specimen should be stored at 2 to 8°C or frozen
in a non-self-defrosting freezer & shipped with
frozen gel packs or dry ice for overnight delivery
SPECIMEN TYPE &
SPECIMEN HANDLING
• BAL:
• 1 to 3 ml collected in a sterile, screw-cap
tube;
• specimen should be stored at 2 to 8°C or
frozen in a non-self-defrosting freezer
• shipped with frozen gel packs or dry ice for
overnight delivery
CAUSES FOR
REJECTION of specimen
• Lipemic, icteric, or hemolyzed
specimens.
• Specimens that have been stored at
ambient temperature.
• Specimens that have been stored at 2
to 8°C for >5 days.
• If storage longer than 5 days is needed,
samples should be frozen at -70°C.
ASSAY RANGE
• The reference range is an index of <0.5.
• Numerical index values will be
reported.
• Patients with an index of >0.5 are
considered to be positive for
galactomannan antigen.
• Patients with an index of <0.5 are
considered to be negative for
galactomannan antigen.
ASSAY LIMITATIONS
• A negative test result cannot rule out
the diagnosis of Invasive Aspergillosis.
• Patients at risk for Invasive
Aspergillosis should be tested twice
per week.
• If a positive result is obtained, a second
specimen should be collected and sent
for testing immediately.
False-positive
galactomannan test results
• patients receiving piperacillin/tazobactam;
interpret results in these patients with caution
& confirm w/ other diagnostic methods.
• Patients with intestinal mucositis caused by
chemotherapy / irradiation, which allows for
extra absorption of dietary galactomannan.
• patients receiving Plasmalyte for IV hydration
or if Plasmalyte is used for BAL collection.
TURNAROUND TIME
• Same day (within 8 to12 hours of
specimen receipt)
Thank you!