Sorrell3,4, david judd1, sue sleiman1, debbie marriott5, tom olma1, sharon c. For the qualitative procedure, specimens are diluted 1. Cryptococcus antigen screen, lateral flow assay, pleural. Early diagnosis is the key to effective treatment, particularly in patients in resourcelimited settings. For more information see plfa cryptococcus antigen screen, lateral flow assay, pleural fluid. Unlike the other tests, the crag lfa is a dipstick immunochromatographic assay, in a format similar to the home pregnancy test, and requires little or no lab infrastructure.
For the semiquantitative procedure, specimens are diluted 1. The test is simple to use, and the results are available in 10 minutes. The crag lateral flow assay to detect cryptococcal antigens photo courtesy of immunomycologics. We sought to determine the costeffectiveness of implementing crag screening using the recently developed crag lateral flow assay in uganda compared to current practice. Lateral flow assays lfas are the technology behind lowcost, simple, rapid and portable detection devices popular in biomedicine, agriculture, food and environmental sciences. The cryptococcal antigen lateral flow assay lfa is a prescriptionuse laboratory assay that provides aid to the diagnosis of cryptococcosis. They are currently used by clinical laboratories, hospitals, and physicians for quick and accurate tests for specific target molecules and gene expression. The test uses specimen wicking to capture goldconjugated anticryptococcal antigen monoclonal antibodies and goldconjugated control antibodies. Immys cryptococcal antigen lateral flow assay training on vimeo. Mar 23, 2017 in 2011, the cryptococcal antigen lateral flow assay immy crag lfa, norman, ok, 2011, was developed. Validation of clinicbased cryptococcal antigen lateral flow assay. What is a lateral flow immunoassay and how does it work. If cryptococcal antigen is present in the specimen, it binds to the gold. Since rapid cryptococcal antigen lateral flow assays crag lfa may.
Immunomycologics, inc 2700 technology pl norman ok 730711127. Evaluation of fingerstick cryptococcal antigen lateral. Oct 29, 2018 the latexcryptococcus antigen test crag is a simple and rapid latex test lateral flow immunoassay test also exist for the semiquantitative or qualitative detection of the capsular polysaccharide antigens of cryptococcus neoformans in cerebrospinal fluid cryptococcal meningitis or cryptomeningitis and serum. Lateral flow assays have a wide array of applications and can test a variety of samples like urine, blood, saliva, sweat, serum, and other fluids. Mayo test id plfa cryptococcus antigen screen, lateral flow assay, pleural fluid additional testing requirements pleural fluid testing for cryptococcal antigen should also be submitted for routine fungal culture. The cryptococcal antigen lateral flow assay crag lfa was evaluated for the. The cryptococcal antigen lateral flow assay lfa immy, norman, ok, usa detects capsular polysaccharide antigens of the four major cryptococcal serotypes a and d for c.
What concentration of the antibodyantigen should i put on my controltest line. Cryptococcal antigen crag can be detected in the blood before onset of meningitis. This lateral flow assay is revolutionising cryptococcal antigen testing by. Cryptococcal antigen leeds teaching hospitals nhs trust. Mcmullan sydney childrenas hospital, randwick, sydney, centre for infec tious diseases and microbiology laboratory services, westmead, and westmead clinical school, university of sydney, sydney nsw, australia cryptococcosis is a lifethreatening. Interpretation the presence of cryptococcal antigen in pleural fluid is indicative of infection with cryptococcus species. The test works by detecting cryptococcal antigen abbreviated crag, an indicator of infection, in serum. Cryptococcal antigen titers were determined by immunoagglutination pastorex and lateral flow assay immunomycologics inc. Oct 07, 2014 the immy crag lfa cryptococcal antigen lateral flow assay is the first and only immunochromatographic dipstick assay for the qualitative and semiquanitative detection of cryptococcal antigen. Given the need for data for a rapid, pointofcare cryptococcal antigen crag lateral flow immunochromatographic assay lfa, we assessed diagnostic performance of cerebrospinal fluid csf culture, crag latex agglutination, india ink microscopy, and crag lfa for 832 hivinfected persons with suspected meningitis during 20062009 n. The presence of two visible bands indicates a positive result. Crag lfa is the only pointofcare diagnostic test for cryptococcosis.
Performance of cryptococcal antigen lateral flow assay using. Testing for the antigen in the serum is a useful initial screening tool in diagnosing cryptococcosis. Cryptococcus lateral flow assay test for serum, plasma, whole. Cryptococcus antigen titer, lateral flow assay, pleural. A prediction of cryptococcal antigen titer based on laser thermal contrast measurement and concept of lateral flow immunochromatographic assay lfa thermal contrast measurement in which a laser irradiates the test line in the lfa. Clinical utility of the cryptococcal antigen lateral flow assay in a diagnostic mycology laboratory brendan j. It is not intended for patients already on arvs treatment. Cryptococcal antigen latex test and lateral flow assay is more sensitive as compare to india ink mount in the detection of cryptococcus neoformans polysaccharide antigens in serum. Cryptococcal antigen latex test and lateral flow assay is more sensitive as. Serotype sensitivity of a lateral flow immunoassay for cryptococcal antigen marcellene a.
Test code plfa cryptococcus antigen screen, lateral flow assay, pleural fluid. At the mycology reference centre, up until 1414 we tested for cryptoccal antigen using a latex agglutination method immy, latex agglutination carrying out a full titration on all positive samples in all cases. It is an immunochromatographic test for detection of the capsular polysaccharide antigens of cryptococcus species in serum and cerebrospinal fluid csf. Performance of the cryptococcal antigen lateral flow assay in non. Cryptococcus antigen titer, lateral flow assay, pleural fluid. Apart from conventional methods of detection like direct microscopy and culture, rapid diagnostic methods to detect cryptococcal antigen by latex agglutination test, lateral flow immunochromatographic assay lfa, or.
Specimens and diluent are added to a test tube and the lateral flow device is added. I am currently developing a lateral flow assay, and i have an antigen with a concentration of 1 mgml and a molecular weight of 20. Class 2 device recall cryptococcal antigen lateral flow assay. An important advance to improve the continuum of hiv care and reduce cryptococcal meningitisrelated mortality jose e. Medical microbiologists at the johns hopkins university school of medicine baltimore, md, usa compared a lateral flow immunoassay lfa to a currently used enzyme immunoassay for detection of cryptococcal antigen in 396 sera and 651 cerebrospinal fluid specimens. Cryptococcus testing thermo scientific remel cryptococcus antigen test kit, latex use for qualitative or semiquantitative detection of polysaccharide antigens associated with cryptococcus neoformans infection in serum or csf. Multisite validation of cryptococcal antigen lateral flow. This test meets all of the world health organization. Cryptococcus antibodies conjugated with gold particles are coated on fiberglass. Methods we searched public databases including pubmed, web of science, elsevier science direct and cochrane library for the.
I am currently developing a lateral flow assay, and i have an antigen with a concentration of 1 mgml and a. The assay consists of crag lateral flow test strips which have a goldconjugated antibody and a goldconjugated, anti cryptococcal antibody deposited onto a sample membrane and anticrypto antibody and controlline capture antibody striped onto a membrane. This is immys cryptococcal antigen lateral flow assay training part 2 of 2 by immy videos on vimeo, the home for high quality videos and the. Specimen wicking captures goldconjugated, anticrag monoclonal antibodies and goldconjugated control antibodies deposited on test membrane. What is the basic principle of a lateral flow assay used to detect cryptococcal antigen. This is a rapid dipstick test, approved by the food and drug administration, with a very high sensitivity and specificity for detecting cryptococcal glucuronylmannan in serum 11 16. Recently, a new dipstick test has been developed for detecting cryptococcal disease. The crag lateral flow assay is an immunochromatographic test system for the qualitative or semiquantitative detection of the capsular polysaccharide antigens of cryptococcus species complex cryptococcus neoformans and cryptococcus gattii in serum, plasma, whole blood and cerebral spinal fluid csf.
The cryptococcal antigen lateral flow assay for diagnosis. Given the need for data for a rapid, pointofcare cryptococcal antigen crag lateral flow immunochromatographic assay lfa, we assessed diagnostic performance of cerebrospinal fluid csf culture, crag latex agglutination, india ink microscopy, and crag lfa for 832 hivinfected persons with suspected meningitis. Chen1,3,4 1centre for infectious diseases and microbiology laboratory services, westmead hospital, westmead, new south wales. The cryptococcal antigen lateral flow assay for diagnosis of. Cryptococcal meningitis is common in subsaharan africa. Cryptococcal antigen lateral flow assay performance. These tests are widely used in medical diagnostics for home testing, point of care testing, or laboratory use. Cryptococcal antigen testing by either latex or lfa was more sensitive than csf culture. Immys cryptococcal antigen lateral flow assay test is the first and only test of its kind. The saliva lateral flow assay performance was overall more sensitive in symptomatic patients 88% than in asymptomatic patients 27%. Csf specimens using the calastm cryptococcal antigen latex agglutination kit, according to the manufacturers instructions 16. Guidelines for the prevention and treatment of opportunistic. A new lateral flow immunoassay lfa for cryptococcal antigen crag.
Signal amplification and quantification on lateral flow. The lfa is in excellent agreement with cultures, latex agglutination and immuno enzymatic assay elisa in serum and cerebrospinal fluid csf. The procedure applies to all facilities performing crag lateral flow assay for the. The test line is formed by goldmonoclonal antibodyantigen sandwich complex with a monoclonal antibody affixed at. Cryptococcal antigen is a csf test for cryptococcus neoformans. Recently, the cryptococcal antigen lateral flow assay crag lfa was included in the armamentarium for diagnosis. I also have an antibody with a concentration of 2 mgml. Cryptococcal antigen from cerebrospinal fluid is the best test for diagnosis of cryptococcal meningitis in terms of sensitivity.
Serotype sensitivity of a lateral flow immunoassay for. Cryptococcus neoformans meningitis with negative cryptococcal. The immy crag lfa is the first and only immunochromatographic dipstick assay for the qualitative and semiquantitative detection of cryptococcal antigen. Crag lateral flow assay for cryptococcosis europe pmc. Shop online for a wide selection of immy crag lateral flow assay prescriptionuse laboratory assay aids in the diagnosis of crytococcosis. L were deposited in duplicate on a brainheart infusion plate supplemented with blood and incubated at 37c with co 2. Latex cryptococcus antigen test crag principle and result. Largescale clinical validation of a lateral flow immunoassay for detection of cryptococcal antigen in serum and cerebrospinal fluid specimens. Cryptococcus antigen in the patients or clients whose cd4 count is less than. Cryptococcus lateral flow assay test for serum, plasma.
While easy to use, lfa suffers from its low sensitivity and poor quantification, which largely limits its applications for early disease diagnosis and requires further testing to eliminate falsenegative results. A new lateral flow immunoassay lfa for cryptococcal antigen crag allows for rapid and inexpensive diagnosis of cryptococcosis at or near the point of patient contact. Traditional methods of diagnosing cryptococcosis can be technically complex, require sample pretreatment and can take an hour or more to deliver results. The cryptococcal antigen lateral flow assay for diagnosis of cryptococcosis brendan j. The cryptococcal antigen crag lateral flow assay lfa has simplified diagnosis as a pointofcare test approved for serum or cerebrospinal fluid csf. Performance of cryptococcal antigen lateral flow assay in serum. Basically, it is a simple to use diagnostic device used to confirm the presence or absence of a target analyte, such as pathogens or biomarkers in humans or animals, or contaminants in water supplies, foodstuffs, or animal feeds. The cryptococcus antigen crag lateral flow assay is a sandwich immunochromatographic assay. The crag lateral flow assay is a dipstick sandwich immunochromatographic assay, which detects cryptococcal antigen in serum. The assay consists of crag lateral flow test strips which have a goldconjugated antibody and a goldconjugated, anticryptococcal antibody deposited onto a sample membrane and anticrypto antibody. The lfa is a pointofcare dipstick test that uses goldconjugated, monoclonal antibodies impregnated onto an immunochromatographic test strip to detect cryptococcal capsular polysaccharide glucuronoxylomannan antigen crag for all 4 c. The diagnostic use for detection of cryptococcal capsular polysaccharide antigen crag in serum and cerebrospinal fluid by latex agglutination test craglatex or. Latex agglutination and enzyme immunoassay are over 90% sensitive, while lateral flow.
Research ethics committee of the hospital research protocol n. Lateral flow immunoassay validated for detection of. Clinical utility of the cryptococcal antigen lateral flow. Boulware3 summary aidsrelated cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. Latex cryptococcus antigen test crag principle and. Multisite validation of cryptococcal antigen lateral flow assay and. What concentration of the antibodyantigen should i put on. Methods we searched public databases including pubmed, web of science, elsevier science. Principle the product uses lateral flow technique and double antibody sandwich format. Lfa is a sandwich immunochromatographic assay that uses specimen wicking to capture goldconjugated, anti cryptococcal antigen anti. Early diagnosis of cryptococcosiseither subclinical or clinicalis a crucial aspect of infectious disease control, especially in resource limited settings. Lateral flow tests, also known as lateral flow immunochromatographic assays, are simple devices intended to detect the presence of a target substance in a liquid sample without the need for specialized and costly equipment. Lfa is a sandwich immunochromatographic assay that uses specimen wicking to capture goldconjugated, anticryptococcal antigen anti. Clinical utility of the cryptococcal antigen lateral flow assay in a.
The antigen test can detect cryptococcal antigen in serum a median of 22 days before. Cryptococcal antigen lateral flow assay performance summary. A new lateral flow assay lfa for detection of crag offers many advantages for diagnosis of cryptococcosis in both resourcelimited and developed countries. Guidelines for the prevention and treatment of opportunistic infections in adults and adolescents with hiv. Immys cryptococcal antigen lateral flow assay training on.
Background a new lateral flow immunoassay lfa for the detection of cryptococcal antigen was developed. Detection of cryptococcal antigen crag by immunoassay of serum and cerebral spinal fluid has emerged as a reliable means for diagnosis of cryptococcosis. Class 2 device recall cryptococcal antigen lateral flow. Five easy steps to perform the detection of cryptococcal antigen using lateral flow assay. Costeffectiveness of craglfa screening for cryptococcal. Evaluation of a new cryptococcal antigen lateral flow. The specificity of saliva lateral flow assay was excellent at 97.
Dynamiker cryptococcal antigen lateral flow assay lfa. The cryptococcus antigen crag lateral flow assay has been developed to overcome these issues. Specimens and specimen diluent are added into a test tube or other reservoir. These guidelines are based on the principle that early diagnosis and. The lfa was performed using the immy cryptococcal lateral flow assay immunomycologics, inc. Joy pelfrey 4053641058 manufacturer reason for recall. The latexcryptococcus antigen test crag is a simple and rapid latex test lateral flow immunoassay test also exist for the semiquantitative or qualitative detection of the capsular polysaccharide antigens of cryptococcus neoformans in cerebrospinal fluid cryptococcal meningitis or cryptomeningitis and serum. Diagnosis of cryptococcosis and prevention of cryptococcal. The presence of cryptococcal antigen in pleural fluid is indicative of infection with cryptococcus species. The cryptococcal antigen lateral flow assay is an immunochromatographic test system for the qualitative or semiquantitative detection of capsular polysaccharide antigens of cryptococcus species complex cryptococcus neoformans and cryptococcus gattii in serum and cerebrospinal fluid csf. The cryptococcal antigen crag lateral flow assay lfa immunomycologics, ok, usa is a key advance in the diagnosis of cryptococcosis in plhas. From 1414 we changed to the lateral flow device immy, lfd and are screening all samples at 1. Fig 1 representative examples of the cryptococcal antigen lateral.
Performance of cryptococcal antigen lateral flow assay. A new lateral flow immunoassay lfa for cryptococcal antigen crag allows for rapid and inexpensive diagnosis of cryptococcosis at or near. Jun 30, 2016 lateral flow assays lfas are the technology behind lowcost, simple, rapid and portable detection devices popular in biomedicine, agriculture, food and environmental sciences. The cryptococcus antigen crag lateral flow assay has been developed to. Cryptococcus neoformans is the most common cause of adult meningitis in subsaharan africa. The crag lateral flow assay is a dipstick sandwich immunochromatographic assay which detects cryptococcal antigen in serum. All specimens with a positive result were tested up to a dilution of 1. The cryptococcal antigen lateralflow assay is read in the same way as that of a urine pregnancy dipstick test. A new strategy for saving lives among people with hivaids. An important advance to improve the continuum of hiv care and reduce cryptococcal meningitisrelated mortality. Class 2 device recall cryptococcal antigen lateral flow assay crag lfa.
Cryptococcal meningitis cm constitutes a significant source of mortality in resourcelimited regions. These tests can be used on csf or serum and can be used for diagnosis of early, asymptomatic cryptococcal infection in hiv infected patients. Cryptococcosis is an important and potentially lethal opportunistic infection in immunocompromised patients, especially in human immunodeficiency virus hiv infected and organ transplant patients. Five steps of the cryptococcal antigen lateral flow assay. Falsenegative result of serum cryptococcal antigen. Lateral flow assay lfa has become one of the most widely used pointofcare diagnostic methods due to its simplicity and low cost. What concentration of the antibodyantigen should i put on my.