Presentation on theme: "Immuno-Mycologics, Inc."— Presentation transcript:
1 Immuno-Mycologics, Inc. Serodiagnosis of MycosesSean K. Bauman, Ph.D.V.P. OperationsImmuno-Mycologics, Inc.
2 Outline Why use serology? Mechanisms of different tests Serology of specific mycoses
3 Why Use Serology For Case Finding? Antigens and antibodies are easier to detectthan finding the organism directly.Antibodies are produced in large quantitiesand circulate in the blood even though they arenot usually protective against mycotic agents.Soluble antigens frequently enter thecirculation of the host and are sometimesexcreted in the urine. They are produced indiscrete infected lesions.Culture is relatively Insensitive due to the lowconcentration of the agents in tissues. Multiplecultures are usually required.
15 Qualitative vs Quantitative Immunodiffusion AgCSPt1243Screening TestQUALitativeUndil.1:21:81:4AgCSPatient 1QUANTitativeUndil.1:21:81:4AgCSPatient 3QUANTitativePositive Undiluted1:4Identity & Partial Identity bands are considered POSITIVE
16 Complement Fixation Serum without antibodies Serum with Antigen binds to antibodiesUnboundantigenDay 1Complementbinds to Ag/AbcomplexUnboundcomplementHemolysin sensitizedred blood cellsserve as an indicatorDay 2No lysisPositiveLysisNegative
29 Aspergillosis The Organism Primary etiologic agents A. fumigatus A. flavusA. nigerA. terreusAspergillus spp. have a global distribution
30 Aspergillosis The Disease Infection initiates by inhalation of Aspergillus sporesA. niger fruiting bodyin a lung cavity(Aspergilloma)Forms of the DiseaseAllergic Bronchopulmonary Aspergillosis (ABPA)Pulmonary Aspergilloma (fungus ball)Invasive Aspergillosis (IA) (usually immunocompromised)
33 Blastomycosis The Organism Etiologic agent: Blastomyces dermatitidis B. dermatitidis is endemic to theOhio and Mississippi river valleysl
34 Blastomycosis The Disease Infection initiates by inhalation of the organism
35 Blastomycosis Antibody Test DiagnosisImmunodiffusion‘A’ antigen (a.k.a. WI-1)120-kDa glycoprotein25-amino acid tandem repeat is immunodominant epitopePrecipitin band indicates current/recent B. dermatitidis infectionSensitivity 100%Specificity 100%J. Med. Vet. Mycol. (1995) 33:123Complement FixationSensitivity 40%Specificity 100%J. Clin. Micro. (1986) 23:294
36 Candidiasis The Organism Primary etiologic agent: Candida albicans C. albicans is part of the normal human flora~80% have positive DTH reactions toCandida antigens by 1 year of age
37 Candidiasis The Disease Immunocompromised states susceptible to CandidiasisNeutropeniaCorticosteroidsDiabetes mellitusHIV infectionCancerOropharyngeal (thrush)Antibiotic therapySystemic/InvasiveInfection types:Vaginal
38 Candidiasis Antibody Test DiagnosisImmunodiffusion 1 band indicates current/recent infectionSystemic candidiasis should be suspected whenNumber of precipitins increases on serial specimens-or-Seroconversion (i.e. negative patient becomes positive)Sensitivity 80% in immunocompetent individuals* Manual of Clinical Laboratory Immunology, 6th EditionSensitivity is less in immunodeficient individuals
43 Coccidioidomycosis Antibody Test DiagnosisImmunodiffusionIDTP120-kDa glycoprotein (BGL2)3-O-methylmannose (3-O-MM) is immunodominant epitopeHeat stable antigen (60°C, 30 min)Predominantly IgM reactivity in early primary casesIDCF47-kDa chitinase enzymeHeat labile antigenPredominately IgG reactivityClosest to the antigen wellSensitivity 100%Specificity 100%J. Clin. Micro. (1995) 33:618
44 Cryptococcus neoformans CryptococcosisThe OrganismEtiologic agent:Cryptococcus neoformansC. neoformans is encapsulated yeast with aglobal distribution often found in soil andbird droppings
45 Clinical microbiology made by M. Gladwin and B. Trattler CryptococcosisThe DiseaseImmunocompromised (e.g. AIDS) are most susceptiblePigeonMeningitisCryptococcusneoformansAIDSAdapted fromClinical microbiology maderidiculously simpleby M. Gladwin and B. Trattler
47 Histoplasmosis The Organism H. capsulatum is endemic to the Etiologic agent:Histoplasma capsulatumH. capsulatum is endemic to theOhio and Mississippi river valleys
48 Histoplasmosis The Disease Infection initiates by inhalation of the organismIntracellular proliferation
49 Histoplasmosis Antibody Test DiagnosisImmunodiffusionM Antigen81-kDa glycoprotein (catalase)M precipitins first to appear in acute diseaseClosest to the antigen wellH Antigen93-kDa glycoprotein (b-glucosidase)H precipitins occur later in infection(likely extrapulmonary dissemination)Closest to the serum wellSensitivity 90%Specificity 94%J. Clin. Micro. (1976) 2:77
52 Paracoccidioidomycosis The OrganismP. brasiliensis is endemic toMexicoCentral AmericaSouth AmericaDoctorfungus Corporation?Etiologic agent:Paracoccidioides brasiliensis
53 Paracoccidioidomycosis The DiseaseInfection initiates by inhalationof the organismUlcerative lesions are commonDoctorfungus Corporation
54 Paracoccidioidomycosis Antibody Test DiagnosisImmunodiffusionUp to 3 precipitin bands are observedgp43 Antigen43-kDa glycoproteingp43 is the immunodominant antigen (closest to Ag well)(a.k.a. E2 or A)Most prevalent and longest lasting of the major precipitinsSensitivity = >90%* Manual of Clinical Laboratory Immunology, 6th Edition
55 Why Use Serology For Case Finding? Antigens and antibodies are easier to detectthan finding the organism directly.Antibodies are produced in large quantitiesand circulate in the blood even though they arenot usually protective against mycotic agents.Soluble antigens frequently enter thecirculation of the host and are sometimesexcreted in the urine. They are produced indiscrete infected lesions.Culture is relatively Insensitive due to the lowconcentration of the agents in tissues. Multiplecultures are usually required.
56 The Fungal Diagnostic Specialists Do one thing, do it well!