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CryptococcosisBhanthumkomol P.
Outline
• Background• Mycology• Taxonomy• Identification• Ecology• Epidemiology• Pathogenicity
• Host response• Pathogenesis• Clinical manifestation• Laboratory diagnosis• Management• Prognosis• Prevention
Mycology
• Budding yeast
• Haploid
Asexual Stage
Sexual Stage
• Two mating types form conjugation
Filaments
Basidiospores
formed by meiosis
Convert to yeast form
Environment
Human
In vitro
Specific, nutrient-poor media
Yeast form
Basidia on end
Taxonomy
C. neoforman2 varieties
5 Capsular serotypes
C. neoforman var. neoformanscapsular serotypes
A D AD
C. neoforman var. gattiicapsular serotypes
B C
Identification
• Culture
routine laboratory agar 72 hr
can grow in hemoculture
white to cream, opaque colony on agar
mucoid if prolonged incubation
(Polysaccharide capsule formation)
Identification• Direct test
• Serotype identification
India ink
Rapid urease test
Laccase activity
Only C. neoformans
Commercial Antibody
Glycine assimilation as carbon source
DNA analysis
Ecology
var. neoformans
A D AD
var. gattiiB C
pigeons
parrots
canaries
oaks
firs
eucalyptus
maples
Epidemiology
• Clinical report of Cryptococcus isolation from human without evidence of Cryptococcosis
• COPD Endobronchial colonization
Access
1. Risk factors
2. Disease evidence
Epidemiology
Infected ?
Epidemiology
HIV
Lymphoproliferative disorder : CLL
Sarcoidosis
Corticosteroid
Hyper IgM, IgE syndrome
Monoclonal Ab : infiximab
SLE
DM
CD4 T cell lymphopenia
Transplant
Kidney
Liver
Peritoneal dialysis
Cirrhosis
Risk factors
Epidemiology
SerotypeA : AIDS All worldwideB : Brazil and other Tropical &
subtropical area(Australia, Southeast Asia, Hawaii, Southern California)
C : same as B but rareD : Denmark, Germany, Italy,
France, Switzerland, USA
Transmission
• Inhalation “Intensive bird exposure area”
• Needlestick injury• Organ transplant
Epidemiology
Capsule
• Antiphagocytosis• Decrease complements• Intracellular local toxicity• Antibody unresponsiveness• Interfere Ag presentation• Negative charge around yeast• Enhance HIV replication• Dysregulate cytokine secretion• Brain edema• Create selectin & TNF-R loss
Pathogenicity
Thicker capsuleMore virulence !!
Melanin
• Antioxidant tolerate oxidative stress
• Antiphagocytosis• Decrease T cell response• Cell wall change• Protection from Temp. and
Antifungals
Pathogenicity
Ability to growth at body Temp
Only C. neoformans
Pathogenicity
37
May associated with calcineurin
Host response
Phagocytes: MΦ, PMN, Microglial cell, NK cell
LΦ (CD4,CD8)
inhibit growth by direct contact
Granuloma
formation
CMIHigh rate
CryptococcalInfection
(DH, Ab +ve)
Low IncidenceCryptococcosis
opsonization
Intracellular killingActivated MΦ primary effector cell
IFN-γ
GM-CSF
Complement mediatedAntibody mediated
Inhalation
Pathogenesis
dissemination
1
Stim. Th1 response
Contact alv. MΦ
alveoli
Effective
Im.Response
Clinical
Cryptococcosis
Dormant
Small lung or
LN complexCrypto totally
Eliminated Reactivation
Im.supp.host32
Lung [Normal Host]
Clinical Manifestation
o Prior Chronic lung disease
o No immunosuppression
o No evidence of active lung parenchymal disease
o Serum Crypto Ag Negative
o Negative CSF and urine C/S
o May have lung nodule
o1 in 3 of cases
oPresented with Abn CXR
oFever, productive cough
oChest pain, wt loss
CXR finding
• Infiltration : either lobar or interstitial
• Hilar adenopathy
• Cavity
• Pleural effusion
• Mass/ nodule
Serum crypto antigen
• In pulmonary crypto– Negative Limited lung disease– Positive Extrapulmonary source
include LP for CSF fungus C/S
in High risk Pt for dissemination
Early asymptommatic CNS
• In pulmonary crypto
Normal CSF profile
only positive fungus c/s
Lung [Immunocompromised Host]
Constitutional symptom
ARDSMay presented with CNS infection
Common CXR
Alv & Inst. Infiltration
DDX: PCP
Coinfection must be worked up
CMV, PCP, Atypical mycobacteria, Nocardia
Clinical Manifestation
CNS
4 forms
• Meningitis: Acute, Subacute, Chronic
• Cryptococcoma
• Spinal cord granuloma
• Chronic dementia (Hydrocephalus)
Cryptococcal Meningitis
FindingPatient
with AIDSPatient
without AIDS
Duration of symptoms Usually <2wk Usually >2wk
Positive india ink for CSF ~70% ~50%
CSF antigen titer > 1:1024 Common Rare
Serum antigen positive 93-99% 50%
CSF antigen positive 91-99% >90%
CSF WBC <20/mm3 69-97% 3%
Extraneural involvement Common Rare
Opening pressure >200mm 62-65% 65%
IRIS
• Develop 1-2 mo after HAART
• Correlate with significant drop of HIV-VL
• Manifestation : worsening symptom– Acute meningitis : increase Headache– Lymphadenitis : - peripheral
- Hilar
- Mediastinal
LAB
• Increase inflammatory cell in CSF
• Increase ICP increase headache
• But negative CSF & LN aspirate C/S
• Smear may positive !! Not recommended
IRIS
CNS of Var gattii
• Invade brain parenchyma > var neoformans
• Cryptococcoma & hydrocephalus
• May response
poorly to Rx
• Immuno-
Competent
host !!
Clinical Manifestation
Skin
• Marker of dissemination > direct inoculation
• Need biopsy of Dx because of variety of skin manifestation
• Common : papule, MP with ulcerated center
• DDX : mollucum, Acne vulgaris, SCC/BCC
Clinical Manifestation
Prostate
• Most case Asymtommatic
• Sanctury site for antifungal Rx before HAART
• Dx : C/S from urine or seminal fluid
• Require prolonged Rx
Clinical Manifestation
EYE
• Secondary to CNS = occular palsies & papilledema
• Small white retinal exudate w/o retinitis
• Severe immunocompromised host1. occur simultaneously with HIV & CMV2. Extensive retinal & vitritis
- Blindness from optic neuritis
- Blindness from increase ICP
Clinical Manifestation
Lab Dx
1. Microscopic exam.
India ink : CSF 50% positive in Non-AIDS
80% positive in AIDS
Biopsy and cytology
staining
Alcian blue
Fontana-masson
H&EGomori
India ink
• Positive when CSF yeast > 10000 CFU/ml
• Negative when CSF yeast < 1000 CFU/ml
• Still positive during and after Treatment– Not a marker for
treatment failure !!
2. cultures
• Growth in both Bacterial & Fungus media
• Isolate : - biochemical & DNA-based
- Rapid urease test
- Staib’s birdseed, DOPA, Caffeic acid media melanin
Laboratory Diagnosis
3. serology
• Detection of Cryptococcal polysaccharide Ag
Latex agglutination
EIA
False positive less likely if titer > 1:4
False negative in : Early asymptomatic meningitis
Chronic indolent meningitis Laboratory
Diagnosis
>90% sensitivity and specificity
Remark in Serology
• Screening Crypto Ag in high incidence area in High risk : febrile AIDS patient with headache
• CSF and Serum Crypto Ag not cross BBB
• Titer > 1:1024 therapeutic failure
Laboratory Diagnosis
Remark in Serum Crypto Ag
• Serum Crypto Ag Screening HIV with headache – If negative Crypto meningitis not likely !
• Not use in : Follow up, Evaluate Rx response and relapse rate
• False +ve : RF +ve Pt, Trichosporon
• False –ve : Thin capsule,
Prozone phenomenonLaboratory Diagnosis
Radiology
• CXR
• CT finding– Normal– Hydrocephalus– Gyral enhancement– Single or multiple nodule that may or may not
enhanced
• MRI
Laboratory Diagnosis
MRI
• More sensitive than CT
• Numerous, clustered foci of hyperintensity in T2W
• Non-enhancing on postcontrast T1W in Basal gg & midbrain Laboratory
Diagnosis
Remark in imaging
• No pathognomonic sign
• In AIDS must DDx– Lymphoma– Toxoplasmosis– Nocardia
• Follow-up scan may see increased lesion from increased inflammatory response
NOT MARKER OF Rx FAILURE
Management
• Cryptococal meningitis– Amphotericin B 0.7 mg/kg/day– Liposomal form 4 mg/kg/day : toxicity
decreased– Flucytosine : no monotherapy resistance– Fluconazole : fungistatic in suppresive phase– Itraconazole : inferior to fluco, alternative
Meningitis in HIV
3 Phases
1. Initial phase : Ampho + flucytosine 2 wk
2. Maintainance phase : Fluco 400-800 mg/d for 8-10 wk
3. Chronic suppressive phase : Fluco 200 mg/d
decrease relapse rate 50-60% 5%
Management
Meningitis in Non-HIV
• 6-8 wk of Amphotericin B Renal toxicity
• Amphotericin B 0.5-1.0 MKD for 2wk
then LP for CSF C/S
if +ve continue Ampho longer
and change to Fluconazole 400 mg/d for 8-10 wk
• May consider Fluconazole 6-12mo
Management
Other site not meningitis
• Disseminated disease : Rx as meningitis
• Lung in healthy: Fluco 200-400 mg/d for 3-6 mo
• Cryptococcoma : Fluco for longer period, rarely need surgical intervention (<3cm)
• Chronic endobronchial colonization No treatment !!
Management
Remark in Treatment relapse
• Defined by
1. New clinical Sign & Symptom
2. Repeat positive C/S
• Positive india ink or Crypto Ag not precise indication for Relapse !!
Other treatment modality
• Care of increase ICP– Repeated LP or shunt– Detect hydrocephalus in the F/U period
• Control of HIV
• Immunomodulation– G-CSF– GM-CSF– IFN-γ
Management
Management of ICP
No contraindication for LP
Sign of Inc ICP CN VI palsy Papilledema
HIV Pt with headache
Symptom of Inc ICP Consciousness
alteration Severe headache Visual or hearing loss
Indication for brain imaging Duration > 2wk Focal neurological deficit Papilledema, CN VI palsy
LP 1-2/d Release CSF til Close
pr < 20 cm Or Close pr < 50%
Open pr At least 10-20 ml CSF
Neurosurgical Consultation Open pr still > 20 cm in 7 days Indication of Emergency CSF
drainage
Sign and symptom of Inc ICP
Coma VA drop / Hearing loss Obstructive Hydrocephalus LP open pr ≥40 cm
Prognosis
• Most important prognosis is Ability to control host underlying disease
• Two major prognostic finding1. Burden of yeasts at presentation
- strongly positive india ink
- high titer ≥ 1:1024
- CSF inflammatory cell < 20 cell/ųL
2. Level of sensorium at presentation
Lucid < Stuporous < coma
Prevention
• Fluconazole prophylaxis in AIDS CD4<100 : risk drug resistance
• Active immunization with vaccine in high risk : GXM-tetanus toxoid conjugate vaccine, no human trial
• Protective serotherapy by specific monoclonal Ab : repeat injection
• Avoid high risk environment