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