2: HIV-related infections Flashcards
symptoms and signs of pneumocystis jiroveci
sx: gradual onset fever, dry cough, dyspnea
signs: fever, tachypnea, chest exam normal in 50%
what will you see on imaging of pneumocystis jiroveci
CXR with diffuse bilateral interstitial infiltrates
-normal in 10-25% of cases
HRCT highly sensitive, helpful when CXR negative/ equivocal
how do you diagnose pneumocystis jiroveci
- immunofluorescent Ab staining
- induced sputum
- bronchoscopy/ BAL
- LDH elevated
how to patients initially respond to pneumocystis treatment?
patients typically worsen after 2-3d of therapy
what is the role of corticosteroids in pneumocystis treatment?
give if PaO2
antimicrobial options for pneumocystic treatment
- IV TMP/SMX or pentamidine
- po TMP/SMX, TMP-dapsone, clindamycin-primaquine, atovaquone
pneumocystic prophylaxis
when CD4
when do you discontinue pneumocystic prophylaxis
increase in CD4>200 for >3mos
cryptococcal meningitis sx and signs
- subacute meningitis w/ fever
- HA
- malaise
- occasional encephalopathic sx
- often few sx even with very elevated ICP
-meningeal signs in minority
CSF findings with cryptococcal meningitis
- lymphocytic pleocytosis
- mildly elevated protein
- low-normal glucose
- OP elevated to > 200mmH2O in up to 75% of cases
cryptococcal meningitis diagnosis
- serum and CSF crypto Ag very sensitive
- routine blood cultures + CSF fungal culture
cryptococcal antifungal therapy
induction - amphoB + flucytosine for at least 2 wks
-if clinical progress maintenance: fluconazole 400 mg daily for 8 wks
secondary prophylaxis: fluconazole 200mg daily, can be stopped only if CD4>200 on HAART for >6 mos
cryptococcal therapy: managing elevated ICP
- if ICP>250 mmH2) and/or neuro signs: daily LP recommended to reduce ICP
- consider CSF shunt if sx/signs of cerebral edema or daily LP no longer tolerated
at what CD4 level do patients usually get CMV infection?
CD4
end organ manifestations of CMV
- retinitis most common
- colitis
- esophagitis
- neuro disease - dementia, ventriculoencephalitis, ascending polyradiculomyelopathy
- CMV viremia
- CMV pneumonitis
diagnosing latent TB in HIV
- test all at HIV diagnosis, continue annual testing if high risk
- PPD or IFNgamma release assay
how do you treat latent TB in HIV
INH daily or twice weekly for 9 mo
rifampin
rifabutin for 4 mos
how does TB present in severely immunocompromised, advanced HIV patients?
CXR:
- less upper lobe cavitation
- can see lower lobe
- interstitial and miliary infiltrates
- hilar/mediastinal adenopathy
- occasionally normal
extrapulmonary manifestations more common with higher yield of AFB smear/culture of extrapulmonary specimens
histopathology with poorly formed or no granulomas
what is an independent predictor of mortality in HIV?
disseminated M. avium complex (MAC)
clinical presentation of MAC
- fever
- weight loss
- sweats
- diarrhea
- lymphadenopathy
- hepatosplenomegaly
abnormal lab values of MAC
- anemia
- elevated alkphos
- CD4
how to diagnose MAC
- blood culture (very sensitive)
- culture from other site (bone marrow)
what predicts increased risk of dissemination of MAC
respiratory colonization
disseminated MAC prevention
- azithromycin 1200mg po/week
- clarithromycin 500mg po BID
- rifabutin 300mg po daily
rule out primary disease by clinical assessment before starting prophylaxis
when do you stop primary prophylaxis for MAC
when CD4>100 for more than 3mo
signs and symptoms of toxoplasmosis
sx: headache, fever, behavioral, lethargy, coord/gait, seizure, coma
signs: hemi, ataxia, cranial nerves, aphasia, visual, extrapyramidal
what do you see in neuroimaging in toxoplasmosis
- focal lesions on CT/MRI (except rare diffuse encephalitis form)
- multiple lesions in 2/3 of cases
- ring enhancement ~90%
- mass effect
- edema
preferential location: basal ganglia, grey-white jxn, white matter
what does CSF analysis look like in toxoplasmosis
- mild elevation of proteins
- moderate mononucleared pleocytosis (60 cells/ml)
- occasional decreased glucose
what is toxoplasmosis sometimes confused with?
primary CNS lymphoma
-diagnose for sure by seeing response on imaging to empiric treatment of toxopalsmosis (vs biopsy)
how often do you see primary CNS lymphoma in AIDS patients?
2-4%
what are CD4 counts like in AIDS patients with primary CNS lymphoma?
signs and sx of primary CNA lymphoma
- confusion
- lethargy
- memory loss
- hemiparesis or aphasia
- seizures
- cranial nerve palsy
- headache (uncommon)
NO FEVER unless concomitant infection
what do you see on neuroimaging of primary CNS lymphoma
CT/MRI:
- multiple lesions as frequent as single lesion
- nodular or patchy enhancement
- subependymal enhancement (more specific)
- variable mass effect
- localization to cortex, deep structures
- thallium-201 SPECT shows increased metabolic activity
what will CSF show in primary CNS lymphoma
-mild mononucleared pleocytosis (
how does one get PML (progressive multifocal luekoencephalopathy)
asymptomatic JC virus infection in childhood - latency in kidneys, lymphoid organs, bone marrow, brain
percent of AIDS patients with PML before and on cART
before: 5%
on: 0.06%
diagnosis of PML
brain biopsy or CSF PCR detection of JCV DNA
cure for PML
none - ~50% survival at one year in HIV+ patients, no effective treatment
