HIV related infections and complications Flashcards
cryptococcal meningoencephalitis
invasive fungal infection caused by Cryptococcus neoformans seen in HIV pts
originates from lungs but can get to CNS and present with traditional meningitis symptoms
Treatment of cryptococcal meningoencephalitis in HIV pts
Needs yeast eradication and given in several phases: induction, consolidation and maintenance
Induction therapy: consists of 2 weeks of amphotericin B +/- flucytosine.
Consolidation: After CSF is clear can be switched to 8 weeks of fluconazole
Maintenance: Then 1 year of fluconazole therapy
When do you discontinue fluconazole or maintenance therapy in HIV pts who had cryptococcal meningoencephalitis?
after consolidation therapy are on fluconazole for 1 yr post infection. However can be discontinued once CD4 >100 with antiretroviral therapy
When to do serial LP in HIV pts w/ cryptococcal menigoencephalitis ?
when there is increased ICP (CSF>200 mmHg) and (seen in 50% of pts) AND headache, AMS, visual hearing loss and cranial nerve deficits
Goal to reduce ICP <200 or by 50% and decreases mortality
If do not respond, need to get ventriculostomy drain.
Is there any role for acetazolamide to lower ICP in cryptococcal
No.
If newly diagnosis HIV pt without ART who has cryptococcal meningoencephalitis, when do you start antiviral therapy?
wait 2-10 weeks after starting antifungal therapy to treat HIV because thought is that if started right away the ART can cause IRIS (immune reconstitution inflammation syndrome)
Drugs that interfere with folic acid metabolism
methotrexate
phenytoin
pyrimethamine
trimethoprim
treatment of systemic CNS toxoplasmosis
sulfadiazine and pyrimethamine
if unable to tolerate sulfadiazine can take clindamycin (preferred) over atovaquone or azithromycin.
longterm side effect of pyrimethamine
inhibits dihydrofolate reductase (similar to methotrexate and trimethoprim)
Blocks dividing cells and can first manifest as bone marrow suppression.
How to treat folic acid deficiency while on pyrimethamine
leucovorin - reduced folic acid that bypasses the blocked enzyme and has equivalent activity to folic acid.
Should be given concurrently with pyrimethamine to prevent leukopenia, megaloblastic anemia, and thrombocytopenia
do we give anti seizure medications to pts who have toxoplasmosis of CNS?
no unless they have seizure history.
Also try to avoid phenytoin with pts who are on pyrimethamine
PCP prophylaxis
bactrim or TMP SMX but if already treated with sulfadiazine and pyrimethamine for CNS toxoplasmosis - no need for additional coverage
toxoplasma encephalitis clinical presentation
fever, headache, confusion, focal neurological deficits/seizures
primary CNS lymphoma presentation
fever, night sweats, weight loss (80% of pts) , confusion, memory deficits, aphasia, and motor deficits, and focal neurological deficits, seizures
progressive multifocal leukoencephalopathy PML presentation
rapidly progressive neurological deficits (confusion, motor deficits, ataxia, aphasia, visual symptoms, and cognitive impairment)
lab findings with toxoplasma encephalitis
CD4 count<100
toxoplasma IgG antibodies
lab findings with primary CNS lymphoma
CD4 count<50
positive CSF cytology or Epstein Barr virus polymerase chain reaction positivity
lab findings for PML (progressive multifocal leukoencephalopathy)
CD 4 count <200
imaging studies for toxoplasma encephalitis
multiple ring enhancing lesions with mass effect and edema
commonly seen involving the basal ganglia
imaging studies for primary CNS lymphoma
solitary enhancing lesions with mass effect and edema
larger lesions >4cm compared to toxoplasma encephalitis. generally can involve the corpus callosum, periventricular or periependymal areas.
PML imaging findings:
bilateral usually asymmetrical white matter lesions
no mass effect, enhancement or edema
brain abscess etiology
direct extension of a dental sinus or ear infection and hematolgenous dissemination tends to be drom IVDA and endocarditis that leads tomultiple findings.
bacteria that can cause a brain abscess are:
streptocuccus and staph aureas but HIV pts can have listeria, nocardia, fungal and parasitic (toxoplasmosis)
unilateral headache, focal neurological deficits, seizures, papilledema and see single or multiple ring enhancing lesions at the grey white matter junction and significant vasogenic edema and mass effect
brain abscess- may not see systemic fever or sepsis in brain abscess
treatment of brain abscess
antibiotics and surgical drainage.
HIV associated encephalopathy
affects whole brain and see progressive dementia and brain atrophy on CT. No ring enhancing lesions
what causes PML?
JC virus reactivation and this happens with CD4 counts <200 and we see multifocal areas of white matter demyelination without mass effect, edema or enhancement.
Prophylaxis for PCP in HIV
bactrim
alternate therapies:
dapsone
atovaquone
pentamidine
when is HIV pt at risk for PCP infection
CD4 count <200
OR oropharyngeal candidasis is present
or history of PCP infection
when is HIV pt at risk for toxoplasma gondii infection?
CD4 count <100 and positive IgG antibody
prophylaxis against toxoplasma gondii in HIV pt
bactrim
alternate therapies:
dapsone + pyrimethamine + leucovorin (folinic acid)
atorvaquone + pyrimethamine + leucovorin
remember need leucovorin to prevent toxic effects of methotrexate or pyrimethamine.
when is a HIV pt at risk for histoplasma capsulatum
CD4 count <150 and in endemic area
prophylaxis against histoplasma capsulatum in HIV pt
itraconazole
when is a HIV pt at risk for varicella zoster virus infection?
close contact with person with chicken pox or shingles and no history of prior dx or negative antibody to VSV