Noon conference kardasheva 4 16 2019

1. Noon Conference
ALEKS KARDASHEVA, DO
INTERNAL MEDICINE, PGY-3

2. Pneumocystis Pneumonia
 Background and biology
 Risk factors
 Clinical manifestations
 Diagnosis
 Prevention
 Treatment

3. Background
 First identified in 1909 by Chagas; reported as part of the
life cycle of Trypanosoma cruzi
 Recognized as separate organism in 1912; named
Pneumocystis carinii
 1940s and 50s: cause of pneumonia epidemics in
premature and malnourished infants
 1980s and 90s: leading cause of death in AIDS

4. Biology
 Initially classified as protozoa; now fungus
 Each species affected with unique strain:
- Pneumocystis carinii: rats
- Pneumocystis jirovecii: humans
 Worldwide distribution
 Ubiquitous exposure: nearly all infected in infancy

5. Risk factors
Key = immunosuppression
Multicenter AIDS Cohort Study
Incidence with CD4 count 201-350: 0.5%
Within 6 months of falling below 200: 8.4%
Within 12 months of falling below 200: 18.4%
Within 6 months of developing thrush: 29.5%
Environmental Factors?

6. Risk Factors
Factors associated with development of PCP:
 CD4 count < 200 cells/mm3
 CD4 percentage < 14%
 Previous episodes of PCP
 Oral thrush

7. Clinical manifestations
Symptoms (usually subacute) Signs CXR Findings
Fever Hypoxia (esp w/ exertion)
Diffuse, bilateral, hazy
infiltrates (“butterfly”)
Dyspnea (door-stop) Tachy, tachypneic Pneumothorax
Dry cough Inspiratory crackles
Pleural effusion, lobar
infiltrates, nodules less
common
Pleuritic chest pain Elevated A-a gradient CXR normal in 25%
Malaise Chest exam normal in 50%

10. Diagnosis
 Gold standard: identification of organism on stain of
respiratory secretions or tissue
 Induced sputum: Sn < 50-90%
 Generally not improved by repeating
 Bronch w BAL: Sn 90-99%
 Lung biopsy: Sn 95-100%

11. Diagnosis: Non-invasive Tests
LDH
Non specific
Prognosis?
PCR
Infections vs
colonization?
Not commercially
available
Beta-D-Glucan
Sn: 92.8%
Sp: 75%
PPV: 96.3%
NPV: 60%

13. Summary of Dx Evaluation
 CXR, if normal and high suspicion -> chest CT
 ABG, beta-glucan, +/- LDH
 Induced sputum, if negative -> Bronch/BAL
 Lung bx if still unclear

14. Initiating Prophylaxis
Indications:
 CD4 count< 200 cells/mm3 (AI)
 Oral thrush (AII)
 CD4%< 14 or other AIDS-defining illnesses (BII)
 Following PCP treatment (secondary prophy)

15. Options for Prophylaxis
•DS or SS tab daily (1A)
•DS tab 3x/week an alternative (1B)
TMP-SMX
•Check G6PD level
•100mg daily
Dapsone
•Liquid, expensive
•1500mg daily
Atovaquone
•Several limitations
•300mg monthly
Inhaled Pentamidine

16. Treatment
Mild disease
Oral TMP-
SMX
Clindamycin-
primaquine
Atovaquone
Severe Disease
IV TMP-SMX
IV
Pentamidine
Clindamycin-
primaquine
Inpatient
Significant hypoxia
Steroids
Unable to take PO
Comorbidities
Need pentamidine
Outpatient
No sig hypoxia
Able to take PO
Adherent to meds

17. Key treatment considerations
 Empiric treatment ok?
 Standard course duration
 When to add corticosteroids

18. Treatment Failure
May worsen in first 2-3 days but should improve by
days 5-7; if not consider the following:
 R/o other infections
 Switch PO to IV meds/alternative agents?
 Add additional agent?
 Increase steroids dose?
 Extend duration?
 Add an echinocandin?

19. Prognosis
 Severe disease: Hypoxia, ICU, mechanical ventilation
 Advanced immunosuppression
 Older age
 Higher LDH
 Prior episodes of PCP
 Low albumin

20. Summary
 Prophylaxis indicated if CD4 < 200, thrush, prior PCP
 Stop if CD4 > 200 x 3 months, though likely safe if CD 4 100-200 and VL
undetectable
 Should likely separate patients with PCP from other immunosuppressed
pts
 First line for prophy and tx: TMP-SMX
 No clear guidelines for managing treatment failure