[CIS PIDD] 3 month old Pneumocystis pneumonia, normal labs

[Fleisher, Thomas (NIH/CC/DLM) [E]]

Karen,
I referred this our resident PCP expert, Joe Kovacs and his response is below. We are always concerned about PCR positive results without a positive DFA on BAL, ie carriage vs infection which he does refer to below. I also included a copy of the paper he notes.
Tom

Hi Tom,

With a BAL that was negative for Pneumocystis organisms by DFA or some other stain I would be concerned that it is not PCP. The clinical response may have been to steroids rather than the Bactrim (or some other Bactrim-responsive pathogen). Obviously there are no large studies on PCR of BAL samples in healthy infants. However, the current hypothesis is that most infants become infected with Pneumocystis very early on. Attached is a paper by Ben Beard and colleagues that was originally designed to examine the role of Pneumocystis in SIDS. They examined autopsy lungs of 58 infants with or without SIDS by PCR, but with no know immunodeficiencies. The mean age was ~
3 months. 100% of the lungs, whether from SIDS or other causes of death, were positive by PCR. We received some of the samples and were able to amplify a different gene in some of them (we got very small amounts of DNA), and Ben's lab was very careful so I do believe their results. Whether they would also have been positive had a BAL been performed is unknown, but it is conceivable to me that some of them would have been.

There are very limited immunodeficiencies associated with PCP: scid, CD40L, and per the discussion in Grand Rounds recently, potentially IL-21. TLR def.
does not appear to be associated with PCP. We looked at MyD88 KO mice and they cleared fine. 

Hope this helps some.

Thanks.

Joe 

Joseph A. Kovacs, M.D.
Senior Investigator, CCMD
Attending Physician, NIAID/CCMD HIV/AIDS Program NIH, Building 10, Room 2C145
Phone: 301 496-9907
Direct Fax: 301-480-2466
Department Fax: 301 402-1213
Cell: 301 938-0326
e-mail: jkovacs at nih.gov

Thomas A. Fleisher, M.D. 
Chief, Department of Laboratory Medcine
NIH Clinical Center
Bethesda, MD 20892
301 496-5668 (tel)
301 402-1612 (fax)

-----Original Message-----
From: pagid-bounces at list.clinimmsoc.org [mailto:pagid-bounces at list.clinimmsoc.org] On Behalf Of Karin Chen
Sent: Wednesday, September 05, 2012 1:07 PM
To: pagid at list.clinimmsoc.org
Subject: [CIS PIDD] 3 month old Pneumocystis pneumonia, normal labs


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