1659. Significance of histologically-proven mycobacterial infection in lungs explanted from patients undergoing lung transplantation (LTx).
Session: Poster Abstract Session: Mycobacterial Infections
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Background: Little is known about the significance of mycobacterial (Myc) infections in the explanted lungs (ExL) of LTx patients (pts).

Methods: Retrospective review of LTx pts from 2005-10 who had AFB+ lesions consistent with Myc infection within ExL.

Results: Myc infections were present in ExL of 2% (13/698) of pts. Histopathologic findings were distributed across a broad continuum, from fibrocalcified granuloma (7) to necrotizing granuloma (6, one of whom also had AFB+ vasculitis and lymphadenitis). No AFB cultures were obtained on tissue samples. DNA probes on paraffin sections from 9 pts were non-diagnostic. Myc infection was more likely in ExL of pts with emphysema (14%) or COPD (7%) than other lung diseases (0.6%; p<0.001 for both). 23% (3/13) of pts were skin test (TST)+ pre-LTx. Although chest CT was abnormal in all pts pre-LTx, Myc disease was expected in only one TST+ pt with a cavity and sputa + for M. xenopi. 2 pts received single LTx (SLTx) and were treated for MTB and MAI, respectively: one (TST+) had AFB+ vasculitis in the ExL, and one had + culture for MAI within 3 months of LTx. The first pt did well at >3 yrs follow-up, and the second died from nocardiosis. 11 pts received double LTx (DLTx). The pt with M. xenopi was treated post-LTx due to chest wall involvement, and was well at >3 yrs. 4 pts were treated for latent TB because of a history of +TST or TB exposure; 2 of these pts were later diagnosed with M. abscessus and MAI pulmonary infection at 302 and 819 days post-LTx. One pt had BAL colonization with M. gordonae 14 days post-LTx. This pt and the 5 remaining pts did not receive therapy and did not develop Myc infection at median 1023 days post-LTx. Nontuberculous Myc (MOTT) infections were diagnosed in 27% and 7% of pts with and without Myc infections in ExL, respectively (p=0.05).

Conclusion: For incidental finding of AFB within ExL, our data support the following: 1) pts with +TST or history of TB exposure should be treated for latent TB if undergoing DLTx, and for active TB if undergoing SLTx; 2) pts without +TST or history of TB exposure can be safely observed without therapy if undergoing DLTx; SLTx pts should be treated. AFB cultures of ExL are important to guide therapy, and should be sent from suspicious lesions. Pts with AFB in ExL are at increased for MOTT post-LTx, which may reflect host predisposition for this infection.

Oveimar De La Cruz., MD., Infectious Diseases, University of Pittsburgh Medical Center, Pittsburgh, PA, Cornelius Clancy, MD, Infectious Disease, University of Pittsburgh and VA Pittsburgh, Pittsburgh, PA and Minh-Hong Nguyen, MD, University of Pittsburgh, Pittsburgh, PA

Disclosures:

O. De La Cruz., None

C. Clancy, None

M. H. Nguyen, None

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