(628) - Is Routine Respiratory Viral PCR Testing in Lung Transplant Recipients Helpful?

Abstract

Our unit adopted routine screening for a panel of respiratory viruses using quantitative PCR on all bronchoalveolar lavage (BAL) samples from LTx recipients since 2009. We evaluated diagnostic yield and usefulness of this approach. Retrospective examination of BAL viral PCR results in all LTx performed from January 2009 to December 2013 at our institution. Total number of samples and number of positive samples per patient were noted. Results were stratified by single (SLTx) vs. double (DLTx) lung recipients and by surveillance bronchoscopy (SB) vs. bronchoscopy clinically indicated by a drop in spirometry and/or radiographic changes (CB). 123 LTx were performed in the study period (35 SLTx, 88 DLTx; 70 males, mean age 52 yrs [range 17-65]; SLTx indications: IPF 25, other fibrosis 8, COPD 1, sarcoid 1; DLTx indications: CF 13, non-CF bronchiectasis 4, COPD 49, alpha 1 antitrypsin deficiency 8, obliterative bronchiolitis 3, IPF 2, other fibrosis 3, iPAH 4, CTEPH 1, sarcoid 1). Mean follow up was SLTx: 1001 days (range 10-2392) and DLTx 1034 (0-2344) during which 84 and 222 BAL viral PCR panels were performed respectively. 6 positive PCR results in 5 SLTx and 24 in 19 DLTx were noted (P=NS) at a median of 56 (range 40-845) vs 201 (range 3-1232) days post op (P=NS). Rhinovirus was most prevalent (18 samples vs. parainfluenza 6, adenovirus 4, respiratory syncytial virus 3, metapneumovirus 3). Rhinovirus co-existed with adenovirus in 2 patients and with parainfluenza in 1 patient. 7/228 (3%) SB vs 23/78 (29%) CB samples were PCR positive (P<0.05). Apart from 2 RSV episodes treated with oral ribavarin, no targeted therapy was implemented. Our data suggest a limited diagnostic yield from a respiratory viral PCR panel in routine surveillance BAL samples post LTx. Most viruses identified are self-limiting with no proven effective therapy and the cost of expensive routine testing is therefore unjustified. In contrast, clinically indicated BAL is 10 times more likely to reveal positive viral DNA. Freedom from respiratory viruses appeared numerically, though not statistically, shorter in SLTx recipients but this is confounded by the small sample size. Native lung factors may be relevant and this merits further investigation.