Outcomes of a Routine Screening Protocol to Prevent <i>Metamycoplasma</i> and <i>Ureaplasma</i> Infection in Lung Transplant Recipients

BACKGROUND: Metamycoplasma hominis and Ureaplasma species (Mollicutes) can cause clinically significant Mollicute infections (csMI) early after lung transplantation (LT). Mollicute infection is associated with hyperammonemia syndrome (HS), a complication resulting in cerebral edema and death. We sought to describe the results before and after a screening protocol to detect and preemptively treat Mollicutes early after LT. METHODS: We retrospectively reviewed LT data at our institution before (January 1, 2020-September 4, 2022) and after (September 5, 2022-August 31, 2023) a screening protocol to detect Mollicutes by PCR on bronchoalveolar lavage within 24 h post-LT and serum ammonia monitoring every 48 h. Antibiotics were initiated for ammonia > 60 µmol/L or if PCR+. We assessed risk factors and recipient outcomes for Mollicute PCR+ and PCR-. We compared the incidence of HS and csMI in the protocol and pre-protocol groups. RESULTS: Screening detected Mollicutes in 24/125 (19.2%). All were treated ≥ 14 days. On multivariable analysis, donor age ≤ 40 years was associated with PCR+ (OR: 4.28, 95% CI: 1.65-12.13, p = 0.004). There were no differences in 6-month mortality (8.3% vs. 7.9%, p = 0.61), 3-month rejection (46% vs. 37%, p = 0.19), or mean ICU length of stay (35 days [SD = 29] vs. 42 days [SD = 54], p = 0.14) between PCR+ and PCR-. csMI occurred in 1/125 (0.8%) in the protocol group with no HS. Pre-protocol, 15/1373 (1.09%) developed csMI or HS with two deaths from HS. CONCLUSIONS: Mollicute detection by PCR screened early post-LT was inversely associated with donor age. Preemptive treatment for Mollicute detection and elevated ammonia in the early posttransplant setting may prevent serious donor-derived infection.