*Purpose: Within 5 years after lung transplant (LT), half of recipients have lost 20% or more of lung function. Despite a consistent link between social and environmental factors with respiratory health, there has not been a place-based investigation of these factors in LT outcomes. Place can be measured via contextual ‘geomarkers’. Similar to how biomarkers (e.g. blood tests) inform clinical decisions, geomarkers are upstream data that precisely risk stratify patients to inform interventions at the patient and policy level. We leveraged U.S. census tracts, which are federally designated small area spatial units that allow for precise patient geolocation and linkage to important non-clinical datasets. Our hypothesis was that census tract-based geomarkers were associated with the risk for biopsy proven acute cellular lung rejection– a serious but mutable risk factor for lung function loss and early mortality.

*Methods: We identified recipients transplanted at our center between January 1, 2016-December 31, 2017 who were permanent residents of Ohio and experienced ≥1 episode of moderate grade biopsy proven acute lung rejection (International Society of Heart and Lung Transplant grade ≥A2). We focused on >3 months after transplant where lung rejection was likely from place-based factors and less likely peri-operative issues. We next identified the latitude and longitude of the residential address in order to geocode the census tract. The tract was then linked to the Center for Disease Control and Prevention’s Social Vulnerability Index (SVI), which scores all U.S. census tracts in four domains: Socioeconomic status, Household composition, Race/ethnicity /language, and Housing/transportation. The SVI ranges from 0 to 1, with higher values indicating greater vulnerability.

*Results: Of 239 transplants during the study period, 45 patients experienced moderate grade rejection. 31 were within 3 months of transplant and 14 were >3 months. Among patients with >3 months rejection, there was a correlation with census tracts predominantly of underrepresented minorities or where English is not the predominant language (SVI: 0.64) when compared to socioeconomic status (SVI: 0.31), household composition (SVI: 0.36) or housing/transportation (SVI: 0.37) (p = 0.007).

*Conclusions: Non-clinical place-based geomarkers may correlate with the risk for lung rejection. Census tracts likely play a key role in identifying and addressing geographic disparities in transplantation. Because acute lung rejection is a mutable risk factor, and a patient’s SVI is readily identifiable, this approach could be quickly translated to individualized clinical care through shortened outpatient follow-up intervals or augmented immunosuppression to improve outcomes for at-risk patients.

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