Pre-lung transplant monocyte counts predict post-lung transplant survival and adverse outcomes in IPF

IntroductionAccurate pre-lung transplant biomarkers of post-lung transplant survival are lacking in Idiopathic Pulmonary Fibrosis (IPF). MethodsThis was a retrospective, observational study including consecutive patients diagnosed with IPF at the University of South Florida/ Tampa General Hospital. First, we compared survival differences in patients with IPF that received lung transplant versus non- recipients, then we investigated whether pre-transplant monocyte counts could predict post- lung transplant survival, Primary Graft Dysfunction (PGD), Acute Cellular Rejection (ACR), Antibody-Mediated Rejection (AMR) and Chronic Lung Allograft Dysfunction (CLAD) using Cox Proportional Hazards (CoxPH) models adjusted to Gender, Age and Physiology index (GAP). ResultsA total of 201 patients with IPF were included in the analysis [lung transplant recipients: n=103, non-recipients of lung transplant: n=98]. Patients with IPF that did not undergo lung transplantation had significantly worse survival compared to patients with IPF that underwent lung transplantation [3.13 years (95% CI: 2.30 to 3.72) vs 7.05 years (95% CI: 5.41 to 8.48), HR: 2.95 (95% CI: 2.18 to 4.00), p<0.0001]. Patients with IPF and pre-lung transplant monocyte counts>700 K/L had increased risk of post-lung transplant mortality [HR: 1.71 (95%CI: 1.10 to 2.65), p=0.016] or adverse outcomes defined as either PGD, ACR, AMR or CLAD, [HR: 2.05 (95% CI: 1.11 to 3.78), p=0.02] compared to patients with monocyte counts[&le;]700 K/L. ConclusionLung transplantation substantially prolongs survival of patients with IPF. Incorporation of pre-lung transplant monocyte counts in the pre-transplant evaluation of patients with IPF could optimize the selection of ideal lung transplant candidates with increased probability of survival.