B53-35 3 Days Without Medications = Acute Transplant Rejection?

Abstract A 46-year-old man with cystic fibrosis underwent bilateral lung transplantation four months prior and presented with acute dyspnea after running out of all immunosuppressive and prophylactic medications for three days (Mycophenolate Mofetil, Tacrolimus, Prednisone). His last follow up bronchoscopy a month before this admission did not reveal any signs of rejection. He had previously discontinued inhaled tobramycin three weeks earlier. Imaging revealed diffuse ground-glass opacities and interlobular septal thickening (Fig.1.), markedly worsened from a prior scan. Bronchoalveolar lavage was negative for infection, favoring acute rejection secondary to medication non-adherence. Despite high-dose methylprednisolone, G-CSF, and empiric antibiotics, his respiratory status deteriorated, requiring mechanical ventilation. Acute rejection is a major cause of early graft failure after lung transplantation, and its risk increases with lapses in immunosuppressive therapy. Even short interruptions trigger a strong alloimmune response, especially within the first year when immune activation is most pronounced. Our patient’s abrupt discontinuation of tacrolimus, mycophenolate, and prednisone likely precipitated acute cellular rejection, given the absence of infection and rapid radiologic worsening. Radiographically, diffuse ground-glass opacities and septal thickening are common but nonspecific findings that can represent edema, infection, or rejection. In this case, the negative infectious workup and worsening CT pattern supported rejection. Transbronchial biopsy remains the diagnostic gold standard, but clinical instability necessitates empiric treatment with pulse corticosteroids. High-dose methylprednisolone remains first-line therapy; refractory cases may require plasmapheresis, IVIG, or lymphocyte-depleting agents. Medication non-adherence is a leading cause of graft loss and mortality. Studies show that up to one-third of lung transplant recipients demonstrate some degree of non-adherence, frequently related to psychosocial or access barriers. Continuous patient education, structured medication delivery systems, and close outpatient follow-up are essential to prevent such catastrophic events. This case underscores how quickly rejection can develop when immunosuppression lapses. Despite aggressive therapy, prognosis remains guarded once mechanical ventilation is required, as mortality in ventilated lung transplant patients exceeds 50%.This case illustrates fulminant acute allograft dysfunction following a brief period of medication non-adherence in a recent bilateral lung transplant recipient. The rapid deterioration and imaging findings consistent with rejection emphasize the importance of uninterrupted immunosuppressive therapy and vigilant follow-up. Preventive strategies, including early pharmacy coordination, education, and monitoring of drug levels, are vital to minimize avoidable graft loss. This case highlights the critical importance of strict immunosuppression adherence after lung transplantation and the rapid onset of potentially fatal acute allograft dysfunction following even brief interruption. This abstract is funded by: None