Systemic Sweet Syndrome Recurrence in Lung Allograft: Autopsy Findings from First Reported Case

Abstract Introduction/Objective Sweet syndrome is a non-vasculitic neutrophilic dermatosis characterized by acute, neutrophilic inflammation, most classically in the skin. Sweet syndrome can, however, manifest with systemic organ involvement including the lungs. Pulmonary involvement by Sweet syndrome is exceedingly rare, and its recurrence in a pulmonary allograft is understudied. Methods/Case Report A 43-year-old female with a history of Sweet syndrome with pulmonary involvement developed chronic bronchiolitis obliterans requiring bilateral lung transplantation. Seven years after transplantation, the patient began exhibiting shortness of breath requiring hospitalization. During the patient’s hospital stay, cytomegalovirus viremia and SARS-CoV-2 positivity were detected, and new oral lesions were concerning for a Sweet syndrome flare. Her respiratory status continued to decline requiring escalating ventilatory support. An autopsy limited to the chest and abdomen was performed after she expired. The pleural cavities had extensive adhesions, and both lungs were heavy. Microscopically, the lungs showed extensive, intralumenal acute inflammation of the bronchi and bronchioles with marked chronic inflammation of the submucosa, histologically similar to the patient’s explanted lung specimen. There was also focal endogenous lipoid pneumonia due to bronchiolar obstruction. In addition to the inflammatory findings, multiple infectious agents were identified in the patient’s respiratory tract including SARS-CoV-2, cytomegalovirus, Epstein-Barr virus, Candida glabrata, Klebsiella pneumoniae, and Stenotrophomonas maltophilia. No underlying malignancy was identified. (This patient’s earlier course was reported previously: PMC8411443) Results (if a Case Study enter NA) NA Conclusion Pulmonary involvement in Sweet syndrome can cause significant morbidity, and prior to this case, allograft recurrence of Sweet syndrome had not previously been reported. For transplant patients with a history of pulmonary Sweet syndrome, recurrence should be considered in cases of allograft dysfunction. This case also highlights the importance of thorough microbiological studies in autopsies of patients with systemic inflammatory diseases being treated with extensive immunosuppressive therapies.