Tacrolimus-induced interstitial lung injury in a pediatric cardiac transplant recipient: a case report and literature review

Tacrolimus-induced interstitial lung injury (TI-ILI) is a rare but potentially fatal adverse effect of calcineurin-inhibitor therapy. To our knowledge, TI-ILI has not previously been reported in a paediatric heart-transplant recipient. A 6-year-old boy with PLN-related dilated cardiomyopathy underwent orthotopic heart transplantation. Maintenance immunosuppression comprised tacrolimus, mycophenolate mofetil and prednisone. On post-operative day 13 he developed bilateral ground-glass opacities with interlobular septal thickening on chest CT. Broncho-alveolar lavage metagenomics showed only low-abundance Pseudomonas aeruginosa and Acinetobacter baumannii; extensive microbiological, cardiac work-up was negative. Infiltrates progressed despite targeted antibiotics, but resolved within 4 weeks after tacrolimus was replaced by cyclosporine and corticosteroids were doubled. No relapse occurred during 6 months of follow-up. TI-ILI should be considered in any heart transplant recipient with unexplained progressive bilateral pulmonary infiltrates. Early tacrolimus withdrawal and prompt corticosteroid therapy are associated with complete recovery; re-exposure to tacrolimus is contraindicated.