Autoantibodies against granulocyte macrophage colony‐stimulating factor and Nocardia infection in solid organ transplant recipients

Dear Editors, Nocardiosis is a rare but potentially severe bacterial opportunistic infection that may occur after solid organ transplantation (SOT), typically among thoracic transplant recipients and/or in recipients with a high degree of immunosuppression due to anti-rejection therapy [1]. However, nocardiosis may also occur late after transplantation among minimally immunosuppressed patients, suggesting that additional risk factors exist [1]. Recently, autoantibodies against granulocyte macrophage colony-stimulating factor (GM-CSF) have been identified among five previously healthy patients with disseminated nocardiosis [2]. These autoantibodies likely promote nocardiosis by reducing neutrophil and macrophage activation, phagocytosis, and bactericidal activity [2]. We hypothesized that anti-GM-CSF autoantibodies might be involved in post-SOT nocardiosis, especially in patients who apparently have a relatively low degree of immunosuppression. [...]