Eosinophilic alveolitis in BAL after lung transplantation

Abstract

Lung transplantation has become a therapeutic option for patients with end stage lung disease. However, outcome after transplantation is complicated by episodes of rejection and infections. Bronchoalveolar lavage is a valuable tool in monitoring patients after transplantation, since it allows the detection of pathogens. A marker specifically indicating rejection from changes in BAL fluid has not been found yet. Especially changes in differential cell count, like lymphocytosis or an increase in polymorphnuclear granulocytes, are unspecific. The role of high eosinophil levels in BAL has not been elucidated yet. We analyzed 25 BAL samples and clinical data of 4 patients who underwent lung transplantation and presented with recurrent episodes of eosinophilic alveolitis in BAL. All patients demonstrated a deterioration of clinical condition, lung function, and blood gas analysis during times of eosinophilia in BAL, compared to previous examinations. In all cases, eosinophilia in BAL was accompanied by rejection. All patients were finally treated with high doses of steroids, resulting in improvement of all parameters. Eosinophilia was not associated with significant changes in the IL-5 concentration in BAL or the pattern of IL-5 expression in BAL cells. In conclusion, eosinophilic alveolitis may indicate acute rejection in patients after lung transplantation, if other causes of eosinophilia are excluded.

Mechanistic differences between phenotypes of chronic lung allograft dysfunction after lung transplantation

“…In addition, the detected eosinophilia in RAS is a potential new concept to consider. Eosinophilia has been reported in the past in chronic rejection 38 , yet never explored further. Classical BOS is becoming an increasingly difficult phenotype to increase mechanistic understanding of.…”

Diagnostic value of plasma and bronchoalveolar lavage samples in acute lung allograft rejection: differential cytology

“…eosinophil cationic protein and major basic protein) [ 52 ]. Eosinophils have been associated with various pulmonary conditions such as asthma, eosinophilic granulomatosis with polyangiitis (“Churg-Strauss syndrome”), drug reactions, helminthic infections, hypereosinophilic syndrome as well as acute and chronic eosinophilic pneumonia [ 16 , 53 – 56 ]. More specifically, eosinophils have been shown to damage the lung by degrading connective tissue and injuring epithelial and micro-vascular structures [ 57 , 58 ].…”

“…Eosinophils injure the graft by releasing cytotoxic agents such as eosinophil cationic protein [ 65 , 68 ]. Activation of eosinophils by helper T lymphocytes through IL-3 and IL-5 and by macrophages through IL-1 has been suggested [ 16 , 71 , 72 ]. However, Bewig and colleagues found no correlation between lymphocytes expressing IL-5 and the number of eosinophils in BAL [ 16 ].…”

“…Activation of eosinophils by helper T lymphocytes through IL-3 and IL-5 and by macrophages through IL-1 has been suggested [ 16 , 71 , 72 ]. However, Bewig and colleagues found no correlation between lymphocytes expressing IL-5 and the number of eosinophils in BAL [ 16 ]. This group also found that patients with BAL eosinophilia during acute AR responded well to steroids, which was confirmed in other studies [ 16 , 73 ].…”

“…However, these patterns only allow delayed and retrospective diagnosis [ 14 ] and are of limited sensitivity [ 14 , 15 ]. Moreover, cough, dyspnoea, low-grade fever, perihilar infiltrates and deterioration of pulmonary function may appear in other common conditions after transplantation and do not distinguish AR from infection [ 14 , 16 ].…”