Bronchoalveolar lavage neutrophilia in acute lung allograft rejection and lymphocytic bronchiolitis.

Background: Acute cellular rejection and lymphocytic bronchiolitis can impair allograft function after lung transplant (LTx). Both may be refractory to corticosteroid treatment. We hypothesized that bronchoalveolar lavage (BAL) neutrophilia may be increased in either acute rejection or lymphocytic bronchiolitis or may increase with increasing histologic severity.

Methods: All consecutive BAL with subsequent transbronchial biopsy (TBB) specimens, performed in 339 LTx recipients from 2001 to 2008, were retrospectively analyzed. TBB specimens were classified according to histologic grade with analysis of BAL total cell count and cell differentials.

Results: The analysis included 768 TBB specimens. After adjustment for possible confounders, BAL total cell count significantly increased both with grade A or B severity (p < 0.0001). A higher A grade was characterized by a significant increase in BAL lymphocytosis and neutrophilia (p < 0.0001), whereas for higher B grades, only a more prominent BAL neutrophilia was seen (p < 0.0001).

Conclusions: Higher grade A, but, particularly, higher grade B severity scores are characterized by increased BAL neutrophilia.