High Prevalence of Anti-Saccharomyces Cerevisiae Antibodies in Cystic Fibrosis Patients after Lung Transplantation

Background: Autoimmune antibodies (Ab) can be found in up to 80% of CF patients prior to lung transplantation and anti-neutrophil cytoplasmic antibodies (ANCA) may be associated with severity of lung disease and disease prognosis¹. In this pilot study, we investigated the prevalence of autoimmune antibodies in CF patients after lung transplantation (LuTx). Methods: Consecutive patients attending our outpatient clinic were screened for a wide range of autoantibodies in serum (ANA, AMA, SMA, EMA, TTG Ab, p-ANCA, c-ANCA, ASCA, SLA, LC-1 Ab), as well as immunoglobulins (IgG, IgA and IgM). Autoimmune diseases were excluded. Results: 36 patients (median age 30 y, IQR 25 – 38 y; 42% male) were included in the study. Median time since LuTx was 4.5 y (IQR: 2.3 – 8.3 y). IgG levels were elevated in 8% (3/36) of patients. Overall prevalence of autoantibodies was 83%. However, only 12% (4/34) of patients had elevated ANAs, only one patient tested positive for SMAs. Of note, 83% (24/29) of patients had elevated anti-saccharomyces cerevisiae antibodies (ASCA), so far implicated in Crohn's disease of the small bowel. Of these, 4 of 24 ASCA IgG only, in 8 of 24 ASCA IgA only, and in 12 of 24 both were positive. Yet, in none of the patients neither AMA, EMA, TTG Ab, SLA, LC-1 Ab, nor ANCA were detected. Conclusion: In contrast to published data in pre LuTx CF patients, in this study ASCAs were found in about twice as many patients, whereas ANCA were not found post LuTx. ASCAs were the dominant fraction in our panel of autoantibodies. These data draw attention to the clinical course of CF-associated small bowel disease after LuTx. ¹Lachenal et al, Prevalence and clinical significance of autoantibodies in adults with cystic fibrosis, Europ Resp J, 2009