Malin Carlsson

Deficiency of the mannan-binding lectin pathway of complement and poor outcome in cystic fibrosis: bacterial colonization may be decisive for a relationship.

In cystic fibrosis (CF) prognosis concerning lung damage development is highly variable and difficult to predict. Mannan‐binding lectin (MBL) deficiency has been reported to be associated with poor outcome in CF lung disease. MBL is a recognition molecule of the MBL pathway of the complement system and is encoded by a gene characterized by a high degree of polymorphism. Some genotypes result in low serum concentrations of MBL. MBL‐associated serine protease 2 (MASP‐2) is another protein belonging to the MBL pathway. A mutation resulting in low levels of MASP‐2 in serum has been described recently. In the present study, 112 CF patients aged 4–54 years were investigated for MBL and MASP‐2 genotypes, serum levels of MBL and MASP‐2 and the MBL pathway function in serum. No correlation to reduced lung function or need for lung transplantation was seen, either for MBL deficiency, MASP‐2 gene mutation or reduced MBL pathway function. However, in the 27 patients colonized with Staphylococcus aureus, MBL‐deficient genotypes were associated with decreased lung function. As expected, MBL pathway function in serum was reduced both in MBL‐deficient patients and in patients carrying a mutant MASP‐2 allele. An unexpected finding was that CF patients had higher serum levels of MBL than healthy controls when corrected for MBL genotype. In conclusion, MBL pathway function was affected both by MBL and by MASP‐2 genotypes. However, MBL or MASP‐2 levels in serum did not affect the clinical outcome in the cohort of CF patients studied.

Pseudomonas aeruginosa in cystic fibrosis: Pyocyanin negative strains are associated with BPI-ANCA and progressive lung disease

The clinical consequence of chronic Pseudomonas aeruginosa colonization in cystic fibrosis (CF) varies between individuals for unknown reasons. Auto-antibodies against bactericidal/permeability increasing protein (BPI-ANCA) are associated with poor prognosis in CF. We hypothesize that there is a correlation between the presence of BPI-ANCA, the properties of the colonizing bacteria and the clinical conditions of the host. We compared isolates of P. aeruginosa from BPI-ANCA positive CF patients who have deteriorating lung disease with BPI-ANCA negative CF patients who are in stable clinical conditions. Epithelial cells (A549) and isolated polymorphonuclear granulocytes (PMNs) were stimulated with the isolates and cell death was analyzed with flow cytometry. We found that the ANCA associated strains in most cases showed pyocyanin negative phenotypes. These strains also induced less inflammatory response than the non-ANCA associated strains as shown by apoptosis and necrosis of epithelial cells and neutrophils. Our results suggest that colonization with strains of P. aeruginosa that induce a weak inflammatory response is associated with unfavorable outcome in CF. We speculate that inadequate control of pathogen proliferation through an insufficient inflammatory response results in a slowly increasing number of bacteria and accumulation of dying PMNs in the airways, contributing to progression in CF lung disease.

Extensive Endoscopic Image-Guided Sinus Surgery Decreases BPI-ANCA in Patients with Cystic Fibrosis

Antineutrophil cytoplasm autoantibodies (ANCA) directed against bactericidal/permeability‐increasing protein (BPI) are common in patients with cystic fibrosis (CF), and serum levels are correlated with lung colonization by Pseudomonas aeruginosa and the severity of lung damage. The production of BPI‐ANCA may be due to the costimulation of BPI when mounting an immune response against P. aeruginosa. The effect of surgery aiming to eradicate bacteria and infected tissue on BPI‐ANCA levels is sparsely described. A cohort of patients with CF were included: 53 patients having extensive image‐guided sinus surgery (EIGSS) with topical postoperative antibiotic treatment, 131 non‐operated controls and 36 who had double lung transplantation (LTX). In all 219 patients, serum samples before and after surgery or at similar intervals were analysed for IgG and IgA BPI‐ANCA. The EIGSS group showed a highly significant decrease in both IgA and IgG BPI‐ANCA levels compared with their own preoperative values and control group values (P < 0.001–0.02). The LTX patients also showed a highly significant decrease in both IgA and IgG BPI‐ANCA levels (P < 0.001). EIGSS and LTX decrease IgA and IgG BPI‐ANCA levels in patients with CF, indicating that extensive removal of infected tissue influences the pathogenic process of autoantibody production. The results shown herein are in favour of applying EIGSS in selected patients with CF and for using BPI‐ANCA as a surrogate marker for guiding further therapeutic interventions.

BPI-ANCA and long-term prognosis among 46 adult CF patients: a prospective 10-year follow- up study

Introduction. Anti-neutrophil cytoplasmic antibodies specific for bactericidal/permeability-increasing protein (BPI-ANCA) are frequent in CF patients and mainly develop in response to infection with Pseudomonas aeruginosa. It is not known to what extent BPI-ANCA correlates to prognosis. Objectives. To evaluate the prognostic value of IgA-BPI-ANCA, measured at the beginning of the study, for transplantation-free survival. Methods. A cohort of 46 adult, nontransplanted CF patients was generated, 1995–1998, and characterized using Leeds criteria, lung function, and IgA-BPI-ANCA levels measured by ELISA. The cohort was followed until December 2009, using the combined endpoint of death or lung transplantation. Results. Lung function and IgA-BPI-ANCA, but not Leeds criteria, were significantly associated with adverse outcome. No patient with normal lung function at baseline reached endpoint. Within 10 years 8/11 with high BPI-ANCA reached an endpoint compared to 3/17 ANCA-negative patients. A similar result was seen within the Leeds I group where 7 out of 9 BPI-ANCA-positive patients reached endpoint, compared to none of the 5 patients without BPI-ANCA. Conclusions. IgA-BPI-ANCA is associated with adverse outcome among Pseudomonas aeruginosa infected CF patients, suggesting that BPI-ANCA is a biomarker of an unfavourable host-pathogen interaction.

BPI-ANCA Provides Additional Clinical Information to Anti-Pseudomonas Serology: Results from a Cohort of 117 Swedish Cystic Fibrosis Patients.

Patients with cystic fibrosis (CF) colonized with Pseudomonas aeruginosa (P. aeruginosa) have worse prognosis compared with patients who are not. BPI-ANCA is an anti-neutrophil cytoplasmic antibody against BPI (bactericidal/permeability increasing protein) correlating with P. aeruginosa colonization and adverse long time prognosis. Whether it provides additional information as compared to standard anti-P. aeruginosa serology tests is not known. 117 nontransplanted CF patients at the CF centre in Lund, Sweden, were followed prospectively for ten years. Bacterial colonisation was classified according to the Leeds criteria. IgA BPI-ANCA was compared with assays for antibodies against alkaline protease (AP), Elastase (ELA), and Exotoxin A (ExoA). Lung function and patient outcome, alive, lung transplanted, or dead, were registered. BPI-ANCA showed the highest correlation with lung function impairment with an r-value of 0.44. Forty-eight of the 117 patients were chronically colonized with P. aeruginosa. Twenty of these patients experienced an adverse outcome. Receiver operator curve (ROC) analysis revealed that this could be predicted by BPI-ANCA (AUC = 0.77), (p = 0.002) to a better degree compared with serology tests. BPI-ANCA correlates better with lung function impairment and long time prognosis than anti-P. aeruginosa serology and has similar ability to identify patients with chronic P. aeruginosa.

170 BPI-ANCA correlates better with lung function impairment than bacterial serology

169* Bactericidal activity of human cystic fibrosis macrophages against Pseudomonas aeruginosa N. Cifani1, S. Guarnieri2, M.A. Mariggio2, F. Spadaro3, S. Guglietta4, M. Anile5, F. Venuta5, S. Quattrucci6, F. Ascenzioni1, P. Del Porto1. 1Sapienza University, Dept. Biology and Biotechnology, Rome, Italy; 2G. d’Annunzio University ChietiPescara, Dept. Neurosciences and Imaging, Pescara, Italy; 3Istituto Superiore Sanita, Dept. Cell Biology and Neurosciences, Rome, Italy; 4European Institute of Oncology, Dept. Exp. Oncology, Milan, Italy; 5Sapienza University, Dept. Thoracic Surgery, Rome, Italy; 6Sapienza University, Dept. Pediatrics, Rome, Italy

153 Pseudomonas aeruginosa isolates from cystic fibrosis patients with and without autoantibodies to bactericidal/permeability increasing protein (BPI-ANCA) exhibit different gene expression profile

153 Pseudomonas aeruginosa isolates from cystic fibrosis patients with and without autoantibodies to bactericidal/permeability increasing protein (BPI-ANCA) exhibit different gene expression profile S. Shukla1, A. Petterson1, M. Carlsson1, T. Hellmark1, K. Riesbeck2, M. Segelmark1. 1Lund University, Department of Clinical Sciences, Lund, Sweden; 2Lund University, Department of Laboratory Medicine, Malmo, Sweden