Anti-Pseudomonas aeruginosa antibody detection in patients with bronchiectasis without cystic fibrosis.
BACKGROUND
Pseudomonas aeruginosa is a frequent cause of infection in patients with bronchiectasis. Differentiation between non-infected patients and those with different degrees of P aeruginosa infection could influence the management and prognosis of these patients. The diagnostic usefulness of serum IgG antibodies against P aeruginosa outer membrane proteins was determined in patients with bronchiectasis without cystic fibrosis.


METHODS
Fifty six patients were classified according to sputum culture into three groups: group A (n=18) with no P aeruginosa in any sample; group B (n=18) with P aeruginosa alternating with other microorganisms; and group C (n=20) with P aeruginosa in all sputum samples. Each patient had at least three sputum cultures in the 6 months prior to serum collection. Detection of antibodies was performed by Western blot and their presence against 20 protein bands (10-121 kd) was assessed.


RESULTS
Antibodies to more than four bands in total or to five individual bands (36, 26, 22, 20 or 18 kd) differentiated group B from group A, while antibodies to a total of more than eight bands or to 10 individual bands (104, 69, 63, 56, 50, 44, 30, 25, 22, 13 kd) differentiated group C from group B. When discordant results between the total number of bands and the frequency of P aeruginosa isolation were obtained, the follow up of patients suggested that the former, in most cases, predicted chronic P aeruginosa colonisation.


CONCLUSIONS
In patients with bronchiectasis the degree of P aeruginosa infection can be determined by the number and type of outer membrane protein bands indicating which serum antibodies are present.
Caballero
E
E
Servei de Microbiologia, Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain.
Drobnic
M E
ME
Pérez
M T
MT
Manresa
J M
JM
Ferrer
A
A
Orriols
R
R
D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis*; D015153:Blotting, Western / Q000592:standards; D001987:Bronchiectasis / Q000276:immunology*; D003550:Cystic Fibrosis / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011550:Pseudomonas aeruginosa / Q000276:immunology*; D013183:Sputum / Q000737:chemistry; D018709:Statistics, Nonparametric
D000907:Antibodies, Bacterial