Measurement of immunoglobulin G against Mycobacterial antigen A60 in patients with cystic fibrosis and lung infection due to Mycobacterium abscessus.
BACKGROUND
The diagnosis and prognosis of lung infections due to the emerging nontuberculous mycobacterium (NTM) Mycobacterium abscessus are difficult to establish in children with cystic fibrosis.


METHODS
We evaluated the usefulness of an enzyme-linked immunosorbent assay for detecting serum IgG antibodies against the ubiquitous mycobacterial antigen A60.


RESULTS
A total of 186 patients with cystic fibrosis (mean age+/-SD, 12.0+/-5.0 years) were studied, including 15 M. abscessus-positive patients who fulfilled American Thoracic Society (ATS) criteria for NTM infection (M. abscessus-infected patients), 7 M. abscessus-positive patients who did not fulfill ATS criteria, 20 patients positive for various other NTM who did not fulfill ATS criteria, and 144 NTM-negative control patients; mean IgG titers (+/-SD) for these 4 groups were 718+/-342 U, 193+/-113 U, 129+/-49 U, and 121+/-53 U, respectively (M. abscessus-infected patients vs. each of the other groups, P<.005). The A60 IgG test was both sensitive (approximately 87%) and specific (approximately 95%) if adapted cutoff values were used (150 U and 250 U for patients aged <or=10 years and patients aged >10 years, respectively) and correlated well with results of acid-fast bacilli smears.


CONCLUSIONS
Measurement of anti-A60 IgG may be useful for both the diagnosis and assessment of activity of M. abscessus lung infection in persons with cystic fibrosis.
Ferroni
Agnès
A
Laboratoire de Microbiologie, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Paris, France.
Sermet-Gaudelus
Isabelle
I
Le Bourgeois
Muriel
M
Pierre-Audigier
Catherine
C
Offredo
Catherine
C
Rottman
Martin
M
Guillemot
Didier
D
Bernède
Claire
C
Vincent
Véronique
V
Berche
Patrick
P
Gaillard
Jean-Louis
JL
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000942:Antigens, Bacterial / Q000032:analysis*; D002648:Child; D003550:Cystic Fibrosis / Q000276:immunology / Q000382:microbiology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D007700:Kinetics; D008171:Lung Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology / Q000382:microbiology*; D009161:Mycobacterium / Q000737:chemistry* / Q000145:classification / Q000276:immunology; D009164:Mycobacterium Infections / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology / Q000382:microbiology*; D012680:Sensitivity and Specificity
D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D007074:Immunoglobulin G