Antinuclear autoantibodies are more prevalent in COPD in association with low body mass index but not with smoking history.
BACKGROUND
Chronic obstructive pulmonary disease (COPD) is associated with a higher prevalence of antinuclear autoantibodies (ANAs). However, a significant subgroup of patients is ANA negative. It remains to be determined which patient groups carry autoantibodies.


METHODS
The association of smoking behaviour, disease status, gender, age and body mass index (BMI) with the presence of autoantibodies in the serum was determined in 124 patients with COPD and 108 non-COPD control subjects. In addition, the role of B cells in autoantibody generation in COPD was investigated by sequencing the antibody repertoire of B cells in the lungs of patients with COPD and of ex-smoking and never-smoking control subjects.


RESULTS
Patients with COPD had a significantly higher risk of being serum positive for ANAs (OR 3.12, 95% CI 1.68 to 5.76, p<0.001). ANAs were not significantly associated with age, smoking status, gender or pack-years of smoking. Within the COPD population, subjects with BMI <22 kg/m2 had a significantly higher risk of ANAs (OR 4.93, 95% CI 1.50 to 16.50, p=0.009) than those with normal or high BMI. The antibody repertoire of B cells in the lungs of patients with COPD had a high frequency of positively charged CDR3 residues, a feature which is associated with self-reactive antibodies.


CONCLUSIONS
The results show that COPD is a heterogeneous disease with respect to the prevalence of ANAs. ANAs are primarily associated with the presence of COPD and with low BMI, but not with smoking and forced expiratory volume in 1 s.
Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
H P J
HP
Bonarius
C A
CA
Brandsma
H A M
HA
Kerstjens
J A
JA
Koerts
M
M
Kerkhof
E
E
Nizankowska-Mogilnicka
C
C
Roozendaal
D S
DS
Postma
W
W
Timens
D000367:Age Factors; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood; D000974:Antibodies, Antinuclear / Q000097:blood*; D001402:B-Lymphocytes / Q000276:immunology; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000276:immunology; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000276:immunology; D008168:Lung / Q000276:immunology; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology* / Q000503:physiopathology; D012737:Sex Factors; D012907:Smoking / Q000276:immunology*; D014797:Vital Capacity / Q000276:immunology
D019268:Antibodies, Antineutrophil Cytoplasmic; D000974:Antibodies, Antinuclear; D007143:Immunoglobulin Heavy Chains