Autoantibodies in patients with primary pulmonary hypertension: association with anti-Ku.
OBJECTIVE
Patients with primary pulmonary hypertension (PPH) frequently have Raynaud's phenomenon, serum antinuclear antibodies (ANAs), and/or pulmonary vascular lesions similar to those seen in certain connective tissue diseases, especially scleroderma. A number of relatively disease-specific autoantibodies have been described in connective tissue diseases but have not been studied in patients with PPH. Therefore, sera from PPH patients were studied for a variety of autoantibodies, seeking a possible link between this pulmonary disorder and connective tissue diseases.


METHODS
Sera from 31 patients with PPH and 24 with secondary pulmonary hypertension (SPH) were studied for the following autoantibodies: anti-centromere (indirect immunofluorescence of Hep-2 cells), anti-CENP-B by immunoblotting and enzyme immunoassay (EIA) using cloned CENP-B fusion protein, anti-topoisomerase I (Scl-70), anti-Ku using immunoblotting of affinity purified antigens, anti-cardiolipin using EIA, and anti-Ro (SS-A), La (SS-B), Sm, nRNP, Jo-1, PM-Scl, and Mi-2 by counter-current immunoelectrophoresis.


RESULTS
Anti-Ku antibodies were found in 23% of patients with PPH, 4% with SPH, and none of 24 normal controls (PPH versus SPH, p = 0.06: PPH versus controls, p = 0.01). Antibodies to CENP-B were found in one patient each with PPH and SPH, anti-topoisomerase I in one with SPH, and anti-Ro (SS-A) and La (SS-B) in one with PPH. Overall, 12 patients (39%) with PPH had Raynaud's phenomenon or positive ANA results, with 9 (29%) having more specific autoantibodies associated with connective tissue diseases.


CONCLUSIONS
These results further suggest a link between at least a subgroup of patients with PPH and autoimmune connective tissue diseases, with anti-Ku antibodies being a possible new serologic marker.
Isern
R A
RA
Department of Internal Medicine, University of Texas Medical School, Houston 77225.
Yaneva
M
M
Weiner
E
E
Parke
A
A
Rothfield
N
N
Dantzker
D
D
Rich
S
S
Arnett
F C
FC
D000328:Adult; D034961:Antigens, Nuclear; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D003240:Connective Tissue Diseases / Q000276:immunology; D004265:DNA Helicases; D004268:DNA-Binding Proteins / Q000276:immunology*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000276:immunology*; D015151:Immunoblotting; D000072200:Ku Autoantigen; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000276:immunology*
D034961:Antigens, Nuclear; D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D004265:DNA Helicases; C106893:XRCC5 protein, human; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen