Primary biliary cirrhosis (PBC), PBC autoantibodies, and hepatic parameter abnormalities in a large population of systemic sclerosis patients.
OBJECTIVE
To investigate the diagnostic accuracy of antimitochondrial antibodies (AMA), sp100, and gp210 antibodies for primary biliary cirrhosis (PBC) in a large population of patients with systemic sclerosis (SSc); to examine concordance of these antibodies with subsets of SSc. Further, to assess the association of SSc-related antibodies with hepatic parameter abnormalities.


METHODS
We obtained medical records to verify the diagnoses of SSc and PBC. Sera from all participants were examined for the presence of SSc- and PBC-related antibodies, as well as for abnormalities in hepatic parameters.


RESULTS
We examined 817 patients with SSc, of whom 16 (2%) had confirmed PBC. The sensitivity and specificity of AMA by a MIT3 ELISA for PBC were 81.3% and 94.6%, respectively. Sp100 had a sensitivity and specificity of 31.3% and 97.4%, respectively, while gp210 had an even lower sensitivity. We were able to detect all PBC cases using AMA(MIT3) and sp100 as a combined marker, resulting in a significantly improved sensitivity of 100% (p = 0.042) with an incremental decrease in specificity to 92.6%. Independent of AMA or sp100 status, there was an association of anticentromere B (CENP-B) and anti-topoisomerase antibodies (ATA) with higher alkaline phosphatase levels (p = 0.051 and p = 0.003, respectively) while anti-RNA polymerase III (anti-RNAP) was associated with lower alkaline phosphatase levels (p = 0.019) among the patients with SSc.


CONCLUSIONS
Utilization of AMA(MIT3) and sp100 antibodies as a combined diagnostic marker leads to an improved detection of PBC in patients with SSc. CENP-B and ATA are associated with alkaline phosphatase elevation.
Assassi
Shervin
S
The University of Texas-Health Science Center at Houston, 6431 Fannin, MSB 5.232, Houston, TX 77030, USA. shervin.assassi@uth.tmc.edu
Fritzler
Marvin J
MJ
Arnett
Frank C
FC
Norman
Gary L
GL
Shah
Kairav R
KR
Gourh
Pravitt
P
Manek
Neil
N
Perry
Marilyn
M
Ganesh
Devi
D
Rahbar
Mohammad H
MH
Mayes
Maureen D
MD
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000469:Alkaline Phosphatase / Q000097:blood; D034961:Antigens, Nuclear / Q000276:immunology; D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D008099:Liver / Q000473:pathology; D008105:Liver Cirrhosis, Biliary / Q000097:blood / Q000175:diagnosis / Q000209:etiology; D008930:Mitochondria, Liver / Q000276:immunology; D010980:Platelet Membrane Glycoproteins / Q000276:immunology; D012042:Registries; D012189:Retrospective Studies; D012595:Scleroderma, Systemic / Q000150:complications / Q000276:immunology / Q000473:pathology; D012680:Sensitivity and Specificity; D028861:Nuclear Pore Complex Proteins
D000469:Alkaline Phosphatase; D034961:Antigens, Nuclear; D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D010980:Platelet Membrane Glycoproteins; C066642:SP100 protein, human; C063865:NUP210 protein, human; D028861:Nuclear Pore Complex Proteins