Objective: To assess the clinical, serological and genetic features of Japanese patients with CREST syndrome.
Patients and methods: Clinical features, autoantibodies and human histocompatibility leukocyte antigen (HLA) typing were studied in thirty patients with CREST syndrome, including 29 females and one male, with a mean age of 59.0 years (ranging from 40 to 76 years).
Results: Interstitial pneumonia on chest X-ray and renal involvement were rare. Mitral regurgitation and tricuspid regurgitation were present in 56.7% and 76.7%, respectively. Sjören's syndrome (SS) and primary biliary cirrhosis (PBC) were highly associated, however the positivity of the marker antibodies to those syndromes, such as anti-SSA, anti-SSB, anti-mitochondrial (AMA) and anti-smooth muscle autoantibodies were less frequent than that of primary SS and PBC without the other autoimmune diseases. The histological findings of PBC were all early stages in Scheuer's classification. HLA-Cw6 were associated with CREST-PBC overlap syndrome (p<0.05). However the HLA antigen was not correlated with CREST syndrome, and the frequency of HLA-DR2 between CREST syndrome with or without PBC was significantly different (p<0.01).
Conclusion: It was suggested that there was a genetic difference between CREST syndrome alone and CREST-PBC overlap syndrome and there were differences (the positivity of AMA and the severity of bile duct lesion) between PBC and CREST-PBC overlap syndrome.