FROM THE JOURNAL OF RHEUMATOLOGY
The use of outdated criteria for the identification of systemic sclerosis in primary biliary cholangitis likely led to an underestimation of the comorbidity’s prevalence.
Furthermore, more recent criteria estimate the prevalence of systemic sclerosis in primary biliary cholangitis to be around 23%.
In 1980, the American College of Rheumatology defined “highly specific but not sensitive” criteria for the identification of primary biliary cholangitis patients who also had systemic sclerosis, reported the study’s lead investigator Dr. Boyang Zheng of the University of Montreal Hospital Center and associates (J Rheumatol. 2016 Oct 28. doi: 10.3899/jrheum.160243 ).
In 2001, LeRoy and Medsger proposed and validated a new set of criteria that centrally required the observation of Raynaud phenomenon and “allowed for greater sensitivity and diagnosis of earlier disease by incorporating advances in nailfold capillary microscopy and [systemic sclerosis]–specific antibodies,” the investigators wrote.
Most recently, the ACR and the European League Against Rheumatism jointly developed new “weighted-point criteria endorsed for use in systemic sclerosis inclusion studies.” These new criteria, which were published in 2013, “the addition of at least a clinical or radiological feature to be positive.”
The purpose of this study, the first of its kind, according to investigators, was to compare the prevalence estimates of systemic sclerosis in primary biliary cholangitis patients as predicted by each of the three criteria sets.
A total of 100 patients who had previously been diagnosed with primary biliary cholangitis but not systemic sclerosis were recruited into the study. The majority of the patients were female (91%), the mean age at first visit was 57 years, and the mean primary biliary cholangitis Mayo score of disease severity and survival was 4.14.
At time of study enrollment, medical histories were obtained. All patients also underwent nailfold capillary microscopy, and serum samples were collected and analyzed for the presence of primary biliary cholangitis antibodies and the following systemic sclerosis–specific antibodies: anti–CENP-B, anti–topo I, anti–RNAP III, anti-Th/To.
Clinical data, presence of antibodies, and capillarascopic patterns were analyzed, and patients were retroactively evaluated for the fulfillment of each of the three systemic sclerosis criteria sets.
“A total of 23 patients satisfied at least one set of criteria, with 22 being positive for LeRoy and Medsger criteria, 17 for ACR/EULAR criteria, and only 1 for the ACR 1980 criteria,” Dr. Zheng and his associates reported.
The most frequent systemic sclerosis–associated features in the study population were Raynaud phenomenon (39%), systemic sclerosis antibodies (26%), abnormal nailfold capillary microscopy (20%), and capillary telangiectases (17%), while clinically evident skin changes were the most rare, investigators explained.
The 1980 ACR criteria likely led to an underestimation of systemic sclerosis in primary biliary cirrhosis, and given the benefit of early diagnosis and treatment of systemic sclerosis, patients with primary biliary cholangitis should be screened for Raynaud phenomenon and systemic sclerosis antibodies and undergo nailfold capillaroscopic microscopy, the investigators recommended.
“Clinicians need to remain alert for this sometimes insidious comorbidity,” the researchers added.
Dr. Zheng had no relevant financial disclosures.
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