PSC-IBD study shows need for regional management guidelines
PSC frequency lower in Asian countries than in West
The frequency of primary sclerosing cholangitis (PSC) in people with inflammatory bowel disease (IBD) is lower in Asian countries than in the West, according to a large-scale retrospective study that researchers said could help doctors develop guidelines tailored to those countries.
IBD is an umbrella term for diseases marked by gastrointestinal tract inflammation that often occur alongside PSC.
Data also showed that the severity of liver disease in IBD patients at the time of PSC diagnosis has become milder in recent years, likely due to the increased use of advanced imaging techniques that allow earlier detection of PSC.
“This study is the first systematic effort in identifying PSC cases among patients with IBD in Asia,” according to a news story from the University of Tsukuba, in Japan. The study’s first author, Shintaro Akiyama, MD, PhD, is an assistant professor at the university. “The findings are expected to guide the development of clinical practice guidelines tailored to the unique characteristics and healthcare systems of Asian countries.”
The study, “Prevalence and Outcomes of Primary Sclerosing Cholangitis in Inflammatory Bowel Disease: A Multinational Study across Asia,” was published in Clinical Gastroenterology and Hepatology by a team of researchers across six Asian countries.
Clear differences between regions, but data on Asia lacking
PSC is a chronic form of cholangitis, or inflammation of the bile ducts, the channels that normally carry the digestive fluid bile from the liver to the intestines. This chronic inflammation can lead to tissue scarring, slowing or stalling bile flow (cholestasis), which can cause liver injury and, over time, possible liver failure.
The liver condition often co-occurs with IBD, and this co-existence is typically associated with worse outcomes. IBD can take the form of ulcerative colitis (UC) or Crohn’s disease (CD). UC affects the colon (the longest part of the large intestine) and rectum (the final section of the large intestine), while CD can affect any part of the gastrointestinal tract.
A previous review study covering 30 countries worldwide found the prevalence, or number of established cases, of PSC in people with IBD to be about 1 in 50 (2.16%), with clear differences between those from Asian and Western countries.
“However, most studies on PSC-IBD have been conducted in Western countries, whereas research on Asian populations—particularly in East Asia— remains limited,” the researchers wrote. “To improve clinical outcomes and establish region-specific guidelines, a deeper understanding of the [distribution] and clinical characteristics of PSC-IBD in Asian patients is essential.”
The team retrospectively analyzed the medical records of 51,314 IBD patients from 25 hospitals in Japan, Korea, China (including Hong Kong), Taiwan, Malaysia, and India.
A total of 474 cases of PSC were identified, yielding an overall prevalence of 0.92%, or about 1 in 100. The highest prevalence was found in Mainland China (2.3%), followed by Malaysia (1.5%) and Japan (1.3%). PSC was about 10 times more frequent in people with UC than CD (1.4% vs. 0.13%).
“The prevalence of PSC among Asian patients with IBD is lower than that reported in Western populations,” the team wrote.
Of the 375 patients with available clinical data, the median age at diagnosis was 29 for IBD and 32 for PSC. The median interval between IBD and PSC diagnoses was 1.1 years. More than half (55%) were diagnosed with IBD before PSC, and 11% received the two diagnoses at the same time.
At the time of PSC diagnosis, patients had high blood levels of ALP, a liver damage marker, but normal levels of other liver damage markers. Fewer than half (40%) showed symptoms such as abdominal pain, fever, and jaundice (yellowing of the skin and the whites of the eyes). During follow-up, 34% developed cirrhosis, or permanent liver scarring.
The team also found that the age at IBD and PSC diagnoses significantly rose over time, whereas the time between the two diagnoses became shorter.
Earlier detection may explain rise in milder PSC cases
The proportion of patients without symptoms and with lower levels of liver damage markers at the time of PSC diagnosis has increased in recent years. The team suggested that the widespread use of MR cholangiopancreatography, a noninvasive scan to assess the liver and surrounding tissues, may have facilitated earlier detection of milder PSC.
Only those with CD and PSC developed abnormal growth, benign or cancerous, in the colon or rectum (9.6%). In contrast, only people with UC and PSC developed cancer of the bile ducts (7.6%).
Nearly one-fifth (24%) of PSC-IBD patients underwent a liver transplant. The time to liver transplant was significantly longer in people diagnosed with PSC in more recent years.
The overall death rate was 16%, with liver cirrhosis being the most common cause (46%). Older age, lower albumin levels (indicative of liver damage), and elevated ALP levels at the time of PSC diagnosis were each significantly linked to a higher risk of death. However, there were no significant differences in survival rates over time.
“PSC appears less prevalent and associated with comparable or potentially more favorable outcomes in Asian than in Western [patient groups],” the researchers concluded. “These findings have direct implications for clinical practice and highlight the need for tailored surveillance protocols and evidence-based management guidelines for PSC-IBD, not only in Asia but also globally.”
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