Multiple Correspondence Analysis reveals two different phenotypes of idiopathic chronic pancreatitis

BACKGROUND: Chronic pancreatitis (CP) is a heterogeneous disease in which etiology influences presentation; however, idiopathic forms remain poorly characterized, and conventional approaches may not capture their complexity. AIMS: This study aimed to compare clinical features at diagnosis across etiologies, using unsupervised Multiple Correspondence Analysis (MCA)-based clustering to define distinct groups, focusing on idiopathic subtype. METHODS: A retrospective analysis of a prospectively maintained database of CP patients was performed. Demographics, clinical characteristics, and imaging features categorized based on the TIGAR-O classification were compared. MCA was performed to explore the underlying structure of a series of categorical variables related to CP. RESULTS: 282 patients were included. Toxic was the leading etiology (47.2%), followed by idiopathic (18.8%). Genetic patients were younger and leaner, whereas the toxic group had more men, pulmonary disease and calcifications; idiopathic cases were more often painless and incidentally diagnosed. MCA identified six clusters. Autoimmune and obstructive etiologies formed distinct clusters, while early-onset idiopathic cases (≤ 35 years) mapped near the genetic group, late-onset cases (> 35 years) were positioned between the genetic and the toxic and were characterized by painless incidental presentation. CONCLUSION: Early-onset idiopathic CP clustered near genetic CP, suggesting unidentified genetic components, whereas late-onset idiopathic CP resembled toxic CP and was characterized by painless presentation.