Introducción
The clinical presentation of primary biliary cholangitis (PBC) has undergone changes globally over time. However, these changes have not been sufficiently analyzed in our setting.

Objetivos
To analyze changes in the presentation of PBC over the past 40 years at a university hospital in Argentina.

Material y métodos
A retrospective study was conducted using data from 596 patients registered in the Hepatology Section of the Hospital de Clínicas "José de San Martín." Patients over 18 years old with a PBC diagnosis based on international guidelines and with follow-up data spanning more than 40 years were included. Patients with incomplete information or overlap syndrome with autoimmune hepatitis were excluded. The patients were divided into four groups according to the year of diagnosis: <1990 (N=113), 1990-1999 (N=206), 2000-2009 (N=151), and >2009 (N=106). Variables such as age at diagnosis, sex, and liver function tests (LFTs) were evaluated. The clinical presentation, whether asymptomatic or symptomatic (defined by pruritus, asthenia, or jaundice), as well as biochemical stages according to Rotterdam criteria (early stage: normal LFTs; moderate: abnormal LFTs; advanced: abnormal LFTs) and histological stages of the disease according to the classification of Ludwing et al. and Scheuer (early stages I-II and advanced stages III-IV), were analyzed.

Resultados
The female-to-male ratio was 24:1, remaining stable over time. There was an increase in the mean age at diagnosis, from 54.3 years (±11.6) before 1990 to 57.2 years (±12.2) after 2009 (p=0.0185). Symptomatic clinical presentation decreased from 73.7% to 50.0% (p<0.001). ALP and TB values progressively decreased from 5.49 x ULN and 3.45 mg/dl before 1990 to 2.69 x ULN and 0.92 mg/dl after 2009 (p<0.001). AST and ALT levels did not show statistically significant changes over time. The diagnosis in early biochemical stages increased from 18.0% to 77.4% (p<0.001) during the same period. Advanced histological stages (III-IV) decreased from 60.2% before 1990 to 20.8% after 2009 (p<0.001).

Conclusiones
Over time, patients with PBC have shown a change in their clinical presentation, characterized by an older age at diagnosis, earlier biochemical and histological stages, and a predominance of asymptomatic clinical forms. These findings are consistent with global reports and may be attributable to better knowledge of the disease, greater availability and access to diagnostic tests, and possibly changes in environmental triggers over time.