Trends of autoimmune liver diseases in the University Hospital, UANL for 26 years. A single-center experience in Mexico

Introduction and Objectives: Autoimmune liver disease (AILD) is one of the main causes of chronic liver disease (CLD). It comprises autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC), and immunoglobulin G4-associated cholangitis (IgG4-AC). Patients who exhibit features of two or more AILD are classified as overlap syndromes (OS); the most commonly seen is AIH/PBC. The aim of this study was to report trends of AILD in a liver unit (LU) over 26 years. Material and Methods: Clinical records of patients who attended for the first time to LU, from January 1995 to December 2020 were included. There were 469 patients classified as AILD, and 462 were included, 408 (88%) females, mean age was 48 ± 14 (range. 4 - 78yo). Patients were divided into the three most common AILD: AIH, PBC, and OS. PSC and IgG4-AC were not included because they are very rare in our population. Diagnosis of AILD was made according to international guidelines, considering clinical manifestations, autoantibodies such as antinuclear antibodies (ANA), smooth muscle antibody (SMA), liver-kidney microsomal antibody (LKM), antimitochondrial antibodies (AMA), and when available: type 2 AMA, ANA gp210, liver biopsy, and non-invasive study of liver fibrosis. Inclusion criteria: patients with confirmed or suspected AILD in their first visit to the outpatient clinic. Diagnosis could be confirmed in subsequent visits. Other etiologies of CLD were excluded. Results: Over 26 years, trends of AILD have increased at the expense of AIH mainly (figure). The distribution of AILD was: AIH 289, PBC 143, and OS 30. Half the patients had cirrhosis (48%) on admission (AIH 58%, PBC 41%, and OS 31%). We found no statistically significant difference between AILD groups in cases and percentage of cases, (F (2,23) = 3.252, p = 0.057) and (F (2,23) = 0.996, p = 0.385) respectively. Autoantibodies available on admission were 95% in AIH, 82.5% in PBC, and 93% in OS. In AIH patients, 95% had ANA and/or AML positivity (≤1:40), and 78% (≤1:80), 11% had LKM positive. In PBC patients, 80% were positive for AMA, and of these, 48% had AMA2 positive. OS patients had 68% ANA and 69% AMA positivity. (Figure 1). Conclusions: The most common AILD seen in a period of 26 years was AIH; a high proportion of these patients had ANA and/or AML positive. Half of the PBC patients with AMA positive were also AMA2 positive. Two-thirds of OS patients exhibited ANA and AMA, confirming AIH/PBC. As in other CLD in Mexico, half the patients had cirrhosis on admission. Funding: The resources used in this study were from the hospital without any additional financing Declaration of interest: The authors declare no potential conflicts of interest.