Analysis of the Evolution and Treatment of Low Phospholipid Associated Cholelithiasis (LPAC) Syndrome in Patients Followed at the Hospital das Clínicas da FMUSP

• Grant number: 25/10266-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2025
• End date: October 31, 2026
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Estela Regina Ramos Figueira
• Grantee: Pedro Pereira Ramires
• Host Institution: Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Low phospholipid-associated cholelithiasis (LPAC) syndrome is a rare condition in Western populations, characterized by intrahepatic stone formation due to defects in canalicular phospholipid secretion, often linked to mutations in the ABCB4 gene and recurrence even after cholecystectomy. Early diagnosis is crucial to prevent severe complications and guide appropriate management, which differs from common cholelithiasis. Ursodeoxycholic acid (UDCA) has proven effective in reducing symptoms and avoiding unnecessary surgeries. Given its underdiagnosis and uncertain prevalence, further studies are needed to better understand its progression and treatment. Objective: To evaluate the clinical progression and therapeutic outcomes of different clinical and surgical treatments in LPAC patients. Methods: This is a retrospective observational analytical study. Patients followed at the Services of the Department of Gastroenterology at HCFMUSP between 2000 and 2025 will be analyzed. Patients diagnosed with intrahepatic lithiasis will be included. Medical records and the HCMED and MV electronic databases will be reviewed, and the following parameters collected: 1) Clinical data: Date of birth, sex, color, weight, height, place of origin, onset of symptoms, diagnosis, family history, clinical signs (pain, cholangitis, choledocholithiasis, etc.), hospital admission, previous cholecystectomy, date of the cholecystectomy, preoperative risk evaluation (ASA), pregnancy, comorbidities (hypertension, diabetes, etc.). 2) Clinical treatment: indication for clinical treatment, medications (UDCA, fibrates, etc.), clinical evaluation, date and cause of death. 3) Surgical treatment: indication for surgical treatment, previous surgeries, date of the surgical procedure, type of surgery, intraoperative data (bleeding, transfusions, vasoactive drugs, duration of the surgery), perioperative complications, ICU stay, postoperative complications, recurrence of symptoms, recurrence date and type of symptom, discharge date and conditions, date and cause of death. 4) Laboratory examination: Pre-, intra-, and postoperative results, including hemoglobin, leukocyte count, prothrombin time, glucose, urea, creatinine, bilirubin, albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), C-reactive protein (CRP), cholesterol, triglycerides, CA 19-9. 5) Imaging: Ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasound (EUS), Endoscopic Retrograde Cholangiopancreatography (ERCP), Percutaneous Transhepatic Biliary Drainage (PTBD). 6) Pathological evaluation: liver biopsy. Statistical Analysis: Comparisons between two groups will be performed using the Student t test, Mann-Whitney or Chi-square test. We will analyze the variables associated with disease recurrence and patient survival. The 5-year disease-specific survival will be analyzed using the Kaplan-Meier method and the univariate and multivariate logistic regression analysis will be performed to identify factors of poor prognosis. P values <0.05 will be considered significant.