Correlates of gallbladder stones among patients with sickle cell disease: A meta-analysis.

Sickle cell disorders are the most common hemoglobinopathies worldwide. Clinical variability of sickle cell disease (SCD) and susceptibility to its complications have been attributed to hematologic, genetic, and other influencing factors. This review aimed to provide further summary and analyses of the prevalence and factors associated with cholelithiasis among patients with SCD. A systematic database search was conducted in MEDLINE (PubMed), ScienceDirect, Google Scholar, World Health Organization Virtual Health Library, Cochrane Library databases, and System for Information on Gray Literature in Europe (SIGLE). Pooled prevalence, odds ratio (OR), and standardized mean difference (SMD) with the corresponding 95% confidence interval (CI) were calculated using Comprehensive Meta-Analysis Software version 3.3. A total of 34 studies that fulfilled the eligibility criteria were included in the analyses. The overall prevalence of cholelithiasis among SCD patients was 25.3% (95% CI 19.4-32.3%). The risk of developing cholelithiasis was significantly associated with lower total hemoglobin level (SMD = -0.45;  = 0.002), lower hemoglobin F (HbF) level (SMD = -0.85;  = 0.003), higher total serum bilirubin level (SMD = 1.15;  < 0.001), higher reticulocytes count (SMD = 0.44;  = 0.007), and UDP-glucuronosyltransferase-1A1 enzyme (UGT1A1) promoter polymorphism. This review provides a comprehensive view of the high rate of cholelithiasis and its associated factors in SCD patients.