Real-World Experience of L-Glutamine in Sickle Cell Disease: A Retrospective Observational Study

Sickle cell disease (SCD) affects millions globally, with approximately 0.26% of the Saudi population impacted. Despite standard treatments, patients frequently experience vaso-occlusive crises (VOCs). This retrospective observational study evaluated the real-world effectiveness of L-glutamine (Endari^®) in reducing SCD-related complications in the Saudi population, where data remain limited. Patients aged five and older who received L-glutamine from June 2019 to June 2023 were included. The primary endpoint was VOC frequency through week 48. Descriptive statistics and paired t-tests compared outcomes before and after treatment. Fifteen patients (median age 12 years, 53% female) met the inclusion criteria; all were on maximum tolerated hydroxyurea. Eleven completed 48 weeks, showing a median VOC reduction from 4 to 3 (p = 0.44). Hospital stay duration remained unchanged (median 7 days, p = 0.72). Laboratory parameters were largely stable, except for a 61.9% increase in reticulocyte count (p = 0.03). The estimated annual treatment cost exceeded SAR 2 million (USD ~547,840). L-glutamine did not produce statistically significant improvements in VOC frequency, though numerical trends were observed. Given the small sample size and limited statistical power, the findings are exploratory. Larger, well-powered, multicenter studies are needed to confirm L-glutamine's potential benefits in this population.