The Effect of L-Glutamine on Pain Crisis Reduction in Patients with Sickle Cell Anemia and Sickle β°-Thalassemia

Background: A low level of L-glutamine, a precursor of nicotinamide adenine dinucleotide (NAD) in red blood cells (RBCs), is identified as an underlying mechanism for the potential decrement of the NAD redox and the incidence of pain crisis in sickle cell anemia (SCA). The aim of this study is to assess the impact of oral L-glutamine therapy on pain crisis reduction in patients with SCA and sickle β°-thalassemia. Materials and Methods: In this pilot clinical trial, 15 patients with SCA and sickle β°-thalassemia with the mean age of 17.2 ± 6.07 were examined to evaluate the efficacy of L-glutamine therapy in pain crises. All the subjects received oral L-glutamine (0.3 gr /kg of body weight) every day for 8 weeks. With respect to the effects of L-glutamine on pain crisis, the subjects were in contact with the physicians at least once or more per week. Blood samples were taken at different follow-up times to evaluate the laboratory characteristics of the patients. Results: Pain crises occurred for 1-3 times (mean: 1.29 ± 1.05) during 12 months before the L-glutamine therapy. With no significant change, the patients had lower numbers of painful crises (mean: 0.80 ± 0.58) at the end of a 4-week period compared to the period before the L-glutamine therapy (P = 0.466). Fewer pain crises with a mean of 0.33 ± 0.51 occurred during 8 weeks of L-glutamine therapy than in the pre-treatment period (P = 0.038). Conclusion: The results of the present study showed that oral L-glutamine can mitigate a pain crisis and improve the sickle RBCs and reticulocyte count in SCA. This suggests that L-glutamine therapy can increase the antioxidant potential of sickle RBCs.