Background: Sickle cell disease is the most common monogenic disease in the world caused by a mutation in the β-globin gene which creates abnormal hemoglobin called HbS. This polymer deforms the erythrocyte, making it more fragile and less flexible, thus leading to the occlusion of small blood vessels. This obstruction is the cause of painful vaso-occlusive crises and ischemia-reperfusion phenomena.

Patients with sickle cell disease undergo major acute and chronic pain responsible for a significant deterioration in their quality of life and a significant consumption of analgesics, often daily, sometimes with the development of addictive behavior. Improved analgesic management was associated with improved disease prognosis. Several studies have shown the effectiveness of the osteopathic approach in the management of chronic pain. Our hypothesis is that the association with the standard treatment of osteopathy sessions could improve but also prevent the chronic pain frequent in patients with sickle cell disease.

Objectives: Our main objective is to study the effectiveness of an osteopathic treatment in adult sickle cell patients with chronic pain on the reduction of the consumption of level I and II analgesics at 3 months (D90 +/- 15 days).

Methods/Experimental design: This is a single-blind prospective randomized controlled monocentric study. The study population will be composed of 37 sickle cell patients aged over 18 years. The patients included will be allocated into two groups: one group will receive the osteopathic treatment and the 2nd group will receive the "placebo" treatment. Analgesic consumption will be assessed by weekly self- questionnaire. The evaluation of the pain will be carried out by the visual analogue scale (VAS). The degree of stress will be measured using the Perceived Stress Scale (PSS). Patients will receive an osteopathic treatment or a "placebo" treatment, one session every 4 weeks for 12 weeks with a total of 3 sessions per patient. The duration of each session is 45 minutes. Pain and stress assessments will be done before each session. A final evaluation will be carried out 3 months after the end of the osteopathic or "placebo" treatment. Data analysis will be performed using SPSS version 17.0 software. The significance threshold will be set at 0.05. This is the first protocol that aims to evaluate, with scientific rigor, the impact of the osteopathic approach in the management of pain in patients with sickle cell disease.

Inclusion Criteria:

• patients with major sickle cell syndrome
• Suffering from acute or chronic pain
• Aged over 18 and legally responsible
• The informed consent of the patients will be collected

Exclusion Criteria:

• Pregnant or breastfeeding women
• Patients who underwent surgery in the 6 months prior to inclusion
• Patients with known medical contraindications to osteopathic manipulations: vertebral compression, severe osteoporosis, progressive osteonecrosis and not treated with a prosthesis
• Patients with acute stroke
• Patients with cerebral arteriovenous malformation or cerebral aneurysm
• Patients participating in another interventional clinical research protocol