Evaluation of Plasma Vitamin C Levels in a Population of Chronic Rheumatism in Immuno-Rheumatology (VitCRIC)

Scurvy is an almost forgotten carential pathology, caused by a deep vitamin C (or ascorbic acid) deficiency, a priori exceptional in industrialized countries. According to the French National Authority for Health standards, hypovitaminosis C is defined as a plasma vitamin C level of less than 23 μmol/L. This deficiency would affect 5 to 10% of the general population in industrialized countries and from 17% (clinical scurvy) to 47% (biological hypovitaminosis C) of vulnerable populations (malnutrition, hospitalized patients...). Vitamin C is essential for collagen synthesis. It plays a cofactor role in the synthesis of catecholamines precursors and takes action in synthesis of certain amino acids. In rheumatology, pain is a recurring reason for consultation. In a context of treated chronic inflammatory rheumatism (RIC), while most of patients seem in remission or in reduced activity of their disease, all real-life studies show that 30 to 40% of them complain of residual pain, 70% of chronic fatigue and 20-25% of symptoms similar to secondary fibromyalgia. Currently, authors suggest the interest of vitamin C analgesic properties, especially in musculoskeletal pain, due to the role of ascorbic acid in neurotransmitters. Vitamin C would act as a cofactor for a family of biosynthetic and regulatory metalloenzymes. Thus, the authors suggest the potential of vitamin C in an analgesic mechanism involving the biosynthesis of opioid peptides.

Population of patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Several questionnaire will be completed by patients to evaluate quality of life: Analog and visual scale (EVA) pain, Neuropathic pain (DN) 4 questionnaire, EVA fatigue, Short Form (SF) 12 questionnaire and Hospital Anxiety and Depression scale (HAD questionnaire)

Describe prevalence of hypovitaminose C (ascorbemia below 23 µmol/L) in a population of patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Among patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain and included in this study, the prevalence of hypovitaminosis C will be the proportion of patients with ascorbemia below 23 μmol/L measured at inclusion. Plasma ascorbemia will be measured using HPLC fluorimetric detection, using a Chromsystems kit.

Age of patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Sexe of patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Socio-professional category of patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Type of disease of patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Length of illness of patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Type of disease's treatment for patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Pain felt by patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Pain felt will be assessed with a visual and analog scale for pain which ranges from 0 (no pain) to 10 (maximum imaginable pain)

Tiredness felt by patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Tiredness felt will be assessed with a visual and analog scale for tiredness which ranges from 0 (no tiredness) to 10 (extreme tiredness).

Neuropatic pain felt by patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Neuropatic pain felt will be assessed with the neuropatic pain 4 (DN4) questionnaire, which ranges from 0 to 10. A score greater than 4 indicates a positive test.

Quality of life of patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Anxiety and depression of patients followed for chronic inflammatory rheumatism in remission or lupus in low activity, with chronic residual pain

Anxiety and depression will be assessed with the Hospital Anxiety and Depression (HAD) scale, splited in 2 scores which ranges from 0 to 21. A score less than 7 indicates a lack of symtomatology, a score between 8 and 10 indicates doubtful symptomatology and a score higher than 11 indicates a sure symptomatology.

Inclusion Criteria: patient over 18 years-old, followed for chronic inflammatory rheumatism (RIC): spondylo-arthritis (including spondylitis and psoriatic rheumatism) and lupus, with RIC in remission or low activity definec according to the following criteria: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) criteria and Bath Ankylosing Spondylitis Fonctional Index (BASFI) questionnaire for spondylitis and psoriatic rheumatism, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) 2K score for lupus, having given written consent after written and oral information, member of the social security system, basic treatment for the disease not modified for at least 3 months, persistence of painful complaints not objectively explained by his RIC, with a score on the EVA pain upper to 2. Exclusion Criteria: pregnant or nursing patient, patient protected by law or under guardianship or curatorship, or not able to participate in a clinical trial under L.1121-16 article of French Public Health Regulations, patient participating in or having participated in another drug clinical trial in the month prior to inclusion.