A clinical study of hyperhomocysteinemia in rheumatological diseases

Objective: To analysis plasma homocysteine (Hcy) level and some relative factors in some rheumatological diseases.

Methods: 54 cases with systemic lupus erythematosus (SLE), 48 cases with rheumatoid arthritis (RA), 60 cases with ankylosing spondylitis (AS), 30 cases with undifferentiated spondyloarthropathy (uSpA) and 62 controls were recruited to participate the study. Plasma Hcy, vitamin B(12), folate and the MTHFR gene C677T polymorphism were measured in all patients and controls.

Results: (1) Plasma Hcy levels were higher significantly in all disease groups than in the controls, the mean plasma Hcy level was (19.04 +/- 6.86) micromol/L for SLE, (19.07 +/- 7.43) micromol/L for RA, (16.47 +/- 6.50) micromol/L for AS, (16.59 +/- 6.72) micromol/L for uSpA and (12.24 +/- 3.58) micromol/L for controls (P < 0.01). (2) Significant inverse correlation was found between plasma Hcy level and vitamin B(12), folate (r = -0.701, -0.443, respectively; P < 0.01). (3) The MTHFR gene mutation make Hcy level dramatically rise, CC genotype (13.41 +/- 5.78) micromol/L, CT genotype (16.81 +/- 4.22) micromol/L, TT genotype (20.88 +/- 6.60) micromol/L (P < 0.05). TT genotype is susceptible for hyperhomocysteinemia and SLE (OR = 84.46, 7.56 respectively; P < 0.05).

Conclusions: (1) Hyperhomocysteinemia is found in most SLE, RA, AS and uSpA patients. (2) There are lots of factors associated with Hcy concentration, such as folate, vitamin B12 and MTHFR gene mutation. (3) TT genotype of MTHFR is susceptible for hyperhomocysteinemia and SLE.