Pruzanski W, Goulding N J, Flower R J, Gladman D D, Urowitz M B, Goodman P J, Scott K F, Vadas P
Inflammation Research Group, University of Toronto, Canada.
J Rheumatol. 1994 Feb;21(2):252-7.
Lipocortin (LC) and phospholipase A2 (PLA2) are involved in phospholipid metabolism, and on the cellular level LC seems to be an antagonist of PLA2. Since anti-LC1 autoantibodies were found in systemic lupus erythematosus (SLE), we undertook a study of the relationship between PLA2, anti-LC1, and disease activity in a large group of patients with SLE.
Sera from 81 patients with SLE were tested for the activity of extracellular PLA2 and the presence and level of antilipocortin 1 [anti-LC1 (IgM) and anti-LC1 (IgG)] antibodies. Both were compared to SLE activity.
Mean PLA2 activity was 4.6-fold higher in patients with SLE than in healthy controls (707 +/- 219 vs 154 +/- 6 u/ml, p < 0.01). PLA2 activity correlated significantly with PLA2 immunoreactivity as estimated by an ELISA method using monoclonal antibodies against "synovial type" PLA2 (n = 21, r = 0.984, p < 0.001). Anti-LC1 IgM and IgG antibody levels were significantly higher in SLE than in healthy individuals [anti-LC1 (IgM) 54.5 +/- 4.6 vs 22.6 +/- 2.3 EU/ml, p < 0.001 and anti-LC1 (IgG) 54.3 +/- 3.4 vs 22.9 +/- 2.3 EU/ml, p < 0.001]. There was no correlation between PLA2 activity and anti-LC1 antibody titers. Elevated levels of PLA2 [> normal mean + 2 SD (i.e., > 300 u/ml)] were found in 41/81 patients with SLE. Anti-LC1 antibody titers were high (> 64 EU/ml) in 23/41 patients; 14/40 patients with SLE with normal PLA2 (< 300 u/ml) also had higher titers of anti-LC1 antibodies. PLA2 activity was significantly associated with the presence of synovitis, being markedly increased in 11/12 patients. Mean PLA2 in this group of patients (1593 +/- 957 u/ml) was significantly higher (p < 0.001) than that (553 +/- 188 u/ml) in the group of 69 patients with SLE without synovitis.
There was no correlation of PLA2 activity with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) or the Lupus Activity Criteria Count (LACC). Circulating PLA2 activity in SLE correlated only with active synovitis. There was no correlation of anti-LC1 titers with duration of the disease, age, steroid dosage, SLEDAI, or LACC or any individual clinical or laboratory variable included in the assessment of SLEDAI and LACC.
脂皮质素（LC）和磷脂酶A2（PLA2）参与磷脂代谢，在细胞水平上LC似乎是PLA2的拮抗剂。由于在系统性红斑狼疮（SLE）患者中发现了抗LC1自身抗体，我们对一大群SLE患者中PLA2、抗LC1与疾病活动度之间的关系进行了研究。
检测了81例SLE患者血清中细胞外PLA2的活性以及抗脂皮质素1[抗LC1（IgM）和抗LC1（IgG）]抗体的存在情况和水平。将两者与SLE活动度进行比较。
SLE患者的平均PLA2活性比健康对照者高4.6倍（707±219对154±6 U/ml，p<0.01）。PLA2活性与使用抗“滑膜型”PLA2单克隆抗体通过ELISA法估计的PLA2免疫反应性显著相关（n=21，r=0.984，p<0.001）。SLE患者中抗LC1 IgM和IgG抗体水平显著高于健康个体[抗LC1（IgM）54.5±4.6对22.6±2.3 EU/ml，p<0.001；抗LC1（IgG）54.3±3.4对22.9±2.3 EU/ml，p<0.001]。PLA2活性与抗LC1抗体滴度之间无相关性。81例SLE患者中有41例PLA2水平升高[>正常均值+2个标准差（即>300 U/ml）]。41例患者中有23例抗LC1抗体滴度高（>64 EU/ml）；40例PLA2正常（<300 U/ml）的SLE患者中有14例抗LC1抗体滴度也较高。PLA2活性与滑膜炎的存在显著相关，12例患者中有11例显著升高。该组患者的平均PLA2（1593±957 U/ml）显著高于69例无滑膜炎的SLE患者组（553±188 U/ml）（p<0.001）。
PLA2活性与系统性红斑狼疮疾病活动指数（SLEDAI）或狼疮活动标准计数（LACC）无相关性。SLE患者循环中的PLA2活性仅与活动性滑膜炎相关。抗LC1滴度与疾病持续时间、年龄、类固醇剂量、SLEDAI或LACC或SLEDAI和LACC评估中包含的任何个体临床或实验室变量均无相关性。
