血清IgG水平正常的系统性红斑狼疮临床特点

Clinical features of systemic lupus erythematosus with normal serum IgG levels

摘要:

目的探讨血清免疫球蛋白G（IgG）水平正常的系统性红斑狼疮（SLE）的临床特点，提高对血清免疫球蛋白水平正常的SLE认识。方法回顾性分析259 例初诊SLE患者，比较血清IgG 水平正常组和血清IgG水平升高组的肾外临床表现，狼疮肾炎表现，血沉（ESR）、超敏C 反应蛋白（hs-CRP）、免疫学指标及系统性红斑狼疮疾病活动度（SLEDAI）评分的差别，分析血清IgG 水平与血清补体C3、C4 水平及SLEDAI 积分的相关性，并分析血清IgG水平与尿蛋白、尿IgG水平的相关性。结果①IgG 正常组非感染性发热、脱发、关节炎及贫血的发生率低于IgG 升高组（p <0.05）,而血小板减少的发生率高于IgG 升高组（ p<0.05）；②两组狼疮性肾炎发生率相似，但IgG 正常组的尿蛋白、尿IgG水平高于IgG 升高组（p <0.05），IgG正常组肾病水平蛋白尿、血尿的发生率高于IgG 升高组（p <0.05）。尿蛋白水平、尿IgG 水平与血清IgG 水平呈负相关性（p <0.05）；③IgG 正常组的ESR、hs-CRP 水平低于IgG 升高组（p <0.01）。IgG 正常组血清IgG、IgA 及IgM 水平低于IgG 升高组（p <0.01）。IgG正常组ANA、dsDNA、sm、AnuA 阳性率低于IgG 升高组（p <0.05）。两组C3 水平、C3 下降发生率比较差异无统计学意义（p >0.05），两组SLEDAI积分比较差异无统计学意义（p >0.05）。两组血清IgG 水平与C3、C4 水平及SLEDAI 评分无直线相关性（ p>0.05）。结论血清IgG 水平正常的活动性SLE 患者并不少见，其肾脏损害相对明显，而SLE相关的自身抗体阳性率较低。IgG 水平与狼疮疾病活动度不相关。

Abstract:

To investigate the clinical characteristics of systemic lupus erythematosus (SLE) with normal serum IgG levels. Methods A retrospective study of 259 newly diagnosed SLE patients was conducted to compare extrarenal clinical manifestations, renal manifestations, erythrocyte sedimentation rate (ESR), high sensitivity C-reactive protein (hs-CRP), immunological indexs and SLEDAI scores between normal serum IgG levels group and increased serum IgG levels group. The correlation of serum IgG levels to serum C3, serum C4 and SLEDAI scores was analyzed. The correlation of serum IgG levels to urinary protein and urinary IgG levels was analyzed too. Results Normal serum IgG levels group had lower incidences of non-infectious fever, alopecia, arthritis and anemia (p < 0.05) while higher incidences of thrombocytopenia (p < 0.05). Incidences of lupus nephritis were similar between the two groups. However, normal serum IgG levels group had higher levels of urinary protein and urinary IgG (p < 0.05), except higher incidences of nephrotic proteinuria and hematuria (p < 0.05). The levels of urinary protein and urinary IgG were negative correlated with serum IgG levels (p <0.05). The levels of ESR and hs-CRP in Normal serum IgG levels group were lower than those in increasedserum IgG levels group(p < 0.01). Normal serum IgG levels group had lower levels of serum IgG, IgA and IgM (p < 0.01), except lower positive rate of ANA, dsDNA, Sm and AnuA (p < 0.05). There was no significant difference in the serum C3 levels, the incidences of decreased serum C3 level and the SLEDAI scores between the two groups (p < 0.05). Serum IgG levels was not correlated with serum C3, serum C4 and SLEDAI scores (p < 0.05). Conclusions The active SLE patients with normal serum IgG levels is not rare. In these patients, the renal damage is more obvious relatively and the positive rate of the SLE-related autoantibody is lower than the SLE patients who have high serum IgG levels. The serum IgG levels is not correlated with the lupus disease activity.