Kammer G M
Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
Arthritis Rheum. 1999 Jul;42(7):1458-65. doi: 10.1002/1529-0131(199907)42:7<1458::AID-ANR20>3.0.CO;2-P.
To estimate the prevalence of protein kinase A type I isozyme (PKA-I) deficiency in a cohort of systemic lupus erythematosus (SLE) patients, and to establish whether the isozyme deficiency is associated with SLE disease activity.
Thirty-five SLE patients and 35 age-, sex-, and race-matched normal controls were studied. Fifteen subjects were restudied on at least 3 occasions over a 4-year interval. Clinical disease activity was estimated by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and the T cell activation markers CD25+ and HLA-DR+ were quantified by flow cytometry. PKA-I isozyme activities were quantified in enriched T cells. Statistical analyses were performed by Student's t-test, Mann Whitney U test, and Pearson product moment test.
The mean PKA-I activity in SLE T cells (540 pmoles/minute/mg of protein) was significantly lower than that in control T cells (1,578 pmoles/ minute/mg of protein) (P<0.001). The prevalence of isozyme deficiency in this cohort was 80%. During a 4-year interval, PKA-I activities remained significantly reduced, whereas SLEDAI scores significantly improved. There was no relationship between deficient PKA-I activity and either SLEDAI scores or the proportion of T cells bearing CD25+ or HLA-DR+ activation markers.
There is a high prevalence of deficient T cell PKA-I isozyme activity in SLE that persists over time and is independent of SLE disease activity.
评估系统性红斑狼疮（SLE）患者队列中蛋白激酶A I型同工酶（PKA-I）缺乏的患病率，并确定该同工酶缺乏是否与SLE疾病活动相关。
研究了35例SLE患者和35例年龄、性别及种族匹配的正常对照。15名受试者在4年的时间间隔内至少接受了3次重新研究。通过系统性红斑狼疮疾病活动指数（SLEDAI）评估临床疾病活动度，并通过流式细胞术对T细胞活化标志物CD25+和HLA-DR+进行定量。在富集的T细胞中对PKA-I同工酶活性进行定量。采用学生t检验、曼-惠特尼U检验和皮尔逊积矩检验进行统计分析。
SLE患者T细胞中的平均PKA-I活性（540皮摩尔/分钟/毫克蛋白）显著低于对照T细胞中的活性（1578皮摩尔/分钟/毫克蛋白）（P<0.001）。该队列中同工酶缺乏的患病率为80%。在4年的时间间隔内，PKA-I活性仍显著降低，而SLEDAI评分显著改善。PKA-I活性缺乏与SLEDAI评分或携带CD25+或HLA-DR+活化标志物的T细胞比例均无关联。
SLE患者中T细胞PKA-I同工酶活性缺乏的患病率较高，且这种情况随时间持续存在，与SLE疾病活动无关。
