Isshi K, Hirohata S
Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan.
Arthritis Rheum. 1996 Sep;39(9):1483-90. doi: 10.1002/art.1780390907.
Although it has been reported that anti-ribosomal P protein antibodies (anti-P) are highly specific for lupus psychosis, there have been discrepancies among the studies regarding the clinical correlation of these antibodies with systemic lupus erythematosus (SLE). The present study was therefore carried out to reappraise the association of anti-P and neuropsychiatric SLE.
Highly purified synthetic ribosomal P peptides of the carboxyl-terminal 22-amino acid sequence were conjugated to human serum albumin (HSA) with the use of glutaraldehyde. Anti-P in sera from 75 patients with SLE (26 without central nervous system disease [non-CNS], 28 with lupus psychosis, and 21 with nonpsychotic CNS involvement [nonpsychotic CNS lupus]) were analyzed with an enzyme-linked immunosorbent assay (ELISA), using HSA-ribosomal P peptide conjugates as antigens. Anti-P levels were quantitated by subtracting the nonspecific binding activities to HSA.
The ELISA was found to be specific for anti-P, as determined by comparison with the results of Western blotting using extracts of HEp-2 cells. Serum anti-P levels were significantly elevated in patients with lupus psychosis, including organic brain syndrome and nonorganic psychosis, compared with those with non-CNS SLE or those with nonpsychotic CNS lupus. There were no significant differences in serum anti-P levels between patients with organic brain syndrome and those with nonorganic psychosis. Anti-P antibodies were not detected in the cerebrospinal fluid of patients with either lupus psychosis or nonpsychotic CNS lupus.
Our results, obtained from the highly specific ELISA using HSA-ribosomal P peptide conjugates, confirm the correlation of serum anti-P with lupus psychosis. The data also suggest that differences in the purity of the ribosomal P peptides used might be a major reason for the conflicting results in the literature regarding the association of anti-P with lupus psychosis.
尽管已有报道称抗核糖体P蛋白抗体（抗P抗体）对狼疮性精神病具有高度特异性，但关于这些抗体与系统性红斑狼疮（SLE）的临床相关性，各项研究结果存在差异。因此，本研究旨在重新评估抗P抗体与神经精神性SLE之间的关联。
使用戊二醛将羧基末端22个氨基酸序列的高度纯化的合成核糖体P肽与人血清白蛋白（HSA）偶联。以HSA-核糖体P肽偶联物作为抗原，采用酶联免疫吸附测定（ELISA）法分析75例SLE患者血清中的抗P抗体，其中26例无中枢神经系统疾病（非CNS），28例患有狼疮性精神病，21例有非精神病性中枢神经系统受累（非精神病性中枢神经系统狼疮）。通过减去与HSA的非特异性结合活性来定量抗P抗体水平。
通过与使用HEp-2细胞提取物的蛋白质印迹结果进行比较，发现ELISA对抗P抗体具有特异性。与非CNS SLE患者或非精神病性中枢神经系统狼疮患者相比，患有狼疮性精神病（包括器质性脑综合征和非器质性精神病）的患者血清抗P抗体水平显著升高。器质性脑综合征患者和非器质性精神病患者的血清抗P抗体水平无显著差异。狼疮性精神病患者或非精神病性中枢神经系统狼疮患者的脑脊液中均未检测到抗P抗体。
我们使用HSA-核糖体P肽偶联物的高度特异性ELISA获得的结果证实了血清抗P抗体与狼疮性精神病之间的相关性。数据还表明，所用核糖体P肽纯度的差异可能是文献中关于抗P抗体与狼疮性精神病关联的结果相互矛盾的主要原因。
