Aslpaugh M A, Tan E M
Arthritis Rheum. 1976 Jul-Aug;19(4):711-9. doi: 10.1002/1529-0131(197607/08)19:4<711::aid-art1780190409>3.0.co;2-i.
A cell-free extract of human diploid B lymphocytes (Wil2) in continuous culture was used as the source of antigen in immunodiffusion to detect a precipitating antibody referred to as rheumatoid arthritis precipitin (RAP) in sera of patients with rheumatoid arthritis (RA). The prevalence of RAP was determined in various arthritides and other connective tissue diseases. It was found in 67% of patients with seropositive RA and in 62% of patients with Sjögren's syndrome associated with RA. But its frequency was lower in many other connective tissue diseases, including seronegative RA and Sjögren's syndrome without associated RA. Matching sera and synovial fluids from patients with seropositive RA were also studied. Differences in serum and synovial fluid RAP titers were demonstrated, but generally when RAP was present in serum, it was also present in synovial fluid and vice versa. Indirect immunofluorescence (IF) with Wil2 cells as substrate was used to demonstrate RAP and to determine morphologically the nature of the reactive cellular antigen. When cells were treated with commonly used fixatives, little or no staining with RAP positive sera was observed. This outcome was shown to be the result of the extreme solubility of the cellular antigen reactive with RAP. The antigen was retained best in a reactive form in Wil2 cells after fixation of cells with dry heat at 37 degrees C for 30 minutes, and it was demonstrated by IF staining as small round granules distributed in the nucleus and cytoplasm. IF was also employed to demonstrate that RAP is immunoglobulin belonging to IgG and IgM classes and not to IgA or IgD.
连续培养的人二倍体B淋巴细胞（Wil2）的无细胞提取物被用作免疫扩散中的抗原来源，以检测类风湿关节炎（RA）患者血清中一种称为类风湿关节炎沉淀素（RAP）的沉淀抗体。在各种关节炎和其他结缔组织疾病中测定了RAP的患病率。在67%的血清阳性RA患者和62%与RA相关的干燥综合征患者中发现了它。但在许多其他结缔组织疾病中其频率较低，包括血清阴性RA和无相关RA的干燥综合征。还研究了血清阳性RA患者的配对血清和滑液。证实了血清和滑液中RAP滴度存在差异，但一般来说，当血清中存在RAP时，滑液中也存在，反之亦然。以Wil2细胞为底物的间接免疫荧光（IF）用于证明RAP并从形态学上确定反应性细胞抗原的性质。当细胞用常用固定剂处理时，用RAP阳性血清几乎没有或没有观察到染色。结果表明，这一结果是与RAP反应的细胞抗原具有极高溶解性的结果。在用37℃干热处理细胞30分钟后，抗原以反应性形式在Wil2细胞中保留得最好，并通过IF染色显示为分布在细胞核和细胞质中的小圆形颗粒。IF还用于证明RAP是属于IgG和IgM类的免疫球蛋白，而不是IgA或IgD。
