Van Lieshout L, De Jonge N, el Masry N A, Mansour M M, Krijger F W, Deelder A M
U.S. Naval Medical Research Unit No. 3, Cairo, Egypt.
Am J Trop Med Hyg. 1992 Oct;47(4):463-9. doi: 10.4269/ajtmh.1992.47.463.
Serum and urine levels of two Schistosoma circulating antigens, the circulating anodic antigen (CAA) and the circulating cathodic antigen (CCA), were determined by monoclonal antibody-based enzyme-linked immunosorbent assays in 56 Egyptian patients infected with S. mansoni and in 12 patients infected with both S. mansoni and S. haematobium. Both CAA and CCA could be specifically demonstrated in 82% and 88% of the serum samples and in 88% and 87% of the urine samples, respectively. While complete specificity was maintained, sensitivity was increased to a range of 91-98% by parallel use of the two circulating antigen assays, i.e., an individual with a positive titer for at least one of the assays was considered to be infected. A combination of CAA and CCA determinations in urine samples only resulted in a sensitivity of 94%. However, the highest sensitivity was achieved when the serum-CCA assay was combined with the urine-CCA assay (98%) or with the urine-CAA assay (97%). Sensitivity could not be increased further by combining more than two tests. A significant correlation was demonstrated between the level of circulating antigen and the number of parasite eggs in feces in each of the four assays. In addition, the levels of CAA and CCA in serum and urine were significantly correlated with each other. Our results indicate that diagnosis of schistosome infections by detection of circulating antigens can be significantly improved by parallel testing for multiple antigens.
采用基于单克隆抗体的酶联免疫吸附试验，对56例感染曼氏血吸虫的埃及患者以及12例同时感染曼氏血吸虫和埃及血吸虫的患者，检测了两种血吸虫循环抗原即循环阳极抗原（CAA）和循环阴极抗原（CCA）的血清及尿液水平。CAA和CCA分别能在82%和88%的血清样本以及88%和87%的尿液样本中被特异性检测到。在保持完全特异性的同时，通过同时使用两种循环抗原检测方法，敏感性提高到了91% - 98%的范围，即至少有一种检测方法呈阳性滴度的个体被视为感染。仅对尿液样本进行CAA和CCA联合检测时，敏感性为94%。然而，当血清CCA检测与尿液CCA检测联合（98%）或与尿液CAA检测联合（97%）时，敏感性最高。联合超过两种检测方法不能进一步提高敏感性。在四项检测中的每一项中，循环抗原水平与粪便中寄生虫卵数量之间均显示出显著相关性。此外，血清和尿液中CAA和CCA的水平彼此之间也显著相关。我们的结果表明，通过对多种抗原进行平行检测，可显著提高通过检测循环抗原诊断血吸虫感染的能力。
