배경 : 장기부족을 겪고 있는 임상이식분야에서 이종이식은 하나의 가능한 대안으로 여겨지고 있으나 이종이식시의 초급성 거부반응이 큰 장애이다. 이미 형성되어 있는 자연항체가 이종항원에 결합하여 이에 따라 발생하는 보체의 활성화가 초급성 거부반응의 주요 기전이다. 본 연구에서는 이종이식의 초급성 거부반응을 모니터하기 위한 보체 용혈도 검사를 마련하고 이의 정밀도와임상적 중요성을 알아보았다. 방법 :사람 혈청에 대한 보체 용혈도 검사를 토끼와 돼지의 혈구로 dextrose 함유 또는 함유하지 않는 gelatin veronal buffer에서 비교하여 가장 검사에 적합한 조건을 조사하였다. 얻어진최적 조건 하에서 검사의 정밀도와 정상 성인 혈청의 보체 용혈도 범위를 조사하였다. 또한 여러 가지 이종이식 동물실험에서얻은 혈청에서 보체 용혈도를 측정하여 보체 용혈도와 다른 임상소견과의 연관성을 살펴보았다.결과 :토끼 혈구와 저이온강도의 dextrose 함유 gelatin veronalbuffer를 사용한경우에서 가장 낮은 기저 용혈을 보였고 가장 넓은 혈청 희석 범위에서 용혈도의 직선성을 보였다. 이 방법의 검사내, 검사간 정밀도는 1.3%와 8.1%이었다. 보체 용혈도는 혈중C3와 IgM치에 의존적으로 변화하였으며, 이식 전에 비하여 이종이식 후에 보체 용혈도의 감소가 큰 경우 더 심한 초급성 거부반응을 보였다. 결론 : 토끼 혈구를 이용한 이종항원에 대한 보체 용혈도검사는 임상적으로 적합한 정밀도를 보였으며 추후 이종이식의 초급성 거부반응의 모니터에 유용하리라 사료된다.

Background : Xenotrasplantation is a possible alternative for organ shortage in clinical transplantation, but hyperacute xenograft rejection has been a big huddle. Pre-existing natural xenoreactive antibodies and consequent activation of the complement system are thought to play major roles in hyperacute rejection. To set a monitorig test for the hyperacute rejection in xenotransplantation, we optimised a complement hemolytic assay and evaluated its in-vitro precisions and clinical implications. Methods : Complement hemolytic activities of normal human sera on rabbit or porcine red blood cells (RBCs) in each gelatin veronal buffer with or without dextrose were compared to retrieve optimal conditions for assay. The precision and activity range of normal human sera were evaluated at a given optimum condition. And we also assayed complement hemolytic activities of the sera obtained from various models of xenotransplantated animal, and assessed its association with other clinical parameters. Results : The assay with rabbit RBCs in gelatin veronal buffer containing dextrose showed linear hemolytic reactions in the broadest range of serum dilutions with the least background hemolysis. Its intra- and inter-assay coefficient variation was 1.3% and 8.1%, respectively. The complement hemolytic activity was dependent on the serum levels of C3 and IgM. Severe hyperacute rejection in lung xenotransplantation was accompanied with a rapid decline of serum complement hemolytic activities compared to the basal level. Conclusions : The complement hemolytic assay using rabbit red cells has a clinically acceptable range of precision, and seems to be useful for the evaluation of hyperacute rejection in clinical xenotransplantation. (Korean J Lab Med 2004; 24: 415-20)

Background : Xenotrasplantation is a possible alternative for organ shortage in clinical transplantation, but hyperacute xenograft rejection has been a big huddle. Pre-existing natural xenoreactive antibodies and consequent activation of the complement system are thought to play major roles in hyperacute rejection. To set a monitorig test for the hyperacute rejection in xenotransplantation, we optimised a complement hemolytic assay and evaluated its in-vitro precisions and clinical implications. Methods : Complement hemolytic activities of normal human sera on rabbit or porcine red blood cells (RBCs) in each gelatin veronal buffer with or without dextrose were compared to retrieve optimal conditions for assay. The precision and activity range of normal human sera were evaluated at a given optimum condition. And we also assayed complement hemolytic activities of the sera obtained from various models of xenotransplantated animal, and assessed its association with other clinical parameters. Results : The assay with rabbit RBCs in gelatin veronal buffer containing dextrose showed linear hemolytic reactions in the broadest range of serum dilutions with the least background hemolysis. Its intra- and inter-assay coefficient variation was 1.3% and 8.1%, respectively. The complement hemolytic activity was dependent on the serum levels of C3 and IgM. Severe hyperacute rejection in lung xenotransplantation was accompanied with a rapid decline of serum complement hemolytic activities compared to the basal level. Conclusions : The complement hemolytic assay using rabbit red cells has a clinically acceptable range of precision, and seems to be useful for the evaluation of hyperacute rejection in clinical xenotransplantation. (Korean J Lab Med 2004; 24: 415-20)

Complement hemolytic activity, Rabbit red cells, Xenotransplantation, Precision