Detection Of Murine IgG And Human-anti-mouse Antibody In Serums Of HFRS Patients Treated With Murine McAb

Hemorrhagic fever with renal syndrome(HFRS) is an acute infectious disease caused by Hantavirus, and transmission occurs by rodents, and clinically characterized with fever, hemorrhage and acute renal impair. In china, the HFRS is wide spread, high incidence, high case fatality rate, and the epidemic situation is most severely in the world. HFRS still can't be cured effectively.Our department harvested several murine McAb, which gave high neutralization and hemagglutination inhibition titers for HFRS virus and high protective activity for suckling mice infected with the HFRS virus. Base from it, we made it into injection preparation("Injection of anti-HFRS-virus McAb") cooperated with Wu-han Inst Biological Product. SFDA had given approval to this McAb preparation to clinical research in 2000.To study the blood drug level of murine McAb of anti-HFRS-virus and the production of human anti-mouse antibody in patients treated with this drug, firstly we established two methods: sandwich ELISA to detect the murine IgG and indirect ELISA to human anti-mouse antibody. We optimized the ELISAsystem through selecting optimal concentration of coating and labled antibody. The results of substitution test and blocking test showed that both of two methods were highly specific. The detection limitation is 1ng/mL of murine IgG and 1:6400 of human-anti-mouse antibody. The coefficients of variant (CV) of intra-assay (lower than 10%) and inter-assay (lower than 15%) indicated that these ELISA are reproducible. With these methods we detected 165 sera of 69 patients in the second-period and third-period clinical trial of the anti-HFRS-virus McAb injection preparation(every patient injected 10mg McAb injection preparation). The blood drug level of McAb(murine IgG) reached its peak 1-3 days after the McAb injection, and the average concentration was 1.04+0.84 mg/L. 6-10 days after injection the average concentration rapidly declined to 0.21+0.21 mg/L. 12 days after injection the murine IgG could not be detected in most cases. The elimination half-time was 2.03 days. However, production of human anti-mouse antibody occurred mainly after 12 days. The positive rate of detection was 78.0%, and the average titer was 1:557. The results suggest that the decline of blood drug level of anti-HFRS-virus McAb dues to the natural metabolism, and that human anti-mouse antibody generated 12 days later doesn't influence the metabolism of murine McAb.