Establishment of passive hemagglutination assay (PHA) system for anti-HBc in plasma.

Abstract

A sensitive and specific assay system for anti-HBc, the passive hemagglutination (PHA) method, has been established. The reactivity of PHA cells prepared by conjugating purified recombinant HBcAg-particles with fixed sheep blood cells (SRBC) was highly specific to monoclonal-and polyclonal anti-HBc IgGs. The sensitivity of PHA method was higher than that of radioimmunoassay (RIA). However, uncertainty for the positivity of anti-HBc still remained in plasma with the PHA titers lower than 25. A relatively high ratio (19%, 37 of 196) of anti-HBc-positive plasma, which had been confirmed to be HBsAg negative, was demonstrated in blood donors whose bloods have been considered suitable for transfusion. The hazards of anti-HBcpositive bloods and the importance of anti-HBc detection in plasma are discussed in this paper.

Development of monoclonal antibodies against human gastrointestinal cancer.

“…As shown in Table 2, KM10 showed as much as 23% ADCC at 300 E/T ratio and 0.5,cg/ml of antibody. Non-specific monoclonal antibody such as anti-HBs monoclonal antibody, 1D6 (Uemura et al 1986), showed little activity. Other anti-CEA monoclonal antibody, BD6(IgG3), developed from the same series of experiment in which KM10 was obtained, showed some activity, although at far lower levels compared with KM10, in spite that the expression ratio of the antigen of this antibody on MKN-45 cells was greater than that of KM10 (Fig.…”

“…The another method was based on the passive hemagglutination assay (PHA). According to the method of Uemura et al (1986), CEA was coupled with SRBC(CEA-PHA). CEA-RPHA-CEA reagent was prepared by coupling CEA with SRBC via murine anti-CEA monoclonal antibody (BD6), which was previously coupled to SRBC.…”

Selection of monoclonal antibodies detecting KM01 antigen.

“…For the screening of KMOI-related antibodies, MoAbs were examined for their inhibitory effect on KMOITM RPHA (The Green Cross Corp., Osaka) in which KMO1 was coupled to SRBC according to the method of Uemura et al (1986). The spent medium of COLO-201 was used for the KMO1 antigen solution.…”

“…Normal human serum was collected from healthy donors. The antigen in serum sample was determined by RPHA reagent, in which each purified MoAb was coupled to SRBC according to the method of Uemura et al (1986). The specimen under examination was judged as positive, if a 2 well or greater difference in the endpoint of hemagglutination exists between MoAb-coated SRBC and control SRBC annexed to KM01 RPHA kit.…”