A serum factor which inhibits serologic reactions with enzyme-treated red blood cells

Abstract

Two patients' sera inhibited agglutination of enzyme-treated red blood cells by antibodies. This blocking effect was detected by using a mixture of antibodies as an enzyme test reagent for the routine control of a two-stage papain test. The blocking factor appeared to be IgG and its effect was complement dependent. It blocked reactions with red blood cells treated with papain, bromelin, or ficin. Reactions with both IgM and IgG antibodies of various specificities were blocked. The presence of the blocking factor in a patient's serum may result in failure to detect clinically significant antibodies unless a control system is used which will confirm that the cells in each test can be agglutinated by enzyme reacting antibodies.

ABO reverse grouping: effect of varying concentrations of the enzyme bromelain

“…1,8 Thus, each red cell attracts fewer ions from the suspending medium (usually saline) and reduces the zeta potential. 19 The minimum distance between red cells decreases, permitting them to move closer together. 6,8 This allows some antigens to become more accessible to their corresponding antibody, thereby allowing these cells to agglutinate in a saline medium.…”

Confirmation of Anti-ELO as a Cause of Haemolytic Disease of the Newborn

“…Further investigation revealed the pres ence of a papain inhibitor as described by Lown et al [4], Amniotic fluid AOD45o at 30 weeks gesta tion indicated a moderately affected baby. Fetal cells, obtained by fetal sampling at 32 weeks gestation, were group 0 Rh(D) pos itive , DAT positive (score 5).…”