Observations on the Thermal Optimum, Saline Agglutinating
Activity and Partial Neutralization Characteristics of
IgG Anti-A Antibodies

Maternal sera were titrated after 2-mercaptoethanol treatment for anti-A and anti-B agglutinations by the saline and the anti-globulin methods; the results were expressed in titration scores. Each case was graded into mercaptoethanol-stable antibody (MESA) grade 1 : A and B mothers with compatible infants; 2: mothers with unaffected incompatible infants; 3 : mothers with mild hemolytic disease of the infant, and 4: mothers with severe hemolytic disease of the infant. 925 cases were submitted for the ABO incompatibility tests in 2 years; the babies’ sequelae were reported in 131 ABO-incompatible cases. If the tests were done in late pregnancy, severe cases of hemolytic disease of the newborn corresponded to mothers’ antenatal antibodies in MESA grade 4, and mild cases to MESA grade 3.

Section: Discussionsupporting

confidence: 93%

Mercaptoethanol-Stable Antibody Test Predicting Hemolytic Disease of the Newborn Due to ABO Incompatibility

Hasekura¹

1974

“…This type of behaviour is also seen with IgG antibodies and lectins, thus potent reagents of IgG anti-A [26] and Dolichos biflorus anti-A [29] show far higher titres in saline tests with At cells that have about 1,000,000 A sites than they do with A2 cells that only have about 250,000 A sites.…”

Section: Discussionmentioning

confidence: 71%

“…Thermal optimum studies and 2-mercaptoethanol treatment of the reagents were carried out as previously described [25,26].…”

Section: Methodsmentioning

confidence: 99%

A Study of the Serological Behaviour and Nature of the Anti-B/P/P^k Activity of Salmonidae Roe Protectins

Voak¹,

Todd²,

Pardoe³

1974

Self Cite

Salmonidae protectins cross-react with human red cells having B, P, P(1) and P^k antigens, probably combining with an a-galactosyl-like determinant common to all these antigens. They have an apparent molecular weight of the order of 2 x 10^5 (S(20)w=8·9), which may explain the enhanced haemagglutinating activity in albumen displacement or enzyme tests. The saline anti-B activity for A(1)B cells rapidly deteriorated in storage. Cells previously suspended with albumin were no longer agglutinated by the protectins. It was only possible to obtain serologically active partially purified protectins from Sephadex G-200 gel filtration when normal human serum was added to the crude protectin reagent before applying to the gel. This may reflect lability of the tertiary structure of these proteins.

“…The importance of site density has been stressed by Hoyer and Trabold [14], and Voak et al [33] have shown that IgG anti-A antibodies may give high titres in saline tests and that the titres are lower with cells that have a I lower total number of A sites, e.g. 256 with A!…”

Section: Discussionmentioning

confidence: 99%

“…There fore, we prevented the possibility of any anti-T activity of the ferritin-conjugated anti-D reagent by prewarming the cells and serum to 37 °C for 30 min before carrying out the tests. Anti-T activity in the other incomplete anti-D reagents was destroyed by treating the sera with 2-mercaptoethanol [33].…”

Section: Methodsmentioning

confidence: 99%

The Role of Enzymes and Albumen in Haemagglutination Reactions

Voak¹,

Cawley²,

Emmines³

et al. 1974

Self Cite

In albumen and papain tests, strong haemagglutination showed large areas of cell to cell contact, whereas neuraminidase only caused loose agglutination with small areas of cell to cell contact, confirming a previous suggestion that reduced zeta-potential is not the significant factor in Rh haemagglutination. The ferritin-labelled anti-D was only clustered on neuraminidase- and papain-treated cells, possibly these enzymes cause limited membrane mobility. It is postulated that the loose agglutination in neuraminidase tests is due to localised high density of D sites and that the much greater agglutinating activity in papain tests is due to clustering and protease activity. Increased anti-D antibody uptake is not a critical factor in enzyme tests because cells sensitized and then washed before enzyme treatment were strongly agglutinated. Recent studies have revealed that dextran does not reduce zeta-potential but acts by adsorption between adjacent cells. We suggest that a similar mechanism may explain the action of albumen.