William Pollack

A Study of the Forces Involved in the Second Stage of Hemagglutination

Agglutination of antibody coated human erythrocytes has been found to depend on the zeta‐poten‐tial at the surface of shear and the dimensions of the antibody molecules. The critical zeta‐potential above which agglutination cannot occur has been shown to be —23 millivolts and —13 millivolts for saline and albumin antibodies respectively. A zeta‐potential below —18 millivolts for 19S molecules and below —8 millivolts for 7S molecules has been found to be necessary to give optimum agglutination and titer.

Successful Prevention of Experimental Rh Sensitization in Man with an Anti-Rh Gamma2-Globulin Antibody Preparation: A Preliminary Report

An anti‐Rh gamma2‐globulin antibody preparation has been developed which can be administered intramuscularly and appears to be both safe and effective in the prevention of experimental Rh sensitization. Nine unsensitized Rh‐negative male volunteers were challenged once a month for five successive months with intravenous injections of 2 ml. of Rh‐positive blood. Four of these nine volunteers were passively protected each month with intramuscular injections of 5 ml. of this antibody preparation, administered 24 hours prior to the antigenic challenge. Three months after the last injection the passively acquired Rh antibodies were no longer demonstrable (by either the saline or indirect antiglobulin technics) in any of the four protected subjects and there was no sign of active antibody production six months after the last injection, whereas four of the five controls were all strongly sensitized.

Hepatitis B Immune Globulin as a Prophylactic Measure for Spouses Exposed to Acute Type B Hepatitis

Because the value of usual immune globulin preparations in preventing Type B hepatitis is doubtful, we carried out a double-blind comparison of a control human immune globulin preparation with one--identified as HBIG--that had a high concentration (442 mug per milliliter) of antibodies to surface components of hepatitis B virus. Effectiveness was tested in spouses of patients with acute Type B hepatitis. Within 150 days after injection, nine of 33 spouses in the control group had symptomatic Type B hepatitis, compared with one of 25 spouses receiving HBIG. One non-B case also occurred in the HBIG group. Five control globulin recipients had evidence of subclinical hepatitis B infection, compared with one HBIG recipient. Thus, HBIG appeared effective in suppressing not only disease, but also infection itself. Prophylactic value has been demonstrated in persons who should now be recognized as being at exceptionally high risk.

Rh Factor: Prevention of Isoimmunization and Clinical Trial on Mothers

The results on the use of γG-immunoglobulin to Rh factor for the prevention of active immunization of Rh-negative mothers at risk appear most promising. One hundred and seven mothers in the clinical trial have been followed for periods of about 6 months to 1�12 years after delivery. Of these, 48 were treated mothers who received 5 ml γG-immunoglobulin to Rh, and 59 were untreated mothers. Of the 48 treated mothers none are actively immunized; seven of the 59 control mothers have become actively immunized to Rh.

Results of Clinical Trials of RhoGAM in Women

Intramuscularly administered RhoGAM, Rh0 (D) Immune Globulin (Human) has been evaluated for its capacity to prevent the primary Rh immunization of Rh negative women giving birth to ABO compatible Rh positive infants. Since March 1964, over 3,000 women have been admitted to clinical studies in 43 centers ranging geographically from Argentina to Ganada and from Australia to Scotland. RhoGAM prepared at the Ortho Research Foundation used throughout these studies is derived from plasma of persons previously immunized to the Rh0 (D) antigen, and the antibody content of the final preparation is determined by a modification of the radioimmune assay of Hughes-Jones.8

Suppression of the primary Rh immune response with passive Rh IgG immunoglobulin.

THAT passive immunity can block active immunity is an established concept dating from as early as 1909.1 The precise mechanism of the immunosuppressive action, however, is still not clearly underst...

A Reappraisal of the Forces Involved in Hemagglutination

The underlying principles governing the second stage of hemagglutination, as described in 1965, have been reevaluated. This reappraisal reaffirms that red cell aggregation is dependent on the potential energy barrier (zota) between erythrocytes. This in turn is dependent on the ionic strength and dielectric constant of the bulk medium. Hemagglutination by IgG and IgM antibody is a function of the effective length of these immunoglobulins and the zota of the cells in the reaction mixture. Agglutination of cells occurs when the zota-potential is below a critical level. The enhancing action of natural and synthetic polymers (e. g., bovine albumin) is to lower zeta by raising the dielectric constant of the bulk medium. Several other recent concepts are discussed and the major differences discussed in light of data available.

A Comparative Clinical Evaluation of HAA Detection

Tests for hepatitis‐associated antigen (HAA) of blood donor sera were performed by conventional counter‐immunoelectrophoresis and by a new complete test system devoid of wicks, buffers, or complicated power supply. An over‐all correlation of 93 per cent was obtained between the two counter‐immunoelectrophoretic methods.