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G Garratty

Publications and source records attributed to G Garratty.

At least 145 records · Page 8Linked to original sources
PubMed1968

Complement.

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Antigen-Antibody Reactions↗
PubMedDate not supplied

The significance of red cell bound complement components in development of standards and quality assurance for the anti-complement components of antiglobulin sera.

Human red blood cells, sensitized with complement in vivo and by a variety of methods in vitro, (e.g. blood group antibody, low ionic strength, alternate pathway), were tested with a battery of anti-complement sera (anti-C3, -C3c, -C3d, -C4, -C4c). Red blood cells could be prepared by relatively simple methods to yield cells sensitized with C3 and C4, C3 but not C4, C4 but no C3, C3d with no C3c and C4d with no C4c. These cells are suitable for standarization and quality assurance of antiglobulin sera (AGS). Anti-C3d is necessary for optimal detection of sensitization of red blood cells by complement in vivo by the direct anti-globulin test (DAT). Anti-C3d may also be optimal for the indirect antiglobulin test (IAT) especially if incubation periods greater than one hour are employed. Potent anti-C4 and anti-C3 antisera made in the authors' laboratory resulted in numerous weakly positive antiglobulin tests when testing red blood cells from refrigerated clots (especially anti-C4) but red blood cells from refrigerated anticoagulated segments gave negative results. When red blood cells were incubated in normal serum at room temperature (as in the room temperature phase of a compatibility test), some positive results were again obtained with the potent anti-C4 and anti-C3 antisera. However, one commercial antiglobulin serum containing anti-complement antibodies that were at least as potent as any other commercial antiglobulin serum gave uniformly negative results under the above conditions. Anti-C4 antibodies may be omitted from anti-globulin sera without decreasing the efficacy of such antisera to be used in compatibility testing. Thus, positive results in the compatibility test due to detection of clinically insignificant cold antibodies in the IAT by the anti-complement antibodies in AGS, may be avoided if anti-C4 is omitted or is in low concentration and if the concentration of anti-C3d is carefully standardized. A higher concentration of anti-C3d could be used for compatibility tests if red blood cells from anticoagulated segments were used instead of those from clots and if a separate tube were used for the IAT at 37 C rather than using one tube for both room temperature and 37 C incubations.

Antibody Specificity↗
PubMedDate not supplied

Autoimmune hemolytic anemia associated exclusively with IgA of Rh specificity.

A nine-year-old boy had typical clinical, hematologic and blood group serologic findings of autoimmune hemolytic anemia except for one important exception; with most commercially available broad spectrum anti-human sera the direct antiglobulin tests were negative. With reagents prepared in the laboratory which were found to be relatively less potent in and anti-IgG and IgM activity but which utilize a short period of incubation after mixing with the washed cells, the tests were all clearly positive. If incubation were employed with the commercial reagents, the tests were positive. Further studies showed that the patient's cells were coated exclusively with IgA and that a commercial reagent, although potent in anti-IgG and anti-IgM, was relatively deficient in anti-IgA. It is proposed that incubation compensates for the latter and is cautioned that incubation, with reagents potent in anti-IgG, could lead to false negative reactions with weakly IgG sensitized cells due to antibody surplus prozones of inhibition. This case illustrates that the rare instances of "Coombs negative immune hemolytic anemias" may be based on mechanisms such as those reported here and, that to be ideal, a broad spectrum anti-human serum should have balanced anti-immunoglobulin activities in relation to its incubation time.

Anemia, Hemolytic, Autoimmune↗
PubMedDate not supplied

Autoimmune hemolytic anemia associated with IgG auto anti-N.

A second case of autoimmune hemolytic anemia mediated by an IgG auto Anti-N is described. The patient's red blood cells were sensitized with both IgG and complement. The serum antibody was not inactivated by 2-mercaptoethanol treatment, and reacted by indirect antiglobulin test at 37 C with monospecific anti-IgG. The IgG antibody eluted from the red blood cells and in the serum showed anti-N specificity. The patient was thought to have systemic lupus erythematosus. Following steroid therapy, the hemolytic anemia resolved with disappearance of the anti-N.

Adult↗
PubMedDate not supplied

Elution of antibody from red blood cells using xylene--a superior method.

Chan-Shu and Blair's findings that xylene produces a strongly reactive eluate from red blood cells have been confirmed and extended. Alloantibodies of 21 different blood group specificities and red blood cells sensitized in vivo, including ABO sensitization of babies' blood, were tested. The xylene method produced stronger reacting eluates than the modified ether method in 70 per cent of the tests. Ether, acid, and heat methods never produced significantly stronger eluates than did xylene. Ether eluates prepared from red blood cells sensitized with anti-S and anti-s were nonreactive, but the same cells yielded easily detectable anti-S and anti-s when xylene eluates were prepared. The xylene method is sensitive and simple. In addition, xylene is not subject to such stringent control of storage conditions by inspection agencies as is ether.

ABO Blood-Group System↗
PubMedDate not supplied

M and N specific hemagglutinins of human erythrocytes stored in glucose solutions.

Alloagglutinins of M and N specificites with unique characteristics found in normal sera are described. Specific M or N agglutination by these sera occurred only when erythrocytes had been exposed to glucose-containing solutions. Conversion to the form of MN recognized by these sera required incubation of the cells in 1 to 2% glucose buffered to physiological or alkaline pH and was dependent on time and temperature of exposure, occurring in hours at 37 C and in days at 4 C. The sera appeared to be detecting an antigenic structure in which interaction between glucose and the amino group of the N-terminal amino acid of the MN receptor has produced a new specificity, analogous to the action of formaldehyde on N receptors and the resulting N-like structure detected by sera from hemodialysis patients.

Absorption↗
PubMedDate not supplied

Clinical significance of the anti-complement component of antiglobulin antisera.

The need for anti-complement (anti-C') activity in antiglobulin antisera (AHG) for the detection of clinically significant antibodies was evaluated during a three-year period. While performing routine compatibility testing using standard blood banking procedures, eight patients were found whose antibodies were detectable primarily or only by AHG containing anti-C' activity; monospecific anti-igG AHG gave weak or negative reactions. Seven of the antibodies were anti-jka or jkb. Two of the anti-jka antibodies were responsible for clinically unsuspected delayed hemolytic transfusion reactions. The anti-jkb antibody resulted in a shortened survival of incompatible 51Cr-labelled red blood cells. The incidence of such "complement-only" Kidd antibodies was 23 percent of all Kidd antibodies found. These data suggest that the omission of anti-C' in AHG in routine compatability testing could result in substantial risk of failure to detect clinically significant antibodies.

Aged↗
PubMedDate not supplied

An apparent anti-Jka reacting only in the presence of methyl esters of hydroxybenzoic acid.

An apparent anti-Jka, reacting only in the presence of methyl esters of hydroxybenzoic acid (HBA), was detected in an individual with Jk (a+) red blood cells. The antibody was first detected when a commercial low-ionic-strength-solution preparation containing the preservative methyl paraben (a methyl ester of hydroxybenzoic acid) was used in compatibility testing. Negative reactions were obtained when regular saline, albumin, and enzyme technics were employed. The positive indirect antiglobulin tests were due to cell-bound complement; no IgG was detected. The patient had no clinical or hematologic evidence of hemolytic anemia and was transfused with Jk(a+) red blood cells with no ill effects. It is postulated that immune complexes formed between the antibody and the chemical may result in a site complementary to some aspect of the Jka antigen. When this complex binds to Jk(a+) cells, complement is activated and some complement components remain on the cells. We do not know why only Jk(a+) cells were involved in these reactions.

Antigen-Antibody Complex↗