Marco Pizzolato

Mild Hemolytic Disease of the Newborn due to Anti-Lewisa

We are reporting a mild case of hemolytic disease of the newborn (HDN) due to antiha. As far as we and others [l-51 have been able to determine, such a case has hot been previously published. A 27-year-old white woman, primigravida, delivered a baby girl with a positive direct antiglobulin test (DAT). She underwent a cesarean section because of a prolonged pregnancy of 42 weeks associated to her being nonreactive to the contraction tolerance test. She had no history of transfusions, and was typed as group 0, DcEe, Le (a-b-). The maternal serum gave positive reactions in antibody screening; two reagent red cell panels for antibody identification (Gamma and Immucor) showed that only anti-Lea was present. This specificity was confirmed by neutralization of the antibody by commercialy available Lewis substance (Gamma). The antibodydidnot react insaline tests, but it did react in albumin tests at 37°C (titer 16) and in the antiglobulin phase (titer32). Its titer was 64 in an indirect antiglobulin test using ficintreated red blood cells. With monospecific antihuman globulin reagents, the antibody was found to be IgG and complement binding. Furthermore, IgG and IgM were isolated by ammonium sulfate precipitation from the serum of the patient and purified by gel filtration on Sephadex G-200 column in 0.1 M acetic acid followed by immunoabsorbtion. The purity of the IgGand IgM-containing fractions was determined by immunoelectrophoresis, and electrophoresis in SDS-PAGE. me presence of anti-Lea activity only was Mild Hemolytic Disease of the Newborn due to Anti-Lewis”

Thin layer gel filtration immunofixation: Identification of abnormal molecular weight immunoglobulins or related fragments

A simple procedure is described to identify immunoglobulin (Ig) fragments without isolation from biological fluids. It involves an initial separation based on molecular weight (MW) by thin layer gel filtration (TLG) followed by immunofixation (IF) in cellulose acetate strips with monovalent antisera. TLG-IF permits detection of differences about 10,000 Da MW and specific immunological typing, making it a useful tool in the accurate identification of protein fragments.