Alterations of lymphocytes and of antibody content of human milk after processing

The effects of pasteurization, lyophilization, and freezing on immunoglobulin and lymphocytes in human milk was studied. We found a significant decrease in total lymphocyte count after all three processing methods. Pasteurization and lyophilization caused a significant decrease in immunoglobulin concentration and in specific antibody titer to Escherichi coli . Freezing specimens up to four weeks resulted in no significant alteration of IgA content or in E. coli antibody titer. Since a major advantage of human milk is the transference of passive local immunity, these quantitative changes may have clinical importance.