[1] Institute of Biochemistry of Uppsala, Uppsala
[2] Children's Asthma Research Institute and Hospital, Denver, CO
[3] The Blood Centre, University Hospital, Uppsala
[4] WHO International Reference Centre for Immunoglobulins Institut de Biochimie, Lausanne
[5] Department of Experimental Pathology, University of Birmingham Birmingham, England
[6] National Cancer Institute, National Institute of Health, Bethesda, MD