Salivary immunoglobulins in recipients of bone marrow grafts. II. Transient secretion of donor-derived salivary IgA following transplantation of T cell-depleted bone marrow

Patients undergoing bone marrow transplantation (BMT) have decreased levels of salivary Ig over long periods of time. However, shortly after transplantation, a transient rise of Ig concentration in their saliva gland is detected. In order to trace the origin of this Ig, seven BM donors were immunized with tetanus toxoid (TT) 4-7 days prior to BMT harvesting. Four patients received BM from non-immunized donors. All but one of the patients had no detectable anti-TT IgA in their parotid saliva prior to BMT. Recipients of T cell-depleted BM from pre-immunized donors transiently displayed high titers of salivary anti-TT IgA 7-28 days after transplantation. No significant anti-TT IgA titers were detected in saliva of patients grafted with non-immunized BM. We conclude that antibody-producing cells activated in the donor are passively transferred with the BM to the recipient. IgA committed cells home to the mucosa-associated lymphoid tissues (MALT) and continue to secrete antibodies until senescence.