A unique experience with human pre-immune (12 weeks) and hypo-immune (16 weeks) fetal thymus transplant in a vascular subcutaneous axillary fold in patients with advanced cancer: a report of two cases.

BACKGROUND: The successful development of fetal cell/tissue transplantation in adults has resulted in the possibility of eventual therapeutic solutions with a variety of intractable diseases. Umbilical cord whole blood transplantation appears to be safe in the adult system. In severe forms of DiGeorge Syndrome, cultured thymus transplant can help in the reconstitution of the immune condition of the host. Successful fetal tissue transplant in adults has raised the hope of future effective gene transplant and its manipulation prospects to combat many diseases including hemopathies, inborn errors of metabolism, immunodeficiencies and even cancer and AIDS.

MATERIALS AND METHOD: Two cases of advanced cancer were treated with fetal (pre-immune 12 weeks and hypo-immune 16 weeks) thymus transplants in subcutaneous vascular axillary folds, which were removed after one month. Thymuses were collected from consenting mothers undergoing hysterotomy and ligation.

RESULTS AND ANALYSIS: Patient I was suffering from non-Hodgkins lymphoma (Ann Arbor Stage IV) and was receiving cyclophosphomide, doxorubicin, vincristine and prednisolone after a course of radiotherapy; she developed leucopenia (2.400/cmm), which improved after receiving a 16-week human fetal thymic graft. The leucopenia was eventually over-corrected and the leucocyte count reached 44,000/cmm within a month, which was reversed after the thymus was taken out. Histology of the excised thymic graft showed growth and proliferation without any graft vs. host (GVH) reaction. Patient 2 was suffering from breast duct carcinoma (T4, N2, M0,) with estrogen, progesterone, and epidermal growth factor negative status, and was treated with modified radical mastectomy and axillary clearance followed by chemotherapy with cyclophosphomide, methotrexate and 5-fluorouracil for six cycles. She also received a 12-week-old human fetal thymus at the contra-lateral axilla which was removed after one month. In this case the peripheral leucocyte count did not show appreciable variation as in the first case. However, histology of the excised thymic graft showed growth and proliferation with an appearance of Hassel's corpuscles.

CONCLUSION: Pre-immune and hypo-immune human fetal thymic transplant is not rejected in patients suffering from advanced cancer within one month (observation period). Thymic lymphocyte shedding in the correction of leucopenia in the background of non-Hodgkin's lymphoma may have many therapeutic implications.