s20

OS. THE EZBV-RELATED LYWPHORA OCCURRING IN TRANSPLANT PATIENTS, A

MODEL OF MALIGNANCY UNDER IWK7NR CONTROL

Touraine J.L.

Transplant Unit, Pav. P., Hopital Edouard Herriot, Place

d'Arsonva1 , 69431 Lyon CIdex 3, France.

Although no case of lymphoproliferative syndrome occurred

among our first 680 patients treated by organ transplantation,

14 cases developed in a subsequent series of 420 patients. This

severe condition involved a proliferation of B cells and/or

plasma cell6 that invaded the spleen, the liver, the lungs, the

bone marrow and the transplanted organs, but did not lead to

adenopathies. Nine of the patient6 died of this lymphoma. Early

tapering of immunosuppressive therapy enabled five patients to

recover without loss of the transplant. When the B-cell6 were

typed, at the time of end-stage lymphoma, they were of host

type, but this doe6 not rule out a pO66ible proliferation of

donor B-cell6 at an initial stage. The factor6 likely to be

involved in the occurrence of malignant lymphoproliferation are

EBV and immunosuppression. Reactivation of EBV or introduction

of HLA-mismatched EBV-infected cell6 ie a difficult challenge

to face for a patient with depressed cell-mediated immunities.

Restoration of T-cell function6 and NK cell activity by the

mere discontinuation of immunosuppressive drug6 can result in

control of the EBV infection and of the dramatic B-cell

proliferation, except if the diS6666 is already at a late

stage. The monitoring of imunoglobulin heterogeneity is of

value for the early detection of patients at risk of developing

this type of lymphoma and to suggest partial reduction of

immunosuppressive drugs. In this disease, the host

inuuunodeficiency seem6 to be important both at the time of the

initial EBV infection and at the phase of the resulting B-cell

proliferation.