Cytotoxic drug sensitivity of Epstein-Barr virus transformed lymphoblastoid B-cells

Abstract

Background: Epstein-Barr virus (EBV) is the causative agent of immunosuppression associated lymphoproliferations such as post-transplant lymphoproliferative disorder (PTLD), AIDS related immunoblastic lymphomas (ARL) and immunoblastic lymphomas in X-linked lymphoproliferative syndrome (XLP). The reported overall mortality for PTLD often exceeds 50%. Reducing the immunosuppression in recipients of solid organ transplants (SOT) or using highly active antiretroviral therapy in AIDS patients leads to complete remission in 23-50% of the PTLD/ARL cases but will not suffice for recipients of bone marrow grafts. An additional therapeutic alternative is the treatment with anti-CD20 antibodies (Rituximab) or EBV-specific cytotoxic T-cells. Chemotherapy is used for the non-responding cases only as the second or third line of treatment. The most frequently used chemotherapy regimens originate from the non-Hodgkin lymphoma protocols and there are no cytotoxic drugs that have been specifically selected against EBV induced lymphoproliferative disorders.

Methods: As lymphoblastoid cell lines (LCLs) are well established in vitro models for PTLD, we have assessed 17 LCLs for cytotoxic drug sensitivity. After three days of incubation, live and dead cells were differentially stained using fluorescent dyes. The precise numbers of live and dead cells were determined using a custom designed automated laser confocal fluorescent microscope.

Results: Independently of their origin, LCLs showed very similar drug sensitivity patterns against 29 frequently used cytostatic drugs. LCLs were highly sensitive for vincristine, methotrexate, epirubicin and paclitaxel.

Conclusion: Our data shows that the inclusion of epirubicin and paclitaxel into chemotherapy protocols against PTLD may be justified.

Figure 1

Drug sensitivity pattern of 17 lymphoblastoid cell lines for epirubicin. The mean value of survival of LCLs is represented by the black curve, ± SD value is marked with grey. 1× : highest concentration, 16×: 16 times dilution of the highest concentration etc.

Figure 2

Mean values and standard deviations of drug sensitivity of 17 lymphoblastoid cell lines for 28 different cytostatic drugs. y axis: fraction of surviving cells 0–100% x axis: drug dilutions (1× represents the highest concentration).

Figure 3

Drug sensitivity of LCLs for anthracyclines, vinca alkaloids and taxans.

Figure 4

Drug sensitivity mean values of 17 lymphoblastoid cell lines plotted against the Ratio of Maximum Achieved Plasma Concentration (RMAPC) values. The different drug families are labelled with different colours. The highly effective (Group 1) and partially effective (Group 2) drugs are identified.