Evaluation of chemosensitivity in vitro of non-Hodgkin's lymphoma using trypan blue cell viability test, a pilot study

ABSTRACT

The response of 10 patients with nodal non-Hodgkin's lymphoma to several chemotherapeutic regimes including CHOP, BECOP, and C-MOPP was evaluated by in-vitro assessment of cell viability using trypan blue dye exclusion test. Tumor cell samples were obtained by needle aspiration of the largest lymph node prior to treatment and/or during the course of chemotherapy. In freshly prepared cell suspension, the total number of cells and the number of viable cells which excluded the dye were counted to calculate percent viability. Air dried smears from the same samples were stained with Romanowsky stain for cytomorphologic studies. The percent viability of tumor cells ranged between 78 and 99% [mean 92.5%] in the samples examined prior to treatment. Persistence of high percent viability [mean 96.6%], while receiving chemotherapy occurred in 5 patients. Four out of these 5 patients still did not achieve clinical complete remission [CR]. Marked drop of percent viability [mean 23.3%] was noticed in 3 patients. Two of them entered into CR and the third showed clinical partial remission [PR] in a very short time. This drop in percent viability may provide an early prediction to the response of cases to treatment. Cytomorphologic evaluation confirmed the previous findings in most of samples examined. Thus, percent cell viability test may prove to be a simple and efficient technique for monitoring the effects of chemotherapy, specially in cases not responding to treatment. However, a final conclusion needs a larger number of cases and a longer period of follow-up