Flow cytometric analysis of DNA indices, expression of p53 and multidrug resistance genes in multiple myeloma patients

OBJECTIVE: To perform a quantitative analysis of DNA ploidy, S-phase fraction % (SPF%), p53 and multidrug resistance (MDR) gene expression as independent prognostic parameters and to compare these parameters with stage of the disease in multiple myeloma (MM) patients. STUDY DESIGN: Peripheral blood bone marrow samples were analyzed for DNA ploidy and SPF% using a FACScan flow cytometer (Becton Dickinson). Detection of p53 and MDR gene expression was done using immunocytochemistry. RESULTS: Aneuploidy was found in 5/48 (10.42%) total myeloma patients, all of whom revealed hyperdiploidy. High SPF% was noted in 18/37 (48.65%) newly diagnosed MM patients and 5/11 (45.45%) follow-up cases of myeloma. p53 Gene product was noted in 8/48 (16.66%) myeloma patients, 6 newly diagnosed and 2 on follow-up. MDR gene expression was detected in 4/27 (10.81%) newly diagnosed patients and in 1/11 (9.09%)follow-up patients. CONCLUSION: All myeloma patients with aneuploidy revealed hyperdiploidy. The majority of cases with high SPF% were at advanced stages, indicating the prognostic significance of SPF%. Although, there was no statistical significance of DNA ploidy, SPF%, p53 and MDR gene product expression, they are important prognostic parameters. Our results can provide baseline data for comparison with future studies since these parameters have not been reported earlier from the Indian subcontinent.