Preliminary experience in external quality control of RT-PCR PML-RAR alphadetection in promyelocytic leukemia

To standardize the results obtained in PML/RAR alpha RT-PCR detection by la boratories of hospitals involved in the Spanish Program for Treatment of He matological Malignancies (PETHEMA) LPA-96, designed for the treatment of ac ute promyelocytic leukemia (APL), cDNA samples obtained by reverse transcri ption of RNA from bone marrow samples of patients with APL were sent to par ticipating laboratories. During the first year of this external quality ass essment trial nine samples were tested by a maximum of 12 laboratories. The control gene was satisfactorily amplified in 90% of the samples (62 of 69 samples), supporting the adequacy of the cDNA to be used as control sample. There was an 83% concordance between laboratories for PML/RAR alpha detect ion with similar results for the type of PML/RR alpha rearrangements. Howev er, 17% disagreement still remained, attributable to low sensitivity or ina dequacy of methods followed. The results stressed the need for implementati on of an external quality assessment scheme to ensure the standardization o f the results.