Assessment of residual disease in acute leukemia by means of polymerase chain reaction.

Along a 5-year period in a single institution, specific molecular markers were prospectively looked for in consecutive patients with acute leukemia, by means of polymerase chain reaction (PCR): In patients with acute lymphoblastic leukemia (ALL), the BCR/ABL and TEL-AML1 fusion transcripts as well as clonotypic immunoglobulin gene rearrangements were investigated, whereas in patients with acute myelogenous leukemia (AML) the PML-RAR alpha, AML1-ETO and CBF beta-MYH11 fusion proteins were assessed. Specific molecular markers were identified in 15/75 patients: Four with ALL (three with clonotypic IgG rearrangements and one with BCR/ABL) and 11 with AML (nine with the PML/RAR alpha fusion protein--M3 AML-, and two with the AML1/ETO fusion protein--M2 AML-). During follow-up periods ranging from 1 to 60 months, seven patients cleared the residual disease assessed by PCR (RD-PCR), whereas eight patients had either persistence of RD-PCR or a molecular relapse. For patients without or with RD-PCR, the 30-month survival (SV) was 86% and 14%, respectively, whereas median SV was > 60 and two months, also respectively (p < 0.01). Six of eight patients with detectable RD-PCR died, all of them within three months after the detection of the RD-PCR, whereas two of the patients that relapsed were rescued with treatment and entered a second molecular remission. Two of the three molecular relapses were detected without an overt morphological relapse. It is concluded that PCR is a valuable method for assessing residual disease and that early diagnosis of relapses may lead into effective salvage treatment in some instances.

Assessment of residual disease in acute leukemia by means of polymerase chain reaction / Evaluación de enfermedad residual en leucemia aguda por medio de reacción en cadena de la polimerasa

Empleando reacción en cadena de la polimerasa (PCR) se buscaron marcadores moleculares específicos en 75 pacientes consecutivos con leucemia aguda en una sola institución a lo largo de un periodo de cinco años. En leucemia aguda linfoblástica se buscaron BCR/ABL t (9:22), TEL-AML1, t (12:21) y rearreglos clonotípicos de los genes de inmunoglobulinas, en tanto que en leucemia aguda mieloblástica se buscaron PML-RARa t (15:17), AML1-ETO t (8:21) y CBFb-MYH11 (inv16). Se identificaron marcadores moleculares en 15 de 75 casos: cuatro LAL (tres rearreglos de Ig y uno BCR/ABL) y 11 LAM (9 PML/RARa y 2 AML1/ETO). A lo largo de seguimientos de 1 a 60 meses después de haber hecho el diagnóstico, en siete pacientes se eliminó la enfermedad residual evaluada por PCR (ER-PCR) y en ocho persistió. Para pacientes sin o con ER-PCR, la supervivencia (SV) a 30 meses fue de 86 por ciento y 14 por ciento, y la mediana de SV >60 y dos meses, respectivamente (p < 0.01). Seis de los ocho pacientes con ER-PCR fallecieron y en dos se pudo lograr una nueva remisión molecular. Dos de las tres recaídas moleculares pudieron detectarse antes de la recaída hematológica florida. Se concluye que la PCR es útil para vigilar la persistencia de ER en leucemia aguda y en ocasiones, para decidir los tratamientos antileucémicos de rescate, de manera oportuna.

Detection of the presence of soya protein in milk powder by sodium dodecyl sulfate capillary electrophoresis.

Two different commercial kits for sodium dodecyl sulfate capillary electrophoresis (SDS-CE) were evaluated for the detection of the presence of soya protein in milk powder. The results obtained showed that SDS-CE allowed the separation of the basic subunits of glycinin and the alpha and alpha' subunits of beta-conglycinin from the main milk protein peaks. However, a detection limit lower than 10% (w/w) of soya protein in total protein could not be achieved. The use of a tetraborate-EDTA sample treatment minimized interferences from milk proteins, allowing the detection of at least 1% (w/w) of soya protein in total protein. The addition of soya protein hydrolysates could not be determined using SDS-CE.