Prognostic significance of bi/oligoclonality in childhood acute lymphoblastic leukemia as determined by polymerase chain reaction

CONTEXT: The CDR-3 region of heavy-chain immunoglobulin has been used as a clonal marker in the study of minimal residual disease in children with acute lymphoblastic leukemia. Southern blot and polymerase chain reaction studies have demonstrated the occurrence of bi/oligoclonality in a variable number of cases of B-lineage acute lymphoblastic leukemia, a fact that may strongly interfere with the detection of minimal residual disease. Oligoclonality has also been associated with a poorer prognosis and a higher chance of relapse. OBJECTIVES: To correlate bi/oligoclonality, detected by polymerase chain reaction in Brazilian children with B-lineage acute lymphoblastic leukemia with a chance of relapse, with immunophenotype, risk group, and disease-free survival. DESIGN: Prospective study of patientsÆ outcome. SETTING: Pediatric Oncology Unit of the University Hospital, Faculty of Medicine of Ribeiräo Preto, University of Säo Paulo. PARTICIPANTS: 47 children with acute lymphoblastic leukemia DIAGNOSTIC TEST: Polymerase chain reaction using consensus primers for the CDR-3 region of heavy chain immunoglobulin (FR3A, LJH and VLJH) for the detection of clonality. RESULTS: Bi/oligoclonality was detected in 15 patients (31.9 percent). There was no significant difference between the groups with monoclonality and biclonality in terms of the occurrence of a relapse (28.1 percent versus 26.1 percent), presence of CALLA+ (81.2 percent versus 80 percent) or risk group (62.5 percent versus 60 percent). Disease-free survival was similar in both groups, with no significant difference (p: 0.7695). CONCLUSIONS: We conclude that bi/oligoclonality was not associated with the factors investigated in the present study and that its detection in 31.9 percent of the patients may be important for the study and monitoring of minimal residual disease

Analysis of the p53 gene by PCR-SSCP in ten cases of WilmsÆ tumor

CONTEXT: Mutations of the p53 tumor suppressor gene are the most frequent alterations observed in human neoplasias affecting adults. In pediatric oncology, however, they have seldom been identified. WilmsÆ tumor is a renal neoplasia commonly occurring in children and is associated with mutations of the WT1 gene. The correlation between WilmsÆ tumor and alterations of the p53 gene has not been well established, with a low frequency of mutations having been reported in this type of tumor. Mutation may be associated with advanced stage disease and unfavorable histology. OBJECTIVE: To screen for mutations of the p53 gene by the PCR-SSCP method and DNA sequencing in cases of WilmsÆ tumor sug-gestive of mutation. DESIGN: Case Report. CASE REPORT: Evaluations of exons 5-9 of the p53 gene in DNA samples extracted by PCR-SSCP from 10 WilmsÆ tumors in children at different stages, and DNA sequencing. Changes in SSCP analy-sis were observed in exon 8 in two samples. The probable muta-tions were not confirmed by DNA sequencing. The absence of point mutations in p53 gene observed in the 10 samples of WilmsÆ tumor studied agrees with literature data, with DNA sequencing being of fundamental importance for the confirmation of possible mutations

Estudo citogenético de leucemia näo-linfóide aguda da infância: análise de doze casos / Cytogenetic study of acute nonlymphoid childhood leukemia. Analysis of 12 cases

Os autores analisam citigeneticamente doze caos de leucemia näo-linfóide aguda da infância (LNLA), objetivando estabelecer correlaçöes entre alteraçöes cromossômicas, evoluçäo e progressäo da doença. 91,66 por cento dos casos exibiam anomalias. Dois pacientes com classificaçäo FAB M1 e M2 apresentaram translocaçäo t(8;21), associada à monossomia do X e à trissomia desse cromossomo, mais alteraçäo do 7, respectivamente. Ambos faleceram, o primeiro após transplante de medula óssea com recidiva da doença e o segundo com septicemia, confirmando o caráter agerssivo dessa translocaçäo quando associada a outras alteraçöes cromossômicas. Em um dos casos a presença de alteraçöes cromossômicas complexas foi fundamental p[ara a confirmaçäo diagnóstica de eritroleucemia. Cinco pacientes exibiram alteraçöes cromossômicas primárias e seis do tipo secundário. No grupo com alteraçöes primárias se encontram os três pacientes vivos livres da doença. No grupo com alteraçöes secundárias, todos foram a óbito, dois por recidiva, dois por resistência à doença e dois por septicemia, após entrar em remissäo...