The Cytogenetic Abnormalities Of Multiple Myeloma And Their Significance Detecting By Fluorescence In Situ Hybridization

Objective To explore the molecular cytogenetic aberrations and clinical significance of multiple myeloma patients detected by flurorescence in situ hybridization.Method To combine a panel probes of LSI 1q21/RB1,D13S319/P53,IGH and interphase flurorescence in situ hybridization (FISH) were used to detect 33 MM patientes.Meanwhile its results were compared with that of conventional cytogenetic R banding,and the clinical implications of chromosomal abnormalities were investigated.Results(1)From 33 cases of MM patients,conventional cytogenetic can detect 8 cases(26.4%) with abnormalities,while 23 cases(69.6%) can be detected by FISH.1q amplification was detected in 16(48.4%) cases,RB-1 and D13S319 deletions have been detected in 6(18.1%) and 11(33.3%) cases,respectively.IGH rearrangement was detected in 9(27.2%) cases and 17p deletions in 5(15.1%) cases.(2) 33 cases were detected by both R banding and FISH,Compared with conventional cytogenetic,FISH can elevated the detection rate of chromosome aberration and obviously superior to CC,is the valid method to detect chromosome aberration of MM.(3) There is significant correlation between Del(13q14) and Del p53,all the 6 RB-1 Del positive patients also existence of D13S319 Del;all the 5 p53 Del positive patients also showed 13q14 deletion positive.(4)Of the 16 1q21 Amp positive patients,there were 9 cases of IgG type,5 cases of IgA type,2 cases of non-secretory type,11 cases were classified as ISS StageⅢ,5 cases as ISS StageⅡ.All of RB-1 Del were classified as ISS StageⅢ, there were 4 cases of IgG type,1 cases of IgA type,1 cases of non-secretory type.In the of 11 cases D13S319 Del patients, there were 9 cases of IgG type,1 cases of IgA type,1 cases of non-secretory type,9 cases were classified as ISS StageⅢ,2 cases as ISS StageⅡ. All of p53 Del were classified as IgG type, 4 cases were classified as ISS StageⅢ,1 cases as ISS StageⅡ.Of the 9 cases with IGH rearrangement, there were 5 cases of IgG type,3 cases of IgA type,1 cases of non-secretory type,7 cases were classified as ISS StageⅢ.No significant differencen in relationship of the chromosome aberration and type, the chromosome aberration and stage also have not significant differencen in relationship. (5) The plasmacytes in bone andβ2-MG from MM patients with Del(13q14) were higher than those with normal karyotypes. The plasmacytes in bone from MM patients with IGH rearrangement were higher than those with normal karyotypes to.Conclusion Chromosome complex aberration is the mainly cytogenetic characteristics of multiple myeloma,where multiple numerical or structural aberrations are involved. RB-1 Del and D13S319 Del often co-exist in the same patients.There is significant correlation between Del(13q14) and Del p53.On the basis of data diplay:the 13q14 Del and p53 Del positive patients were all ISS stageⅢ,indicating that the two chromosome aberrations were associated with poor prognosis in patients with MM.The sample size was too small to perform a meaningful statistical test.To verify this hypothesis, an expanded sample size was required.Both conventional cytogenetic analysis and FISH are suggested for patients at diagnosis and during the disease progression so as to evaluate the prognosis.The patients with chromosome complex aberration may have poor prognosis,especially those with Del13q14 and Del p53.