RESUMO
To evaluate the significance of bone marrow (BM) and peripheral blood (PB) cells with clonal gene rearrangement of the third complementary determining region of immunoglobulin heavy chain (IgHCDR3) in the diagnosis, clinical staging, determination of treatment effects and prediction of relapse in B-NHL, clonal IgH gene rearrangement of BM from 46 and PB from 38 cases with B-NHL were tested by semi-nested polymerase chain reaction (SnPCR) and polyacrylamide gel electrophoresis before treatment, and ten of them were tested in complete remission after treatment. Results showed that this method was applicable to detecting one clonal IgHCDR3 gene rearrangement positive cell from up to 1 000 normal cells. Specificity of detection was 97%. Clonal IgHCDR3 rearrangement was shown in all 3 cases of BM and 2 of PB specimens with morphologic involvement. The clonal IgHCDR3 was detected in 65.1% of the BM and 44.4% of the PB without morphologic involvement in untreated patients with B-NHL, independent of Ann Arbor staging and systemic symptoms. In 10 cases of B-NHL with clonal IgHCDR3 rearrangement in diagnostic tissues, the molecular marker became negative in 7 patients who entered and remained in complete remission. Two cases relapsed in whom clonal IgHCDR3 rearrangements were detected in serial samples of BM or PB after autologous PBSCT. One patient in whom clonal IgHCDR3 rearrangement was detected at 10 months post-PBSCT remained in complete remission up to now. It was concluded that clonal IgHCDR3 gene rearrangements were found in BM and PB from B-NHL patients without morphologic abnormality. Persistence of molecular marker-positive may be associated with relapse for patients in complete remission, and the patients without clonal IgHCDR3 rearrangement will be in continuous complete remission. Little is known about a few patient who was a long-term disease-free survivor despite the presence of PCR-IgH rearrangement in the marrow.