[Detection of bone marrow involvement by lymphoma cells in patients with B-NHL by using flow cytometry analysis]

This study was purposed to investigate the significance of using (FCM) flow cytometry for detection bone marrow involvement by lymphoma cells in untreated patients with B cell non-Hodgkin's lymphoma (B-NHL). Bone marrow samples of 54 patients with B-NHL were analyzed by flow cytometry, morphological method and molecular biology technique. Bone marrow involvement was diagnosed based on the results of morphology, FCM and molecular biology. The results indicated that the positive ratios of bone marrow involvement were different detected by three methods, the most sensitive method was FCM (positive rate was 27.5%), the moderately sensitive method was molecular biology (positive rate was 22.2%), the inferior method was morphology method (positive rate was 5.6%). Combined with three methods, the positive rate increased to 38.9%. The monoclonal B lymphocytes were detected by FCM in fourteen patients, the ratios of kappa light chain/lambda light chain were far beyond the diagnostic threshold. Even in patients with early stage, lymphoma cells still could be detected by FCM in involved bone marrow. Monoclonal B lymphocytes were detected by FCM in three patients who were diagnosed bone marrow involvement by morphological method. The concordance between FCM and molecular biology was relatively high (70.4%, p=0.14). It is concluded that the detection of monoclonal B lymphocytes by using FCM has high sensitivity and accuracy in patients with B-NHL. Evaluation whether the bone marrow has been involved by lymphoma cells should be recommend to every patient with B-NHL before chemotherapy and every disease stages. Combined application of FCM and molecular biology method would enhance diagnostic efficacy.