Clinical Significance of Oligoclonal Bands in Patients with Multiple Myeloma after Autologous Stem Cell Transplantation

BACKGROUND: Oligoclonal bands or isotype switch detectable by serum immunofixation electrophoresis (IFE) has been reported following chemotherapy and stem cell transplantation in patients with multiple myeloma (MM). We studied the significance of oligoclonal bands appearing after chemotherapy and autologous stem cell transplantation (ASCT) in Korean MM patients, and its impact on relapse. And we investigated the serial serum free light chain (FLC) ratio to establish its possible relationship with the relapse of MM. METHODS: We conducted a retrospective analysis of the serial serum IFE and FLC ratio in 16 MM patients treated with chemotherapy and ASCT. RESULTS: Eleven out of 16 patients (68.8%) had oligoclonal bands with or without isotype switch after ASCT and the median interval from transplantation was 2.0 months. And relapse or persistence rate of monoclonal gammopathy was lower in patients with oligoclonal bands (27.3% vs. 60.0%), though without statistical significance (P=0.299). In eight patients who developed oligoclonal bands and did not relapse, the serial serum FLC ratio was normal in range. But one patient who developed oligoclonal bands and showed increase of plasma cells in bone marrow, the serial serum FLC ratio was abnormal in range. CONCLUSIONS: The occurrence of oligoclonal bands after chemotherapy and ASCT in Korean MM patients is not significantly associated with adverse consequence of relapse or persistence of monoclonal gammopathy. Therefore oligoclonal bands may be not bad prognostic criterion. And the measurement of serum FLC ratio may be a useful indicator to predict relapse in MM patients who developed oligoclonal bands.

Type Distribution of Unexpected Red Cell Antibodies in Patients with Malignancy / 대한수혈학회지

BACKGROUND: Performance of antibody screening and identification tests before blood transfusion is important because the unexpected presence of red cell antibodies may cause hemolytic transfusion reactions. Many patients with malignancy undergo transfusion in order to overcome pancytopenia due to disease itself or chemotherapy. We investigated the type distribution of unexpected red cell antibodies in cancer patients and compared our results with those of other institutions. METHODS: From January 2008 to June 2011, 30,989 serum samples were screened using a LISS/Coombs card and ID-DiaCell I, II (DiaMed AG, Morat, Switzerland). Data-Cyte Plus Reagent Red Blood Cells (Medion Diagnostics, Dudingen, Switzerland) were used in performance of antibody identification tests. RESULTS: Out of 30,989 serum samples, 180 cases (0.58%) showed screening-positive results, and unexpected antibodies were identified in 72 cases. The type of unexpected antibody observed most often in cancer patients was a member of the Rh antibody group, anti-E in 17 cases (29.8%), followed by anti-Lea in five cases (8.8%) and anti-e in three cases (5.3%). While Rh group antibodies were observed in the colon cancer group, non-Rh group antibodies were observed in the rectal cancer group. And, in the genitourinary cancer group, Lewis group antibodies were more frequently detected than others. CONCLUSION: Findings from our study demonstrated a type distribution of unexpected red cell antibodies that was similar to those reported in previous studies. Compared with non-cancerous patients, no difference in type distribution of unexpected red cell antibodies was observed in cancer patients. Some antibodies were frequently observed in certain cancer groups. Further comprehensive research on unexpected antibodies based on location or histologic type of cancer is needed.

A Case of a 63-bp Deletion in the mpt64 Gene of Mycobacterium tuberculosis Strains Which Showed False Negativity in the Immunochromatographic Assay / 대한임상미생물학회지

Mycobacterium tuberculosis complex (MTBC) is discriminated from non-tuberculous mycobacteria (NTM) via an immunochromatographic assay (ICA) which is based on the reactions of monoclonal antibodies against MPT64, one of the predominant proteins excreted by MTBC. Recently, the authors of the present study discovered SD TB-negative Mycobacterium tuberculosis strains. In addition, sequence analysis of the mpt64 genes in these strains was performed and showed a deletion of 63 bp from nucleotides 196 to 258. In cases of MPT64-negative mycobacterium, the authors recommend performing TB PCR for correct diagnosis.