Korean Journal of Laboratory Medicine最新文献

Levels of soluble interleukin-2 receptor alpha (sIL-2Rα) are known to increase in the sera of patients with certain malignancies, including malignant lymphoma. This study aimed to assess the clinical significance of the sIL-2Rα level in non-Hodgkin's lymphoma (NHL). We used ELISA to measure the sIL-2Rα levels in 48 newly diagnosed and untreated patients with NHL and evaluated the correlation between the sIL-2Rα levels and clinical characteristics and the International Prognostic Index (IPI). We monitored serum sIL-2Rα in 7 patients to compare the changes in their clinical progress with these levels. High levels of serum sIL-2Rα (≥ 2,000 U/mL) correlated well with parameters defining the high risk group according to the IPI, i.e., high tumor burden at diagnosis (stage III+IV) and lactate dehydrogenase ≥ 472 U/L. The levels were also associated with B symptoms, bone marrow involvement, and poor response to therapy. The sIL-2Rα level decreased during complete remission and was elevated during disease progression or relapse. A high level of sIL-2Rα was significantly associated with a low survival rate. These results suggest that serum sIL-2Rα might be useful as a biomarker for evaluating the prognosis of patients with NHL at the time of diagnosis and during therapy. A well-controlled, large-scale study is needed to clarify the clinical significance of sIL-2Rα in specific groups of NHL.

Background: We evaluated the clinical significance of revised 2008 WHO classification needed to diagnose mixed phenotype acute leukemia (MPAL).

Methods: A total of 22 MPAL patients, previously diagnosed by applying the scoring system of the European Group for Immunological Classification of Acute Leukemias (EGIL) were reclassified based on the 2008 WHO classification.

Results: In 2008 WHO classification, the number of monoclonal antibodies (mAbs) required for assigning more than one lineage was markedly decreased, from 26 to 11, compared with that of EGIL. Seventeen of the 22 MPAL patients were reclassified as MPAL with following details: 6 MPAL with t(9;22)(q34;q11.2); BCR-ABL1, 1 MPAL with t(v;11q23); MLL rearranged, 7 MPAL, B/Myeloid, not otherwise specified (NOS) and 3 MPAL, T/Myeloid, NOS. Five patients were excluded from MPAL in the revised classification: 4 cytoplasmic myeloperoxidase (cMPO)-negative and 1 CD19-negative. The failure of complete remission achievement and occurrence of relapse were associated with poor prognosis (P=0.0002 and P=0.009, respectively). But the presence of Philadelphia chromosome was not significantly related with patient outcome (P=0.082). One patient with cCD79a, CD20, CD38, cMPO and CD15, whose diagnosis was reclassified from MPAL to AML has survived during the study period.

Conclusions: Because of decreased number of mAbs needed, it is possible that acute leukemia panel is designed to include all mAbs required to diagnose MPAL according to 2008 WHO classification. When diagnosing MPAL, it is critical to figure out positivity in either cMPO or CD19, and AML expressing more than 2 lymphoid antigens are considered as MPAL.

Background: Late-onset neutropenia (LON) following rituximab therapy has been reported in recent years. However, its incidence has not been reported in Korea. The aim of this study is to investigate the incidence of LON after rituximab therapy in Korean patients with diffuse large B-cell lymphoma (DLBCL).

Methods: Ninety-eight cases of DLBCL treated with rituximab between 2004 and 2008 were evaluated. We identified LON as defined by the neutrophil count of <1.5 × 10(9)/L without apparent cause after the recovery of neutrophil count following rituximab therapy. Bone marrow aspiration and biopsy specimens at the time of neutropenia were available for retrospective review in only 5 of the patients.

Results: LON was observed in 15 (15.3%) of the 98 patients. In the bone marrow specimens of the 5 patients, promyelocytes were relatively increased and the maturation index of the granulopoiesis was 2:1-3:1, which reflects maturation arrest.

Conclusions: The incidence of LON following rituximab therapy was 15.3% in Korean patients with DLBCL. Although there are several hypotheses about the causative mechanisms of LON, we suggest that maturation arrest at the promyelocyte stage of granulopoiesis may be one of the mechanisms involved in the development of LON.

Background: It has been demonstrated that flow cytometric detection of minimal residual disease (MRD) has a prognostic significance in the treatment of patients with acute leukemia. We investigated the significance of flow cytometric MRD detection for the first time in Korea.

Methods: We analyzed the results of MRD detection in morphologically complete remission bone marrow aspirates from 89 patients with newly-diagnosed or relapsed acute leukemia, in which leukemic cells had cross-lineage antigen expression. Patients were grouped based on MRD frequencies: ≥ 1.0%, high MRD; <1.0%, low MRD.

Results: Forty-seven ALL patients consisted of 10 with high and 37 with low MRD levels. Patients with high MRD levels showed a tendency of more frequent relapse than those with low MRD levels (40.0% and 13.5%, respectively) (P=0.08). High MRD group showed a tendency of short relapse-free survival (RFS) and overall survival (OS), although the differences were not statistically significant. Forty-two AML patients consisted of 16 with high and 26 with low MRD levels. There were no correlations between the MRD levels and relapse rate, RFS or OS. AML patients with high MRD levels showed significantly higher rate of unfavorable cytogenetic risk categories and lower rate of favorable risk categories (P=0.03).

Conclusions: MRD detection by flow cytometric assay of cross-lineage antigen expression would be useful in predicting treatment outcome in patients with ALL rather than AML. We expect that the establishment of the standardization of methods, time to test or antibody combination would be achieved through further trials in this country.

Background: Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is associated with Helicobacter pylori infection and H. pylori eradication is used as its first-line therapy. However, controversies exist about the prognostic value of H. pylori infection in these patients. We evaluated the prognostic impact of H. pylori infection and eradication therapy in gastric MALT lymphoma.

Methods: A total of 292 patients diagnosed with MALT lymphoma since 2000 were analysed. MALT lymphoma was diagnosed with tissue biopsy and H. pylori infection was diagnosed with hematoxylin-eosin and additional Warthin-Starry stains on tissue sections. Clinical variables such as bone marrow (BM) involvement, multiorgan involvement, tumor stage at diagnosis, and remission were obtained with retrospective review of electronic medical records.

Results: Non-gastric MALT lymphoma patients showed higher multiorgan involvement rates (26.6% vs. 9.6%, P<0.001) and higher proportion of stage ≥ 3 (27.7% vs. 16.7%, P=0.029) than gastric cases. Regarding gastric MALT lymphoma, patients with H. pylori infection at diagnosis showed significantly less BM (2.1% vs. 21.8%, P<0.001) and multiorgan involvement rates (6.3% vs. 18.2%, P=0.011) than those without infection. But there was no significant difference in remission rates between them. In contrast, those with successful H. pylori eradication therapy showed significantly higher remission rates (81.0% vs. 30.8%, P<0.001) than those with failure.

Conclusions: Non-gastric MALT lymphoma patients showed worse prognosis compared to gastric cases. As for remission rates in patients with gastric MALT lymphoma, successful H. pylori eradication therapy could be a good prognostic factor even if H. pylori infection was present at diagnosis.

Background: Epstein-Barr virus (EBV) is a well-known causative agent of various diseases including post-transplant lymphoproliferative disorders. Although the level of EBV viral load in donors is expected to have a direct effect on recipients after hematopoietic stem cell transplantation (HSCT), little has been studied providing a clear evidence for that. We performed EBV DNA quantitation in donors and analyzed the effect of donors' EBV viral load on the recipients after HSCT.

Methods: EBV DNA quantitation of peripheral blood in 94 healthy HSCT donors was performed by real-time PCR. We analyzed the distribution of EBV viral load in HSCT donors and EBV positivity in the recipients transplanted from donors who had detectable EBV.

Results: Fifteen HSCT donors (16%) showed positive results in EBV real-time quantitative PCR. EBV viral load was below 500 copies/mL in 5 donors and above 500 (680-11,300) copies/mL in 10 donors. Five of the recipients (33.3%) transplanted from these 15 donors showed positivity in EBV PCR after HSCT. All of the EBV PCR positive recipients were transplanted from donors with viral load of >1,000 copies/mL, and 5 (71%) of 7 donors with viral load of >1,000 copies/mL was associated with posttransplant EBV PCR positivity in the recipients.

Conclusions: Higher levels of EBV viral load in donors appear to be associated with EBV transmission to recipients in HSCT. EBV real-time quantitative PCR may be needed for screening EBV DNA level in HSCT donors.

A variant Philadelphia chromosome (Ph) is generated from translocation of one or more partner chromosomes in addition to chromosomes 9 and 22. We have described the cases of 2 patients bearing variant Ph detected by interphase FISH but not detected by G-banded karyotyping and metaphase FISH. FISH was performed using BCR/ABL dual color dual fusion translocation probes (Abbott Molecular, USA). A 52-year-old man was diagnosed with acute leukemia of mixed phenotype. G-banded karyotyping showed 46,XY,t(9;22)(q34;q11.2)[12]/47,idem,+der(22)t(9;22)[5]/46,XY[3]. Interphase FISH revealed nuc ish(ABL1,BCR) × 3(ABL1 con BCR × 2)[329/450]/(ABL1,BCR) × 4(ABL1 con BCR × 3)[5/450]/(AL1,BCR) × 3(ABL1 con BCR × 1)[44/450]. Metaphase FISH showed ish (9;22)(ABL1+,BCR1+;BCR+,ABL+)[22]/der(22)(BCR+,ABL1+)[3]. The other case was that of a 31-yr-old male patient diagnosed with CML in the blastic phase. G-banded karyotyping of all 20 metaphase cells showed 47,XYYc,dup(1)(q21q32),del(7)(p11.2),t(9;22)(q34;q11.2). Interphase FISH revealed nuc ish(ABL1,BCR) × 3(ABL1 con BCR × 2)[254/600]/(ABL1,BCR) × 3(ABL1 con BCR × 1)[191/600]. Metaphase FISH showed ish t(9;22)(ABL1+,BCR+;BCR+,ABL1+)[16]. These results suggest that typical t(9;22) and variant Ph may coexist in the same patient, and interphase FISH may facilitate the detection of the variant Ph that cannot be detected by G-banded karyotyping alone.

Background: One of the major concerns with biobanking is the absence of standard operating procedures to eliminate pre-analytical variation arising from sample collection, preparation, and storage. Currently, there is a lack of tools to carry out quality control procedures for stored blood samples. The aim of this study is to assess the quality of stored blood samples in our biobank and to suggest appropriate indicators for their quality control.

Methods: The stored blood samples that we tested have been registered into our biobank since 2003. These were transferred to our biobank after carrying out routine requested tests, because the samples would have otherwise been discarded. For the purpose of quality control, we analyzed the concentrations and the integrity of DNA and RNA extracted from the stored samples and tested the levels of several serum proteins; the results were compared with the corresponding pre-storage levels.

Results: A total of 19 samples were stored from 2006 to 2009. Of the 22 samples stored between 2003 and 2005, 50% showed complete DNA integrity. However, sufficient RNA integrity was noted in only 1 sample stored as recently as 2009. High blood urea nitrogen levels were also noted in the stored sera, but the increase did not correlate to the duration of storage.

Conclusions: The amount and integrity of nucleic acids extracted from stored blood samples are potential indicators that can be used for quality control. A guideline for the quality assessment of stored blood samples in a biobank is urgently needed.

Background: In unrelated hematopoietic stem cell transplantation, the accuracy of HLA registry typing (RT) of donors is important for timely search and coordination of HLA-matched donors. We analyzed discrepancies between HLA RT and confirmatory typing (CT) results of stem cell donors in Korean and foreign registries.

Methods: We analyzed the HLA typing results of 834 donors for whom CT was performed at Seoul National University Hospital between April 1997 and March 2010. For CT, DNA typing was used in majority of the cases and HLA-A and HLA-B serological typing was used in some early cases. The discrepancies between the typing results were analyzed at the serological/generic level.

Results: The overall discrepancy rate (RT error rate) was 3.2%, and the rate was similar in the Korean and foreign registries. The discrepancy rates in the Korean and foreign registries were more than 10% in the 1997-2001 searches, but decreased to less than 3% in the 2002-2010 searches. Analysis of 19 cases of RT errors in the Korean registry revealed 3 cases of sample switchover errors and 16 cases of typing errors in one of the HLA-A, HLA-B, or HLA-DR loci. The RT error rate in Japan Marrow Donor Program was lower than those in other foreign registries.

Conclusions: The error rate of HLA RT results of unrelated stem cell donors in the Korean registry was similar to those in the foreign registries, and has decreased in the recent searches following the change in the typing method from serological to DNA typing.

Crystal-storing histiocytosis (CSH) is a rare event observed in association with lymphoproliferative diseases, and mainly occur in plasma cell dyscrasias. It is presumed to be an intra-lysosomal accumulation of the secreted paraproteins. Crystal formation can be seen inside histiocyte-like cells with phagocytosed crystalline inclusions in the bone marrow and extramedullary sites. CSH is a rare morphological entity with poor prognostic implications and may be confused with Gaucher or pseudo-Gaucher cells. Herein we report a case of non-secretory myeloma associated with CSH showing a poor clinical course. A 79-yr-old male presenting with dizziness was evaluated in hematology department for anemia. Laboratory tests revealed Hb of 4.9 g/dL and β2-microglobulin of 21,000 ng/mL (reference range, 0-370). Presence of monoclonal protein was not detected on protein electrophoresis and immunofixation in serum and urine. However, serum free light chain assay showed an increased kappa-light chain level of 126 mg/L (reference range, 3.3-19.4) resulting in an increased kappa/lambda ratio. The bone marrow touch print showed numerous plasma cells and crystal-laden histiocytes and immunohistochemical stainings on bone marrow biopsy revealed positivity for CD38, CD56 and kappa in the plasma cells and CD68 and kappa in crystal-laden histiocytes.