Performance of Xpert Carba-R Assay for Identification of Carbapenemase Gene in the Clinical Microbiology Laboratory / 이화의대지

Objectives@#The Xpert Carba-R Assay is a diagnostic test designed for the rapid detectionand differentiation of the blaKPC, blaNDM, blaVIM, blaOXA-48, and blaIMP-1 genes. We verifiedthe performance of Xpert Carba-R Assay for identification of carbapenemase genein the clinical microbiology laboratory. @*Methods@#The analytical limit of detection was determined with two suspensions ofcarbapenemase-producing Enterobacteriaceae (CPE) isolates (KPC and NDM). A totalof 52 specimens were evaluated: 21 bacterial isolates from clinical specimens, 21 rectalswabs, and 10 contrived stool specimens. @*Results@#In bacterial isolates, concordant results between the Xpert Carba-R Assayand PCR were found in 20 of 21; 8 KPC, 8 NDM, 1 IMP, and 2 multiple carbapenamasegenes (KPC/NDM, NDM/OXA) were detected both by Xpert Carba-R Assay and PCR.In one GES-positive isolate, Xpert Carba-R Assay showed a negative result as expected.One VIM-positive isolate tested negative by Xpert Carba-R Assay. Complete concordancewas seen in rectal swab specimens: 4 specimens with KPC and 17 specimenswith negative results both by Xpert Carba-R Assay and surveillance culture. Among the10 contrived stool specimens, Xpert Carba-R Assay detected carbapenemase genes in9 specimens as expected according to the CPE strains spiked into the contrived stool; 2KPC, 4 NDM, 1 IMP, and 2 multiple carabapenamase genes (NDM/KPC, NDM/OXA).One VIM-positive specimen tested negative by Xpert Carba-R Assay. @*Conclusion@#In conclusion, the Xpert Carba-R Assay can be used to identify carbapenemasegene in bacterial isolates cultured from clinical specimens and detect CPE carrierusing rectal swab in clinical laboratories.

Clinicopathological Characteristics of Hyperdiploidy with High-Risk Cytogenetics in Multiple Myeloma

In multiple myeloma (MM), hyperdiploidy (HD) is known to impart longer overall survival. However, it is unclear whether coexistent HD ameliorates the adverse effects of known high-risk cytogenetics in MM patients. To address this issue, we investigated the clinicopathological characteristics of HD with high-risk cytogenetics in MM. Ninety-seven patients with MM were included in the study. For metaphase cytogenetics (MC), unstimulated cells from bone marrow aspirates were cultured for either 24 or 48 hours. To detect HD by interphase fluorescence in situ hybridization (iFISH), we assessed trisomies of chromosomes 5, 7, 9, 11, 15, and 17. Of the 97 MM patients, 40 showed HD. The frequency of co-occurrence of HD and high-risk cytogenetics was 14% (14/97). When the clinicopathological characteristics were compared between the two groups of HD with high-risk cytogenetics vs. non-HD (NHD) with high-risk cytogenetics, the level of beta 2 microglobulin and stage distribution significantly differed (P=0.020, P=0.032, respectively). This study shows that some of the clinicopathological characteristics of MM patients with high-risk cytogenetics differ according to HD or NHD status.

GATA1 Expression in BCR/ABL1-negative Myeloproliferative Neoplasms

BACKGROUND: This study aimed to determine GATA1 expression levels to better characterize subgroups in BCR/ABL1-negative myeloproliferative neoplasms (MPNs). METHODS: This study enrolled 49 patients diagnosed as having BCR/ABL1-negative MPN on the basis of the 2016 World Health Organization classification : nine polycythemia vera (PV), 17 essential thrombocythemia (ET), 12 prefibrotic primary myelofibrosis (prePMF), and 11 overt primary myelofibrosis (PMF). Relevant clinical and laboratory data were retrieved from the medical records. The molecular analysis of CALR and MPL mutations and quantification of JAK2 V617F allele burden were performed. GATA1 expression was assessed by an immunohistochemical assay on bone marrow biopsy. GATA1 expression was analyzed serially in 18 patients. RESULTS: GATA1 expression decreased significantly in PMF compared with that in other subtypes, while no statistical difference was identified between ET and prePMF. GATA1 expression did not differ according to the mutation profiles or the allele burden of JAK2 V617F, but it decreased significantly in patients with overt fibrosis or leukemic transformation. CONCLUSIONS: Our results suggest that GATA1 expression is significantly low in PMF and decreases with progressive fibrosis and possibly with leukemic transformation, although our attempt to accurately distinguish between subgroups using GATA1 immunohistochemical approach did not achieve statistical significance. A large patient cohort with long term follow-up is required to evaluate the prognostic value of GATA1 expression.

Therapeutic Plasma Exchange for a Patient with Severe Cold Agglutinin Disease / 대한수혈학회지

Cold agglutinin disease is a kind of autoimmune hemolytic anemia, caused by cold agglutinin, serum autoantibodies activated at reduced body temperatures to produce red blood cell agglutination and hemolysis. In this paper we described a case of severe hemolytic anemia in a cold agglutinin disease patient treated with therapeutic plasma exchange. Therapeutic plasma exchanges were performed four times every other day. Over the same period, a total of 8 units of washed red blood cells were transfused. Then hemoglobin was increased from 4.0 g/dL to 7.8 g/dL. On the 12th hospital day hemoglobin level was decreased again to 4.2 g/dL and fludarabine chemotherapy was started on the 14th hospital day. The patient's symptoms were relieved and she was discharged on the 30th hospital day. As in this case, therapeutic plasma exchange could be considered as secondary therapy for temporary improvement of acute severe hemolytic anemia in cold agglutinin disease.

Systemic Epstein-Barr Virus-Positive T-cell Lymphoproliferative Disease of Childhood Presenting as Hemophagocytic Lymphohistiocytosis with Chromosomal Abnormalities / 임상검사와정도관리

Epstein-Barr virus (EBV)-positive T-cell lymphoproliferative disease (EBV+ T-cell LPD) is characterized by a clonal proliferation of T-cells, which may trigger hemophagocytic lymphohistiocytosis (HLH). Chromosomal abnormalities in patients with HLH are usually found in association with underlying malignancies. We report here a case of systemic EBV+ T-cell LPD of childhood initially presenting with HLH. A 19-year-old man was admitted to the hospital with a 2-week history of fever. Laboratory data revealed pancytopenia, hypertriglyceridemia, high ferritin levels, and abnormalities in liver function tests. EBV infection was confirmed by serologic tests and real-time polymerase chain reaction. Examination of the bone marrow showed histiocytic hyperplasia and hemophagocytosis. Further investigation revealed atypical lymphoid cells expressing EBV-encoded RNA, CD3, CD4, and CD8. A chromosomal analysis displayed a complex karyotype. Despite intensive treatment, the patient died 15 days after initial presentation. In conclusion, systemic EBV+ T-cell LPD of childhood presenting with HLH and chromosomal abnormalities may progress rapidly and be fatal. Therefore, a diagnostic workup for chromosomal aberration is essential.

Inflammatory myofibroblastic tumor in colon / 대한외과학회지

Inflammatory myofibroblastic tumor (IMT) is an uncommon mesenchymal solid tumor commonly documented in children and young adults. Here, we report a case of IMT in colon confirmed pathologically after laparoscopic anterior resection. A 35-year-old man presented with anal bleeding after defecation for 2 weeks. Colonoscopy demonstrated a mass with shallow ulceration in the central area and irregular margin accompanied by intact mucosa in the descending colon. Computer tomography showed a well-demarcated and homogenous solitary mass in the descending colon. We performed laparoscopic anterior resection. This case was diagnosed as IMT after microscopic examination. The tumor was composed of a proliferation of spindle-shaped cells arranged in the hyaline material with chronic inflammatory cells, composed mainly of plasma cells and lymphocytes. Immunohistochemically, tumor cells were positive for smooth muscle actin, and vimentin, and negative for desmin, CD117 (c-kit), anaplastic lymphoma kinase-1.