Clinical Implications of Quantitative JAK2 V617F Analysis using Droplet Digital PCR in Myeloproliferative Neoplasms

BACKGROUND: JAK2 V617F is the most common mutation in myeloproliferative neoplasms (MPNs) and is a major diagnostic criterion. Mutation quantification is useful for classifying patients with MPN into subgroups and for prognostic prediction. Droplet digital PCR (ddPCR) can provide accurate and reproducible quantitative analysis of DNA. This study was designed to verify the correlation of ddPCR with pyrosequencing results in the diagnosis of MPN and to investigate clinical implications of the mutational burden. METHODS: Peripheral blood or bone marrow samples were obtained from 56 patients newly diagnosed with MPN or previously diagnosed with MPN but not yet indicated for JAK2 inhibitor treatment between 2012 and 2016. The JAK2 V617F mutation was detected by pyrosequencing as a diagnostic work-up. The same samples were used for ddPCR to determine the correlation between assays and establish a detection sensitivity cut-off. Clinical and hematologic aspects were reviewed. RESULTS: Forty-two (75%) and 46 (82.1%) patients were positive for JAK2 V617F by pyrosequencing and ddPCR, respectively. The mean mutated allele frequency at diagnosis was 37.5±30.1% and was 40.7±31.2% with ddPCR, representing a strong correlation (r=0.9712, P < 0.001). Follow-up samples were available for 12 patients, including eight that were JAK2 V617F-positive. Of these, mutational burden reduction after treatment was observed in six patients (75%), consistent with trends of hematologic improvement. CONCLUSIONS: Quantitative analysis of the JAK2 V617F mutation using ddPCR was highly correlated with pyrosequencing data and may reflect the clinical response to treatment.

Chromothripsis in Treatment Resistance in Multiple Myeloma

Multiple myeloma (MM) is a malignant disease caused by an abnormal proliferation of plasma cells, of which the prognostic factors include chromosomal abnormality, β-2 microglobulin, and albumin. Recently, the term chromothripsis has emerged, which is the massive but highly localized chromosomal rearrangement in response to a one-step catastrophic event. Many studies have shown an association of chromothripsis with the prognosis in several cancers; however, few studies have investigated it in MM. Here, we studied the association between chromothripsis-like patterns and treatment resistance or prognosis. First, we analyzed nine MM cell lines (U266, MM.1S, RPMI8226, KMS-11, KMS-12-BM, KMS-12-PE, KMS-28-BM, KMS-28-PE, and NCI-H929) and bone marrow samples of four patients who were diagnosed with MM by next-generation sequencing-based copy number variation analysis. The frequency of the chromothripsis-like pattern was observed in seven cell lines. We analyzed the treatment-induced chromothripsis-like patterns in KMS-12-BM and KMS-12-PE cells. As a result, breakpoints and chromothripsis-like patterns were increased after drug treatment in the relatively resistant KMS-12-BM. We further analyzed the patients’ results according to the therapeutic response, which was divided into sensitive and resistant, as suggested by the International Myeloma Working Group. The chromothripsis-like pattern was more frequently observed in the resistant group. In the sensitive group, the frequency of the chromothripsis-like pattern decreased after treatment, whereas the resistant group showed increased chromothripsis-like patterns after the treatment. These results suggest that the chromothripsis-like pattern is associated with treatment response in MM.

Preparation of Quality Control Slides and Establishment of an External Quality Assessment Program for Five Special Stains Routinely Used in Diagnostic Hematology

BACKGROUND: In general, internal/external quality control of special stains for diagnosis of hematological diseases may be unavailable in a clinical laboratory owing to the lack of an appropriate positive/negative control material. METHODS: We developed a protocol on positive/negative control materials for five special stains (iron, myeloperoxidase [MPO], periodic acid-Schiff [PAS], Sudan black B [SBB], and alpha-naphthyl acetate esterase [ANAE]) using a hematological malignant cell line. First, we compared stainability of seven cell lines (HL-60, THP-1, K562, Kasumi-1, KG-1, KO52, and NKM-1), then confirmed duration of stable stainability. A proficiency test using external quality control materials was conducted at eleven institutions, which participated voluntarily. RESULTS: HL-60 and THP-1 cell lines, which showed good stainability among the seven cancer cell lines, were selected as external quality control materials. The stainability of a prepared cell line fixed on control slides was stable for 3–4 weeks (MPO, SBB, and PAS) or 9–10 weeks (ANAE). The stainability of paraffin-embedded control material for iron stain was stable for 3 months. The results from 11 institutions were the same on iron, MPO, SBB, and ANAE. Nevertheless, two of 10 institutes showed discrepant results on PAS. CONCLUSIONS: In this study, we demonstrated that cell lines could serve as a standard quality control material for special stains. Most institutions showed representative results on special stains except for PAS. This protocol for special stain may be useful as an external or internal quality control in a haematology laboratory.

A Questionnaire Survey of Quality Control of Flow Cytometry in Korea and Development of New Quality-Control Materials

BACKGROUND: There are few commercial quality-control (QC) materials for internal QC of flow cytometric analysis, especially for leukemia/lymphoma immunophenotyping. The purpose of this study was to investigate the current QC status of flow cytometry in Korea through a questionnaire survey, and develop new QC materials using cultured cell lines for markers which QC materials are unavailable. METHODS: The current state of internal QC of flow cytometry in Korea was investigated via a questionnaire survey. Cell lines to be used as QC materials were cultured and produced as QC materials. Cell viability and the expression of markers on the cultured cell lines were tested by flow cytometry to confirm the stability of the QC materials. Simulated quality assessment results for the cultured cell line QC materials were sent to laboratories for external proficiency testing (PT). RESULTS: Seventeen medical institutions completed the questionnaire survey. Hematopoietic stem cell count (CD34) and lymphocyte subset panel items in most of these institutions were managed using commercialized QC materials. The markers that could not be managed by QC materials were CD117, MPO (myeloperoxidase), TdT (terminal deoxynucleotidyl transferase), CD20, CD10, CD64, CD79α, FMC7, cytoCD22, CD23, CD34, and CD61. Five cell lines expressing these markers were selected and sent as QC materials. PT results for most of the markers were in concordance, except those for FMC7 and CD64. CONCLUSIONS: For the QC control of flow cytometry without commercialized QC materials, cultured cell lines are useful and can be used as an alternative for management of reagents used in flow cytometric analysis.

A Case of Bilateral Renal Cortical Necrosis Associated with Acute Pancreatitis / 대한신장학회잡지

Bilateral cortical necrosis accounts for up to 2% of cases of acute renal failure. More than half of cases of bilateral renal cortical necrosis occure in association with pregnancy complicated by antipartum or postpartum hemorrhage. Other causes including severe bacterial infections, hemolytic uremic syndrome, trauma, postoperative shock, burns, Acute pancreatitis, diabetic ketoacidosis, snake venoms, and phosphorus poisoning. A 53-year-old woman presented with acute pancreatitis and acute renal failure. Diffuse bilateral renal cortical necrosis was diagnosed by renal biopsy and computed tomography. The patient recovered from the attack of pancreatitis but remained anuric. Then, we report this case of acute renal cortical necrosis associated with acute pancreatitis.

A Case of Bilateral Renal Cortical Necrosis Associated with Acute Pancreatitis / 대한신장학회잡지

Bilateral cortical necrosis accounts for up to 2% of cases of acute renal failure. More than half of cases of bilateral renal cortical necrosis occure in association with pregnancy complicated by antipartum or postpartum hemorrhage. Other causes including severe bacterial infections, hemolytic uremic syndrome, trauma, postoperative shock, burns, Acute pancreatitis, diabetic ketoacidosis, snake venoms, and phosphorus poisoning. A 53-year-old woman presented with acute pancreatitis and acute renal failure. Diffuse bilateral renal cortical necrosis was diagnosed by renal biopsy and computed tomography. The patient recovered from the attack of pancreatitis but remained anuric. Then, we report this case of acute renal cortical necrosis associated with acute pancreatitis.

A comparative study on aberrations of chromosome 17 and proliferating cell fraction in lung cancer

To better understand the relationship between specific chromosome changes found in human lung tumors and their phenotypic consequences a the tissue level, an in situ hybridization (ISH) procedure of chromosome 17 and immunohistochemistry of proliferating cell nuclear antigen (PCNA) were done. The deparaffinized sections were stained with pericentromeric probes for chromosome 17 and an immunohistochemical study of a monoclonal antibody against PCNA were performed. The numbers of chromosome signals were than compared with the positivity of PCNA expression. The mean numbers of chromosome were 1.62 in normal lymphocytes and 2.48 in lung cancer cells. Tumors showed a high mean positivity of PCNA of 43.4%. Mean PCNA expression was higher in squamous carcinomas than in adenocarcinomas (p<0.05). A linear correlation between numbers of ISH signals and PCNA expression was not demonstrated, but there was a tendency of increasing PCNA positivity according to increasing numbers of ISH signals in adenocarcinomas of the lung and the tumor tissues which were over 50% positive PCNA expression. There was no linear correlation between numbers of ISH signals, PCNA positivity and tumor stages, and keratinization of squamous cell lung cancer. These results suggest that ISH will prove to bo an important tool for determining the underlying genetic basis for tissue phenotypic heterogeneity by allowing genetic determinations to be made on paraffin-embedded tissue sections where histologic architecture is preserved, and immunohistochemical nuclear staining with anti-PCNA on routinely processed tissue is a simple technique for the assessment of proliferation in non-small cell lung carcinoma.

Pulmonary Lymphangiomyomatosis: A case report

Pulmonary lymphangiomyomatosis is a rare disease of haphazard overproliferation of smooth muscle from perilymphatics, peribronchial and perivascular regions of the lung that leads to chylous effusion, hemoptysis, spontaneous pneumothorax and pulmonary insufficiency. The disease only affects women of child-bearing age. There is presently no successful therapy and most of the patients die within 10 years of diagnosis. We experienced a case of pulmonary lymphangiomyomatosis in a 30-year-old woman who had suffered from three episodes of spontaneous pneumothorax for 4 years. Open lung biopsy was performed. Microscopically, abnormal excess proliferation of smooth muscle tissue was identified in the wall of perivascular lymphatic channels as well as around small bronchi, and more distal air spaces. Varying sized cytic spaces Iined by cuboidal cells were also present. Tamoxifen, given if February 1991, did not influence the course of her disease. She died of respiratory failure at age of 31 in April 1991.