Landscape of driver mutations and their clinical effects on Down syndrome-related myeloid neoplasms.

ABSTRACT: Transient abnormal myelopoiesis (TAM) is a common complication in newborns with Down syndrome (DS). It commonly progresses to myeloid leukemia (ML-DS) after spontaneous regression. In contrast to the favorable prognosis of primary ML-DS, patients with refractory/relapsed ML-DS have poor outcomes. However, the molecular basis for refractoriness and relapse and the full spectrum of driver mutations in ML-DS remain largely unknown. We conducted a genomic profiling study of 143 TAM, 204 ML-DS, and 34 non-DS acute megakaryoblastic leukemia cases, including 39 ML-DS cases analyzed by exome sequencing. Sixteen novel mutational targets were identified in ML-DS samples. Of these, inactivations of IRX1 (16.2%) and ZBTB7A (13.2%) were commonly implicated in the upregulation of the MYC pathway and were potential targets for ML-DS treatment with bromodomain-containing protein 4 inhibitors. Partial tandem duplications of RUNX1 on chromosome 21 were also found, specifically in ML-DS samples (13.7%), presenting its essential role in DS leukemia progression. Finally, in 177 patients with ML-DS treated following the same ML-DS protocol (the Japanese Pediatric Leukemia and Lymphoma Study Group acute myeloid leukemia -D05/D11), CDKN2A, TP53, ZBTB7A, and JAK2 alterations were associated with a poor prognosis. Patients with CDKN2A deletions (n = 7) or TP53 mutations (n = 4) had substantially lower 3-year event-free survival (28.6% vs 90.5%; P < .001; 25.0% vs 89.5%; P < .001) than those without these mutations. These findings considerably change the mutational landscape of ML-DS, provide new insights into the mechanisms of progression from TAM to ML-DS, and help identify new therapeutic targets and strategies for ML-DS.

Inhalation of hydrogen gas mitigates sevoflurane-induced neuronal apoptosis in the neonatal cortex and is associated with changes in protein phosphorylation.

Inhalation of hydrogen (H2) gas is therapeutically effective for cerebrovascular diseases, neurodegenerative disorders, and neonatal brain disorders including pathologies induced by anesthetic gases. To understand the mechanisms underlying the protective effects of H2 on the brain, we investigated the molecular signals affected by H2 in sevoflurane-induced neuronal cell death. We confirmed that neural progenitor cells are susceptible to sevoflurane and undergo apoptosis in the retrosplenial cortex of neonatal mice. Co-administration of 1-8% H2 gas for 3 h to sevoflurane-exposed pups suppressed elevated caspase-3-mediated apoptotic cell death and concomitantly decreased c-Jun phosphorylation and activation of the c-Jun pathway, all of which are induced by oxidative stress. Anesthesia-induced increases in lipid peroxidation and oxidative DNA damage were alleviated by H2 inhalation. Phosphoproteome analysis revealed enriched clusters of differentially phosphorylated proteins in the sevoflurane-exposed neonatal brain that included proteins involved in neuronal development and synaptic signaling. H2 inhalation modified cellular transport pathways that depend on hyperphosphorylated proteins including microtubule-associated protein family. These modifications may be involved in the protective mechanisms of H2 against sevoflurane-induced neuronal cell death.

Serum Growth Differentiation Factor 15 Levels Predict the Incidence of Frailty among Patients with Cardiometabolic Diseases.

INTRODUCTION: Frailty is a crucial health issue among older adults. Growth differentiation factor 15 (GDF15) is associated with inflammation, oxidative stress, insulin resistance, and mitochondrial dysfunction, which are possible pathogeneses of frailty. However, few longitudinal studies have investigated the association between GDF15 and the incidence of frailty. Therefore, we investigated whether high serum GDF15 levels are associated with the incidence of frailty. METHODS: A total of 175 older adults (mean age: 77 ± 6 years; 63% women) with cardiometabolic diseases and no frailty out of the two criteria at baseline participated. Individuals with severe renal impairment or severe cognitive impairment were excluded. Serum GDF15 levels were measured at baseline. Patients were asked to assess frailty status at baseline and annually during follow-up using the modified version of the Cardiovascular Health Study (mCHS) and the Kihon Checklist (KCL). We examined the association between GDF15 tertiles and each frailty measure during follow-up (median 38-39 months). In the multivariate Cox regression analysis, with the GDF15 tertile groups as the explanatory variables, hazard ratios (HRs) and 95% confidence intervals (CIs) for incident frailty were calculated after adjusting for covariates and using the lowest tertile group as the reference. RESULTS: During the follow-up period, 25.6% and 34.0% of patients developed frailty, as defined by the mCHS and KCL, respectively. The highest GDF15 tertile group had a significantly higher incidence of mCHS- or KCL-defined frailty than the lowest GDF15 tertile group. Multivariate Cox regression analysis revealed that the adjusted HRs for incident mCHS- and KCL-defined frailty in the highest GDF15 tertile group were 3.9 (95% CI: 1.3-12.0) and 2.7 (95% CI: 1.1-6.9), respectively. CONCLUSION: High serum GDF15 levels predicted the incidence of frailty among older adults with cardiometabolic diseases and could be an effective marker of the risk for frailty in interventions aimed at preventing frailty, such as exercise and nutrition.

Increased expression of glucagon-like peptide-1 and cystic fibrosis transmembrane conductance regulator in the ileum and colon in mouse treated with metformin.

Metformin, an oral medication, is prescribed to patients with type 2 diabetes mellitus. Although the efficacy, safety, and low economic burden of metformin on patients have long been recognized, approximately 5% of the patients treated with this drug develop severe diarrhea and discontinue the treatment. We previously reported that 1,000 mg·kg-1·day-1 of metformin induced diarrhea in diabetic obese (db/db) mice and wood creosote (traditional medication for diarrhea) ameliorated the symptoms. In this study, we attempted to elucidate the molecular mechanisms by which metformin induces diarrhea. Cystic fibrosis transmembrane conductance regulator (CFTR) is a key ion (chloride) channel in cyclic adenosine monophosphate (cAMP)-induced diarrhea. Metformin treatment increased bile flow (bile acids and bilirubin) in the ileum of mice. In addition, the treatment was accompanied by an increase in mRNA and protein levels of CFTR in the mucosa of the ileum and colon in both wild-type (C57BL/6J) and db/db mice. Glucagon-like peptide-1 (GLP-1), as well as cholic acid, induces CFTR mRNA expression in human colon carcinoma Caco-2 cells through cAMP signaling. Although wood creosote (10 mg/kg) ameliorated diarrhea symptoms, it did not alter the mRNA levels of Glp-1 or Cftr. Similar to overeating, metformin upregulated GLP-1 and CFTR expression, which may have contributed to diarrhea symptoms in mice. Although we could not identify db/db mouse-specific factors associated with metformin-induced diarrhea, these factors may modulate colon function. Wood creosote may not interact with these factors but ameliorates diarrhea symptoms.

Neurogenic intermittent claudication caused by vasculitis in the cauda equina: an autopsy case report.

PURPOSE: Intermittent claudication (IC) refers to leg pain that is induced by walking and relieved by rest. Neurogenic IC is usually associated with lumbar canal stenosis (LCS). We present rare findings from an autopsied patient who had neurogenic IC caused by vasculitis in the cauda equina. METHODS: We performed antemortem neurological and electrophysiological assessments, sural nerve biopsy, and post-mortem examination of the spinal cord and brain. RESULTS: A 61-year-old man noted sudden-onset leg pain that was not associated with any traumatic trigger. His leg pain consistently appeared when the patient walked and quickly faded on stopping. Spine surgery and cardiovascular departments both made a diagnosis of IC. However, magnetic resonance imaging (MRI) did not show LCS, and all ankle-brachial pressure indices were normal. He subsequently developed diffuse muscle weakness of the legs a month after disease onset. Myeloperoxidase antineutrophil cytoplasmic autoantibody was seropositive (140 IU/mL), and a sural nerve biopsy revealed axonal injury and angiitis. MRI showed multiple cerebral infarctions. He was diagnosed with microscopic polyangiitis (MPA) and underwent corticosteroid therapy. He died from complications two months after the onset. A post-mortem study revealed vasculitis in the subarachnoid space of the cauda equina, spinal cord, and brain parenchyma. The cauda equina showed a combined loss of small and large axonal fibres. The lumbar cord displayed central chromatolysis of the lower motor neurons. CONCLUSION: MPA is a rare cause of neurogenic IC when the symptom is acute and multimodal. Small-vessel vasculitis affecting the cauda equina may underlie MPA-associated IC.

Prospective validation of the provisional entity of refractory cytopenia of childhood, proposed by the World Health Organization.

In 2008, the World Health Organization proposed a new entity of childhood myelodysplastic syndrome (MDS), which was referred to as refractory cytopenia of childhood (RCC). However, whether this morphological classification reflects clinical outcomes remains unclear. We performed a prospective evaluation of bone marrow morphology in 252 children with acquired bone marrow failure between 2009 and 2013. Of 252 patients, 63 were diagnosed with aplastic anaemia (AA), 131 with RCC without multilineage dysplasia (RCC-w/o-MLD) and 58 with RCC with MLD (RCC-MLD). One patient with AA, three with RCC-w/o-MLD and nine with RCC-MLD presented with chromosomal abnormalities at diagnosis (P = 0·001). The response rates to immunosuppressive therapy (IST) at 6 months and the cumulative incidence of clonal evolution at 5 years did not significantly differ among the three groups. A multivariate analysis revealed that the morphological classification of RCC-MLD was a significant risk factor for secondary graft failure after haematopoietic cell transplantation (HCT) (P = 0·003). In view of these findings, RCC could be divided into two categories, RCC-w/o-MLD and RCC-MLD, because children with this condition exhibited a distinct morphology, frequent chromosomal abnormalities at diagnosis and a high frequency of secondary graft failure after HCT.

Neurolymphomatosis in follicular lymphoma: an autopsy case report.

Neurolymphomatosis is a neurological manifestation of lymphoma that involves the cranial or spinal peripheral nerves, nerve roots, and plexus with direct invasion of neoplastic cells. Neurolymphomatosis is rare among patients with low-grade lymphoma. We report an autopsied case of neurolymphomatosis that arose from follicular lymphoma. A 49-year-old woman who presented with pain of her neck and shoulder and numbness of her chin. Computed tomography revealed enlarged lymph nodes in her whole body, and biopsy from the axillary lymph node revealed grade 2 follicular lymphoma. Although the patient underwent chemotherapy, she gradually developed muscle weakness in the upper limbs and sensory disturbances of the trunk and limbs. 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) revealed increased tracer uptake of the cervical nerve roots. Repeated FDG-PET after additional therapy revealed progression of disease within the nerve roots and brachial plexus, whereas gadolinium-contrast magnetic resonance imaging (MRI) showed weak enhancement of the cervical nerve roots without formation of mass lesions. She died after a total disease duration of 12 months. Postmortem observations revealed invasion of lymphoma cells into the cervical nerve roots, dorsal root ganglia, and subarachnoid spaces of the spinal cord. Neurolymphomatosis was prominent at the segments of C6-Th2. Combined loss of axons and myelin sheaths was observed in the cervical nerve roots and posterior columns. Lymphoma cells also invaded the cranial nerves. The subarachnoid and perivascular spaces of the brain demonstrated focal invasion of the lymphoma. Mass lesions were not observed in the central nervous system. The lymphoma cells did not show histological transformation to higher grades, and the density of the centroblasts remained at grade 2. Our report clarifies that low-grade follicular lymphoma can manifest as neurolymphomatosis and central nervous system invasion in the absence of transformation toward higher histological grades. FDG-PET may be more sensitive to non-mass-forming lesions, including neurolymphomatosis, than gadolinium-contrast MRI.

CREB3L1 overexpression as a potential diagnostic marker of Philadelphia chromosome-negative myeloproliferative neoplasms.

Discrimination of Philadelphia-negative myeloproliferative neoplasms (Ph-MPNs) from reactive hypercytosis and myelofibrosis requires a constellation of testing including driver mutation analysis and bone marrow biopsies. We searched for a biomarker that can more easily distinguish Ph-MPNs from reactive hypercytosis and myelofibrosis by using RNA-seq analysis utilizing platelet-rich plasma (PRP)-derived RNAs from patients with essential thrombocythemia (ET) and reactive thrombocytosis, and CREB3L1 was found to have an extremely high impact in discriminating the two disorders. To validate and further explore the result, expression levels of CREB3L1 in PRP were quantified by reverse-transcription quantitative PCR and compared among patients with ET, other Ph-MPNs, chronic myeloid leukemia (CML), and reactive hypercytosis and myelofibrosis. A CREB3L1 expression cutoff value determined based on PRP of 18 healthy volunteers accurately discriminated 150 driver mutation-positive Ph-MPNs from other entities (71 reactive hypercytosis and myelofibrosis, 6 CML, and 18 healthy volunteers) and showed both sensitivity and specificity of 1.0000. Importantly, CREB3L1 expression levels were significantly higher in ET compared with reactive thrombocytosis (P < .0001), and polycythemia vera compared with reactive erythrocytosis (P < .0001). Pathology-affirmed triple-negative ET (TN-ET) patients were divided into a high- and low-CREB3L1-expression group, and some patients in the low-expression group achieved a spontaneous remission during the clinical course. In conclusion, CREB3L1 analysis has the potential to single-handedly discriminate driver mutation-positive Ph-MPNs from reactive hypercytosis and myelofibrosis, and also may identify a subgroup within TN-ET showing distinct clinical features including spontaneous remission.

Proteomic analysis of extracellular vesicles identified PI3K pathway as a potential therapeutic target for cabazitaxel-resistant prostate cancer.

BACKGROUND: Cabazitaxel (CBZ) is now widely used for prostate cancer (PC) patients resistant to docetaxel (DOC), however, most patients eventually acquire resistance. It will, therefore, be of great benefit to discover novel therapeutic target for the resistance. We aimed to identify candidate therapeutic targets for CBZ-resistance by proteomic analysis of extracellular vesicles (EVs) isolated from serum of DOC-resistant PC patients who later developed CBZ-resistance as well as those harvested from culture medium of DOC- and CBZ-resistant PC cell lines. METHODS: Using T-cell immunoglobulin domain and mucin domain-containing protein 4 (Tim4) conjugated to magnetic beads, EVs were purified from serum of PC patients with DOC-resistance that was collected before and after acquiring CBZ-resistance and conditioned medium of DOC-resistant (22Rv1DR) and CBZ-resistant (22Rv1CR) PC cell lines. Protein analysis of EVs was performed by nanoLC-MS/MS, followed by a comparative analysis of protein expression and network analysis. The cytotoxic effect of a phosphatidylinositol-3-kinase (PI3K) inhibitor, ZSTK474, was evaluated by WST-1 assay. The expression and phosphorylation of PI3K and PTEN were examined by western blot analysis. RESULTS: Among differentially regulated proteins, 77 and 61 proteins were significantly increased in EVs from CBZ-resistant PC cell line and patients, respectively. A comparison between the two datasets revealed that six proteins, fructose-bisphosphate aldolase, cytosolic nonspecific dipeptidase, CD63, CD151, myosin light chain 9, and peroxiredoxin-6 were elevated in EVs from both cell line and patients. Network analysis of the increased EV proteins identified pathways associated with CBZ-resistance including PI3K signaling pathway. ZSTK474 significantly inhibited growth of 22Rv1CR cells and improved their sensitivity to CBZ. In 22Rv1CR cells, PI3K was activated and PTEN that inhibits PI3K was deactivated. CONCLUSIONS: Proteomic analysis of serum EVs was successfully accomplished by using Tim-4 as a tool to isolate highly purified EVs. Our results suggest that the combination use of CBZ and PI3K inhibitor could be a promising treatment option for CBZ-resistant PC patients.

Difference in the distribution of tumor-infiltrating CD8+ T cells and FOXP3+ T cells between micronodular thymoma with lymphoid stroma and micronodular thymic carcinoma with lymphoid stroma.

Micronodular thymoma with lymphoid stroma (MNT) is a rare thymic epithelial neoplasm subtype characterized by a micronodular tumor cell growth pattern and abundant lymphoid stroma. Micronodular thymic carcinoma with lymphoid stroma (MNCA) is considered as a malignant counterpart of MNT and exhibits a growth pattern similar to that of MNT but has histologic features reminiscent of thymic squamous cell carcinoma, such as cytologic atypia and CD5 and CD117 immunoexpression. Although both MNT and MNCA are characterized by abundant lymphoid stroma, it remains unknown whether there are differences in infiltrating lymphocytes between MNT and MNCA. We analyzed the immune microenvironment profile in eight MNT and three MNCA cases. The cell density of CD8-positive T cells was significantly higher in MNT than in MNCA, whereas that of FOXP3-positive T cells was significantly higher in MNCA than in MNT. There was no significant difference in the cell density of programmed death protein 1-positive T cells and programmed death ligand 1 expression between the MNT and MNCA cases. Our findings indicated that the immune microenvironment of MNCA differed from that of MNT and, compared with the T-cell profile of MNT, that of MNCA was more suppressive to patients' antitumor immune response.

Integrated molecular profiling of juvenile myelomonocytic leukemia.

Juvenile myelomonocytic leukemia (JMML), a rare and aggressive myelodysplastic/myeloproliferative neoplasm that occurs in infants and during early childhood, is characterized by excessive myelomonocytic cell proliferation. More than 80% of patients harbor germ line and somatic mutations in RAS pathway genes (eg, PTPN11, NF1, NRAS, KRAS, and CBL), and previous studies have identified several biomarkers associated with poor prognosis. However, the molecular pathogenesis of 10% to 20% of patients and the relationships among these biomarkers have not been well defined. To address these issues, we performed an integrated molecular analysis of samples from 150 JMML patients. RNA-sequencing identified ALK/ROS1 tyrosine kinase fusions (DCTN1-ALK, RANBP2-ALK, and TBL1XR1-ROS1) in 3 of 16 patients (18%) who lacked canonical RAS pathway mutations. Crizotinib, an ALK/ROS1 inhibitor, markedly suppressed ALK/ROS1 fusion-positive JMML cell proliferation in vitro. Therefore, we administered crizotinib to a chemotherapy-resistant patient with the RANBP2-ALK fusion who subsequently achieved complete molecular remission. In addition, crizotinib also suppressed proliferation of JMML cells with canonical RAS pathway mutations. Genome-wide methylation analysis identified a hypermethylation profile resembling that of acute myeloid leukemia (AML), which correlated significantly with genetic markers with poor outcomes such as PTPN11/NF1 gene mutations, 2 or more genetic mutations, an AML-type expression profile, and LIN28B expression. In summary, we identified recurrent activated ALK/ROS1 fusions in JMML patients without canonical RAS pathway gene mutations and revealed the relationships among biomarkers for JMML. Crizotinib is a promising candidate drug for the treatment of JMML, particularly in patients with ALK/ROS1 fusions.

Serum Exosomal Gamma-Glutamyltransferase Activity Increased in Patients with Renal Cell Carcinoma with Advanced Clinicopathological Features.

BACKGROUND: There has been no clinically useful diagnostic or prognostic biomarker for renal cell carcinoma (RCC). Serum γ-glutamyltransferase (GGT) activity has been reported to be a prognostic marker for several types of cancer including RCC. Exosomes or small extracellular vesicles present in body fluids have potential as a biomarker. We have recently demonstrated that GGT activity on exosomes isolated from serum is useful for the differential diagnosis of prostate cancer and benign prostate hyperplasia. In this study, we aimed to examine if serum exosomal GGT activity could be a marker for RCC. METHODS: We examined GGT1 expression and GGT activity in cell lysates and exosomes from culture medium of HK-2 proximal tubule epithelial and RCC cell lines. GGT activity was measured using a fluorescent probe for GGT, γ-glutamyl hydroxymethyl rhodamine green. Serum and serum exosomal GGT activities were measured in patients with RCC. GGT1 expression in RCC tissues was evaluated by immunohistochemical staining. RESULTS: GGT1 levels in exosomes from KMRC-1, OS-RC-2 and 786-O cells were elevated compared with those from HK-2 cells. In exosomes, GGT1 expression correlated with GGT activity determined using a fluorescent probe for GGT. In RCC patients, serum exosomal GGT activity was elevated in those with advanced stages (III/IV vs. I/II, p = 0.037) and those with microvascular invasion (with vs. without, p = 0.034). Immunohistochemical analysis showed that membranous GGT1 expression was increased in RCC with microvascular invasion. Notably, preoperative serum exosomal GGT activity could predict the likelihood of having microvascular invasion diagnosed by pathological examination of surgically resected specimens. CONCLUSIONS: Our results suggest that serum exosomal GGT activity could be a clinically useful marker for advanced clinicopathological features of RCC patients, and its combined use with conventional diagnostic modalities may improve the diagnosis and treatment of patients.

Mitochondrial stress and GDF15 in the pathophysiology of sepsis.

Mitochondria are multifunctional organelles that regulate diverse cellular processes. Mitochondrial stress, including stress generated by electron transport chain defects and impaired mitochondrial proteostasis, is intimately involved in various diseases and pathological conditions. Sepsis is a life-threatening condition that occurs when an imbalanced host response to infection leads to organ dysfunction. Metabolic disturbances and impaired immune responses are implicated in the pathogenesis and development of sepsis. Given that mitochondria play central roles in cellular metabolism, mitochondrial stress is predicted to be involved in the pathological mechanism of sepsis. Under mitochondrial stress, cells activate stress response systems to maintain homeostasis. This mitochondrial stress response transcriptionally activates genes involved in cell survival and death. Mitochondrial stress also induces the release of distinctive secretory proteins from cells. Recently, we showed that growth differentiation factor 15 (GDF15) is a major secretory protein induced by mitochondrial dysfunction. In this article, we provide a brief overview of mitochondrial stress response and GDF15, and discuss the potential role of GDF15 in the pathophysiology of sepsis.

Urinary exosome as a potential biomarker for urinary tract infection.

Unlike urinary tract infection (UTI), asymptomatic bacteriuria (ABU) should not be treated, with some exceptions such as pregnant women and patients who will undergo traumatic urologic interventions. However, there has been no clinically available marker for their differential diagnosis. Exosomes or small extracellular vesicles carry proteins contained in cells from which they are derived, thus having the potential as a biomarker of several diseases. On the basis of the hypothesis that the molecular signature of exosomes in urine may differ between UTI and ABU patients, we examined if urinary exosomes could serve as a marker for their differential diagnosis. Exosomes were isolated by ultracentrifugation or affinity-based method from cell culture medium of monocytic THP-1 and uroepithelial SV-HUC-1 cells and human urine. Protein expression was examined by Western blot analysis, ELISA, and CLEIA. The results showed that the levels of intracellular signalling molecules Akt and ERK and transcription factor NF-κB increased in exosomes isolated from THP-1 and SV-HUC-1 cells cocultured with Escherichia coli and/or treated with lipopolysaccharide. In urinary exosomes of UTI patients, Akt significantly diminished, and an exosomal marker CD9 showed a trend to decrease after treatment with antimicrobial agents. More importantly, Akt and CD9 levels in urinary exosomes were higher in UTI patients than in ABU patients, which was also observed after correction by urine creatinine. Collectively, these results suggest that Akt and CD9 in urinary exosomes could be useful markers for differential diagnosis of UTI and ABU.

IgG4 plasma cell myeloma: Clinicopathological characteristics and diagnosis.

Plasma cell myeloma (PCM) is usually associated with the presence of M-protein in the serum and urine of patients, and about half of the PCM cases exhibit the IgG M-protein and increased gamma-globulin fraction on membrane electrophoresis. The IgG4 subclass is located in the beta-2 fraction on membrane electrophoresis. The aim of this study was to develop a method to evaluate IgG4-producing PCM (IgG4-PCM) and its clinicopathological characteristics. We found three cases of IgG4-PCM among 80 cases of IgG-producing PCM by membrane electrophoresis, which were confirmed by IgG4 immunostaining. None of the cases had a clinical history of IgG4-related disease, although they exhibited high levels of serum IgG4. A bone marrow aspiration specimen had an increased number of plasma cells with a relatively mature morphology. No cases exhibited lymphoplasmacytic inflammation, obliterative phlebitis or fibrosis. Immunohistochemistry revealed that tumor cells expressed CD138 and IgG4 and showed monoclonal expression of kappa. We revealed that IgG4-PCM might not be associated with IgG4-related disease and that the detection of M-protein with beta-globulin fraction by electrophoresis may be useful for screening IgG4-PCM.

[Marginal zone lymphoma-like primary bone marrow lymphoma with long-term pancytopenia preceding diagnosis].

A 45-year-old man initially diagnosed with aplastic anemia had been receiving treatment for >4 years when he visited our hospital for a detailed examination. On admission, bone marrow (BM) aspiration showed erythroid dysplasia and chromosomal abnormalities, including trisomy 3 in 1/20 cells. After 3 months of observation, BM aspiration showed the involvement of 5% abnormal lymphocytes, and flow cytometry revealed a monoclonal B-cell phenotype. After a further 5 months of observation, his blood test showed a sudden elevation in white blood cell (WBC) count and the presence of villous lymphocytes. Fluorodeoxyglucose-positron emission tomography (FDG-PET) only revealed strong uptake by systemic BM, and BM aspiration showed the involvement of 76.4% abnormal lymphocytes, which were positive for CD19 and dim CD11c; negative for CD25, CD103, cyclin D1, and BRAF-V600E; and exhibited light chain restriction. The patient was diagnosed with marginal zone lymphoma-like primary bone marrow (BM) lymphoma. Treatment with R-CHOP and R-cladribine failed. He then underwent an allogeneic peripheral blood stem cell transplantation from a human leucocyte antigen (HLA)-identical sibling, and he has since remained in good health and without relapse for 9 years. Further clinical and biological analyses are necessary to establish an optimal treatment strategy for this disease.

[Leukemic pulmonary infiltration diagnosed by sputum Giemsa-staining].

A 54-year-old man with acute myeloid leukemia (AML) underwent allogeneic bone marrow transplantation from a human leukocyte antigen-matched unrelated donor in nonremission status. Bone marrow aspiration performed on day 14 showed that the patient had achieved complete remission; however, he relapsed on day 28. The patient developed a wet cough, and chest computed tomography performed on day 27 revealed pneumonia. Because pneumonia developed along with the leukemic relapse, we suspected that it was due to pulmonary leukemic infiltration (PLI). Giemsa-stained sputum showed some blast cells and fluorescence in situ hybridization indicated that the patient had monosomy 7, which was also detected in bone marrow blasts. Though we prescribed hydroxycarbamide and decreased tacrolimus rapidly, AML progressed and led to the patient's death on day 45. Histopathological findings of the autopsy performed the next day showed diffuse alveolar damage in both lungs. The blast cells were packed in blood vessels of alveolar septa and were also seen in alveoli. PLI was diagnosed pathologically. In conclusion, our case demonstrates that Giemsa stain of sputum is useful in quick diagnosis of PLI without invasive examination.

Differences in the bone marrow histology between childhood myelodysplastic syndrome with multilineage dysplasia and refractory cytopenia of childhood without multilineage dysplasia.

AIMS: Refractory cytopenia of childhood (RCC) is subdivided into myelodysplastic syndrome with multilineage dysplasia (MDS-MLD) and RCC without (w/o) multilineage dysplasia (RCC without MLD). Although RCC is a histomorphological distinct entity, the bone marrow (BM) histology of RCC is not yet characterised in relation to multilineage dysplasia. We investigated the BM histological features of RCC to clarify the characteristics of BM histology of MDS-MLD in childhood compared to RCC without MLD. METHODS AND RESULTS: The BM histology and cytology in 60 RCC patients from the nationwide registry of Japanese Childhood AA-MDS Study Group were reviewed retrospectively. Although a thorough genetic assessment, including GATA2 and/or SAMD9, was not performed, inherited BM failure disorders were excluded by a cytogenetic test, a chromosome fragility test and a telomere length measurement along with careful clinical assessments. Among the 60 patients, 20 (33%) of MDS-MLD and 40 (67%) of RCC w/o MLD were classified according to their BM cytology. We then investigated the BM histological features and compared them between the two groups. The BM cellularity, distribution pattern of haematopoiesis, frequency of left-shifted granulopoiesis, numbers of micromegakaryocytes and p53 immunostaining-positive cells were significantly different between the groups. The BM histology of MDS-MLD in childhood showed higher cellularity, the more common occurrence of diffuse distribution pattern, more frequently left-shifted granulopoiesis and more micromegakaryocytes and p53 immunostaining-positive cells than RCC without MLD. CONCLUSIONS: Our results showed that MDS-MLD in childhood had a characteristic BM histology compared to RCC without MLD. The clinical relevance of MDS-MLD in childhood needs to be evaluated.

Clinical and molecular features of patients with prefibrotic primary myelofibrosis previously diagnosed as having essential thrombocythemia in Japan.

OBJECTIVE: Prefibrotic/early primary myelofibrosis (pre-PMF) and essential thrombocythemia (ET) exhibited different features of bone marrow; however, this is not always easy to judge objectively, making pathologists' distinction often suboptimal. In the WHO 2008 criteria, pre-PMF was not defined as a subgroup of PMF; therefore, affected patients were at a higher risk of misdiagnosis with ET. In this study, we examined the prevalence of pre-PMF patients among those previously diagnosed with ET in Japan. METHOD: We reviewed bone marrow specimens and clinical and molecular parameters of patients who were previously diagnosed with ET by the WHO 2008 criteria. RESULTS: Among 107 ET patients, 13 patients were redefined as having pre-PMF. Pre-PMF patients exhibited a higher frequency of MPL mutation and increased platelet counts compared to true ET patients. Molecular analysis revealed the frequencies of high-risk molecular mutations, such as ASXL1, EZH2, and SRSF2, were significantly increased in pre-PMF patients than those in true ET patients. CONCLUSION: These results demonstrated the value of reexamining clinical records for patients diagnosed with ET by the WHO 2008 criteria and emphasized that adequate examinations of patients' bone marrow are crucial for an accurate diagnosis of pre-PMF and ET.

Mesenchymal-epithelial transition gene amplification and protein overexpression in stage IV pulmonary adenocarcinoma.

BACKGROUND: In non-small cell lung cancer (NSCLC), MET gene copy number gain, including gene amplification and chromosome 7 polysomy, is reportedly associated with patient prognosis. Although relationship between MET copy number gain and poor prognosis has been suggested in surgically resected non-small cell lung cancer, the clinical significance of MET copy number gain and protein overexpression in patients with advanced unresectable tumor is unclear. METHODS: We assessed MET copy number gain and protein expression using fluorescence in situ hybridization and immunohistochemistry in 88 patients with clinical stage IV pulmonary adenocarcinoma receiving chemotherapy, immunotherapy or palliative care. RESULTS: We found MET amplification, polysomy 7 and high MET protein expression in 10.2, 18.2 and 62.5% of 88 cases, respectively. Gene amplification and high protein expression were not significantly associated. A univariate analysis showed that MET amplification-positive patients had increased overall survival (HR 0.335, 95% CI: 0.119-0.945; P = 0.0388). Although it was not statistically significant in the multivariate analysis of the whole cohort, with the removal of patients who did not receive any treatment other than palliative care, MET amplification independently improved the overall survival (HR 0.178, 95% CI: 0.041-0.770; P = 0.0209). Chromosome 7 polysomy and high MET protein expression did not affect the overall survival. CONCLUSIONS: Although MET amplification-positive tumor is considered aggressive, our results suggest that it has a more favorable prognosis than amplification-negative cases in stage IV pulmonary adenocarcinoma with medical treatment.