Makiko Uemura

Potentiated activation of VLA-4 and VLA-5 accelerates proplatelet-like formation

Fibronectin (FN) plays important roles in the proliferation, differentiation, and maintenance of megakaryocytic-lineage cells through FN receptors. However, substantial role of FN receptors and their functional assignment in proplatelet-like formation (PPF) of megakaryocytes are not yet fully understood. Herein, we investigated the effects of FN receptors on PPF using the CHRF-288 human megakaryoblastic cell line, which expresses VLA-4 and VLA-5 as FN receptors. FN and phorbol 12-myristate 13-acetate (PMA) were essential for inducing PPF in CHRF-288 cells. Blocking experiments using anti-β1-integrin monoclonal antibodies indicated that the adhesive interaction with FN via VLA-4 and VLA-5 were required for PPF. PPF induced by FN plus PMA was accelerated when CHRF-288 cells were enforced adhering to FN by TNIIIA2, a peptide derived from tenascin-C, which we recently found to induce β1-integrin activation. Adhesion to FN enhanced PMA-stimulated activation of extracellular signal-regulated protein kinase 1 (ERK1)/2 and enforced adhesion to FN via VLA-4 and VLA-5 by TNIIIA2-accelerated activation of ERK1/2 with FN plus PMA. However, c-Jun amino-terminal kinase 1 (JNK1), p38, and phosphoinositide-3 kinase (PI3K)/Akt were not stimulated by FN plus PMA, even with TNIIIA2. Thus, the enhanced activation of ERK1/2 by FN, PMA plus TNIIIA2 was responsible for acceleration of PPF with FN plus PMA.

Reversible cerebral vasoconstriction syndrome resulted in cerebral infarction after allogeneic stem cell transplantation: a case report

Dear Editor, Reversible cerebral vasoconstriction syndrome (RCVS) has been recognized as a syndrome of diverse conditions characterized by the reversible multifocal narrowing of cerebral arteries [1, 2]. RCVS has been detected in more patients in recent years because of the growing availability of noninvasive MRI and magnetic resonance angiography (MRA) diagnostic technology. Posterior reversible encephalopathy syndrome (PRES) is a form of acute encephalopathy [3]. PRES is responsible for vasogenic edema within the cerebral white matter, predominantly in the posterior of the cerebrum [4]. We report a case of RCVS followed by PRES, which progressed to cerebral infarction due to tacrolimus administration. In August 2004, we diagnosed a 49-year-old female with chronic myelogenous leukemia with 46, XX, t(9;22) [20/20]. She was treated with imatinib and nilotinib at initial doses of 400 and 200 mg/day, respectively, but the myelosuppression provided by these tyrosine kinase inhibitors was progressive. In November 2010, 6 months after the cessation of imatinib and nilotinib, pancytopenia persisted, and her bone marrow aspiration showed myelodysplasia harboring both the Philadelphia (Ph) chromosome [1/20] and an abnormal karyotype, monosomy 7 [7/20] on the Ph-negative clones. In August 2011, she underwent an allogeneic bone marrow transplantation from an unrelated healthy donor with a conventional conditioning regimen (cyclophosphamide 60 mg/kg) and total body irradiation (12 Gy; CY/TBI). She complained of tension headache after the start of the preparation regimen. After the initiation of a continuous intravenous administration of tacrolimus 1 day before the transplantation, the patient’s tension headache shifted to a periodic cluster headache with photoreactivity. On day 17, after transplantation, engraftment was achieved without the progression of any neurological symptoms. On day 27, the sudden onset of paralysis of the patient’s left lower limb prompted us to stop the continuous treatment with tacrolimus, and a cranial MRI showed a highintensity lesion in her posterior lobe on a T2-weighted image as a typical finding of PRES due to tacrolimus (Fig. 1a). MRA revealed vasoconstriction of cerebral basilar arteries (Fig. 1a). The immediate discontinuation of tacrolimus improved the patient’s paralysis. We followed up with MRI and MRA on day 39. The findings indicated a subacute cerebral infarction of her parietal lobe and improvement of the vasoconstriction of cerebral arteries (Fig. 1b). We concluded that the patient’s RCVS resulted in the cerebral infarction because of the severe vasospasm of the regional cerebral artery, most likely because of the tacrolimus. In this case, arterial vasoconstriction was “reversible,” but the infarction remained as an irreversible complication. The association between tacrolimus and the symptoms in this case emerged through the patient’s clinical course. That is, the first MRI/MRA revealed PRES with segmental narrowing signs in the territory of the brain’s basilar artery; after the tacrolimus discontinuation, the second MRI/MRA showed O. Imataki :M. Uemura : T. Shintani :K. Matsumoto Division of Endocrinology and Metabolism, Hematology, Rheumatology and Respiratory Medicine, Department of Internal Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan

Ganciclovir-resistant HHV-6 encephalitis that progressed rapidly after bone marrow transplantation

Human herpesvirus-6 (HHV-6) is a causative microorganism that infects immunocompromised hosts such as stem cell transplant recipients [1]. It has been recognized as an important opportunistic pathogen that reactivates after stem cell transplantation (SCT) [2]. Over the past 10 years, HHV-6 has become an emerging pathogen in transplantation medicine, following a successful era of ganciclovir (GCV) treatment for cytomegalovirus (CMV) and highly immunosuppressive therapy by cyclosporine and tacrolimus. Because HHV-6 may cause limbic demyelinating encephalitis – which is frequently fatal – many SCT physicians emphasize the importance of HHV-6 prophylaxis [3,4]. Many virologists have posited that the antiviral susceptibilities of HHV-6 resemble those of CMV, another emerging pathogen that had already been overcome after the advent of GCV use [5]. Although GCV, foscarnet and cidofovir have been shown to display in vitro inhibitory effects against HHV-6, there is little clinical data to guide recommendations in clinical practice [6]. Prophylactic or preemptive therapy by GCV is practical in SCT settings, but it sometimes fails toattenuate thedevelopmentofHHV-6 infection incases with central nervous system (CNS) infection. We recently treated a patient diagnosed with adult T-cell leukemia/lymphoma (ATLL) who also suffered from fatal HHV-6

Linezolid‐induced pure red cell aplasia in a patient with Staphylococcus epidermidis infection after allogeneic stem cell transplantation

Linezolid (LZD) is the first oxazolidinone antibiotic that is effective against drug‐resistant gram‐positive organisms. Hematological toxicities such as thrombocytopenia, anemia, and leukocytopenia are common in LZD therapy. However, LZD‐induced pure red cell aplasia (PRCA) is very rare. A 56‐year‐old man with myelodysplastic syndrome underwent allogeneic bone marrow transplantation from a human leukocyte antigen‐matched and ABO blood type‐matched unrelated male donor. He had bacteremia caused by Staphylococcus epidermidis after engraftment of neutrophils and red blood cells. We first administered vancomycin, but then changed to intravenous LZD because of kidney damage. Two weeks after LZD therapy, the patients hemoglobin and reticulocyte levels were 6.8 g/dL and 0.3%, respectively. Bone marrow examination revealed red blood cell aplasia (myeloid/erythroid ratio was 402). The patient showed rapid recovery of normal erythropoiesis within 2 weeks of LZD cessation. It is important to be aware of the hematological effects associated with LZD in the setting of stem cell transplantation,particularly for those with pre‐existing myelosuppression, renal insufficiency, and those receiving concomitant drugs that produce bone marrow suppression. We advocate that a reticulocyte count be performed periodically for detecting bone marrow suppression, including PRCA, during LZD therapy.

NKT cell-infiltrating aseptic meningitis on the central nervous system in Philadelphia chromosome-positive acute lymphoblastic leukemia treated with dasatinib.

Dear Editor, Among the TKIs, dasatinib is an ABL kinase inhibitor characterized by strong binding affinity to the ABL kinase domain [1]. Dasatinib is different from the other resting TKIs as a unique immunological activator. It is thought that dasatinib exerts an immunomodulatory effect to enhance the innate immune system involving natural killer (NK), natural killer T (NKT) cells, and large granular lymphocytes (LGL) under certain circumstances [2, 3]. A 53-year-old female was transferred to our institute due to febrile leukocytosis. She was diagnosed as having Ph ALL and received induction chemotherapy consisting of cyclophosphamide, daunorubicin, vincristine, and prednisolone, followed by imatinib 600 mg/day (days 8–63). She achieved complete remission after the induction chemotherapy, as her bone marrow aspiration showed molecular remission confirmed by the evaluation of BCR-ABL messenger RNA (mRNA) (<1.0×10). We performed a first consolidation chemotherapy consisting of high-dose methotrexate 1 g/m and cytarabine 2 g/m/day for 2 days, followed by dasatinib 140 mg/day (days 29–56). The patient maintained complete remission with undetectablemolecular evidence of BCR-ABL oncogene product. We initiated a second consolidation, with the same regimen as the first consolidation, and on day 34, she felt hypersensitivity on both palms. The patient’s neurological examination showed no abnormal findings included. A cranial MRI revealed no intracranial lesion explaining her neurological symptoms, while a spinal tap revealed elevatedmononuclear cell counts. The infiltrating cells consisted of granulocytes (CD3433) 15 %, B cells (CD19) 0.6 %, T cells (CD3) 98.2 %, NK cells (CD356) 1.21 %, and NKT cells (CD356) 3.0 % (Fig. 1a). Some infiltrating cells revealed LGL morphology (Fig. 1b). Cultured cerebrospinal fluid (CSF) showed no bacterial organisms or acid-fast bacillus. Molecular biological methods using CSF, a fluorescence in situ hybridization (FISH) analysis, and mRNA for BCR-ABL did not uncover findings of leukemic involvement of the CNS and bone marrow. Soon after the discontinuation of dasatinib, the patient’s neurological symptoms were ameliorated, and the infiltrating mononuclear cells disappeared completely. A high proportion of NK cells (LGLs) and NKT cells is thought to be an immunological reaction involved in dasatinib-induced immunomodulation, which has been observed several times in various clinical situations [3, 4]. The cell surface antigen analysis we performed by a flow cytometry technique revealed the NK and NKT cell infiltration, and notably, the NKT cell composition was concentrated in the CSF more than in the peripheral blood (at most 0.01 %). Almost all of the infiltrating cell population was T cells, but a minor population of NK and NKT cells was present, which was similar to the case presenting pleural effusion during dasatinib therapy.We did not determine the antigen specificity of Tcells. Even so, an accumulation of NKTcells in the CSF is an unusual event, and this case appeared to be “immunogenic” aseptic meningitis. Although the mechanisms by which activated NKTcells confer disease protection remain to be examined in future studies, those immunomodulatory properties of NKT cells suggested in the present patient may be useful for the development of immunotherapies against hematological malignancies other than Ph ALL that involve the CNS. O. Imataki (*) :A. Matsuoka :M. Uemura Division of Hematology, Department of Internal Medicine, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan e-mail: oima@med.kagawa-u.ac.jp

A nationwide survey of hypoplastic myelodysplastic syndrome (a multicenter retrospective study)

Hypoplastic myelodysplastic syndrome (hMDS) is a distinct entity with bone marrow (BM) hypocellularity and the risk of death from BM failure (BMF). To elucidate the characteristics of hMDS, the data of 129 patients diagnosed between April 2003 and March 2012 were collected from 20 institutions and the central review team of the National Research Group on Idiopathic Bone Marrow Failure Syndromes, and compared with 115 non‐hMDS patients. More RA and fewer CMMoL and RAEB‐t in French‐American‐British (FAB) and more RCUD and MDS‐U and fewer RCMD in World Health Organization (WHO) classifications were found in hMDS than non‐hMDS with significant differences. The overall survival (OS) and AML progression‐free survival (AML‐PFS) of hMDS were higher than those of non‐hMDS, especially in patients at age ≥50 and of lower risk in Revised International Prognostic Scoring System (IPSS‐R). In competing risks analysis, hMDS exhibited decreased risk of AML‐progression in lower IPSS or IPSS‐R risk patients, and higher risk of death from BMF in patients at age ≥50. Poor performance status (PS ≥2) and high karyotype risks in IPSS‐R (high and very high) were significant risk factors of death and AML‐progression in Cox proportional hazards analysis.

Marked Hematopoiesis Masquerading Multiple Bone Metastasis in a Lung Cancer Patient With Myelodysplastic Syndrome.

We diagnosed a 62-year-old man with lung cancer, well-differentiated squamous cell carcinoma, on the right upper lobe and left lower lobe. He had a history of myelodysplastic syndrome and refractory anemia with ringed sideroblasts diagnosed 5 years earlier. The patients ¹⁸F-FDG PET/CT for the clinical staging of lung cancer revealed accumulations of FDG in multiple bones including the rib bones, which strongly suggested multiple bone metastases. He underwent lobectomies and excision of the right fourth and fifth rib bones. The pathological findings of resected rib bones exhibited hypercellular bone marrow without excess of blasts.

Enteral Malakoplakia Prior to Helicobacter cinaedi Bacteremia

associated infectious pathogens are Klebsiella spp. and Escherichia coli ( 7 ), which colonize the mucosa. In a few cases, a rare opportunistic pathogen leads to the development of a systemic infection, which may occasionally become severe ( 7 ). A defective immune system, such as a cellular immune defect in macrophages, directly contributes to the pathological establishment of malakoplakia ( 8,9 ). In malakoplakia, a functional defect of monocytes or macrophages results in the formation of a well-characterized deposit in macrophages known as a Michaelis–Gutmann body ( 10 ). Moran et al. ( 11 ) reported that characteristic pathological fi ndings, such as Michaelis–Gutmann bodies, had been observed in cases of colonic cancer. Th is suggests that an underlying cancer is one of the diff erential diagnoses for defective immunity when malakoplakia is observed. We treated a 49-year-old man with relapsed and refractory multiple myeloma following autologous stem cell transplantation. Th e patient was admitted to our hospital because of febrile diarrhea. We performed colonoscopy and observed multiple focal white mucosal lesions ( Figure 1 ). Th ese lesions were diagnosed on pathological examination to be malakoplakia ( Figure 2 ). Th ree days aft er the colonoscopy, Helicobacter cinaedi was isolated in the peripheral blood culture, as identifi ed by mass spectrometry. H. cinaedi is a spiral, rod-shaped, fastidious bacteria in the Helicobacteraceae family and is one of the enterohepatic nonHelicobacter pylori Helicobacters ( 12 ). H. cinaedi resides in the gastrointestinal tract and results in bacteremia. In this case, we supposed it was translocated into the blood through the mucosal barrier. Another pathogenicity of H. cinaedi in humans has been recognized as a causative pathogen of cellulitis. Th us, H. cinaedi infections have various clinical manifestations, including bacteremia, cellulitis, gastroenteritis, and meningitis ( 12 ). Th is means that malakoplakia represents a systemic defect in the immune response, characteristically in cancer patients. A unique case report of malakoplakia in a patient with myeloma has been published ( 4 ). Th e authors of that case report speculated that malakoplakia was a predisposing condition, giving evidence of altered cellular immunity REFERENCES 1. Sbahi H , Di Palma JA . Faecal microbiota transplantation: applications and limitations in treating gastrointestinal disorders . BMJ Open Gastroenterol 2016 ; 3 : e000087 . 2. Lee CH , Belanger JE , Kazzam Z et al. Th e outcome and long-term follow-up of 94 patients with recurrent and refractory Clostridium diffi cile infection using single to multiple fecal microbiota transplantation via retention enema . Eur J Clin Microbiol Infect Dis 2014 ; 33 : 1425 – 8 . 3. Chang BW , Pimentel M , Chang C et al. Prevalence of excessive intestinal methane production and its variability with age and gender: a large-scale database analysis . Gastroenterology 2015 ; 148 : S-729 – 30 . 4. Rezaie A , Chang BW , Chua S et al. Accurate identifi cation of excessive methane gas producers by a single fasting measurement of exhaled methane: a large-scale database analysis . Am J Gastroenterol 2015 ; 110 : S759 . 5. Moayeddi P , Surette MG , Kim PT et al. Fecal microbiota transplantation induces remission in patients with active ulcerative colitis in a randomized controlled trial . Gastroenterology 2015 ; 149 : 102 – 9 .

The Leading Seafood Cuisine of Anisakidosis in Japan

TO THE EDITOR—Iwata et al [1] reported the suitability and feasibility of freezing raw fish to eliminate the risk of anisakidosis infection. They compared frozen and raw sushi materials, squid, and mackerel, using a suitable scientific method. However, we discuss this study’s misleading interpretation. During the last few decades, many inexpensive sushi restaurants have opened in Japan, where people can enjoy affordable sushi cuisine. The growth of the sushi market has increased 1.5 times within the past decade. The gross market was worth 315 billion yen (

Yersinia pseudotuberculosis enterocolitis mimicking enteropathic γδ T-cell lymphoma with abnormal clonality

2.78 billion) in 2015. According to a nationwide survey, the incidence of anisakidosis (reported as food poisoning) has been rising in Japan (Figure 1) [2], which is discordant with the linear growth in the sushi market. The total frequency of the reported anisakidosis cases has raised 5 times much more than the growth ratio of sushi market in this decade. Therefore, we believe that the increase is due to a reporting bias (official reporting system recommended in 1999 and established in 2013). Some review articles have suggested that the increase in anisakidosis incidence is because of advances in endoscopic techniques and instruments [3, 4]. The substantial difference in anisakidosis prevalence between Japan and China, which has a culture of consuming raw seafood, is under investigation [3]. While Japanese eat fresh raw fish as sushi and sashimi, Chinese eat oil-cooked fish. This difference may be caused by different cooking styles in these countries. Based on the official record, the leading seafood source of anisakidosis is mackerel, of whichmore than half is pickled (Figure 1). Raw or undercooked squid is rarely the cause of food-related anisakidosis (Figure 1), indicating that squid is relatively safe. A comprehensive review on anisakidosis published in Clinical Infectious Disease revealed that seafood served in community sushi bars/restaurants tends to be less contaminated [5]. This may be because all franchised sushi restaurants in Japan use frozen squid. A higher incidence of anisakidosis is anticipated with the use of undercooked seafood in local food houses or homes [5].Epidemiological studies in Japan have revealed that anisakidosis is more frequent in coastal population, with most cases occurring among fishermen [5]. These factors suggest that the most unsafe cuisine in Japan is pickled mackerel. Pickling does not sterilize anisakids. Thus, the recommendations of Iwata et al will not help decrease the incidence of anisakidosis in Japan. We also have concerns on 2 minor issues. The first issue is that medical students and residents are not the most suitable participants to study because they are not the most typical representatives of the community. The second issue is regarding seafood freshness. The authors used seafood purchased unfrozen material 2 days earlier, which cannot be regarded as fresh. All franchised restaurant managers and sushi chefs have been educated to avoid the risk of anisakidosis. It is known that within 20 hours after the death of the host sea fish, anisakid larvae move from fish intestines to the muscles at 20°C but not at 4°C. Consumption of fresh unfrozen sushi without the risk of anisakidosis requires adequate preservation at 4°C and consumption on the day of the catch. In 2014, President Obama visited Japan formally and greatly enjoyed eating fresh seafood at the sushi dining bar Jiro in Ginza. Professionals know that really fresh sushi material, caught in the morning, has a minimal anisakidosis risk.