Two novel high-risk adult B-cell acute lymphoblastic leukemia subtypes with high expression of CDX2 and IDH1/2 mutations.

The genetic basis of leukemogenesis in adults with B-cell acute lymphoblastic leukemia (B-ALL) is largely unclear, and its clinical outcome remains unsatisfactory. This study aimed to advance the understanding of biological characteristics, improve disease stratification, and identify molecular targets of adult B-ALL. Adolescents and young adults (AYA) (15 to 39 years old, n = 193) and adults (40 to 64 years old, n = 161) with Philadelphia chromosome-negative (Ph-) B-ALL were included in this study. Integrated transcriptomic and genetic analyses were used to classify the cohort into defined subtypes. Of the 323 cases included in the RNA sequencing analysis, 278 (86.1%) were classified into 18 subtypes. The ZNF384 subtype (22.6%) was the most prevalent, with 2 novel subtypes (CDX2-high and IDH1/2-mut) identified among cases not assigned to the established subtypes. The CDX2-high subtype (3.4%) was characterized by high expression of CDX2 and recurrent gain of chromosome 1q. The IDH1/2-mut subtype (1.9%) was defined by IDH1 R132C or IDH2 R140Q mutations with specific transcriptional and high-methylation profiles. Both subtypes showed poor prognosis and were considered inferior prognostic factors independent of clinical parameters. Comparison with a previously reported pediatric B-ALL cohort (n = 1003) showed that the frequencies of these subtypes were significantly higher in AYA/adults than in children. We delineated the genetic and transcriptomic landscape of adult B-ALL and identified 2 novel subtypes that predict poor disease outcomes. Our findings highlight the age-dependent distribution of subtypes, which partially accounts for the prognostic differences between adult and pediatric B-ALL.

Outcomes of transplant-eligible patients with myelodysplastic syndrome with excess blasts registered in an observational study: The JALSG-CS11-MDS-SCT.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is the sole curative therapy for myelodysplastic syndrome (MDS). However, whether bridging therapy (BRT) including azacitidine (AZA) and combination chemotherapy (CCT) prior to allo-SCT should be performed is unclear. We analyzed BRT and the outcomes of patients with myelodysplastic syndrome with excess blasts (MDS-EB) who were ≤ 70 years old at the time of registration for a prospective observational study to clarify the optimal allo-SCT strategy for high-risk MDS. A total of 371 patients were included in this study. Among 188 patients (50.7%) who were considered for allo-SCT, 141 underwent allo-SCT. Among the patients who underwent allo-SCT, 64 received AZA, 29 received CCT, and 26 underwent allo-SCT without BRT as the initial treatment. Multivariate analysis identified BRT as an independent factor influencing overall survival (AZA vs. without BRT, hazard ratio [HR] 3.33, P = 0.005; CCT vs. without BRT, HR 3.82, P = 0.003). In multivariate analysis, BRT was independently associated with progression-free survival (AZA vs. without BRT: HR, 2.23; P = 0.041; CCT vs. without BRT: HR, 2.94; P = 0.010). Transplant-eligible patients with MDS-EB should undergo allo-SCT when clinically acceptable, and upfront allo-SCT without BRT may be superior to AZA or CCT.

[Sustaining molecular response with very low dose ponatinib and further response after hemodialysis initiation in a patient with chronic myeloid leukemia].

A 46-year-old man was diagnosed with chronic myeloid leukemia (CML) in chronic phase. He was treated with imatinib, nilotinib, and dasatinib, but failed to achieve a complete cytogenetic response (CCyR). After tyrosine kinase inhibitor therapy, F317L BCR-ABL1 kinase domain mutation was detected. At age 66, the patient started ponatinib (PON) at 45 mg/day, and achieved CCyR within three months. Subsequently, PON was tapered to 15 mg once weekly due to arterial-occlusive events. PON was discontinued after a 3-year deep molecular response (≥ MR4.5). However, the patient lost MR4.0 within two months, and PON (15 mg once weekly) was restarted. He achieved MR4.0 again within one month, and then a deeper molecular response (MR5.0) after starting dialysis therapy at the same PON dose. The trough value of PON (15 mg once weekly) was 5.8 ng/ml, which suppressed F317L mutation in the CML clone. Currently, the patient is 77 years old and is sustaining MR5.0. Chronic renal failure may cause hyperabsorption and metabolic retardation in patients receiving PON. Initiation of hemodialysis may improve homeostasis resulting in enhanced anti-tumor immunity against CML.

[Perforated upper gastrointestinal ulcers potentially attributable to mycophenolate mofetil after allogeneic hematopoietic stem cell transplantation].

A 46-year-old man with myelodysplastic syndrome/myeloproliferative neoplasm-unclassifiable underwent myeloablative bone marrow transplantation from an HLA-DR-1-antigen-mismatched related donor while receiving tacrolimus and mycophenolate mofetil (MMF) for graft-versus-host disease (GVHD) prophylaxis. However, grade III acute GVHD of the gut occurred on day 20 and was treated with prednisolone (PSL) and oral beclomethasone dipropionate while continuing MMF. Subsequently, he presented with progressive epigastric pain. Endoscopy demonstrated multiple stomach and duodenal deep ulcers. The ulcers were suspected to be GVHD; thus, the PSL dose was increased and infliximab was administered; however, the ulcers exacerbated, resulting in repeated perforations and hemorrhagic shock. Furthemore, MMF was suspected as the cause of refractory ulcers and was discontinued on day 156, which resolved the ulcers after 6 months. MMF-induced gastrointestinal (GI) injury resembles anti-inflammatory drug-related ulcers and upper and lower GI tract GVHD, respectively. MMF-induced GI injury has been reportedly resolved after discontinuing or reducing the MMF dose. Several reports suggested that refractory upper GI ulcers and rectal sparing colitis were associated with MMF toxicities rather than GVHD in hematopoietic stem cell transplantations. Physicians should be aware that MMF can induce severe GI injury.

Clinical characteristics and incidence of toxoplasmosis after autologous hematopoietic stem cell transplantation: A retrospective study and literature review.

BACKGROUND: Toxoplasmosis is a rare but life-threatening infection occurring in immunocompromised hosts, including allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. However, thus far, the clinical features and incidence of toxoplasmosis in autologous HSCT (auto-HSCT) recipients remain unknown. This retrospective survey aimed to analyze 152 patients who received auto-HSCT between 1998 and 2017. METHODS: Serological tests for Toxoplasma gondii-specific IgG were performed on 109 (71.7%) recipients, and 12 pre-HSCT recipients (11%) were Toxoplasma seropositive. Among the 12 recipients, three who did not receive trimethoprim-sulfamethoxazole (TMP/SMX) prophylaxis developed cerebral, pulmonary or disseminated toxoplasmosis due to reactivation after auto-HSCT and died despite treatment. RESULTS: The incidences of toxoplasmosis were 2% and 25% among 152 auto-HSCT recipients (five recipients received auto-HSCT two times) and 12 pre-HSCT Toxoplasma seropositive recipients, respectively. Further, we conducted a literature review and identified 21 cases of toxoplasmosis following auto-HSCT. In these previous cases, the mortality rate was high, especially for pulmonary and disseminated toxoplasmosis. Our findings suggest that, similar to toxoplasmosis after allo-HSCT, toxoplasmosis after auto-HSCT is a fatal complication. CONCLUSIONS: Serial screening of T. gondii-specific IgG before HSCT could contribute to the detection of Toxoplasma reactivation and allow for prompt diagnosis and treatment. The present study is the first to reveal the incidence of toxoplasmosis after auto-HSCT among seropositive patients in Japan.

Kinetics and clinical significance of human herpesvirus 6 DNA shedding in saliva after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Little is known about the kinetics and clinical significance of saliva human herpesvirus-6 (HHV-6) DNA after hematopoietic stem cell transplantation (HSCT). METHODS: In this observational study, we quantified HHV-6 DNA in serially collected plasma and saliva from allogeneic HSCT recipients. Associations between the status of salivary HHV-6 DNA and the development of HHV-6 encephalitis, depression, and oral mucosal graft-versus-host disease (GVHD) were retrospectively analyzed. RESULTS: A total of 787 plasma and 434 saliva samples were collected from 56 patients. The cumulative incidence of HHV-6 DNA in plasma and saliva at 60 days after transplantation was 51.8% and 83.9%, respectively. The peak level of salivary HHV-6 DNA was significantly higher in patients who displayed plasma HHV-6 DNA than in those who did not (median, 51,584 copies/mL vs 587 copies/mL; P < .0001). Salivary HHV-6 DNA levels increased after positive plasma HHV-6 DNA was detected and remained high during observation period. Despite the frequent occurrence of positive salivary HHV-6 DNA, no patient developed depression. Positivity of salivary HHV-6 DNA was not significantly associated with the development of HHV-6 encephalitis (P = 1.00, Fisher's exact test) or oral mucosal GVHD (P = .71, Grey's test). No significant relationship between salivary HHV-6 DNA and these diseases was found even when comparing higher HHV-6 DNA loads in saliva. CONCLUSION: Salivary HHV-6 DNA levels increased after HHV-6 DNA was detected in the blood. However, no epidemiological evidence was shown to support a role of salivary HHV-6 in the development of HHV-6 encephalitis, depression, and oral mucosal GVHD.

[Immune thrombocytopenia after BNT162b2 mRNA COVID-19 vaccination].

A 95-year-old male developed general subcutaneous petechiae, tongue hematoma, and melena two days after receiving the second BNT162b2 mRNA COVID-19 vaccine. Two days later, his platelet count decreased to below 1,000/µl. Laboratory testing was positive for a slight increase in D-dimer, Helicobacter pylori (H. pylori) immunoglobulin G (IgG) antibody, lupus anticoagulant, and anticardiolipin IgG antibody levels. There were no severe infections or symptomatic thrombosis. Platelet transfusions were transiently effective. He was diagnosed with newly developed immune thrombocytopenia (ITP). We administered prednisolone (PSL) at 0.5 mg/kg/day and intravenous immunoglobulin (IVIG) at 0.4 g/kg/day. From the following day, his platelet count rapidly increased, with an improvement in bleeding tendency. H. pylori was eradicated after platelet count recovery. Thrombocytopenia did not relapse although PSL was tapered three months later. Causes of thrombocytopenia after SARS-CoV-2 vaccination include ITP, vaccine-induced immune thrombotic thrombocytopenia, and thrombotic thrombocytopenic purpura. Differential diagnosis is important to determine the proper therapy. Case reports of newly diagnosed ITP after SARS-CoV-2 vaccination have been increasing recently. In these cases, including ours, the responses to steroids and IVIG were good. Further follow-up studies are needed to manage thrombocytopenia following SARS-CoV-2 vaccination.

[Miliary tuberculosis with markedly elevated soluble interleukin-2 receptor levels mimicking intravascular large B-cell lymphoma].

An 81-year-old woman with type 2 diabetes mellitus presented to our hospital due to anorexia, leg edema, and respiratory distress. Laboratory results revealed anemia, thrombocytopenia, elevated lactate dehydrogenase, and markedly elevated soluble interleukin-2 receptor levels. Computed tomography showed ground-glass opacities and consolidation in both lung fields, but no lymphadenopathy was noted. Intravascular large B-cell lymphoma (IVLBCL) was considered as a differential diagnosis; therefore, bone marrow and random skin biopsy were performed. Her respiratory condition deteriorated, with the occurrence of acute respiratory distress syndrome, disseminated intravascular coagulation, hemophagocytic syndrome, and further alveolar hemorrhage. Methylprednisolone pulse therapy was performed, but did not improve the patient's condition. On hospital day 6, the acid-fast bacterial smear of the sputum using the Gaffky scale was 2, and on the next day, tuberculosis DNA was detected in the polymerase chain reaction. In the bone marrow biopsy, multiple epithelioid cell granulomas were found; thus, the patient was diagnosed with miliary tuberculosis. Although anti-tuberculosis therapy was started immediately, she died on hospital day 22. The soluble interleukin-2 receptor level increased up to 19,400 U/ml. The differential diagnosis should be cautiously made because miliary tuberculosis can mimic IVLBCL.

[Successful cord blood transplantation for myelodysplastic syndrome with Behçet disease-like refractory stomatitis and multiple ileocecal ulcerations].

A 12-year-old boy was diagnosed with aplastic anemia. He was followed as an outpatient without medication, and his cytopenia improved after several years. When he was 26 years old, an annual medical checkup revealed leukocytopenia, and at the age of 31 years, he was diagnosed with myelodysplastic syndrome (MDS), refractory cytopenia with multilineage dysplasia. Chromosomal analysis of his bone marrow cells revealed trisomy 8. Ten months after being diagnosed with MDS, he developed refractory stomatitis. Two months later, he experienced abdominal pain and bloody stool, and simple punched-out ulcers similar to intestinal Behçet's disease (BD) were noted in the terminal ileum on colonoscopy. Steroids, mesalazine, and adalimumab were ineffective. Nineteen months after the MDS diagnosis, he underwent cord blood transplantation from an HLA 1-locus mismatched unrelated donor in accordance with a non-myeloablative pretransplant conditioning regimen. The patient's stomatitis and ileocecal ulcers improved following the transplantation. Currently, both MDS and BD-like symptoms are in complete remission at 36 months post transplantation, and the patient continues to take low-dose oral tacrolimus for chronic skin GVHD. Allogeneic hematopoietic stem cell transplantation could become a therapeutic choice for MDS associated with BD, even if refractory intestinal BD symptoms are present.

[Successful treatment with mecobalamin in a pernicious anemia patient presenting with false-normal serum vitamin B12].

An 81-year-old woman presented to our hospital with anemia. Complete blood counts revealed macrocytic anemia; however, serum vitamin B12 and folate levels were normal. Bone marrow aspiration revealed multilineage dysplasia, and the patient was initially diagnosed with refractory cytopenia and multilineage dysplasia subtype of myelodysplastic syndrome. However, blood smear revealed hypersegmented neutrophils and bone marrow aspiration showed remarkable megaloblastic changes of erythroid cells. Based on these findings, the patient was administered 1,500 µg mecobalamin per day on a trial basis. Three weeks after initiating mecobalamin, macrocytic anemia improved. Her hemoglobin levels were also normalized along with immediate resolution of peripheral blood dysplasia. The final diagnosis was pernicious anemia (PA) based on anti-intrinsic factor positivity and the efficacy of mecobalamin. Use of automated analyzers may be associated with falsely normal or falsely elevated vitamin B12 levels in the presence of anti-intrinsic factor antibodies. Our case suggests that trial administration of mecobalamin may be an important step to correctly diagnose PA associated with falsely normal or falsely elevated vitamin B12 levels, particularly when typical morphological features of PA are present.

[Clinical characteristics of vascular adverse events and significance of peripheral artery disease as a risk factor in chronic myeloid leukemia patients treated with nilotinib].

Vascular adverse events (VAEs) in chronic myeloid leukemia (CML) patients treated with nilotinib (NIL) has become a; however, studies on strategies to prevent VAEs remain limited. Therefore, the present study investigated VAEs in 19 CML patients treated with NIL at our hospital. The median age of the patients was 65 years and median follow-up period was 55 months after the initiation of NIL. VAEs occurred in 8 patients (peripheral artery disease (PAD), n=6; cerebral infarction (CI), n=3; coronary artery disease (CAD), n=4). The median elapsed time from the initiation of NIL to VAEs was 42 months. The 4-year cumulative incidence of VAEs was 23.5%. Majority of the patients with VAEs were smokers (P=0.074). All the six patients with PAD were diagnosed on the basis of the ankle-brachial index (ABI<0.9) in the asymptomatic phase; 4 of these patients had other VAEs (CI, n=1; CAD, n=2; CI and CAD, n=1). However, antecedent asymptomatic PAD was diagnosed even before CAD was diagnosed in two patients. Nevertheless, in cardiology, extensive studies have indicated that asymptomatic PAD is a risk factor for the development of cardiovascular events. In conclusion, for the effective management of CML patients treated with NIL, a routine screening with ABI to diagnose asymptomatic PAD may be beneficial in preventing severe VAEs.

[Neurolymphomatosis due to enteropathy-associated T-cell lymphoma clinically diagnosed by FDG-PET/CT and subsequently confirmed by autopsy].

A 59-year-old man who complained of abdominal pain was referred to our hospital. Computed tomography (CT) revealed mesenteric lymph node swelling and intestinal perforation. Histopathological study of the resected ileum and lymph node demonstrated diffuse proliferation of medium-sized atypical lymphocytes. Immunohistochemistry results were positive for cluster of differentiation (CD) 3, CD8, and CD56 cells, negative for CD5 and CD4 cells, and negative for Epstein-Barr virus-encoded RNA-fluorescent in situ hybridization (EBER-FISH). It also revealed the expression of γδ T-cell receptors. On the basis of these findings, enteropathy-associated T-cell lymphoma (EATL) was diagnosed. Although the patient received two courses of cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone (CHOP) and dexamethasone, etoposide, ifosfamide, and carboplatin (DeVIC) therapy, facial nerve and lower limb paralysis manifested. Magnetic resonance imaging (MRI) and lumbar puncture revealed central nervous system invasion of the EATL. Despite intrathecal chemotherapy and high-dose cytarabine therapy, the patient's neurological symptoms deteriorated. Fluorodeoxyglucose positron emission tomography (FDG-PET) /CT scan showed the accumulation of FDG along both median and sciatic nerves, and he was diagnosed with neurolymphomatosis (NL). He died on day 120 after admission. Autopsy specimens exhibited infiltration of lymphoma cells in the median and sciatic nerves. Although only one case of suspected NL in a patient with type 2 EATL has been previously reported, we clinically diagnosed NL using FDG-PET/CT and confirmed the diagnosis by autopsy. This case is valuable in terms of the pathological diagnosis of NL.

Successful management of intraperitoneal bleeding with platelet apheresis and von Willebrand factor supplementation in a patient with essential thrombocythemia and acquired von Willebrand syndrome.

A 36-year-old woman with essential thrombocythemia (ET) was admitted to our hospital for acute lower abdominal pain. Given no family history of bleeding disorder, she was diagnosed with acquired von Willebrand syndrome. Despite having a medical history of venous thrombosis, she had never been treated for ET because of her preferences. On admission, CT scan revealed massive hemorrhage in the ascending colon with the leakage of a contrast agent. Furthermore, a delayed enhancement of fluid collection in the Douglas fossa followingcontrast CT indicated bloody ascites. Laboratory data revealed elevated platelets (1,569×103/µl) and reduced von Willebrand factor (VWF) :RCo (32%) and VWF:Ag (48%). Platelet apheresis was initiated, combined with the infusion of VWF-containing concentrates and cytoreductive therapy with hydroxyurea. Three days after admission, her platelet count decreased to 992×103/µl after the second round of platelet apheresis. CT scan revealed no hemorrhage, which implied hemostasis. Because of the absence of symptoms, she was discharged 23 days after admission. These results suggest that platelet apheresis, combined with infusion of VWF-containing concentrates and cytoreductive therapy with hydroxyurea, is an effective approach for the treatment of acquired von Willebrand syndrome characterized by emergent bleeding concomitant with ET.

Cyclic thrombocytopenia synchronizing with the menstrual cycle showing periodic phases of thrombocytopenia and rebound thrombocytosis.

A 37-year-old woman was admitted to our hospital for purpura involving the extremities and thrombocytopenia. Prednisolone (PSL) was administered based on a diagnosis of idiopathic thrombocytopenic purpura (ITP), but was not effective for maintaining her platelet count within the normal range, which showed cyclic fluctuation corresponding to the menstrual cycle. Therefore, we discontinued PSL, and cyclic thrombocytopenia (CTP) was diagnosed. CTP is a rare disease which is usually treated as ITP but with no response. Although the exact cause of CTP is uncertain, in our case, a hormonal mechanism may be responsible for fluctuating platelet count.

Multicentric Castleman's disease with multiple hepatic mass lesions mimicking malignant liver tumors.

Multicentric Castleman's disease (MCD) is a rare, non-malignant lymphoproliferative disorder. We report a case of MCD with multiple liver masses. A 26-year-old woman presented with asymptomatic anemia and hypoalbuminemia. Laboratory tests detected high CRP levels and findings indicative of polyclonal gammopathy. Abdominal CT revealed multiple hepatic large masses (≤10 cm) and partial calcification in the right lobe. Multiple enlarged lymph nodes were also identified in the cardiophrenic angle and porta hepatis. We suspected hepatic malignancy, but pathological examinations of the liver and lymph nodes demonstrated polyclonal plasma cell infiltration and fibrosis. IL-6 staining was positive for plasma cell infiltration of lymph nodes. A few plasma cells were positive for IgG4, and tests for HIV and HHV-8 were negative. Serum IL-6 and plasma VEGF levels were both elevated (45 and 536 pg/ml, respectively). The patient was diagnosed with plasma cell type MCD. We started treatment with PSL 1 mg/kg/day, which led to improvement of anemia, hypoalbuminemia, and high CRP levels. Marginal regression of liver masses was also observed. At the last follow-up, the patient had been progression-free for 18 months. To our knowledge, this is the first report of a plasma cell type MCD with liver masses.

Gastrointestinal post-transplant lymphoproliferative disorder with rapidly forming characteristic lesions after cord blood transplantation: a report of two cases.

Epstein-Barr virus (EBV)-related post-transplant lymphoproliferative disorder (PTLD) frequently involves the gastrointestinal tract, but the endoscopic characteristics of this condition have not been discussed in detail. We report two cases of EBV-related PTLD involving rapidly forming characteristic lesions. Case 1 was a 60-year-old man with acute myeloid leukemia who underwent cord blood transplantation (CBT) after which he initially achieved complete remission (CR). He developed nausea and vomiting on day 99. Gastrointestinal endoscopy showed no tumor-like lesions in his stomach. However, a second endoscopic evaluation, which was performed 7 days after the first, revealed multiple raised lesions in his stomach, and a histopathological examination of the biopsy specimen resulted in a diagnosis of EBV-related PTLD. Case 2 was a 36-year-old man with acute myeloid leukemia who underwent CBT after achieving his second CR. He suffered nausea and pharyngalgia on day 309. Although the initial gastrointestinal endoscopic examination showed only multiple erosive or small ulcerative lesions, a second endoscopic evaluation, which was performed 10 days after the first, revealed a raised lesion with a central ulcer in the duodenum. Histopathological examination of the biopsy specimen yielded a diagnosis of EBV-related PTLD. Both patients were successfully treated by reducing the dose of immunosuppressive agents and administering rituximab.

[Discordant lymphoma of duodenal EBV-positive peripheral T-cell lymphoma not otherwise specified and ileal diffuse large B-cell lymphoma].

A 79-year-old woman was admitted with a 5-kg weight loss and anorexia. Computed tomography showed diffuse lymphadenopathy, and thickening of the duodenal and ileal walls. The patient then underwent biopsy of these sites. Pathological examination revealed duodenal Epstein-Barr virus (EBV)-positive peripheral T cell lymphoma-not otherwise specified (PTCL-NOS) and EBV-negative ileal diffuse large B-cell lymphoma (DLBCL) to be present simultaneously. Combination chemotherapy including rituximab produced a reduction of the duodenal EBV-positive PTCL-NOS lesion, but had no effect on the EBV-negative ileal DLBCL lesion. Thereafter, new lymphadenopathy, high fever, and lactate dehydrogenase (LD) elevation developed, complicated by pneumonia. The patient died due to rapid deterioration of the lymphoma and pneumonia on day 108 after initiation of treatment. EBV-positive PTCL-NOS is reportedly rare and the prognosis is poor. Moreover, EBV-negative ileal DLBCL was diagnosed simultaneously. This case is considered to have had an extremely rare discordant lymphoma, although the exact etiology of its development remains unknown. We speculate that age-related disorders of the immune system and HCV infection may have been associated with the pathogenic mechanism of lymphomagenesis in this case.

Early diagnosis and successful treatment of disseminated toxoplasmosis after cord blood transplantation.

A 66-year-old woman with refractory angioimmunoblastic T-cell lymphoma underwent cord blood transplantation. Prior to transplantation, a serological test for Toxoplasma gondii-specific IgG antibodies was positive. On day 96, she exhibited fever and dry cough. Chest CT showed diffuse centrilobular ground glass opacities in both lungs. The reactivation of T. gondii was identified by the presence of parasite DNA in peripheral blood and bronchoalveolar lavage fluid. Moreover, brain MRI revealed a space occupying lesion in the right occipital lobe. Therefore, disseminated toxoplasmosis was diagnosed. She received pyrimethamine and sulfadiazine from day 99. The lung and brain lesions both showed improvement but the PCR assay for T. gondii DNA in peripheral blood was positive on day 133. On day 146, she developed blurred vision and reduced visual acuity, and a tentative diagnosis of toxoplasmic retinochoroiditis was made based on ophthalmic examination results. As agranulocytosis developed on day 158, we decided to discontinue pyrimethamine and sulfadiazine and the treatment was thus switched to atovaquone. Moreover, we added spiramycin to atovaquone therapy from day 174, and her ocular condition gradually improved. In general, the prognosis of disseminated toxoplasmosis after hematopoietic stem cell transplantation (HSCT) is extremely poor. However, early diagnosis and treatment may contribute to improvement of the fundamentally dismal prognosis of disseminated toxoplasmosis after HSCT.

[Primary graft failure in a patient with refractory acute myeloid leukemia successfully treated with modified 'one-day'-based preparative regimen followed by cord blood transplantation].

A 32-year-old woman with acute myeloid leukemia failed to achieve remission with two courses of induction chemotherapy, and she received cord blood transplantation (CBT) in a non-remission state, using an HLA-matched cord blood (CB) graft after a conditioning regimen of fludarabine (Flu) at 125 mg/m² + melphalan at 140 mg/m² + total body irradiation (TBI) at 4 Gy. Chimerism analysis of the bone marrow (BM) cells performed on day 21 after CBT revealed 99% of these cells to be the recipient type. We diagnosed the patient as having graft failure (GF), and then carried out a second CBT using an HLA-matched male CB graft on day 29 after the first CBT. The conditioning regimen (modified 'one-day'-based regimen) consisted of Flu at 30 mg/m² (3 days) + cyclophosphamide (CY) at 2 g/m² (1 day) + TBI 2 Gy. She achieved neutrophil engraftment on day 18. FISH analysis of BM cells on day 13 showed 96% to be of male origin. She has remained in complete remission for 18 months, to date, since the salvage CBT. This case suggests that salvage CBT following a modified 'one-day'-based regimen may preserve a strong graft versus leukemia effect.

[Chromosomally integrated human herpesvirus-6 requiring differential diagnosis of reactivation after allogeneic hematopoietic stem cell transplantation].

Human herpesvirus-6 (HHV-6) is known to cause critical encephalitis, as a central nervous system infection, in some hematopoietic stem cell transplantation (HSCT) recipients. Chromosomally integrated human herpesvirus-6 (CIHHV-6) persistently shows HHV-6 DNA in blood, but this does not necessarily suggest active infection. The true clinical significance in HSCT is not clear. The prevalence of CIHHV-6 in Japan is reportedly 0.21%. We herein report two HSCTs: from a CIHHV-6-positive donor to a negative recipient and from a negative donor to a positive recipient. In the CIHHV-6-positive donor case, the recipient's plasma, which had been negative for HHV-6 before HSCT, became positive after transplantation and the level then remained high, although the subject was asymptomatic. In the CIHHV-6-positive recipient case, the patient's plasma viral load was high just after transplantation, although the subject was asymptomatic, and the load gradually decreased after engraftment. Antivirals had no effect on the viral load in either case. We should consider CIHHV-6 when the HHV-6 DNA load in blood persists asymptomatically after HSCT, to avoid misdiagnosis of reactivated HHV-6 infection and overuse of antivirals. It is also useful to monitor HHV-6 DNA in blood before HSCT, to distinguish HHV-6 reactivation from CIHHV-6.