Clarithromycin As an Alternative and Prophylactic Agent in a Hematopoietic Stem Cell Transplantation Patient.

BACKGROUND Nocardia infections have rarely been reported in hematopoietic stem cell transplantation (HSCT) patients, who usually receive the prophylactic use of sulfamethoxazole/trimethoprim (ST) against Pneumocystis jiroveci. However, the ST prophylaxis, sensitive to Nocardia species, sometimes induces renal toxicities. Therefore, alternative prophylactic or therapeutic drugs are required for nocardiosis in HSCT patients. CASE REPORT A 34-year-old Japanese man with acute mixed phenotypic leukemia with t(9; 22) received allogenic peripheral blood HSCT from a haplo-identical sibling donor. He developed graft versus host disease (GVHD) with grade II, and was treated with prednisolone and cyclosporine A with concurrent ciprofloxacin, fluconazole, valacyclovir, and ST. However, the prophylactic ST was ceased because of its renal toxicity. He developed a pulmonary nodular lesion with elevated ß-D-glucan and Aspergillus galactomannan antigen. Repeated blood and sputum culture isolated no pathogens. Voriconazole treatment administered once improved these lesions and laboratory findings. One month later, he presented with right pleuritic chest pain and multiple ring-enhancing cavitation lesions along the ribs. A needle biopsy demonstrated Nocardia elegans, which is an extremely rare infection induced by Nocardia species, in the cavitation lesions, shown by 16S rRNA gene sequencing. He was started on doripenem and liposomal amphotericin B, and a subsequent treatment kept him free from Nocardia elegans infection, without any adverse effects, while continuing the cyclosporine A and prednisolone treatment for chronic GVHD. CONCLUSIONS Clarithromycin has fewer adverse effects than ST. This case suggests that clarithromycin is an appropriate alternative and prophylactic therapy for patients with nocardiosis and ST toxicities.

Human SIRT2 and SIRT3 deacetylases function in DNA homologous recombinational repair.

SIRT2 and SIRT3 protein deacetylases maintain genome integrity and stability. However, their mechanisms for maintaining the genome remain unclear. To examine the roles of SIRT2 and SIRT3 in DSB repair, I-SceI-based GFP reporter assays for HR, single-strand annealing (SSA) and nonhomologous end joining (NHEJ) repair were performed under SIRT2- or SIRT3-depleted conditions. SIRT2 or SIRT3 depletion inhibited HR repair equally to RAD52 depletion, but did not affect SSA and NHEJ repairs. SIRT2 or SIRT3 depletion disturbed the recruitment of RAD51 to DSB sites, an essential step for RAD51-dependent HR repair, but not directly through RAD52 deacetylation. SIRT2 or SIRT3 depletion decreased the colocalization of γH2AX foci with RPA1, and thus, they might be involved in initiating DSB end resection for the recruitment of RAD51 to DSB sites at an early step in HR repair. These results show the novel underlying mechanism of the SIRT2 and SIRT3 functions in HR for genome stability.

Nodal histiocytic sarcoma with prominent eosinophilic infiltration: expression of eotaxin-2 on tumor cells.

BACKGROUND: Histiocytic sarcoma (HS) is a rare neoplasm showing morphological and immunophenotypic features of mature tissue histiocytes. We report a patient with nodal HS exhibiting prominent reactive eosinophilic infiltration. CASE PRESENTATION: A 68-year-old man presented with intermittent left lower abdominal pain and weight loss over 3 months. A computed tomography scan revealed multiple abdominal nodules. Open biopsy of the mesenteric tumors was performed for definitive diagnosis. Histologically, the tumor was comprised of a diffuse noncohesive proliferation of pleomorphic large cells, including multinucleated cells. Neoplastic cells were positive for histiocytic markers (CD68, CD163, and LIGHT) and PD-L1 but lacked markers of Langerhans cells, follicular dendritic cells, and epithelial cells. Frequent reactive inflammatory cells were intermingled in the background. Interestingly, prominent eosinophilic infiltration was also noted. Spindle neoplastic cells were prone to be present around areas with little to no eosinophilic infiltration and exhibiting fibrosis and lymphatic vessel proliferation. Conversely, polygonal neoplastic cells were prone to be present around areas with relatively large amounts of eosinophilic infiltration without fibrosis or lymphatic vessel proliferation. Immunohistochemically, the tumor cells and reactive eosinophils expressed eotaxin-2 and eotaxin-3, respectively. CONCLUSION: We revealed that eotaxins induced the selective migration of eosinophils into tissues in this case. These eosinophils may affect the tumor remodeling and tumor biology characteristics of HS, such as fibrosis and lymphatic vessel proliferation.

Impact of comorbidity and relative dose intensity on outcomes in diffuse large B-cell lymphoma patients treated with R-CHOP.

BACKGROUND: Comorbidity and relative dose intensity (RDI) have been associated with survival in diffuse large B-cell lymphoma (DLBCL) patients, but both relationships remain unaddressed in the same patients. METHODS: A retrospective review of consecutive DLBCL patients treated from January 2010 to October 2018 was performed. Data for the clinical characteristics of the patients, including the Charlson Comorbidity Index (CCI) and RDI, on their outcomes were evaluated. RESULTS: A total of 211 patients with a median age of 72 years (range 19-90 years) were analyzed. CCI ≥ 2 was associated with poor event-free survival (EFS) and overall survival (OS). RDI < 70% was associated with worse EFS and OS. A multivariate analysis revealed that RDI < 70% was only a poor risk factor for the reduction of OS in elderly DLBCL patients (65 years <) and independent from the presence of CCI. The relationship between CCI and RDI in elderly patients was analyzed in four groups, based on CCI ≥ 2 or less and RDI ≥ 70% or less. The group with CCI ≥ 2 and RDI < 70% had a poorer OS and EFS, as compared to the other three groups. The group with CCI < 2 and RDI ≥ 70% had a superior OS but an identical EFS, as compared to the two groups with CCI < 2 and RDI < 70% and CCI ≥ 2 and RDI ≥ 70%. CONCLUSIONS: CCI ≥ 2 was associated with a poorer outcome, but maintaining RDI ≥ 70% may improve the outcome, especially in elderly DLBCL patients.

Characterization of reemergent anti-B red blood cell antibodies in a patient with recurrent acute myeloid leukemia with ABO-incompatible allogeneic peripheral blood stem cell transplantation.

BACKGROUND: Isohemagglutinins against ABO antigens absent on both recipient and donor red blood cells (RBCs) increase or decrease after ABO-incompatible hematopoietic stem cell transplantation (HSCT). However, few reports have described the changes in the isohemagglutinin titers and the characteristics in patients with recurrent hematologic conditions after ABO-incompatible HSCT. CASE REPORT: A 59-year-old female with acute erythroid leukemia received a peripheral blood stem cell transplant from her HLA-haploidentical daughter. The patient was typed as group O with anti- A (4+) and B (4+) isohemagglutinins, while the donor was typed as group B. The bone marrow cells achieved complete donor cell chimerism on Day 13 after HSCT. On Day 120, the patient showed 97% B RBC type with persistent anti-A (3+) and without anti-B antibodies. On Day 375, her leukemia relapsed, and recipient type O RBCs and anti-B antibodies sequentially reemerged. However, clinicolaboratory hemolysis and erythroid aplasia were not detected in the patient. RESULTS: The post-HSCT sera agglutinated the allo B RBCs, but not the donor B RBCs, while the pre-HSCT sera agglutinated both RBCs. The burst-forming/colony-forming units of erythroid formation from the donor peripheral blood stem cells were impaired by only the pre-HSCT sera and not by the post-HSCT sera. CONCLUSION: To our knowledge, this is the first report investigating the characteristic changes of isohemagglutinins between the pre- and post-HSCT sera in a patient with recurrent acute myeloid leukemia. The present study suggests that the plasma cells producing anti-donor B RBCs in the patient have been selectively eliminated or induced into an anergic state by the post-HSCT immunologic reconstruction.

Novel function of HATs and HDACs in homologous recombination through acetylation of human RAD52 at double-strand break sites.

The p300 and CBP histone acetyltransferases are recruited to DNA double-strand break (DSB) sites where they induce histone acetylation, thereby influencing the chromatin structure and DNA repair process. Whether p300/CBP at DSB sites also acetylate non-histone proteins, and how their acetylation affects DSB repair, remain unknown. Here we show that p300/CBP acetylate RAD52, a human homologous recombination (HR) DNA repair protein, at DSB sites. Using in vitro acetylated RAD52, we identified 13 potential acetylation sites in RAD52 by a mass spectrometry analysis. An immunofluorescence microscopy analysis revealed that RAD52 acetylation at DSBs sites is counteracted by SIRT2- and SIRT3-mediated deacetylation, and that non-acetylated RAD52 initially accumulates at DSB sites, but dissociates prematurely from them. In the absence of RAD52 acetylation, RAD51, which plays a central role in HR, also dissociates prematurely from DSB sites, and hence HR is impaired. Furthermore, inhibition of ataxia telangiectasia mutated (ATM) protein by siRNA or inhibitor treatment demonstrated that the acetylation of RAD52 at DSB sites is dependent on the ATM protein kinase activity, through the formation of RAD52, p300/CBP, SIRT2, and SIRT3 foci at DSB sites. Our findings clarify the importance of RAD52 acetylation in HR and its underlying mechanism.

Nocardia otitidiscaviarum meningitis in a diffuse large B-cell lymphoma patient with CD4-positive lymphocytopenia and persistent oligoclonal CD8-positive lymphocytes in the peripheral blood.

Nocardiosis, sometimes presenting with multiple granulomatous lesions, is a rare opportunistic infection occurring in immunocompromised patients. However, its immunological features remain largely unaddressed. We investigated the immunological characteristics of human nocardiosis and examined the component cells of the granulomatous lesions. A 66-year-old man with diffuse large B-cell lymphoma presented with fever and multiple nodules in the lung during chemotherapy. The blood culture formed white colonies, but their characterization was difficult by routine microbiological laboratory methods. Matrix-assisted laser desorption ionization-time of flight mass spectrometry identified the colonies as Nocardia otitidiscaviarum. Meanwhile, the patient suddenly experienced an epileptic seizure without a brain abscess. His cerebrospinal fluid (CSF) showed neutrophilic pleocytosis (108/mm3). The conventional agar culturing failed to isolate colonies, but culturing with brain-heart infusion agar generated colonies. These colonies were completely concordant with those from the blood, as confirmed by 16S rRNA gene sequencing. Therefore, the patient had developed meningitis through sepsis induced by N. otitidiscaviarum. His CD4-positive T-lymphocyte counts were low, and oligoclonal CD8-positive αß T-lymphocytes were present in the blood prior to the first and after three cycles of chemotherapy. He had bone marrow granulomatous lesions comprising lymphoma and CD8-positive αß T-cells. Treatment with sulfamethoxazole/trimethoprim relieved all of his symptoms. The combined analysis by microbiological and molecular methods determined the cause of his epileptic seizure. His immunological characteristics, including low CD4-positive or CD8-positive αß T-lymphocytes, may have contributed to the unusual clinical presentations by N. otitidiscaviarum, which rarely involves the central nervous system.

Rapid reduction in BCR-ABL1 transcript predicts deep molecular response in dasatinib-treated chronic-phase chronic myeloid leukaemia patients.

OBJECTIVES: We conducted a phase-II study to evaluate the efficacy and safety of dasatinib in patients newly diagnosed with chronic-phase chronic myeloid leukaemia (CML-CP) in Japan (IMIDAS PART 2 study). METHODS: Seventy-nine patients were administered 100 mg dasatinib once daily. We examined pretreatment and post-treatment influences of various factors. The BCR-ABL1 international scale (IS), halving time (HT) and reduction rate of BCR-ABL1 transcript within the initial 1 or 3 months of therapy (RR-BCR-ABL11m,3m ) were the post-treatment factors investigated to predict the molecular response. RESULTS: The estimated major molecular response (MMR), molecular response 4.0 (MR4.0) and molecular response 4.5 (MR4.5) rates were 77.2%, 49.4% and 35.4%, respectively, at 12 months. Grade 3/4 non-haematologic adverse events were infrequent. Multivariate analysis showed that age >65 years was significantly correlated with MR4.0 and MR4.5 (deep molecular response: DMR) at 12 months. All post-treatment factors at 3 months predicted DMR by univariate analysis. However, RR-BCR-ABL13m was the only significant landmark for predicting DMR by multivariate analysis. CONCLUSIONS: Primary treatment of CML-CP with dasatinib enabled early achievement of MMR and DMR, particularly in elderly patients, with high safety. Furthermore, RR-BCR-ABL13m was found to be a more useful predictor of DMR than HT-BCR-ABL1 and BCR-ABL1 IS.

Differentiation and Molecular Properties of Mesenchymal Stem Cells Derived from Murine Induced Pluripotent Stem Cells Derived on Gelatin or Collagen.

The generation of induced-pluripotential stem cells- (iPSCs-) derived mesenchymal stem cells (iMSCs) is an attractive and promising approach for preparing large, uniform batches of applicable MSCs that can serve as an alternative cell source of primary MSCs. Appropriate culture surfaces may influence their growth and differentiation potentials during iMSC derivation. The present study compared molecular properties and differentiation potential of derived mouse iPS-MSCs by deriving on gelatin or collagen-coated surfaces. The cells were derived by a one-step method and expressed CD73 and CD90, but CD105 was downregulated in iMSCs cultured only on gelatin-coated plates with increasing numbers of passages. A pairwise scatter analysis revealed similar expression of MSC-specific genes in iMSCs derived on gelatin and on collagen surfaces as well as in primary mouse bone marrow MSCs. Deriving iMSCs on gelatin and collagen dictated their osteogenic and adipose differentiation potentials, respectively. Derived iMSCs on gelatin upregulated Bmp2 and Lif prior to induction of osteogenic or adipose differentiation, while PPARγ was upregulated by deriving on collagen. Our results suggest that extracellular matrix components such as gelatin biases generated iMSC differentiation potential towards adipose or bone tissue in their derivation process via up- or downregulation of these master genes.

Intra- and extracellular plasminogen activator inhibitor-1 regulate effect of vitronectin against radiation-induced endothelial cell death.

Plasminogen activator inhibitor-1 (PAI-1) is induced by radiation resulting in endothelial cell impairment, potentially leading to multiple organ failure. Vitronectin (VN) is a 75-kDa glycoprotein (VN75) cleaved into two forms (VN75 or VN65/10) by furin, which is regulated by intracellular PAI-1. VN protects against radiation-induced endothelial cell death, but the mechanisms involved in VN processing and its interactions with intra- and extracellular PAI-1 remain unclear. We examined these processes in cells in vitro using recombinant proteins or overexpression of VN and PAI-1 genes, including furin-susceptible (T381) and furin-resistant VN (A381). VN processing was analyzed using a mutant PAI-1 with relatively weaker binding to VN. VN function was evaluated by survival of radiation-damaged endothelial cells. Wild-type, but not mutant PAI-1 inhibited furin-dependent VN processing. Gene transfer revealed that furin-susceptible VN was processed more than the furin-resistant form, but processing of both was inhibited by PAI-1 overexpression. Intracellular PAI-1 formed a complex with VN75 (T381) in cells and media, and the VN75 form was secreted preferentially. Only VN75 protected against radiation-induced endothelial cell death, in which its effect was abolished by wild-type but not mutant PAI-1. These findings indicate that intracellular PAI-1 inhibits VN processing and protects against radiation-induced endothelial cell death.

Successful high-dose dexamethasone treatment of acquired pure red cell aplasia following ABO major mismatched allogeneic hematopoietic stem cell transplantation.

A 46-year-old man was diagnosed with acute myelomonocytic leukemia involving inv(16)(p13.1q22) in August 2007. He received a human leukocyte antigen-identical, ABO major-mismatched (donor: A, recipient: O) bone marrow transplantation from an unrelated donor in June 2009. Cyclosporin A (CsA) and short-course methotrexate were used for graft versus host disease prophylaxis. Although granulocyte and platelet engraftment were achieved, the patient exhibited persistent anemia and was dependent on red blood cell (RBC) transfusions. Bone marrow aspiration on day 63 revealed the near absence of erythroid precursors, a finding consistent with pure red cell aplasia. No CBFß-MYH11 transcripts were detected. The recipient's anti-A IgM antibody titer was 1:64, and his anti-A IgG antibody titer was 1:1024. The discontinuation of CsA, and the initiation of rituximab and donor lymphocyte infusions were all ineffective against his anemia. He was treated with high-dose dexamethasone (DEXA) (40 mg/day DEXA, days 657-660, days 757-760; 20 mg/day DEXA, days 764-767, days 772-775) in April 2010. A follow-up examination performed at 7 months after the high-dose DEXA treatment showed the patient's anti-A antibody titer to have dropped to an undetectable level. His hemoglobin levels also returned to normal (Hb: 13.4 g/dl), and he no longer required RBC transfusions.

High prevalence of diffuse large B-cell lymphoma in occult hepatitis B virus-infected patients in the Tohoku district in Eastern Japan.

Occult hepatitis B virus (HBV) infection is a clinical challenge, but its relationship to clinicopathologic features and the risk of progression to malignant lymphoma (ML) are poorly defined. We estimated the prevalence of HBV infection of 1,358 patients with newly diagnosed ML. HBV infection was more prevalent in ML than in control patients. The occult HBV infection group had a higher median onset age, no liver or spleen involvement, and higher prevalence of diffuse large B-cell lymphoma than the other groups, indicating that occult HBV infection is a distinct clinicopathologic entity. J. Med. Virol. 88:2206-2210, 2016. © 2016 Wiley Periodicals, Inc.