Quantitative Assessment of Bone Marrow Activity Using 18 F-FLT PET in Aplastic Anemia and Myelodysplastic Syndromes.

PURPOSE: Peripheral cytopenias are typical of blood test abnormalities associated with a variety of conditions, including aplastic anemia (AA) and myelodysplastic syndromes (MDSs). We prospectively investigated the feasibility of quantitative analysis of whole-body bone marrow activity using PET with 3'-deoxy-3'- 18 F-fluorothymidine ( 18 F-FLT) in AA and MDS. PATIENTS AND METHODS: Sixty-eight patients with cytopenia underwent 18 F-FLT PET/MRI scan, with simultaneous bone marrow aspiration and biopsy for hematopoiesis evaluation. SUVs were measured in the vertebrae (Th3, 6, and 9 and L3), bilateral iliac crests, and extremities. SUV and bone marrow pathology were compared between AA and MDS and analyzed in relation to severity of AA and prognosis of MDS. RESULTS: Of the 68 patients with cytopenia, 12 were diagnosed with AA, 27 with MDS, 12 with bone marrow neoplasia, 2 with myelofibrosis, and 15 with other conditions. Iliac 18 F-FLT SUVs were significantly correlated with bone marrow cell numbers and cell density ( r = 0.47, P < 0.001 and ρ = 0.65, P < 0.001, respectively). There was a significant positive correlation between iliac and vertebral SUVs in AA and MDS ( r = 0.65, P < 0.05 and r = 0.70, P < 0.001, respectively), and the slope of the regression line was significantly steeper in AA than in MDS ( P < 0.05). In AA patients, vertebral 18 F-FLT SUVs significantly decreased with disease progression, and in MDS patients, higher whole-body 18 F-FLT uptake was associated with shorter overall survival (hazards ratio, 3.18; 95% confidence interval, 1.07-9.47; P = 0.037). CONCLUSIONS: Quantitative whole-body bone marrow imaging using 18 F-FLT PET helps distinguish AA from MDS and assess the severity of AA and prognosis of MDS.

Integrated [18F]FDG PET/MRI demonstrates the iron-related bone-marrow physiology.

We identified predictors for bone-marrow [18F]FDG uptake and MR signals among complete blood count, C-reactive protein (CRP), and anthropometric factors, and demonstrated the bone-marrow physiology using integrated [18F]FDG-PET/MRI. 174 oncology patients without bone-marrow lesions underwent whole-body [18F]FDG-PET/MRI. The standardized uptake value (SUV), apparent diffusion coefficient (ADC), proton density fat-fraction (PDFF), and a reciprocal of T2* relaxation time (R2*) were measured in lumbar vertebrae (L3-5) and bilateral ilia. Vertebrae, pelvis, and ribs were evaluated by 3-point visual scoring on DWI. The association of the PET/MR features with the predictors was examined. Multi-regression analyses identified CRP as the strongest predictor for lumbar and iliac SUVs (standardized coefficient: ß = 0.31 and ß = 0.38, respectively), and for lumbar and iliac R2* (ß = 0.31 and ß = 0.46, respectively). In contrast, age was the strongest factor influencing lumbar and iliac ADCs (ß = 0.23 and ß = 0.21, respectively), and lumbar and iliac PDFFs (ß = 0.53 and ß = 0.54, respectively). Regarding DWI-visual scores, age was the strongest predictor for vertebrae (ß = - 0.47), and the red cell distribution width (RDW) was the strongest predictor for pelvis and ribs (ß = 0.33 and ß = 0.47, respectively). The bone-marrow [18F]FDG uptake and R2* reflect anemia of inflammation (increased granulopoiesis and reduced iron metabolism), whereas bone-marrow DWI and PDFF reflect age and anemia-responsive erythropoiesis.

Whole-body bone marrow DWI correlates with age, anemia, and hematopoietic activity.

PURPOSE: To identify the predictors of bone-marrow DWI signals from anthropometric, complete blood count (CBC), and C-reactive protein (CRP), and to evaluate the association with fat-content in patients. METHOD: This retrospective study was approved by the institutional review board. A total of 113 consecutive tumor patients underwent whole-body PET/MRI. Apparent diffusion coefficient (ADC) and proton density fat fraction (PDFF) were measured and averaged in lumbar vertebrae (L3-5) and bilateral ilia. Due to respiratory motion, ribs were evaluated by 3-point visual scoring on DWI with b = 800 (1: invisible, 2: partially visible, 3: fully visible). The relationships between ADC/visual scores and anthropometric, CBC, CRP, and PDFF were examined. In females, the age-dependency was evaluated. RESULTS: Multi-regression analyses identified age as the strongest predictor of lumbar ADC (standardized coefficient: ß = 0.45), followed by red cell distribution width (RDW) (ß = -0.24), while age was the strongest predictor of iliac ADC (ß = 0.43), followed by hemoglobin (Hb) (ß = 0.22). RDW was the strongest predictor (ß = 0.47) for rib visual score and age was the second (ß = -0.39). ADC showed significant positive correlations with PDFF at L3-5 and ilium. Lumbar ADC showed a decreasing trend during middle age in females. CONCLUSIONS: Age, anemia (lower Hb), and increased hematopoietic activity (higher RDW) are the predominant predictors of ADC and the visibility of red marrow on DWI. Fat-suppression methods and bone-marrow physiology in middle-aged females may have affected the measured correlations between ADC and PDFF inconsistent with previous studies.

18F-FLT PET/MRI for bone marrow failure syndrome-initial experience.

BACKGROUND: Bone marrow failure syndrome (BMFS) is a heterogeneous group of disorders associated with single- or multiple-lineage cytopenia and failure of normal hematopoiesis. We assessed the feasibility of integrated PET/MRI with 3'-deoxy-3'-18F-fluorothymidine (18F-FLT) to assess the pathophysiology of whole-body bone marrow for the diagnosis and monitoring of BMFS. Twenty-five consecutive patients with BMFS underwent a pre-treatment 18F-FLT PET/MRI scan. They included 7 patients with aplastic anemia (AA), 16 with myelodysplastic syndrome (MDS), and 2 with myeloproliferative neoplasms (MPNs), primary myelofibrosis (MF), and secondary [post-essential thrombocythemia (post-ET)] MF. Two of the seven AA patients underwent a post-treatment scan. Eight of the 16 MDS patients who exhibited decreased 18F-FLT uptake in the pelvis were considered to have hypoplastic MDS (hypo-MDS). 18F-FLT PET and diffusion-weighted imaging (DWI) were visually and quantitatively evaluated. RESULTS: The 18F-FLT uptake in the ilium was strongly correlated with bone marrow cellularity based on biopsy samples (ρ = 0.85). AA patients exhibited heterogeneously decreased uptake of 18F-FLT according to disease severity. Multiple 18F-FLT foci were observed in the proximal extremities, and they were in the central skeleton in severe AA patients. Post-treatment 18F-FLT PET scans of severe AA patients reflected the response of hematopoietic activity to treatment. MDS patients had marked 18F-FLT uptake in the central skeleton and proximal extremities, whereas hypo-MDS patients had heterogeneously decreased uptake, similar to that of non-severe AA patients. 18F-FLT PET and DWI were unable to predict the progression to leukemia for both MDS and hypo-MDS patients. A primary MF patient had slightly decreased 18F-FLT uptake in the central skeleton, but marked expansion of bone marrow activity to the distal extremities and high uptake of tracer in the extremely enlarged spleen (extramedullary hematopoiesis). In contrast, a secondary (post-ET) MF patient demonstrated marked bone marrow uptake, reflecting the hypercellular marrow with fibrosis. DWI revealed diffusely high signal intensities in both the primary and secondary MF patients. CONCLUSION: 18F-FLT PET can be used to noninvasively assess whole-body bone marrow proliferative activity and DWI may reflect the different aspects of bone marrow pathophysiology from 18F-FLT PET. 18F-FLT PET/MRI is useful for the diagnosis and monitoring of BMFS, except for the differentiation between non-severe AA and hypo-MDS, and the prediction of progression to leukemia.

Successful treatment of disseminated intravascular coagulation by recombinant human soluble thrombomodulin in patients with acute myeloid leukemia.

Disseminated intravascular coagulation (DIC) is a life-threatening condition that frequently occurs in patients with hematologic malignancies. Currently, recombinant human soluble thrombomodulin (rTM) is a therapeutic DIC drug that is manufactured and sold in Japan only. We evaluated the efficacy of rTM compared to that of gabexate mesilate (GM), which was previously used routinely for treating DIC in Japan, in patients with acute myeloid leukemia (AML). This retrospective study enrolled 43 AML patients, including 17 with acute promyelocytic leukemia (APL), that was complicated with DIC. DIC resolution rates in non-APL AML and rTM-treated APL patients were 68.4% and 81.8%, respectively. In non-APL AML patients, the duration of rTM administration was significantly shorter than that of GM (7 vs 11 days), suggesting that rTM could improve DIC earlier than GM, although rTM was used in patients with more severe DIC. Moreover, treatment with rTM significantly improved DIC score, fibrinogen, fibrin/fibrinogen degradation product (FDP), and prothrombin time (PT) ratio. Conversely, treatment with GM only improved the DIC score and FDP. In APL patients, the duration of rTM administration was also significantly shorter than that of GM. No severe side effects associated with the progression of bleeding were observed during rTM administration. These findings suggest that rTM is safe, and its anti-DIC effects are more prompt than GM for treating AML patients with DIC.

3A Comparison between R-THP-COP and R-CHOP Regimens for the Treatment of Diffuse Large B-cell Lymphoma in Old Patients: A Single-institution Analysis.

Objective We retrospectively compared the clinical efficacy and toxicity of rituximab (R)-THP-COP (pirarubicin, cyclophosphamide, vincristine, and prednisolone) with that of R-CHOP (rituximab, adriamicin, cyclophosphamide, vincristine, and prednisolone) in previously untreated old patients with diffuse large B-cell lymphoma (DLBCL). Patients and Methods Patients admitted to our institution between 2004 and 2013 were examined. The patients received either R (375 mg/m2, day 1)-THP-COP (pirarubicin 50 mg/m2 day 1, cyclophosphamide 750 mg/m2 day 1, vincristine 1.4 mg/m2 day 1, and prednisolone 100 mg day 1-5) or R-CHOP (adriamicin 50 mg/m2 day 1, cyclophosphamide 750 mg/m2 day 1, vincristine 1.4 mg/m2 day 1, and prednisolone 100 mg day 1-5). The doses of chemotherapeutic agents were adjusted depending on the patient's age and associated complications. The treatment was performed for 6 to 8 cycles. Results Among 74 patients with DLBCL (median 76, range 65-90 years; male 39, female 35), 29 received R-THP-COP, while 45 received R-CHOP. The overall response rates were 94.6% (complete response 86.4%, partial response 8.1%). The 2-year overall and progression-free survival rates were 77.6% and 68.5% for the R-THP-COP regimen and 79.2% and 78.9% for R-CHOP, respectively. No significant differences were found between these two regimens regarding the clinical efficacies. The most frequent adverse event was neutropenia (72.4% for the R-THP-COP regimen, 88.9% for the R-CHOP regimen). The cardiac function as evaluated by ejection fraction values was not impaired in either regimen. Conclusion R-THP-COP was effective and safe as an alternative to R-CHOP.

High Risk of Tumor Lysis Syndrome in Symptomatic Patients with Multiple Myeloma with Renal Dysfunction Treated with Bortezomib.

BACKGROUND/AIM: Tumor lysis syndrome (TLS) is a life-threatening complication associated with cancer chemotherapy. We retrospectively evaluated the risk of developing TLS in patients with symptomatic multiple myeloma undergoing chemotherapy. PATIENTS AND METHODS: Sixty-four patients (median age=71 years, range=48-87 years, 35 males/29 females) who were treated at our Institution between April 2006 and December 2015 were evaluated. RESULTS: A total of 124 chemotherapy courses were administered, of which 63 courses were bortezomib-based regimens and 34 courses were immunomodulatory drug (IMiD)-based regimens. TLS occurred in 13 (10.5%) out of 124 chemotherapy courses with five (4.0%) cases of laboratory TLS and eight (6.5%) cases of clinical TLS. The incidences of TLS were 17.5% for bortezomib-containing regimens and 3.2% for non-bortezomib-based regimens. No TLS occurred in the patients treated with IMiD-containing regimens. TLS occurred more frequently in the patients with elevated uric acid, creatinine, or beta-2-microglobulin levels at baseline. The patients with disease classified as advanced International Staging System also developed TLS more frequently. All the patients who developed clinical TLS received bortezomib-containing regimens (8/63, 12.7%). Among them, patients with elevated values of uric acid or creatinine developed clinical TLS more often than those without such elevation. The incidence of clinical TLS was 33.3% if the patients had renal dysfunction at baseline and were subsequently treated with bortezomib-based regimens (8/24 cases). CONCLUSION: Patients with renal dysfunction or a high uric acid level receiving bortezomib-based chemotherapy have a high risk of developing TLS.

Prognostic effect of peripheral blood cell counts in advanced diffuse large B-cell lymphoma treated with R-CHOP-like chemotherapy: A single institution analysis.

The primary objective of the present study was to correlate blood cell counts (lymphocyte, monocyte and platelet counts) with early disease relapse following the attainment of complete remission (CR) by the rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP)-like regimen in patients with advanced diffuse large B-cell lymphoma (DLBCL). In total, 30 patients were evaluated, with a median follow-up period of 43 months. All the participating patients attained CR. In total, eight patients experienced relapse within two years of the diagnosis, and the three-year overall survival rate was recorded as 77%. The peripheral counts for lymphocytes, monocytes and platelets, and the lymphocyte-monocyte ratio, all of which have been reported to be prognostic in DLBCL, were assessed. None of these parameters were correlated with the incidence of early relapse or with the prognosis. The lymphocyte count was higher in the patients with durable remission than in those who relapsed, however, no significant differences were identified. Thus, the present study concluded that early disease relapse was not predicted by peripheral blood cell counts in advanced DLBCL that reached CR using the R-CHOP-like regimen.

The response to induction therapy is crucial for the treatment outcomes of elderly patients with acute myeloid leukemia: single-institution experience.

BACKGROUND/AIM: The prognosis of acute myeloid leukemia (AML) in elderly patients remains poor due to their poor general condition and the intrinsic chemotherapy-resistant nature of their leukemia cells. The present retrospective study evaluated the clinical background as well as the response to treatment, of an unselected group of elderly patients with AML who were admitted to our Institution over a period of six years. PATIENTS AND METHODS: Patients aged 65 years or older with AML admitted to our Institution between January 2005 and May 2011 were evaluated retrospectively. RESULTS: Forty-six patients were admitted to our Institution, among whom 41 received remission induction chemotherapy. Twenty-four patients received intensive chemotherapy, while 13 received low-dose cytarabine-based chemotherapy. Other modalities were used in four patients. Complete remission was obtained in 20 patients (48.8%). The complete remission rate (50.0%) tended to be higher in patients receiving intensive chemotherapy than in those receiving low-dose cytarabine-based regimens (30.7%; p=0.25). The median survival time for the whole patient group was 12 months and the 2-year overall survival was 18%. The median survival times for patients with complete remission and for non-responding patients were 14 months and 7 months, respectively. The 2-year overall survival in patients with complete remission was 32%, while that of non-responding patients was 6% (p=0.0025, log-rank test). CONCLUSION: The present study suggests the necessity of achieving complete remission for obtaining better survival for elderly patients with AML.

A nelarabine-resistant T-lymphoblastic leukemia CCRF-CEM variant cell line is cross-resistant to the purine nucleoside phosphorylase inhibitor forodesine.

BACKGROUND/AIM: Forodesine inhibits purine nucleoside phosphorylase, resulting in an accumulation of intracellular dGTP and consequently cell death. 9-ß-D-Arabinofuranosylguanine (ara-G) is an active compound of nelarabine that is intracellularly phosphorylated to a triphosphate form, which inhibits DNA synthesis. Both agents show cytotoxicity toward T-cell malignancies. In the present study, we investigated the cytotoxicity of forodesine in vitro using ara-G-resistant leukemia cells. MATERIALS AND METHODS: T-Lymphoblastic leukemia cell line CCRF-CEM and ara-G-resistant CEM variant cell line CEM/ara-G that we had previously established were used. RESULTS: A growth-inhibition assay demonstrated that CEM cells were insensitive to single-agent forodesine treatment. The cells were also insensitive to deoxyguanosine at a maximal concentration of 10 µM. CEM/ara-G cells were 80-fold more resistant to ara-G than were CEM cells, and the mode of sensitivity to forodesine and deoxyguanosine was similar to that of CEM cells. In the presence of 10 µM deoxyguanosine, forodesine effectively inhibited the growth of CEM cells but not that of CEM/ara-G cells. Flow cytometric analyses showed that combination of forodesine and deoxyguanosine induced apoptosis of CEM cells but not of CEM/ara-G cells. The addition of ara-G did not augment the cytotoxicity of the forodesine/deoxyguanosine combination towards CEM cells or CEM/ara-G cells. The combination index revealed antagonism between forodesine and ara-G. The intracellular production of ara-G triphosphate was reduced in the presence of forodesine. CONCLUSION: Nelarabine-resistant CEM/ara-G cells are insensitive to forodesine.

A high serum uric acid level is associated with poor prognosis in patients with acute myeloid leukemia.

Uric acid in serum (S-UA) is produced by the breakdown of the cellular nucleic acids of leukemia cells, and may be a marker of disease aggressiveness. S-UA levels were examined for association with clinical outcomes in patients with acute myeloid leukemia (AML). Fifty-six patients with AML admitted to our Institution were evaluated retrospectively. The median S-UA level at diagnosis was 5.0 mg/dl (range 2-13.8 mg/dl). The S-UA levels did not correlate with peripheral lactate dehydrogenase, peripheral white blood cell counts, or peripheral blast counts, and were not proportional to bone marrow blast counts or marrow cellularity. The S-UA levels in the patients who achieved complete remission were slightly lower than those in those who did not. S-UA levels less than, or equal to the median (5.0 mg/dl) were significantly associated with better prognoses, compared with S-UA levels greater than 5.0 mg/dl. Thus, the S-UA level may predict the prognosis of AML, and is a versatile and cost-effective test for such a purpose.

Detectable Wilms' tumor-1 transcription at treatment completion is associated with poor prognosis of acute myeloid leukemia: a single institution's experience.

BACKGROUND/AIM: The present retrospective study was conducted to measure Wilms' tumor-1 (WT1) mRNA levels in the peripheral blood of patients with acute myeloid leukemia (AML) in order to examine any association with the clinical outcomes. PATIENTS AND METHODS: A total of 58 AML patients were evaluated retrospectively in our institution. WT1 transcripts were determined by real-time reverse transcriptase-polymerase chain reaction in peripheral blood samples. RESULTS: WT1 levels at diagnosis did not vary according to response of induction treatments, and the levels were comparable between the patients with durable remission and the patients with relapse of disease. WT1 levels at the completion of the treatment were higher in the group with relapse of disease than in the group with sustained remission. Detectable WT1 transcripts after the completion of chemotherapy courses were associated with poor prognoses. CONCLUSION: WT1 mRNA levels at treatment completion may predict for prognosis of AML.

Early relapse is associated with high serum soluble interleukin-2 receptor after the sixth cycle of R-CHOP chemotherapy in patients with advanced diffuse large B-cell lymphoma.

The clinical significance of serum soluble interleukin-2 receptor (sIL2R) levels was retrospectively assessed in patients with advanced diffuse large B-cell lymphoma (DLBCL). Twenty-one patients, who were newly-diagnosed with advanced DLBCL (stage III and IV) between 2006 and 2009, were evaluated. The median follow-up period was 37 months. All patients received 6-8 cycles of chemotherapy with rituximab in combination with doxorubicin, cyclophosphamide, vincristine, and prednisolone (CHOP)-like regimens and attained complete remission. Although all patients reached complete remission, six patients experienced disease relapse within 1 year after treatment completion. The overall survival was significantly poorer in patients with relapse than in patients with durable remission. The sIL2R levels after the sixth cycle of treatment were significantly higher in the relapse group than in the non-relapse group. Thus, the present study suggests sIL2R levels to be a valuable predictor for the prognosis of patients with advanced DLBCL.

Wilms' tumor-1 transcript in peripheral blood helps diagnose acute myeloid leukemia and myelodysplastic syndrome in patients with pancytopenia.

BACKGROUND/AIM: Pancytopenia is caused by acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), aplastic anemia (AA), or by non-hematological diseases. Because Wilms' tumor-1 (WT1) is overexpressed in patients with AML and MDS, its expression level may be helpful for diagnosing these hematological malignancies. PATIENTS AND METHODS: We retrospectively investigated the WT1 transcripts in peripheral blood (PB) from 47 patients with decreased blood cell counts. RESULTS: The final diagnoses included AML, MDS, AA, drug poisoning, and non-hematological diseases. PB WT1 mRNA was overexpressed in AML and MDS, whereas the patients with other diseases mostly tested negatively for the transcript. The patients with MDS with higher marrow blast counts had higher PB WT1 mRNA levels. The sensitivity of the PB WT1 transcript in detecting AML and MDS was 78%, and the specificity was 90%. CONCLUSION: The WT1 mRNA level in PB may help diagnose AML and MDS in patients with pancytopenia.

Induction of DNA strand breaks is critical to predict the cytotoxicity of gemtuzumab ozogamicin against leukemic cells.

Gemtuzumab ozogamicin (GO) consists of the CD33 antibody linked to calicheamicin. The binding of GO to the CD33 antigen on leukemic cells results in internalization followed by the release of calicheamicin, thereby inducing DNA strand breaks. We hypothesized that the induction of DNA strand breaks would be a surrogate marker of GO cytotoxcity. Here, two GO-resistant variants (HL/GO-CSA [225-fold], HL/GO [200-fold]) were established by serially incubating human leukemia HL-60 cells with GO with or without a P-glycoprotein (P-gp) inhibitor, cyclosporine A, respectively. The CD33 positivity was reduced in both variants. The HL/GO-CSA cells showed an increased multidrug resistance protein-1 (MRP1) transcript, and an MRP1 inhibitor partially reversed GO resistance. The HL/GO cells had neither P-gp nor MRP1 overexpression. Microarray analysis and Western blotting indicated elevated levels of DNA repair-associated proteins in both variants. Two other leukemic subclones, showing either P-gp or MRP1 overexpression, were also GO-resistant. Using single cell gel electrophoresis analysis, it was determined that GO-induced DNA strand breaks increased dose-dependently in HL-60 cells, whereas the number of breaks was reduced in the GO-resistant cell lines. The induction of DNA strand breaks was correlated with GO sensitivity among these cell lines. The CD33 positivity and the expression levels of transporters were not proportional to drug sensitivity. Using primary leukemic cells, the induction of DNA strand breaks appeared to be associated with GO sensitivity. Thus, GO-induced DNA strand breaks as the final output of the mechanism of action would be critical to predict GO cytotoxicity.

Successful Administration of Recombinant Human Soluble Thrombomodulin α (Recomodulin) for Disseminated Intravascular Coagulation during Induction Chemotherapy in an Elderly Patient with Acute Monoblastic Leukemia Involving the t(9;11)(p22;q23) MLL/AF9 Translocation.

Patients with acute myelogenous leukemia complicate with disseminated intravascular coagulation (DIC), not only at the time of the initially leukemia diagnosis, but also during induction chemotherapy. In Japan, recently, a recombinant human soluble thrombomodulin alpha (Recomodulin) has been introduced as a new type of anti-DIC agent for clinical use in patients with hematological cancer or infectious disease. We describe a 67-year-old female case in which 25,600 units of Recomodulin for 6 days were successfully administered for both initially complicating and therapy-induced DIC without any troubles of bleeding in an acute monoblastic leukemia (AML-M5a) patient with the MLL gene translocation. Furthermore, the levels of DIC biomarkers recovered rapidly after the Recomodulin treatment. Our case suggests that DIC control using Recomodulin is one of the crucial support-therapies during remission induction chemotherapy in patients with acute leukemia of which type tends to complicate extramedullary or extranodal infiltration having potential to onset DIC.