Dennis Dong Hwan Kim

The risk of polyomavirus BK-associated hemorrhagic cystitis after allogeneic hematopoietic SCT is associated with myeloablative conditioning, CMV viremia and severe acute GVHD.

Hemorrhagic cystitis (HC) is a common complication after allogeneic hematopoietic SCT (allo-HSCT). Several risk factors have been suggested including BU-containing myeloablative conditioning, unrelated donors and GVHD, but these have not been consistently reported. We conducted a retrospective study including 339 allo-HSCT recipients between 2009 and 2012. Of 339 patients, 79 (23.3%) developed HC with 2-year cumulative incidence of 24.0% (95% confidence interval, 19.4–28.9). The median onset time was 45 days (range, 16–430) after allo-HSCT. Sixty-two patients (84%) out of 74 evaluated for urine BK virus PCR testing showed a positive result (mean 2.0 × 1010 copies of DNA per mL). In univariate analysis, myeloablative conditioning, HLA-mismatched donor, CMV viremia and acute GVHD (aGVHD) grade 3–4 were significantly associated with the risk of HC. Multivariate analysis confirmed all associating factors identified in univariate analysis except for HLA-mismatched donor: myeloablative conditioning (hazard ratio (HR) 2.63, P=0.003), CMV viremia (HR 1.88, P=0.014) and aGVHD grade 3–4 (HR 1.71, P=0.029). HC did not affect OS or non-relapse mortality. Symptomatic HC is a frequent complication following allo-HSCT, with a 2-year cumulative incidence of 24.0%. Three clinical factors associated with HC were identified including myeloablative conditioning, CMV viremia and severe aGVHD.

Validation of National Institutes of Health Global Scoring System for Chronic Graft-Versus-Host Disease (GVHD) According to Overall and GVHD-Specific Survival

A new severity grading system for graft-versus-host disease (GVHD) was established by the National Institutes of Health (NIH) consensus criteria (NCC). However, its prognostic value still needs to be validated. Four hundred twenty-five consecutive patients who survived beyond 100 days after allogeneic stem cell transplantation were reviewed and reclassified using NCC. GVHD-specific survival (GSS) and cumulative incidence of relapse were compared according to the NIH global score at the onset and peak of chronic GVHD (cGVHD). Of 346 patients with cGVHD diagnosed by the Revised Seattle Criteria, 317 patients were reclassified according to the NCC as classic cGVHD (n = 144) and overlap syndrome (n = 173). The NIH global scores at onset were mild (43.2%), moderate (42.3%), and severe (14.5%), whereas more moderate (55.5%) and severe (31.6%) cGVHD was observed at the peak of cGVHD. With a median follow-up duration of 34 months, the 5-year GSS was significantly worse for the severe group than the moderate/mild groups at onset and at peak: 50.9% ± 7.8% versus 89.7% ± 3.2% versus 93.5% ± 2.4% at onset (P < .001) and 69.1% ± 5.2% versus 93.2% ± 2.1% versus 97.3% ± 2.7% at peak (P < .001). Severe NIH global score at onset and peak were confirmed as a poor prognostic factor for GSS in multivariate analysis. The cumulative incidence of relapse did not differ among the severity groups at onset or peak. In conclusion, the new NIH global scoring system was shown to differentiate a high-risk group of patients (with severe grade cGVHD) in terms of long-term transplant outcomes.

Incidence and Risk Factors for Early Hepatotoxicity and Its Impact on Survival in Patients with Myelofibrosis Undergoing Allogeneic Hematopoietic Cell Transplantation

Allogeneic hematopoietic cell transplantation (HCT) is commonly associated with hepatic complications. Patients with myelofibrosis (MF) often develop liver dysfunction in the early posttransplantation period; however, this has not yet been studied in a systematic fashion. We retrospectively evaluated 53 patients with MF who underwent HCT to assess the prevalence of acute liver toxicity and risk factors and the impact on survival. We compared the prevalence of acute hepatic complications in that group and a matched control group of 53 patients with myelodysplastic syndrome (MDS). In the MF group, during the first 6 weeks after HCT, the incidence of mild (34.2-102.6 μM), moderate (102.6-342 μM), and severe (>342 μM) hyperbilirubinemia was 34%, 40%, and 4%, respectively (normal, <22 μM). The incidence of mild/moderate transaminitis (2-10 times the upper limit of normal) was 23%, and that of severe transaminitis (>10 times the upper limit of normal) was 6%. Veno-occlusive disease as defined by the Baltimore criteria was observed in 19 patients (36%) in the MF group. Compared with MDS, MF was associated with a significantly higher incidence of moderate/severe hyperbilirubinemia (44% versus 21%; P = .02) and veno-occlusive disease (36% versus 19%; P = .05). A history of portal hypertension, biopsy-proven hepatic iron overload, or splanchnic vein thrombosis was a strong predictor of moderate/severe hyperbilirubinemia (P = .02). Acute hepatocellular injury with moderate/severe hyperbilirubinemia or transaminitis was associated with inferior survival at 12 months (P = .02) in the MF group. We conclude that patients with MF are at significant risk of early hepatotoxicity after HCT, which is associated with an adverse impact on survival.

Clonal dynamics in a single AML case tracked for 9 years reveals the complexity of leukemia progression

Most types of cancers are made up of heterogeneous mixtures of genetically distinct subclones. In particular, acute myeloid leukemia (AML) has been shown to undergo substantial clonal evolution over the course of the disease. AML tends to harbor fewer mutations than solid tumors, making it challenging to infer clonal structure. Here, we present a 9-year, whole-exome sequencing study of a single case at 12 time points, from the initial diagnosis until a fourth relapse, including 6 remission samples in between. To the best of our knowledge, it covers the longest time span of any data set of its kind. We used these time series data to track the hierarchy and order of variant acquisition, and subsequently analyzed the evolution of somatic variants to infer clonal structure. From this, we postulate the development and extinction of subclones, as well as their anticorrelated expansion via varying drug responses. In particular, we show that new subclones started appearing after the first complete remission. The presence and absence of different subclones during remission and relapses implies differing drug responses among subclones. Our study shows that time series analysis contrasting remission and relapse periods provides a much more comprehensive view of clonal structure and evolution.

Duration of first remission, hematopoietic cell transplantation-specific comorbidity index and patient age predict survival of patients with AML transplanted in second CR.

Allo-SCT is potentially curative for patients with AML. Patients transplanted in CR2 tend to experience inferior survival compared with those in CR1. We retrospectively investigated the impact of pretransplant variables on the outcome of patients transplanted with AML in CR2. Ninety-four patients with AML in CR2 received a transplant between 1999 and 2011 with myeloablative (MA, n=65) or reduced-intensity conditioning regimens (RIC, n=29). Variables investigated included cytogenetic risk at diagnosis (SWOG), hematopoietic cell transplantation-specific comorbidity index (HCT-CI), CMV status, duration of CR1 and age. Median age of all patients was 47 years (range 18–70). Multivariable analysis for OS identified three prognostically significant categories: a favorable risk group included patients with duration of CR1 ⩾6 months, age <55 years and HCT-CI score 0–3, an intermediate risk group with duration of CR1 ⩾6 months, age <55 years and HCT-CI score 4–5 and a high-risk group with duration of CR1 <6 months or age ⩾55 years (P=0.0001) with 5-year survivals of 53%, 31% and 6%, respectively. Acute and chronic GVHD did not influence this risk stratification. The stated risk factors discriminate patients with different OS and may assist in decision making for allo-SCT.

Benefit of allogeneic transplantation in patients age ≥ 60 years with acute myeloid leukemia is limited to those in first complete remission at time of transplant.

We evaluated the impact of age and remission status on 242 consecutive patients who underwent allogeneic hematopoietic cell transplantation for acute myeloid leukemia (AML) in our program between 1999 and 2011. Median age of all patients was 48 years (range, 18 to 71). Based on age and remission status, patients were divided into 4 groups: first complete remission (CR1) age <60 years (n = 116), second complete remission (CR2) age <60 years (n = 78), CR1 age ≥60 years (n = 32), and CR2 age ≥60 years (n = 16). Donors were matched related (n = 155, 64%) or matched unrelated (n = 87, 36%). Median follow-up of survivors was 65 months (range, 12 to 145). In a univariate analysis, 3-year overall survival rates of the 4 groups were 57%, 43%, 39%, and 16% (P = .003), respectively. In a multivariable analysis, hazard ratios of nonrelapse mortality and survival were 2.08 (P = .06) and 1.52 (P = .23), respectively, in patients ≥60 years in CR2 compared with ≥ 60 years in CR1. Although a plateau in survival was observed for patients ≥60 years in CR1 similar to those <60 years in CR1 and CR2, no long-term survivors were seen in patients ≥60 years in CR2. Our data suggest disappointing outcomes in AML patients ≥60 years of age transplanted in CR2. Therefore, if a transplant is indicated, early referral is recommended in patients ≥60 years with AML.

Patient age, remission status and HCT-CI in a combined score are prognostic for patients with AML undergoing allogeneic hematopoietic cell transplantation in CR1 and CR2

For AML, older age, advanced disease and increased hematopoietic cell transplant comorbidity index (HCT-CI) are associated with worse prognosis following allogeneic hematopoietic cell transplantation (HCT). This single-center retrospective study investigated the influence of pre-transplant characteristics on outcomes of 387 patients undergoing allogeneic HCT for AML in CR1 and CR2. The multivariable analysis model for overall survival (OS) included age (hazard ratio (HR)=2.24 for ages 31–64 years and HR=3.23 for age ⩾65 years compared with age ⩽30 years, P=0.003), remission status (HR=1.49 for CR2 compared with CR1, P=0.005) and HCT-CI score (HR=1.47 for ⩾3 compared with <3, P=0.005). Transplant year was significantly associated with OS (P=0.001) but this did not influence the model. A weighted score was developed with age ⩽30, CR1 and HCT-CI score <3 receiving 0 points each, and CR2 and HCT-CI score ⩾3 receiving 1 point each. Ages 31–64 received 2 points, age ⩾65 received 3 points. Scores were grouped as follows: scores 0–1 (low risk, n=36), score 2 (intermediate–low risk, n=147), score 3 (intermediate–high risk, n=141) and scores 4–5 (high risk, n=63) with 3-year OS of 71%, 55%, 42% and 29% for scores 0–1, 2, 3 and 4–5, respectively (P<0.0001). The score predicted nonrelapse mortality (P=0.03) but not cumulative incidence of relapse (P=0.18). This model should be validated for the pre-HCT assessment of AML patients in CR1 and CR2.

Large granular lymphocytosis and its impact on long-term clinical outcomes following allo-SCT.

A total of 418 patients receiving hematopoietic SCT and surviving beyond day 100 were examined for the occurrence of large granular lymphocytes (LGLs). LGL lymphocytosis was defined as the presence of at least two of the following criteria: (1) sustained lymphocytosis above 3.0 × 109/L observed in at least three consecutive determinations over a time frame of 2–3 months, (2) predominance (>30%) of LGLs in peripheral blood, (3) confirmation of monoclonality by T-cell receptor analysis using PCR 77 patients developed LGL lymphocytosis during their post-transplant course with a median onset of 312 days from transplant. The cumulative incidence at 1-, 2- and 3-years was 12.3±1.8, 20.8±2.4 and 23.6±2.7%. Patients with LGL lymphocytosis showed an OS advantage (86.2 vs 53.8%, P<0.001), lower non-relapse mortality (NRM; 3.2 vs 27.3%, P<0.001) and lower relapse incidence (9.6 vs 29.4%, P<0.001). Three clinical factors were associated with the development of LGL lymphocytosis: (1) CMV seropositive recipients (CMV-R+) compared with CMV seronegative recipients (CMV-R−; P<0.001) regardless of CMV serostatus of donor; (2) CMV reactivation (P<0.001); (3) chronic GVHD (P=0.007). In conclusion, the incidence of LGL lymphocytosis following allogeneic hematopoietic SCT was detected in ∼20% of recipients and is associated with favorable outcomes.

Adverse prognostic effect of homozygous TET2 mutation on the relapse risk of acute myeloid leukemia in patients of normal karyotype.

Mutation in ten-eleven-translocation oncogene family member 2 ( TET2 ) has been extensively investigated in the context of several hematologic malignancies and occurs in 7%–23% of patients with acute myeloid leukemia (AML).[1][1]–[4][2] TET2 acts to demethylate DNA, and TET2 mutations are

Allogeneic Peripheral Blood Stem Cell Transplantation Significantly Increases Risk of Chronic Graft-versus-Host Disease of Lung Compared with Bone Marrow Transplantation

The risk factors for lung chronic graft-versus-host disease (cGVHD) are not fully elucidated. We attempted to identify clinical risk factors for lung cGVHD after allogeneic hematopoietic cell transplantation (HCT). A total of 401 patients who underwent allogeneic HCT between 2000 and 2007 at Princess Margaret Hospital, Toronto, Canada, were evaluated for lung cGVHD serially starting on day 120 and then annually therafter. The stem cell source for HCT was peripheral blood stem cells (PBSCs) in 280 patients (69.8%) and bone marrow (BM) in 121 patients (30.2%). With a median follow-up of 36.8 months, 68 patients (17%) had a diagnosis of lung cGVHD, with a median time of onset of 11.4 months after HCT. Stem cell source was the sole risk factor identified in univariate analyses. The incidence of lung cGVHD was significantly higher in the patients receiving PBSCs (14.2% at 1 year and 22.7% at 2 years) compared with those receiving BM (6.8 at 1 year and 14.9% at 2 years; hazard ratio, 1.937; P = .02). Multivariate analyses also confirmed the use of PBSCs as an independent risk factor for lung cGVHD (hazard ratio, 2.408; 95% confidence interval, 1.289-4.496; P = .0058). The use of PBSCs is associated with an increased risk of lung cGVHD compared with the use of BM for allogeneic HCT.