Austin Kulasekararaj

TP53 Mutations in Low-Risk Myelodysplastic Syndromes With del(5q) Predict Disease Progression

PURPOSE To determine the frequency of TP53 mutations and the level of p53 protein expression by immunohistochemistry (IHC) in low-risk myelodysplastic syndromes (MDS) with del(5q) and to assess their impact on disease progression. PATIENTS AND METHODS Pre- and postprogression bone marrow (BM) samples from 55 consecutive patients with International Prognostic Scoring System low risk (n = 32) or intermediate-1 risk (n = 23) were studied by next-generation sequencing of TP53. IHC for p53 was performed on 148 sequential BM samples. RESULTS TP53 mutations with a median clone size of 11% (range, 1% to 54%) were detected in 10 patients (18%) already at an early phase of the disease. Mutations were equally common in low-risk and intermediate-1-risk patients and were associated with evolution to acute myeloid leukemia (5 of 10 v 7 of 45; P = .045). Nine of 10 patients carrying mutations showed more than 2% BM progenitors with strong p53 staining. The probability of a complete cytogenetic response to lenalidomide was lower in mutated patients (0 of 7 v 12 of 24; P = .024). CONCLUSION By using sensitive deep-sequencing technology, we demonstrated that TP53 mutated populations may occur at an early disease stage in almost a fifth of low-risk MDS patients with del(5q). Importantly, mutations were present years before disease progression and were associated with an increased risk of leukemic evolution. TP53 mutations could not be predicted by common clinical features but were associated with p53 overexpression. Our findings indicate a previously unrecognized heterogeneity of the disease which may significantly affect clinical decision making.

Prognostic impact of SNP array karyotyping in myelodysplastic syndromes and related myeloid malignancies

Single nucleotide polymorphism arrays (SNP-As) have emerged as an important tool in the identification of chromosomal defects undetected by metaphase cytogenetics (MC) in hematologic cancers, offering superior resolution of unbalanced chromosomal defects and acquired copy-neutral loss of heterozygosity. Myelodysplastic syndromes (MDSs) and related cancers share recurrent chromosomal defects and molecular lesions that predict outcomes. We hypothesized that combining SNP-A and MC could improve diagnosis/prognosis and further the molecular characterization of myeloid malignancies. We analyzed MC/SNP-A results from 430 patients (MDS = 250, MDS/myeloproliferative overlap neoplasm = 95, acute myeloid leukemia from MDS = 85). The frequency and clinical significance of genomic aberrations was compared between MC and MC plus SNP-A. Combined MC/SNP-A karyotyping lead to higher diagnostic yield of chromosomal defects (74% vs 44%, P < .0001), compared with MC alone, often through detection of novel lesions in patients with normal/noninformative (54%) and abnormal (62%) MC results. Newly detected SNP-A defects contributed to poorer prognosis for patients stratified by current morphologic and clinical risk schemes. The presence and number of new SNP-A detected lesions are independent predictors of overall and event-free survival. The significant diagnostic and prognostic contributions of SNP-A-detected defects in MDS and related diseases underscore the utility of SNP-A when combined with MC in hematologic malignancies.

TP53 mutations in myelodysplastic syndrome are strongly correlated with aberrations of chromosome 5, and correlate with adverse prognosis

This study aimed to determine the incidence/prognostic impact of TP53 mutation in 318 myelodysplastic syndrome (MDS) patients, and to correlate the changes to cytogenetics, single nucleotide polymorphism array karyotyping and clinical outcome. The median age was 65 years (17–89 years) and median follow‐up was 45 months [95% confidence interval (CI) 27–62 months]. TP53 mutations occurred in 30 (9·4%) patients, exclusively in isolated del5q (19%) and complex karyotype (CK) with ‐5/5q‐(72%), correlated with International Prognostic Scoring System intermediate‐2/high, TP53 protein expression, higher blast count and leukaemic progression. Patients with mutant TP53 had a paucity of mutations in other genes implicated in myeloid malignancies. Median overall survival of patients with TP53 mutation was shorter than wild‐type (9 versus 66 months, P < 0·001) and it retained significance in multivariable model (Hazard Ratio 3·8, 95%CI 2·3–6·3,P < 0·001). None of the sequentially analysed samples showed a disappearance of the mutant clone or emergence of new clones, suggesting an early occurrence of TP53 mutations. A reduction in mutant clone correlated with response to 5‐azacitidine, however clones increased in non‐responders and persisted at relapse. The adverse impact of TP53 persists after adjustment for cytogenetic risk and is of practical importance in evaluating prognosis. The relatively common occurrence of these mutations in two different prognostic spectrums of MDS, i.e. isolated 5q‐ and CK with ‐5/5q‐, possibly implies two different mechanistic roles for TP53 protein.

Guidelines for the diagnosis and management of adult aplastic anaemia

Sally B. Killick (Writing Group Chair), Nick Bown, Jamie Cavenagh, Inderjeet Dokal, Theodora Foukaneli, Peter Hillmen, Robin Ireland, Austin Kulasekararaj, Ghulam Mufti, John A Snowden, Sujith Samarasinghe, Anna Wood (BCSH Task Force Member), Judith C.W. Marsh on behalf of the British Society for Standards in Haematology. The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust, Bournemouth, Northern Genetics Service, Newcastle upon Tyne, St Bartholomew’s Hospital, Barts Health NHS Trust, London, Barts and The London School of Medicine and Dentistry, Queen Mary University of London and Barts Health NHS Trust, London, Addenbrooks Hospital, University of Cambridge, Cambridge, Leeds Teaching Hospitals, Leeds, Kings College Hospital NHS Foundation Trust, London, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield Great Ormond Street Hospital for Children NHS Foundation Trust, London, West Hertfordshire NHS Trust, Watford.

Somatic mutations identify a subgroup of aplastic anemia patients who progress to myelodysplastic syndrome

The distinction between acquired aplastic anemia (AA) and hypocellular myelodysplastic syndrome (hMDS) is often difficult, especially nonsevere AA. We postulated that somatic mutations are present in a subset of AA, and predict malignant transformation. From our database, we identified 150 AA patients with no morphological evidence of MDS, who had stored bone marrow (BM) and constitutional DNA. We excluded Fanconi anemia, mutations of telomere maintenance, and a family history of BM failure (BMF) or cancer. The initial cohort of 57 patients was screened for 835 known genes associated with BMF and myeloid cancer; a second cohort of 93 patients was screened for mutations in ASXL1, DNMT3A, BCOR, TET2, and MPL. Somatic mutations were detected in 19% of AA, and included ASXL1 (n = 12), DNMT3A (n = 8) and BCOR (n = 6). Patients with somatic mutations had a longer disease duration (37 vs 8 months, P < .04), and shorter telomere lengths (median length, 0.9 vs 1.1, P < .001), compared with patients without mutations. Somatic mutations in AA patients with a disease duration of >6 months were associated with a 40% risk of transformation to MDS (P < .0002). Nearly one-fifth of AA patients harbor mutations in genes typically seen in myeloid malignancies that predicted for later transformation to MDS.

Functional characterization of CD4+ T cells in aplastic anemia

The role of CD4(+) T cells in the pathogenesis of aplastic anemia (AA) is not well characterized. We investigate CD4(+) T-cell subsets in AA. Sixty-three patients with acquired AA were studied. Th1 and Th2 cells were significantly higher in AA patients than in healthy donors (HDs; P = .03 and P = .006). Tregs were significantly lower in patients with severe AA than in HDs (P < .001) and patients with non-severe AA (P = .01). Th17 cells were increased in severe AA (P = .02) but normal in non-severe AA. Activated and resting Tregs were reduced in AA (P = .004; P = .01), whereas cytokine-secreting non-Tregs were increased (P = .003). Tregs from AA patients were unable to suppress normal effector T cells. In contrast, AA effector T cells were suppressible by Tregs from HDs. Th1 clonality in AA, investigated by high-throughput sequencing, was greater than in HDs (P = .03). Our results confirm that Th1 and Th2 cells are expanded and Tregs are functionally abnormal in AA. The clonally restricted expansion of Th1 cells is most likely to be antigen-driven, and induces an inflammatory environment, that exacerbate the functional impairment of Tregs, which are reduced in number.

Eculizumab in Pregnant Patients with Paroxysmal Nocturnal Hemoglobinuria

BACKGROUND Eculizumab, a humanized monoclonal antibody against complement protein C5 that inhibits terminal complement activation, has been shown to prevent complications of paroxysmal nocturnal hemoglobinuria (PNH) and improve quality of life and overall survival, but data on the use of eculizumab in women during pregnancy are scarce. METHODS We designed a questionnaire to solicit data on pregnancies in women with PNH and sent it to the members of the International PNH Interest Group and to the physicians participating in the International PNH Registry. We assessed the safety and efficacy of eculizumab in pregnant patients with PNH by examining the birth and developmental records of the children born and adverse events in the mothers. RESULTS Of the 94 questionnaires that were sent out, 75 were returned, representing a response rate of 80%. Data on 75 pregnancies in 61 women with PNH were evaluated. There were no maternal deaths and three fetal deaths (4%). Six miscarriages (8%) occurred during the first trimester. Requirements for transfusion of red cells increased during pregnancy, from a mean of 0.14 units per month in the 6 months before pregnancy to 0.92 units per month during pregnancy. Platelet transfusions were given in 16 pregnancies. In 54% of pregnancies that progressed past the first trimester, the dose or the frequency of use of eculizumab had to be increased. Low-molecular-weight heparin was used in 88% of the pregnancies. Ten hemorrhagic events and 2 thrombotic events were documented; both thrombotic events occurred during the postpartum period. A total of 22 births (29%) were premature. Twenty cord-blood samples were examined for the presence of eculizumab; the drug was detected in 7 of the samples. A total of 25 babies were breast-fed, and in 10 of these cases, breast milk was examined for the presence of eculizumab; the drug was not detected in any of the 10 breast-milk samples. CONCLUSIONS Eculizumab provided benefit for women with PNH during pregnancy, as evidenced by a high rate of fetal survival and a low rate of maternal complications. (ClinicalTrials.gov number, NCT01374360.).

Loss of heterozygosity in 7q myeloid disorders: clinical associations and genomic pathogenesis

Loss of heterozygosity affecting chromosome 7q is common in acute myeloid leukemia and myelodysplastic syndromes, pointing toward the essential role of this region in disease phenotype and clonal evolution. The higher resolution offered by recently developed genomic platforms may be used to establish more precise clinical correlations and identify specific target genes. We analyzed a series of patients with myeloid disorders using recent genomic technologies (1458 by single-nucleotide polymorphism arrays [SNP-A], 226 by next-generation sequencing, and 183 by expression microarrays). Using SNP-A, we identified chromosome 7q loss of heterozygosity segments in 161 of 1458 patients (11%); 26% of chronic myelomonocytic leukemia patients harbored 7q uniparental disomy, of which 41% had a homozygous EZH2 mutation. In addition, we describe an SNP-A-isolated deletion 7 hypocellular myelodysplastic syndrome subset, with a high rate of progression. Using direct and parallel sequencing, we found no recurrent mutations in typically large deletion 7q and monosomy 7 patients. In contrast, we detected a markedly decreased expression of genes included in our SNP-A defined minimally deleted regions. Although a 2-hit model is present in most patients with 7q uniparental disomy and a myeloproliferative phenotype, haplodeficient expression of defined regions of 7q may underlie pathogenesis in patients with deletions and predominant dysplastic features.

p53 protein expression independently predicts outcome in patients with lower-risk myelodysplastic syndromes with del(5q)

Del(5q) myelodysplastic syndromes defined by the International Prognostic Scoring System as low- or intermediate-1-risk (lower-risk) are considered to have an indolent course; however, recent data have identified a subgroup of these patients with more aggressive disease and poorer outcomes. Using deep sequencing technology, we previously demonstrated that 18% of patients with lower-risk del(5q) myelodysplastic syndromes carry TP53 mutated subclones rendering them at higher risk of progression. In this study, bone marrow biopsies from 85 patients treated with lenalidomide in the MDS-004 clinical trial were retrospectively assessed for p53 expression by immunohistochemistry in association with outcome. Strong p53 expression in ≥1% of bone marrow progenitor cells, observed in 35% (30 of 85) of patients, was significantly associated with higher acute myeloid leukemia risk (P=0.0006), shorter overall survival (P=0.0175), and a lower cytogenetic response rate (P=0.009), but not with achievement or duration of 26-week transfusion independence response. In a multivariate analysis, p53-positive immunohistochemistry was the strongest independent predictor of transformation to acute myeloid leukemia (P=0.0035). Pyrosequencing analysis of laser-microdissected cells with strong p53 expression confirmed the TP53 mutation, whereas cells with moderate expression predominantly had wild-type p53. This study validates p53 immunohistochemistry as a strong and clinically useful predictive tool in patients with lower-risk del(5q) myelodysplastic syndromes. This study was based on data from the MDS 004 trial (clinicaltrials.gov identifier: NCT00179621).

STAT3-mutations indicate the presence of subclinical T cell clones in a subset of aplastic anemia and myelodysplastic syndrome patients

Large granular lymphocyte leukemia (LGL) is often associated with immune cytopenias and can cooccur in the context of aplastic anemia (AA) and myelodysplastic syndromes (MDS). We took advantage of the recent description of signal transducer and activator of transcription 3 (STAT3) mutations in LGL clonal expansions to test, using sensitive methods, for the presence of these mutations in a large cohort of 367 MDS and 140 AA cases. STAT3 clones can be found not only in known LGL concomitant cases, but in a small proportion of unsuspected ones (7% AA and 2.5% MDS). In STAT3-mutated AA patients, an interesting trend toward better responses of immunosuppressive therapy and an association with the presence of human leukocyte antigen-DR15 were found. MDSs harboring a STAT3 mutant clone showed a lower degree of bone marrow cellularity and a higher frequency of developing chromosome 7 abnormalities. STAT3-mutant LGL clones may facilitate a persistently dysregulated autoimmune activation, responsible for the primary induction of bone marrow failure in a subset of AA and MDS patients.