Karyotype in myelodysplastic syndromes: relations to morphology, clinical evolution, and survival

Impact of somatic mutations in myelodysplastic patients with isolated partial or total loss of chromosome 7

Monosomy 7 [-7] and/or partial loss of chromosome 7 [del(7q)] are associated with poor and intermediate prognosis, respectively, in myelodysplastic syndromes (MDS), but somatic mutations may also play a key complementary role. We analyzed the impact on the outcomes of deep targeted mutational screening in 280 MDS patients with -7/del(7q) as isolated cytogenetic abnormality (86 with del(7q) and 194 with -7). Patients with del(7q) or -7 had similar demographic and disease-related characteristics. Somatic mutations were detected in 79% (93/117) of patients (82% in -7 and 73% in del(7q) group). Median number of mutations per patient was 2 (range 0-8). There was no difference in mutation frequency between the two groups. Patients harbouring ≥2 mutations had a worse outcome than patients with <2 or no mutations (leukaemic transformation at 24 months, 38% and 20%, respectively, p = 0.044). Untreated patients with del(7q) had better overall survival (OS) compared with -7 (median OS, 34 vs 17 months, p = 0.034). In multivariable analysis, blast count, TP53 mutations and number of mutations were independent predictors of OS, whereas the cytogenetic subgroups did not retain prognostic relevance. This study highlights the importance of mutational analysis in terms of prognosis in MDS patients with isolated -7 or del(7q).

A nationwide survey of hypoplastic myelodysplastic syndrome (a multicenter retrospective study)

Hypoplastic myelodysplastic syndrome (hMDS) is a distinct entity with bone marrow (BM) hypocellularity and the risk of death from BM failure (BMF). To elucidate the characteristics of hMDS, the data of 129 patients diagnosed between April 2003 and March 2012 were collected from 20 institutions and the central review team of the National Research Group on Idiopathic Bone Marrow Failure Syndromes, and compared with 115 non-hMDS patients. More RA and fewer CMMoL and RAEB-t in French-American-British (FAB) and more RCUD and MDS-U and fewer RCMD in World Health Organization (WHO) classifications were found in hMDS than non-hMDS with significant differences. The overall survival (OS) and AML progression-free survival (AML-PFS) of hMDS were higher than those of non-hMDS, especially in patients at age ≥50 and of lower risk in Revised International Prognostic Scoring System (IPSS-R). In competing risks analysis, hMDS exhibited decreased risk of AML-progression in lower IPSS or IPSS-R risk patients, and higher risk of death from BMF in patients at age ≥50. Poor performance status (PS ≥2) and high karyotype risks in IPSS-R (high and very high) were significant risk factors of death and AML-progression in Cox proportional hazards analysis.

A 4-lncRNA scoring system for prognostication of adult myelodysplastic syndromes

Long noncoding RNAs (lncRNAs) not only participate in normal hematopoiesis but also contribute to the pathogenesis of acute leukemia. However, their clinical and prognostic relevance in myelodysplastic syndromes (MDSs) remains unclear to date. In this study, we profiled lncRNA expressions in 176 adult patients with primary MDS, and identified 4 lncRNAs whose expression levels were significantly associated with overall survival (OS). We then constructed a risk-scoring system with the weighted sum of these 4 lncRNAs. Higher lncRNA scores were associated with higher marrow blast percentages, higher-risk subtypes of MDSs (based on both the Revised International Prognostic Scoring System [IPSS-R] and World Health Organization classification), complex cytogenetic changes, and mutations in RUNX1, ASXL1, TP53, SRSF2, and ZRSR2, whereas they were inversely correlated with SF3B1 mutation. Patients with higher lncRNA scores had a significantly shorter OS and a higher 5-year leukemic transformation rate compared with those with lower scores. The prognostic significance of our 4-lncRNA risk score could be validated in an independent MDS cohort. In multivariate analysis, higher lncRNA scores remained an independent unfavorable risk factor for OS (relative risk, 4.783; P < .001) irrespective of age, cytogenetics, IPSS-R, and gene mutations. To our knowledge, this is the first report to provide a lncRNA platform for risk stratification of MDS patients. In conclusion, our integrated 4-lncRNA risk-scoring system is correlated with distinctive clinical and biological features in MDS patients, and serves as an independent prognostic factor for survival and leukemic transformation. This concise yet powerful lncRNA-based scoring system holds the potential to improve the current risk stratification of MDS patients.

Impacts of cytogenetic categories in the Revised International Prognostic Scoring System on the prognosis of primary myelodysplastic syndromes: results of a single-center study

Recently, the Revised International Prognostic Scoring System (IPSS-R) has been developed for assessing the prognosis of primary myelodysplastic syndromes (MDS) and has shown satisfactory outcomes for prognostic stratification. In this new system, cytogenetics remains the key stratification parameter and karyotypic abnormalities are classified into five prognostic subgroups with more uncommon cytogenetic subsets. Using this system, we analyzed the cytogenetic features of 532 adult Chinese patients with primary MDS and assessed the impacts of the IPSS-R cytogenetic categories on the prognosis of the disease without intensive treatment. Here, we show that the cytogenetic features of this cohort of Chinese patients are different from those of previously reported Western populations with MDS. In our Chinese patients, trisomy 8 was the most common anomaly, and the incidence rate of del(5q) was lower than that in the Western population. In the IPSS-R cytogenetic subgroups, the median survival was 59 months for the good risk, 36 months for the intermediate risk, 15 months for the poor risk and 10 months for the very poor risk subgroups (p < 0.001). In conclusion, the IPSS-R can effectively stratify the prognosis of MDS based on cytogenetics, but the prognostic significances of some karyotypes in the IPSS-R still need to be confirmed by larger multicenter cooperative studies.

Better prognosis for patients with del(7q) than for patients with monosomy 7 in myelodysplastic syndrome

BACKGROUND

Abnormalities involving chromosome 7 are frequent in myelodysplastic syndrome (MDS) and suggest a poor prognosis.

METHODS

The authors examined the hypothesis that the clinical features and survival associated with isolated deletion (del) of part of the long arm of chromosome 7 (7q) in MDS are different from those associated with isolated monosomy 7 (complete loss of chromosome 7). In total, 133 patients with a diagnosis of de novo MDS (according to the World Health Organization [WHO] classification) and chromosome 7 abnormalities in the Spanish MDS Registry were evaluated retrospectively. Four karyotypic groups were identified: isolated del(7q) (n = 29), isolated monosomy 7 (n = 27), del(7q) with additional abnormalities (n = 24), and monosomy 7 with additional abnormalities (n = 53).

RESULTS

Isolated del(7q) was more frequent in patients with less advanced MDS according to the WHO classification or the International Prognostic Scoring System. In addition, isolated del(7q) was associated with fewer blasts in bone marrow than other cytogenetics groups. Survival was significantly superior in patients with isolated del(7) than in those with isolated monosomy 7, del(7q) with additional abnormalities, or monosomy 7 with additional abnormalities. On multivariate analysis, age, the percentage of blasts in bone marrow, and other chromosome 7 abnormalities apart from isolated del(7q) were identified as independent risk factors for survival.

CONCLUSIONS

The current results demonstrated that patients who had MDS with isolated del(7q) had some distinct clinical-pathologic characteristics as well as better survival than patients who had MDS with isolated monosomy 7.

Myelodysplastic syndromes with deletions of chromosome 11q lack cryptic MLL rearrangement and exhibit characteristic clinicopathologic features

Deletions of chromosome 11q[del(11q)] as part of a non-complex karyotype are infrequent in myelodysplastic syndromes (MDS), leaving the clinicopathologic and genetic features largely undefined. From three large medical centers over a 10-year period, we identified 32 MDS cases where del(11q) was present either as a sole (n=23) or associated with another abnormality (n=9), showing an overall 0.6% frequency in MDS. These patients included 15 men and 17 women, with a median age of 68 years. Three were therapy-related, and 29 were primary MDS. These cases were characterized by transfusion-dependent anemia (65%); frequent ring sideroblasts (RS) (59%); bone marrow hypocellularity (22%), and less severe thrombocytopenia. With a median follow-up of 32 months, 9/24 (38%) cases progressed to acute myeloid leukemia (AML), and the overall survival (OS) was 35 months (3-105). Fluorescence in situ hybridization (FISH) showed MLL deletion in 6/10 cases, but no cryptic MLL translocations in all 15 MDS cases tested. In contrast, FISH performed in AML with del(11q) showed MLL rearrangement in 3/17 (18%) cases. In summary, del(11)q occurring in a non-complex karyotype is predominantly associated with primary MDS, lack of cryptic MLL rearrangements, and shows characteristic clinicopathological features. These clinicopathological features are likely attributed to commonly deleted regions of 11q and their involved genes.

Blast phase of essential thrombocythemia: A single center study

Blast phase (BP) may occur as a late event in essential thrombocythemia (ET). This study includes 19 patients with post-ET BP diagnosed and followed in a single institution. At BP, 63% of patients had leukocytosis (white blood cell count >10 x 10(9)/L), 74% had anemia (hemoglobin value <10 g/dL), 74% had thrombocytopenia (platelet count <100 x 10(9)/L), and 84% were over 65 years of age. Cytogenetic analysis was available in 10 patients: six had karyotype aberrations. According to cytogenetic-based risk stratification of de novo acute leukemia (AL), all patients had an unfavorable profile. JAK2 (V617F) mutational status was evaluated in five patients. In two of them, the JAK2 mutation was undetectable in blast cells (one with JAK2-positive ET), whereas in three both granulocytes and blast cells displayed the mutation. Treatment of BP was patient-based according to the performance status and co-morbidities and consisted of palliation in 14 patients, and of induction of remission in five. Median survival was 2.3 months (range 0.2-22.3), irrespective of the treatment received. In conclusion, this study indicates that AL evolved from ET has unfavorable clinical and biological features. JAK2 (V617F)-positive ET may evolve in few instances into JAK2-negative leukemia. The outcome of patients is poor whatever the treatment used.

Myelodysplastic syndrome: An update on diagnosis and therapy

Myelodysplastic syndromes (MDS) are a diverse group of disorders characterized by disorderly and ineffective hematopoiesis. Patients suffer morbidity from associated cytopenias that result in an increased risk of infection, transfusion-dependent anemia, and bleeding. Despite the variable risk of transformation to acute leukemia, the majority of deaths are due to bone marrow failure. No truly effective treatment exists for MDS, and therapy usually focuses on reducing or preventing complications of the disease. Identification of potential cellular and molecular targets, such as epigenetic modification, has led to novel therapeutic approaches in recent years. An increasing number of diagnostic markers, prognostic parameters, and therapeutic strategies are available and becoming widely accepted.

Myelodysplastic syndrome: an update on diagnosis and therapy

Myelodysplastic syndromes (MDS) are a diverse group of disorders characterized by disorderly and ineffective hematopoiesis. Patients suffer morbidity from associated cytopenias that result in an increased risk of infection, transfusion-dependent anemia, and bleeding. Despite the variable risk of transformation to acute leukemia, the majority of deaths are due to bone marrow failure. No truly effective treatment exists for MDS, and therapy usually focuses on reducing or preventing complications of the disease. Identification of potential cellular and molecular targets, such as epigenetic modification, has led to novel therapeutic approaches in recent years. An increasing number of diagnostic markers, prognostic parameters, and therapeutic strategies are available and becoming widely accepted.

Chromosome 5q deletion: Specific diagnoses and cytogenetic details among 358 consecutive cases from a single institution

The purpose of this study was to define the spectrum of hematologic neoplasms and chromosomal breakpoints associated with del(5q); separate analyses were performed to account for prior cytotoxic treatment. A total of 358 consecutive del(5q) cases were identified; specific diagnoses included myelodysplastic syndrome (MDS; 53%), acute myeloid leukemia (AML; 22%), plasma cell proliferative disorder (PCPD; 9%), myeloproliferative disorder (MPD; 7%), acute lymphoblastic leukemia (ALL; 2%), PCPD with MDS (2%), MDS/MPD (2%), and malignant lymphoma (ML; 2%). The corresponding figures in the absence/presence of prior cytotoxic treatment (n=250/108) were 61%/34% for MDS, 24%/19% for AML, 4%/20% for PCPD, 6%/8% for MPD, 1%/4% for ALL, and 2%/4% for ML. del(5q) occurred as the sole cytogenetic abnormality in 88 cases (25%) including 76 without prior cytotoxic therapy. Among the latter, 82% had MDS, 8% AML, 5% MPD, 4% PCPD, and 1% ML. Chromosome 5 breakpoints included q13q33 in 49% of the cases, q15q33 in 22%, q22q33 in 8%, and q13 in 3% and their distribution was not affected by specific diagnosis or treatment history. del(5q)-associated lymphoid disorders featured a higher prevalence of previous cytotoxic therapy and smaller number del(5q)-positive metaphases, when compared to their counterparts with myeloid neoplasms. We conclude that del(5q), although most prevalent in MDS, is seen across the spectrum of myeloid disorders including MPD and its occurrence in lymphoid disorders might signify, for the most part, an occult myeloid clone.

World Health Organization classification in combination with cytogenetic markers improves the prognostic stratification of patients with de novo primary myelodysplastic syndromes

This study correlated chromosomal defects with French-American-British (FAB)/World Health Organization (WHO) classification subtypes, proposed a revised International Prognostic Scoring System (IPSS) cytogenetic grouping; and established which classification, when used with the IPSS cytogenetic categories, best predicted clinical outcome in the myelodysplastic syndromes (MDS). A higher prevalence of chromosomal defects and distinct defects were observed in patients with multi-lineage dysplasia and a blast cell percentage >10%. Abnormalities of the long arm of chromosome 3, del(7)(q31q35), trisomy 8, del(11)(q14q23), del(12p) and 20q- could be segregated from their respective IPSS cytogenetic categories and used to develop new cytogenetic subgroups. Clinical parameters, FAB/WHO classification, IPSS score and standard or revised cytogenetic categories were statistically relevant for overall survival (OS) and progression-free intervals (PFI) and were included within five distinct multivariate models compared by the Akaike Information Criterion. To predict OS, the best models included age, WHO classification and standard or revised IPSS cytogenetic categories; to predict PFI, the best model included the same variables and revised cytogenetic categories. In conclusion, (i) the WHO classification was associated with a more homogeneous cytogenetic pattern than the FAB classification, (ii) WHO classification and standard/revised IPSS cytogenetic categories were much more effective than IPSS for predicting MDS clinical outcome, (iii) revised cytogenetic subgroups predicted PFI more effectively than standard categories.

Unusual complex hyperdiploid karyotypes in myelodysplastic syndromes

Over an 18-year period, 10 myelodysplastic syndrome (MDS) patients with complex hyperdiploid karyotypes were identified. According to the FAB classification, the 10 patients were subclassified as three refractory anemias (RA), three refractory anemias with excess blasts (RAEB), two RAEB in transformation (RAEB-t), and two unclassified MDS. According to the WHO classification, the diagnoses were two RA, one refractory cytopenia with multilineage dysplasia, two RAEB-1, one RAEB-2, two unclassified MDS, and two acute myeloid leukemia. Six were secondary MDS. Four patients showed marked dyserythropoiesis; three of these were secondary MDS. The chromosome number ranged from 47 to 62, and clonal evolution or composite karyotypes were noted in 7 patients. Seven patients had at least one clone with >50 chromosomes. Recurrent defects included chromosome 5, 17, and 13 abnormalities. Notably, trisomy 8 and monosomy 7 were rare in that group of patients. Three of four patients with marked dyserythropoiesis shared abnormalities of both chromosomes 13 and 17.

Incidence and prognostic significance of karyotype abnormalities in de novo primary myelodysplastic syndromes: a study on 331 patients from a single institution

The impact of clinical parameters, International Prognostic Scoring System (IPSS) scores/cytogenetic categories, and some single cytogenetic defects on overall survival (OS) and time to myelodysplastic syndromes (MDS)/AML progression (progression-free interval (PFI)) was evaluated in 331 MDS patients. Statistical analysis demonstrated that OS and PFI were significantly affected by all these parameters. Since single 7q- showed a better survival than the poor IPSS cytogenetic category (P=0.009), it was considered as a new prognostic entity ('modified IPSS categories'). In multivariate analysis OS was significantly influenced by age, marrow blast cell percentage, number of cytopenias and either modified or standard IPSS cytogenetic categories; hazard ratios for MDS/AML progression were influenced by all the former, except for age and cytopenias. Multivariate analysis of del(7)(q31q35) confirmed the results of univariate analysis, but the Akaike Information Criterion showed no difference in evaluating OS and PFI between the modified and standard IPSS cytogenetic grouping. In conclusion, (i) chromosome defects as grouped by IPSS and blast cell percentage are the most relevant parameters for predicting OS and PFI; (ii) the prognostic power of the IPSS cytogenetic grouping is not ameliorated by the introduction of del(7)(q31q35) as a new entity; (iii) complex karyotypes have a prognostic value independent of blast cell percentage.

Cytogenetic analysis of 52 Indian patients with de novo myelodysplastic syndromes?a comparative analysis of results with reports from Asia

Most published data on myelodysplastic syndromes (MDS) are derived from Western countries, which report MDS as a disease of the elderly. However, it was observed that Asian MDS patients were younger than subjects in Western reports. With this in mind, the study was conducted prospectively on 52 Indian patients to define chromosomal abnormalities and to understand ethno-geographical differences, if any, underlying the pathogenesis of MDS among this Asian population. Cytogenetic analysis was performed using GTG banding and karyotyped according to the International System for Human Cytogenetic Nomenclature (ISCN). The incidence of MDS was predominant in the age group of 41-60 years (44.23%), with a median age at diagnosis of 55 years. The disease was more frequent in males (33 patients, 63.46%) than females (19 patients, 36.53%). Of 48 patients successfully karyotyped, 17 had normal karyotype (35.4%) and 31 patients (64.5%) had a chromosomal abnormality. The most frequent chromosome abnormalities were del 5q/-5 in 13 patients (42%), -7/7q- in 10 patients (32.2%), +8 and del 20q- in 6 cases each (19.3%) and i(17)(q10) in 1 patient (3.2%). In addition to these non-random chromosomal abnormalities, some rare abnormalities were also encountered. A higher rate of transformation to acute myeloid leukaemia (AML) was observed in the Chinese population compared to other Asian countries. The incidence of chromosomal abnormalities varied considerably across the different Asian populations. The overall frequency of chromosomal abnormalities in our study was comparable to most Western reports. Further prospective studies are warranted to elucidate precisely the ethnic differences in the pathogenesis of MDS in the Indian population.

Loss of Hspa9b in zebrafish recapitulates the ineffective hematopoiesis of the myelodysplastic syndrome

Myelodysplastic syndrome (MDS) comprises a heterogeneous group of often fatal hematopoietic stem cell disorders for which neither curative nor standard treatment exists. The complex karyotypes and multistep nature of MDS have severely restricted the identification of causative genetic mutations and thus limited insight into new and more effective therapies. Here we describe a zebrafish mutant crimsonless (crs) with a developmental blood defect that closely recapitulates the ineffective hematopoiesis of MDS including anemia, dysplasia, increased blood cell apoptosis, and multilineage cytopenia. By positional cloning, rescue, and morpholino knockdown experiments, we demonstrate that crs encodes a conserved mitochondrial matrix chaperone HSPA9B containing a glycine-to-glutamate substitution within the substrate-binding domain. This mutation compromises mitochondrial function, producing oxidative stress and apoptosis distinctly in blood cells. Thus, we identify an essential role for Hspa9b in hematopoiesis and implicate both loss of HSPA9B specifically and mitochondrial dysfunction generally in the pathogenesis of the MDS.

Antithymocyte globulin (ATG)-based therapy in patients with myelodysplastic syndromes

The purpose of this study was to determine the efficacy of and tolerance to antithymocyte globulin (ATG)-based therapy in patients with myelodysplastic syndrome (MDS). Therapy consisted of ATG 40 mg/kg/day daily intravenously (i.v.) for 4 days; cyclosporine daily orally for 6 months with levels titrated between 200 and 400 mg/dl; and methylprednisone 1 mg/kg i.v. daily before each dose of ATG. Of 32 patients treated, 31 patients were evaluable. The median age was 59 years (range, 28-79 years). A total of 18 patients had refractory anemia (RA) or RA with ringed sideroblasts (RARS), 10 patients had RA with excess blasts (RAEB), two patients had RAEB in transformation, and one patient had chronic myelomonocytic leukemia. ATG, cyclosporine, and methylprednisone induced complete (N=4) or partial (N=1) remission in five patients (16% of total; RA, two patients; RARS, two patients; and RAEB, one patient). Durable complete remissions were observed in three of 18 patients (17%) with RA (N=1) or RARS (N=2) (12, 41+, and 60+ months). The most common adverse events were fever and allergic reactions. Hepatic and renal dysfunction, albeit consistently reversible, occurred in 19 and 13% of the patients, respectively. In conclusion, an ATG-based regimen can produce durable complete remissions in a subset of patients with MDS.

Is FISH a relevant prognostic tool in myelodysplastic syndromes with a normal chromosome pattern on conventional cytogenetics? A study on 57 patients

Conventional cytogenetics (CC) at clinical diagnosis shows a normal karyotype in 40-60% of de novo myelodysplastic syndromes (MDSs). Fluorescence in situ hybridization (FISH) might detect occult aberrations in these patients. Therefore, we have used FISH to check 57 MDS patients who were karyo-typically normal on CC. At clinical diagnosis, FISH revealed a clonal abnormality in 18-28% interphase cells from nine patients, five of whom also presented the same defect on metaphase FISH. In five out of nine patients, the occult defect effected a change in the international prognostic scoring system (IPSS). An abnormal FISH pattern was significantly correlated with marrow blast cell percentage (P<10(-3)) and IPSS (P<10(-3)). Patients with an occult abnormality showed an overall survival and event-free survival significantly inferior in comparison to those of patients with normal FISH (P<10(-3), P<10(-3)). Death and AML progression were 15- and eight-fold more frequent in FISH abnormal patients. In conclusion, occult defects (1) are revealed in about 15% of CC normal MDS patients, (2) are overlooked by CC either because of the poor quality of metaphases or their submicroscopic nature, (3) are clinically relevant as they may cause a change in the IPSS category and may identify a fraction of CC normal patients with an unfavorable clinical outcome.

Distinct clinical outcomes for cytogenetic abnormalities evolving from aplastic anemia

A serious complication of aplastic anemia (AA) is its evolution to clonal hematologic diseases such as myelodysplasia (MDS) and leukemia, which is usually associated with the appearance of a cytogenetic abnormality in bone marrow cells. We present here an analysis of a cohort of 30 patients with otherwise typical AA in whom clonal karyotypic evolution was observed during frequent periodic marrow examinations. The actuarial risk for this complication has been estimated in other studies at around 15% at 5 years. Conversion from normal to abnormal karyotype occurred at a constant rate after initial diagnosis, with about 50% of cases developing within the first 30 months. Transient chromosomal abnormalities were infrequent. Clinically, AA patients with clonal cytogenetic patterns were heterogenous; a variety of karyotypic defects with numerical and structural abnormalities of chromosome 7 accounted for 40% of all cases followed by trisomy 8, structural and numerical abnormalities of chromosome 13, deletion of Y chromosome, and complex cytogenetic abnormalities. Unlike in primary MDS, aberrancies of chromosome 5 and 20 were infrequent. The clinical course depended on the specific abnormal cytogenetic pattern. Most deaths related to leukemic transformation occurred in patients with abnormalities of chromosome 7 or complex cytogenetic alterations or both. Evolution of chromosome 7 abnormalities was seen most often in refractory patients who had failed to respond to therapy. In contrast, trisomy 8 developed in patients with good hematologic responses who often required chronic immunosuppression with cyclosporine A (CsA), and survival was excellent. Although AA patients with monosomy 7 showed a similar prognosis to those with primary MDS, trisomy 8 in AA appears to have a more favorable prognosis than in MDS.

Masked monosomy 7 in myelodysplastic syndromes is uncommon and of undetermined clinical significance

Masked monosomy 7, i.e. detected by FISH but not by conventional cytogenetics, has been reported in varying frequency in MDS. To establish the prevalence and possible clinical significance of the aberration, we studied the 123 previously karyotyped MDS patients using FISH and a DNA probe specific for chromosome 7. Metaphase cytogenetics revealed ten patients (8%) with monosomy 7 (6 RAEB and 4 RAEB-t). FISH confirmed this result and detected four more cases (4%) with masked monosomy 7 (3 RA and 1 RARS). Thus, masked monosomy 7 is less common than has been suggested, and does not seem to carry the same prognostic weight as monosomy 7 diagnosed by metaphase cytogenetics.

Comparative genomic hybridization-aided unraveling of complex karyotypes in human hematopoietic neoplasias

The information obtained by conventional cytogenetics (CC) in human leukemias is sometimes limited, in particular by complex karyotypes with many marker chromosomes. While CC is restricted to metaphases with a good quality, interphase fluorescence in situ hybridization (I-FISH) is also capable of analyzing specific anomalies in the interphase nuclei. Comparative genomic hybridization (CGH) gives additional information about the imbalanced karyotype changes in the whole genome. The aim of this study was to assess the contribution of CGH to the unraveling of complex GTG karyotypes, which are difficult to evaluate by banding analysis, and to compare these results with those by CC and FISH. Thirteen bone marrow samples and one sample obtained from peripheral blood of 13 leukemia patients were examined by CC, FISH and CGH. The GTG banding analysis showed complex karyotypes with many marker chromosomes. The most frequent abnormalities were numerical and structural aberrations on chromosomes 5 and 7. In 12 of the 14 samples, the CGH analysis was able to detect chromosomal imbalances with losses of material on chromosome 5 and 7 as the most frequent aberrations. In all 14 samples, additional FISH analyses were performed. For most of the studied neoplasias, a close correlation between CC, FISH and CGH data was observed. CGH was considerably helpful in adding additional information to classical karyotyping, if the low quality or number of metaphases was insufficient for a reliable CC analysis. Even in cases where whole chromosome painting could be applied, it added information on the breakpoints of the observed rearrangements. In only 2 of the studied 14 samples, neither CGH nor I-FISH could improve the result of karyotyping. CGH, nevertheless, can be regarded as a powerful additional technique in leukemias with unsuccessful CC, incomplete, or complex karyotypes with many marker chromosomes. A systematic analysis by three techniques such as CC, FISH and CGH guarantees an optimal genetic characterization of the neoplasias.

Trisomy 21 as the sole abnormality in a refractory anemia with ring sideroblasts

Numerous chromosome abnormalities have been described in myelodysplastic syndromes, but single karyotypic aberrations are much less frequent. We report the case of a 65-year-old woman who presented a trisomy 21 as the sole karyotypic anomaly for a refractory anemia with ring sideroblasts. The nature of such an anomaly is discussed in regard to pathogenesis and prognosis.

Transient monosomy 7: a case series in children and review of the literature

BACKGROUND

Monosomy 7 and deletions of the long arm of chromosome 7 [del (7q)] are recurrent, nonrandom chromosomal abnormalities associated with both de novo and therapy-related myelodysplastic syndromes (MDS). The overall prognosis for children and adults with these chromosomal abnormalities is poor. In the current report, the authors present five children with MDS associated with monosomy 7/del(7q) who achieved spontaneous hematologic disease remission as well as a review of the literature.

METHODS

Five children with either de novo or treatment-related MDS who achieved spontaneous hematologic disease remission are presented. Relevant clinical, cytogenetic, and fluorescent in situ hybridization data are included.

RESULTS

All patients were boys. Three had de novo MDS whereas two others previously had received chemotherapy for another malignancy. Four patients achieved spontaneous and durable hematologic disease remission that was associated with cytogenetic disease remission in all three patients tested. The fifth patient developed a disease recurrence and died with evidence of clonal evolution after a long interval of hematologic and cytogenetic remission.

CONCLUSIONS

A subset of children who develop MDS associated with monosomy 7 or del(7q) achieve spontaneous hematologic and cytogenetic improvement. Although this appears to be uncommon, further data are needed to determine the percentage of patients who improve without therapy and to define clinical characteristics that may predict this clinical outcome. These findings suggest that monosomy 7/del(7q) is insufficient to produce full leukemic transformation.

Biclonal chromosomal aberrations in a child with myelodysplastic syndrome

Hematological malignancies and premalignant diseases are generally of monoclonal origin. The prognostic and therapeutic significance of finding two genetically independent clones remains to be determined. We followed a case of childhood myelodysplastic syndrome showing biclonal chromosomal abnormalities (+8, -7) by conventional cytogenetic examination and double target fluorescence in situ hybridization (FISH). A 7-year-old girl presented with Plaut-Vincent angina and leukopenia. The cytogenetic aberration of +8 was the first sign to suggest MDS. Serial bone marrow controls, prompted by a progressive clinical course detected myelodysplastic changes and a new clonal aberration (-7). The presence of -7 and +8 in two independent clones was verified by double-target FISH. While at diagnosis and during cytokine treatment more cells showed +8, after successful all-trans retinoic acid (ATRA) therapy, the clone with -7 predominated. Following allogeneic bone marrow transplantation the patient displayed donor-derived hematopoesis. Our data stress the significance of cytogenetic and FISH examinations in detecting specific genetic abnormalities and progressive clonal changes as an indicator and guideline for therapy. Different cell clones characterized by different genetic changes might be associated with different biologic features reflected in their response to treatment.

Exposure to myelotoxic agents and myelodysplasia: case-control study and correlation with clinicobiological findings

To better define the role of exposure to myelotoxic agents in the genesis of myelodysplastic syndrome (MDS), we carried out (a) a case-control study for the determination of the relative risk (RR) of developing MDS, including 178 consecutive patients and 178 sex- and age-matched controls: (b) a study of clinicobiological features in MDS arising after occupational exposure to myelotoxic agents and in MDS in 'non-exposed' patients. The definition of the 'exposure' status was based on a predetermined questionnaire, with calculation of an 'exposure' index (hours/day x days/year x years). Cumulative exposure to pesticides or to organic solvents, for >2400 h, was recorded in 48 and 25 MDS patients, respectively, compared to 27 and four controls (P<0.00001; RR 3.74; 95% confidence interval 2.02-5.37). Older age and an excess of refractory anaemia with ringed sideroblasts and refractory anaemia with excess of blasts was noted among 'exposed' MDS-patients (group 1), compared to non-exposed MDS-patients (group 2). 68.3% patients in group 1 had clonal chromosome changes, compared with 43.2% patients in group 2. Complex karyotypes, -7/7q-, -5/5q-, +8, 7p and 17p aberrations were seen more frequently in group 1, whereas a normal karyotype, isolated 5q- or 20q- occurred more frequently in group 2. The association of exposure to myelotoxic agents with older age at presentation and with unfavourable chromosome changes accounted for the shorter survival observed in 'exposed' patients. These data show that occupational exposure to pesticides and organic solvents in our region resulted in an increased RR of developing MDS and that a distinct cytogenetic profile was associated with MDS in 'exposed' patients. These findings provide strong indirect evidence that these agents may play a role in the pathogenesis of MDS, preferentially targeting some of the chromosome regions which are frequently involved in therapy-related myeloid neoplasias.

Translocation (1;22) in refractory anemia and the prognostic significance of karyotypic abnormalities in refractory anemia

The most common cytogenetic abnormalities associated with myelodysplastic syndromes are deletions of chromosomes 5 and 7 and trisomy 8. Reciprocal translocation is relatively uncommon in refractory anemia. We describe a case of refractory anemia associated with trisomy 8 and a derivative chromosome 22 resulting from t(1;22)(q11;q11.2). The diseases and the role of the various genes that are mapped to these breakpoints are discussed. The prognostic significance of karyotypic abnormalities in refractory anemia are reviewed.

Bcl-2 expression by myeloid precursors in myelodysplastic syndromes: relation to disease progression

RATIONALE AND METHODS

the bcl-2 oncogene blocks apoptosis in various cell types and is expressed by normal myeloid precursors, declining with maturation. To investigate whether bcl-2 plays a role in the increase of myeloblasts in myelodysplastic syndromes (MDS) and their progression to acute myeloid leukemia (AML), we studied bcl-2 expression in initial (pre-therapy) bone marrow biopsies from MDS at early (refractory anemia, RA, with or without ring sideroblasts) and advanced stages (RA with excess blasts, and in transformation). Sequential biopsies were also studied to evaluate the effect of time or disease progression, including evolution to AML, or therapy with granulocyte colony stimulating factor (G-CSF). Early myeloid precursors (EMPs), predominantly myeloblasts, were identified in paraffin sections after immunostaining; bcl-2-positive EMPs were enumerated as a percentage of all EMPs (Bcl-2%), and by their absolute frequency per x 900 microscopic field (Bcl-2 index).

FINDINGS

in initial biopsies, the Bcl-2% and Bcl-2 index in early MDS (9.9+/-2.6 and 1.4+/-0.6, respectively; mean+/-S.E.) were significantly lower than in advanced MDS (26.4+/-3.6, 4.6+/-1.4), but similar to controls (8.1+/-0.3 and 0.8+/-0.1). The Bcl-2% and Bcl-2 index in three patients with AML evolved from MDS (57.4+/-17.9 and 85.1+/-62.4) were similar to values for seven patients with de novo AML (63.0+/-10.0, 98.4+/-29.8) and significantly higher than values for other groups. Bcl-2% showed relative increments with time or disease progression (range, 21-273%; 11 of 18 sequential biopsies from six of ten MDS patients), which was not clearly altered by G-CSF therapy (four of six patients with, two of four patients without treatment).

CONCLUSIONS

bcl-2 expression by EMPs (in both proportion and absolute number) correlated with initial MDS stage, progressed over time independent of G-CSF therapy, and was associated with evolution to AML. These data provide support for the hypothesis that MDS progression is related to accumulation of immature myeloid cells with increased bcl-2 expression and decreased apoptosis.

Randomized clinical study comparing aggressive chemotherapy with or without G-CSF support for high-risk myelodysplastic syndromes or secondary acute myeloid leukaemia evolving from MDS

One hundred and five consecutive primary high-risk myelodysplastic syndromes (MDS) or secondary acute myeloid leukaemia (sAML) evolving from MDS (performance status 0-3, ECOG) entered this study. Induction chemotherapy (CT) consisted of idarubicine 12 mg/m2 i.v. on days 1 and 2, etoposide 60 mg/m2/12h i.v. for 5d, Ara-C 120 mg/ m2/12h i.v. for 5d (one or two courses). Patients were randomized to receive or not G-CSF (5 microg/kg/d subcutaneously 48 h after the end of CT). 52 cases underwent CT alone and 53 CT+G-CSF. The CT+ G-CSF patients had a significantly shorter duration of neutropenia (8 nu 16d) with a lower incidence of infections and significantly better responses (CR+PR: 74% v 52%, P<0.05). 40 patients entered CR: 17 with CT and 2 3 with CT+G-CSF. Responders underwent two consolidation courses with the same CT, followed by high-dose Ara-C (2 g/m2 every 12h for 3 d). Most CRs were clonal. At present 21 responders have relapsed (median relapse-free survival 4 5 months). Eight responders received an allo-BMT, six are alive in CR 7-57 months post-transplant. Therefore allo-BMT only increases the chance of a long survival and possible cure. In conclusion, CT+G-CSF did not prolong either CR duration or survival; the growth factor support, however, increased the number of allo-transplantable cases by inducing higher remission rates and improving clinical conditions.

Clinical aspects, cytogenetics and disease evolution in myelodysplastic syndromes

Myelodysplastic syndrome (MDS) is a morphologically characterized hematologic entity that is one of the clonal myeloproliferative disorders. Approximately 50 approximately 70% of MDS patients have cytogenetic abnormalities; these are usually chromosomal deletions, but some involve translocations such as t(1;7) (q10;p10). Translocations involving chromosomal regions 3q26 or 22q11 are often therapy-related. Recent studies have demonstrated that cytogenetic changes in MDS patients have clinical relevance. Accordingly, there are now scoring systems for predicting the prognoses of MDS patients. In this review, we describe the clinical significance of cytogenetic changes in MDS. We include MDS with some atypical forms, such as MDS with hypocellular bone marrow, MDS with minimal dysplasia, and MDS with myelofibrosis.

Diagnostic and prognostic significance of cytogenetics in adult primary myelodysplastic syndromes

Cytogenetic analysis has proven to be a mandatory part of the diagnosis of myelodysplastic syndromes (MDS) as well as a major indicator for predicting clinical course and outcome. This review concentrates on the cytogenetic classifications, the incidence and types of chromosome defects and the prognostic significance of the karyotype in adult primary MDS. Two cytogenetic classifications are currently used: one is based on the karyotype complexity (normal, single, double or complex defects), the other on clonal status (all metaphases normal, abnormal or admixture of normal and abnormal clones). Chromosome abnormalities are of both numerical and structural types. Aside from the 5q-syndrome, no specific clinico-cytogenetic entity has been reported. However, several distinct clinical and cellular features have been identified that correlate with the presence of specific chromosome defects such as inv(3)/t(3;3), +6, t(5;12), del(17p) and del(20q). The presence of complex defects is associated with reduced survival and a high risk of leukemic transformation. Among single defects, specific abnormalities may define distinct prognostic groups. Patients with del(5q) as a sole chromosome defect and a refractory anemia without excess of blasts have a favourable prognosis. For patients with trisomy 8 or monosomy 7 there may be distinct types of clinical evolution. Most patients with the 3q21q26 syndrome have a short survival. The presence of two chromosome defects may constitute an independent cytogenetic entity probably associated with relative poor prognosis. Karyotypic evolution generally represents a poor risk factor. The combination of cytogenetics with clinical and hematological features has proven to provide for a better prediction of patients' survival, leukemic transformation and response to treatment. Several scoring systems have been developed. They have to be improved by the study of new patients according to strict clinical and cytogenetic criteria and by the addition of newly recognized prognostic indicators such as histopathological features and molecular genetic mutations.

The relationship between age and karyotypic abnormalities in myelodysplastic syndromes

We performed a retrospective analysis of 143 consecutive patients with myelodysplastic syndrome to study the possible relationship between patient age and cytogenetic findings in this disorder. There were 96 men and 47 women, with a mean age of 63 years. Eighty-six patients were 63 years old and above, and 57 patients were younger than 63 years of age. The distributions of the five FAB subtypes were comparable in both groups of patients, except for a higher percentage of refractory anemia with ringed sideroblasts in older patients. The incidences of cytogenetic abnormalities were similar in the two groups. However, the younger patients tended to have a higher frequency of involvement of chromosomes 5 or 7 than the elderly patients (p < 0.05). The implications of our findings in relation to the biology of myelodysplastic syndrome are discussed.