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.

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.

Acute myeloid leukemia (AML) having evolved from essential thrombocythemia (ET): distinctive chromosome abnormalities in patients treated with pipobroman or hydroxyurea.

ET is a chronic myeloproliferative disorder rarely evolving into AML, sometimes preceded by a myelodysplastic syndrome (MDS). Such transformations mostly occur in patients treated with radiophosphorous ((32)P) or alkylating agents, especially busulfan. Recently, concern has also arisen about the long-term safety of hydroxyurea (HU). Pipobroman (PI), a well tolerated and simple to use drug, constitutes a valid alternative to those cytoreductive treatments. The present study reports on 155 ET patients treated at our institution from 1985 to 1995, and monitored until December 2000. A good control of thrombocytosis was achieved with PI as the only treatment in 106 patients and with HU in 23 patients. Twenty-six patients received no treatment. After a median follow-up of 104 months, seven patients (four treated with HU, and three with PI) developed AML whereas one patient treated with PI developed MDS. A significant difference in progression-free survival was observed between HU- and PI-treated patients (P = 0.004). A short-arm deletion of chromosome 17 was most frequently detected in HU-treated patients, while a long-arm trisomy of chromosome 1 and a monosomy 7q were seen in PI-treated patients. No TP53 mutation was discovered in the six patients studied (two HU-treated and four PI-treated). We conclude that these cytogenetic abnormalities are not linked to the natural history of the disease, but rather that they might be induced by the cytoreductive treatment.

Trisomy 11 and a complex t(11;11;22) in a patient with acute myelomonocytic leukemia (AML-M4) following myelodysplasia (MDS): a cytogenetic study of a mechanism of leukemogenesis.

We describe a 73-year-old man diagnosed with acute myelomonocytic leukemia (AML-M4) following myelodysplasia with trisomy 11 and with a t(11;11;22). This is the first case with both abnormalities present in the same cells and with the t(11;11;22) involving a chromosome 11 already duplicated at 11q23. This band contains the MLL gene that undergoes partial tandem duplication in patients with +11, which is "promiscuous," being translocated with a large number of genetic partners. Our patient had a complex karyotype that was completely defined by in situ hybridization. This technique demonstrated that the t(11;11;22) derivative with a duplication of band 11q23 carried from three to four copies of MLL. Two copies of the gene were close to each other and centromeric to the break-point region. Therefore, a partial tandem duplication of the MLL gene might have happened before the occurrence of t(11;11;22). Considering the associated chromosome defects, the monosomy for the long arm of chromosome 7, due to an unbalanced translocation t(7;17), further underlines the possibility that a partial tandem duplication of the MLL gene might have taken place.

A complex translocation (5;7) in a patient with acute nonlymphocytic leukemia evolved from a myelodysplastic syndrome.

Complete or partial monosomy for the long arms of chromosomes 5 or 7 or both is frequently observed in therapy-related myelodysplastic syndromes and acute nonlymphocytic leukemia. Sporadic cases have been reported in which partial monosomy is due to unbalanced translocations. The patient described herein carries one such rearrangement. 46,XY,t(1;2) (q32;p23),del(5)(q13),der(7)(5qter-->5q22::7p15-->7 q21:),del(12)(p12), resulting in partial monosomy for the long arms of chromosomes 5 and 7 and in partial monosomy for the short arm of chromosome 7.

Assay of phagocytic cell functions.

The fundamental role of the immune system is recognition of the self from the non-self; in this way the principal functions of the immune system can be summarized as: resistance against the cells and foreign substances which are potentially damaging the tissues; identification of neoplastic cells to be destroyed. The cells which have this role are essentially lymphocyte, neutrophils and macrophages: extracellular and cellular humoral factors also play their role into the inflammatory process. In fact, we define the normal responses of phagocyte as the capacity of the specific phagocytic cell to respond to various stimuli and to migrate to the location of the damage. This complex cellular defense mechanism comprises several steps that can be summarized as following: opsonization of particles to be ingested, adhesion and aggregation of phagocytes to vascular endothelium, migration of phagocytes through the vessel walls, chemotaxis of phagocytes towards pathogenic agents, recognition of the particles/antigens by the phagocytes which subsequently adhere to their surface, ingestion of the particles with formation of a phagosome. This process is completed with the fusion of the phagosome with cellular granules (lysosomes) and formation of phagolysosomes, degranulation and release of the enzyme laden granules into the phagolysosome, lysis and killing of ingested particles and bacteria. It is clear from this schematic summary, that the response to pathogens can be very complex and each of the processes involved in the above described steps could be deranged leading to various pathological changes. We analyze the most classical and new methods to study the physiopathology of granulocytes, which are important for clinical diagnosis of phagocyte diseases or for phagocytic dysfunction in various syndromes and in neoplastic patients.