A 24-month prospective study on the efficacy and safety of two different monthly regimens of vitamin D supplementation in pre-menopausal women with systemic lupus erythematosus.

BACKGROUND: Low vitamin D (vit.D) serum levels are common in patients with systemic lupus erythematosus (SLE) and seem to correlate with higher disease activity. We investigated the effects of different regimens of vit.D supplementation in SLE patients with inactive disease. METHODS: This 24-month prospective study included 34 SLE women who were randomized to receive, together with their ongoing treatment, a standard regimen (SR) of cholecalcipherol (25,000 UI monthly) or an intensive regimen (IR) (300,000 UI initial bolus followed by 50,000 UI monthly) for one year and then were switched to the other regimen in the second year. Patients were seen quarterly for assessment of 25-OH vit.D levels, disease activity, SLE serology and bone metabolism markers. RESULTS: By intra-patient comparison, only the IR was found able to significantly raise vit.D serum levels. After 12 months, values above 30 ng/ml were found in 75% of patients in IR while in only 28% in SR. No significant differences in disease activity and SLE serology were found at any time point between SR and IR. No changes in the mineral metabolism were observed. CONCLUSIONS: The IR was safe and effective in obtaining sufficient levels of vit.D in most SLE patients. However, both regimens of supplementation did not differently affect disease activity nor SLE serology.

Chromosome aberrations in atypical chronic lymphocytic leukemia: a cytogenetic and interphase cytogenetic study.

To define better the chromosomal profile of atypical chronic lymphocytic leukemia (aCLL), cytogenetic and interphase cytogenetic studies were performed in 43 cases, using mitogen-stimulated cultures and DNA probes detecting the two most frequently occurring aberrations in CLL, ie +12 and 13q14 deletions. All cases showed monoclonal CD5/CD19-positive lymphocytosis, with more than 10% large lymphocytes and/or prolymphocytes in peripheral blood smears and reactivity with FMC7, or bright expression of surface immunoglobulins in a fraction of the cases. Karyotype aberrations were detected in 27 of 43 cases (62.8%). Recurrent chromosome changes were +12 (nine cases), 13q14 aberrations (five cases), 11q anomalies (three cases), 6q21-q23 abnormalities and 4q anomalies with different breakpoints (two cases each). Additional chromosome changes were seen in four cases with +12, in three cases with 13q14 anomalies, in two cases with 11q anomalies, in one case with 6q and 4q anomalies. Trisomy 12 was associated with 13q14 anomalies in three cases, one of which also had an 11q abnormality; other associations, found in one case each, were: 13q14 deletion with a 6q anomaly, 11q anomaly with 13q- and 7q-, a 6q anomaly with 7q- and +12. Interphase cytogenetics confirmed the results of chromosome banding analysis and showed that six patients with normal karyotype or no mitosis in fact had concomitant +12 and 13q14 deletion in four cases and isolated +12 or 13q14 deletion in one case each, with a resultant 76% overall incidence of cytogenetic abnormalities. The presence of +12, 13q14 deletions, 11q, and 6q21-q23 anomalies in 19 cases was associated with a 2-month median interval between diagnosis and start of treatment, as compared with a 24-month median interval in 14 cases with normal karyotype or non-recurrent chromosome changes (P = 0.003). We conclude that aCLL is characterized by a relatively high incidence of chromosome anomalies, with recurrent chromosome changes, involving chromosomes 12, 13q14, 6q21q23, 11q, and, possibly, 4q. The presence of complex karyotypes, with concomitant abnormalities of 13q, +12, 6q, 11q, suggests that the development of sequential chromosome changes, rather than any single specific anomaly, may underlie leukemogenesis in this cytologic subset of CLL, partially accounting for the relatively aggressive clinical course.

Fluorescence in situ hybridization for the detection and monitoring of the Ph-positive clone in chronic myelogenous leukemia: comparison with metaphase banding analysis.

In order to analyze the efficiency of interphase FISH for the detection and monitoring of Ph+ cells in chronic myelogenous leukemia (CML) under interferon (IFN) treatment, the following experiments were performed: (1) 98 specimens derived from 32 patients were analyzed in parallel by dual-color FISH and by conventional chromosome analysis (CCA). A 300/200 kb BCR/ABL probe was used in all tests and a smaller 35.5/39 kb probe was tested in parallel in 22 BM samples; (2) 30 BM samples were prepared by direct harvest and by 24-h culture and were analyzed in parallel; (3) PB and BM samples obtained simultaneously from 11 patients were analyzed. The cut-off point for the recognition of BCR/ABL fusion was set at 2.4%, calculated as the mean percent of false positivity in 11 controls plus 3 s.d. A very close correlation was observed (r=0.994, r2=0.988, P < 0.0001) between the percentages of Ph+ cells as assessed by CCA and by interphase FISH in 98 samples (26 at diagnosis). There was a moderate overestimation of the frequency of Ph+ cells by FISH with respect to CCA, that was more evident at low-to-medium values of Ph positivity. Seven specimens without Ph+ metaphases (17-50 cells analyzed) were shown to carry 2.5-8% interphase cells with BCR/ABL fusion. Similar percentages of BCR/ABL+ nuclei were recorded in 22 samples hybridized using the 300/200 kb and the 35.5/39 kb probe-sets (variation range: 0-5%, mean 2.3%). A very good correlation between the frequency of Ph+ interphase cells was observed when analyzing in parallel BM preparations after direct harvest and after 24-h culture. Underestimation of the percentage of BCR/ABL+ cells was noted to occur in 2/11 PB samples, compared to BM samples, the remaining nine cases showing superimposable results at either sites. We arrived at the following conclusions: (1) dual-color FISH enables an accurate detection and monitoring of the size of the Ph-positive clone in CML at diagnosis and after IFN-therapy; (2) FISH is more accurate than CCA, especially at low levels of Ph-positive cells; (3) testing of directly harvested BM samples is feasible and accurate, giving the opportunity to perform centralized FISH analysis in the context of multicentre trials; (4) the percentage of BCR/ABL+ PB cells usually, though not invariably, reflects the frequency of mutated cells in the BM.

Clinical importance of interphase cytogenetics detecting occult chromosome lesions in myelodysplastic syndromes with normal karyotype.

At diagnosis, approximately half of myelodysplastic (MDS) patients presents a normal karyotype by conventional cytogenetic analysis (CCA). Fluorescent in situ hybridization (FISH) is more sensitive than CCA allowing for the detection of minor clones and of submicroscopic lesions. We have analyzed by FISH 101 MDS patients with normal karyotype for the occurrence of the abnormalities which are most frequently observed in MDS (ie -5/5q-, -7/7q-, +8, 17p-). In 18 patients, 15 to 32% of interphase cells were found to carry one FISH abnormality. Six patients presented trisomy 8, five had del(5)(q31), five del(7)(q31), one monosomy 7 and one del(17)(p13). FISH abnormalities were more frequently observed among patients with an increased percentage of bone marrow blasts (P = 0.001). FISH abnormalities were also associated with a higher rate of progression into AML (13/18 vs 12/83, P < 0.001) and were predictive for a worse prognosis (P < 0.001). Multivariate analysis indicated that FISH positivity and IPSS risk group were independent predictors for a poor survival (P = 0.0057 and 0.0123, respectively) and for leukemic transformation (P = 0.0006 and 0.035, respectively). Leukemic transformation in FISH-positive patients was associated in all cases with an expansion of the abnormal clone. Our data demonstrated that a significant proportion of MDS patients with normal karyotype presented, if analyzed by FISH, clones of cytogenetically abnormal cells which played a determinant role in the progression of the disease. The presence of FISH abnormalities identified a group of MDS patients with normal karyotype characterized by an inferior prognosis.

Morphologic, immunologic and cytogenetic studies in acute myeloid leukemia following occupational exposure to pesticides and organic solvents.

In order to analyze the correlation between environmental exposure and the clinicopathological picture in acute myeloid leukemia (AML), cytogenetic, cyto-immunologic and clinical studies were performed in 70 newly diagnosed AML patients, 30 of which were anamnestically exposed to pesticides (21 cases) or to organic solvents (9 cases). Clonal chromosome aberrations, with involvement of chromosome 5 and/or 7 were more frequently encountered among exposed patients. While the classical t(15;17), t(8;21) and t(9;11) were detected more frequently among non-exposed patients, other recurring chromosome changes in the exposed group were: rearrangements leading to total or partial monosomy 17p (5 cases), structural aberrations involving the band 16q22 (4 cases), trisomy 11q (2 cases), breaks involving bands 6p23, 7p14, 11q13 (2 cases each). Cytologically, trilineage myelodysplasia was observed in 21 exposed patients, whereas morphologic aberrations of the non-blast cell population were confined to a minority of cells in most patients non-exposed. Immunologic studies revealed positivity for the CD34 stem cell marker in 80% exposed patients vs 22% in the non-exposed group. Conventional chemotherapy achieved complete remission in 3/21 patients exposed and in 16/32 patients non-exposed. Median survival was 2 months in the former group and 9 months in the latter group. These findings show that AML following occupational exposure to pesticides and organic solvents may represent a distinct cytogenetic and clinicopathological entity.

A prospective, controlled, nonrandomized study on prophylactic parenteral dichloromethylene bisphosphonate (clodronate) in multiple-myeloma.

Bone resorption by osteoclasts causes neoplastic bone disease, which is a significant cause of death in multiple myeloma (MM). Counteracting bone resorption with prophylactic bisphosphonates has delayed bane disease, and this is expected to improve survival. Between January, 1987 and March, 1990, 341 evaluable previously untreated, consecutive patients with MM entered a prospective, multicenter study in which cytostatic therapy was randomized. The first 148 patients recruited were not planned for prophylaxis and the following 193 were scheduled to receive parenteral, prophylactic clodronate. Clodronate was administered at a dose of 600-1000 mg/4-6 weeks and was started at diagnosis and continued throughout survival time. Data on clodronate prophylaxis were evaluated on both an intention-to-treat and a compliance analysis basis. The rate of response and the duration of response were independent of clodronate prophylaxis. Progression of skeletal disease occurred less often in patients who received the drug than in those who were not given prophylaxis (50.5 vs 34.8%; p<.02 by compliance analysis). Survival was longer for patients on clodronate prophylaxis than for those who were not planned for (p<.02 by intention to-treat-analysis) or for those who did not receive clodronate prophylaxis (p<.009 by compliance analysis). Local pain associated with i.m. administration was the only significant side effect of clodronate. Parenteral clodronate prophylaxis prolongs survival in MM, probably because it allows better control of bone disease and reduces deaths related to it.

Lymphoblastic lymphoma with primary splenic involvement and the classic 14;18 translocation.

Clinicopathologic features of a case of lymphoblastic lymphoma (LyL) with the classic 14;18 translocation are described in this article. The patient had prominent splenomegaly with numerous splenic nodules, exhibiting a homogeneous blast cell infiltrate and occasional cells with cleft nuclei, a picture suggestive of high-grade non-Hodgkin lymphoma (NHL) possibly lymphoblastic. Early B-cell features were detected immunologically, thus confirming the diagnosis of LyL. The presence of primary splenic involvement and of the t(14;18)(q32;q21) are unusual in this histologic subset of B-cell NHL, these cytogenetic and clinicopathologic characteristics being typically associated with low- or intermediate-grade NHL of follicle center origin. These features, along with the presence of some centrocytelike cells in the biopsy sections, suggest that an unusual pattern of histologic evolution from a follicle center cell NHL may have occurred in this case of LyL.

Cytogenetic analysis of different cellular populations in chronic myelomonocytic leukemia.

Karyotypes of different cellular populations made after separation of bone marrow cells on a gradient of Percoll were evaluated in seven patients affected by chronic myelomonocytic leukemia diagnosed according to FAB criteria. Megakaryocytes, monocytic cells, and granulocytic and erythroid precursors were preferentially collected after centrifugation between density layers of 1045-1050 mg/ml, 1050-1060 mg/ml, and 1065-1070 mg/ml, respectively. The enriched cell fractions were cultured separately and submitted to cytogenetic investigation after short-term culture. Some chromosome aberrations (5q-,+8) were observed in all cellular fractions in three patients, thus providing cytogenetic evidence of the involvement of a common progenitor stem cell in this myelodysplastic disorder. On the other hand, chromosome abnormalities such as del(3)(q21) and del(11)(q23) appeared to be confined to the megakaryocytic and the monocytic fractions, respectively, in two patients. It is conceivable that lineage-restricted aberrations may develop as a consequence of a multistep clonal evolution and may show a close relationship with the hemopoietic differentiative processes.

Chromosome aberrations in CD34-positive acute myeloid leukemia. Correlation with clinicopathologic features.

Morphologic, immunologic, and cytogenetic features were studied in 30 newly diagnosed patients with CD34-positive (CD34+) de novo acute myeloid leukemia (AML) in comparison with 30 patients with CD34-negative (CD34-) AML. Karyotype at diagnosis was abnormal in 25/30 CD34+ AML patients, of which nine had major karyotype aberrations (MAKA). Clonal chromosome changes were detected in 9/30 patients with CD34- AML. The most frequent chromosome aberration in CD34+ patients was -5/5q-, an aberration showing a strong association with the M2 FAB subtype of AML. Other recurring chromosome changes involved chromosome 16q (four cases) and chromosome 17p (three cases). Total or partial monosomy 7q was detected in three cases. Among CD34- AML, two patients had the classical t(15;17) and two had structural aberrations of 6q. Among patients with CD34+ AML, nine had MAKA in association with trilineage myelodysplasia (TMDS). TMDS was infrequent in CD34+ AML without MAKA and in CD34- AML. Complete remission (CR) was achieved in 8/30 CD34+ AML (26%), as compared with 22/30 CD34- AML (73%), and median survival was 2 months in the former group and 8 months in the latter. No patient with CD34+ AML and MAKA achieved CR, whereas 8/21 CD34+ AML without complex chromosome changes or with normal karyotype achieved CR. In conclusion, a distinct cytogenetic profile may be associated with CD34+ AML. Cytogenetic findings in CD34+ AML may be clinically relevant in that they may disclose a subset of patients with MAKA with a low CR rate.

5' region and exon 7 mutations of the TP53 gene in two cases of B-cell prolymphocytic leukemia.

We previously found that cases of typical B-chronic lymphocytic leukemia (CLL), atypical B-CLL with t(11;14) and mantle cell lymphomas characterized by rapid progression of the disease and resistance to therapy, had mutations of the TP53 gene. In this paper, abnormalities of the TP53 gene were investigated in two cases of prolymphocytic leukemia, one with t(11;14)(q13;q32), evolving from atypical CLL (patient 1), and one presenting as a de novo condition (patient 2). TP53 DNA was investigated by Southern blot and PCR-SSCP analysis, and TP53 expression was investigated by Northern blot analysis and immunocytochemistry. C-MYC and BCL-1/PRAD1 gene expression were also investigated. Restriction enzyme analysis of TP53 DNA in patient 1 showed alteration of fragments including exon I and intron I, and, in both patients, a specific loss of TP53 DNA. In patient 2, PCR direct sequencing showed in exon VII a 9 bp deletion including codons 252-254. In patient 1, TP53 RNA and protein were not found, indicating that the unusual 5' rearrangement has affected TP53 gene expression. By contrast, patient 2 exhibited detectable TP53 RNA and protein. Detectable but weak BCL-1/PRAD1 RNA was present in both patients, whereas C-MYC RNA expression was clearly present only in case 1. The presence of TP53 hemizygous mutations in both patients suggests that TP53 abnormalities may be important in the pathogenesis of prolymphocytic leukemia (PLL), and may possibly account for the frequent resistance to therapy observed in this disease.

Interleukin-3 plus interleukin-6 may improve chromosomal analysis of multiple myeloma: cytologic and cytogenetic evidence in thirty-four patients.

To better define the role of interleukin-3 (IL-3) and IL-6 in the cytogenetic analysis of multiple myeloma (MM), we performed concomitant chromosome and cytologic studies in 34 patients. In each case, 10-30 x 10(6) bone marrow cells were incubated in two independent cultures consisting of conventional cytogenetic medium with and without IL-3 plus IL-6 added for 72 hours. 1-ml aliquots of each culture were aspirated at 24, 48, and 72 hours and exposed to colcemid for 6 hours. Cytospin preparations were then made and mitotic cells were counted and identified as plasma cells or as nonmalignant cells based on their reactivity with an appropriate anti kappa/lambda serum. Slides for conventional cytogenetic analysis were prepared at 72 hours. A greater than two-fold increase of mitotic plasma cells was observed in cytospin preparations from stimulated cultures versus unstimulated cultures in 15 of 34 cases, whereas a less than 2-fold increase, no variation or no mitosis was recorded in 19 cases. Comparison of the number of mitotic plasma cells in stimulated cultures at 24, 48, and 72 hours showed a decreased mitotic activity at 72 hours. Clonal abnormalities were detected by conventional cytogenetic analysis in 19 of 34 cases (55.8%). Recurrent clonal aberrations involved chromosome 13 (4 cases), chromosomes 1p, and 14q (3 cases); chromosomes 3p, 6q, 7q, and 9q (2 cases). We conclude that IL-3 + IL-6 may increase the number of dividing plasma cells in cytogenetic cultures and that a 2-day culture with these cytokines may facilitate the detection of chromosome abnormalities in MM.

Clinical review on features and cytogenetic patterns in adult acute myeloid leukemia with lymphoid markers.

Cytogenetic patterns in correlation with cytologic, biomolecular and clinical findings were studied in 45 adult patients with AML expressing at least one of the following lymphoid associated markers (LM): CD2, CD7, CD10, CD19, CD22, TdT. Four cytogenetic groups were recognized: group I, including 8 patients with 11q23 rearrangements; group II including 5 patients with the Ph chromosome; group III, with 19 patients and aberrations of the "myeloid type" including 4 cases with aberrations of chromosome 13, 3 cases with 1q and 7q anomalies, 2 cases with trisomy 11q; group IV, including 13 patients with normal karyotype. Patients showing extensive lineage infidelity were encountered more frequently in cytogenetic groups I and II than in groups III and IV. Two of 4 cases with aberrations of chromosome 13 showed two or more lymphoid features either at immunophenotyping or at biomolecular analysis of the configuration of lg and TCR genes. Patients with 11q23 rearrangements and with the Ph chromosome were generally young, presented with high WBC count and had low complete remission rate. Survival in Ph chromosome positive patients was uniformly short. We conclude that, although there is no cytogenetic anomaly specific for AML with LM, chromosome findings may be clinically relevant in AML with LM. A morphologic, immunologic and cytogenetic classification of AML with LM may constitute a working basis for future studies aimed at a better definition of clinicopathological features and optimal treatment strategy for these leukemias.

Trisomy 12 in chronic lymphocytic leukemia and hairy cell leukemia: a cytogenetic and interphase cytogenetic study.

Fluorescent in situ hybridization (FISH) with a chromosome 12-specific pericentromeric probe was performed in 42 patients with B-cell chronic lymphocytic leukemia (CLL) and in 10 patients with hairy cell leukemia (HCL). In all cases, a normal karyotype in more than 10 metaphase cells was obtained by conventional chromosome study. FISH documented that 6/42 patients with CLL in fact had trisomy 12 in 15-49% interphase cells. Sequential FISH studies were performed in 2 cases, showing an increase of percentage of trisomic cells over a 2-month to 4-year period. Two out of 10 patients with HCL, one of whom had morphologic features consistent with a diagnosis of HCL variant, showed 5.5 and 10% interphase nuclei with three fluorescent signals, a finding suggestive of the presence of trisomy 12. Combined immunophenotyping and FISH staining in these patients with HCL documented that trisomic cells were CD11c-positive, CD13-negative, and CD2-negative. We conclude that FISH is a sensitive technique allowing for the detection of trisomy 12 in a fraction of cytogenetically normal patients affected with CLL and HCL.

[Plasma cell dyscrasias and diffuse idiopathic skeletal hyperostosis. Is it a merely accidental association?]. / Discrasie plasmacellulari ed iperostosi scheletrica idiopatica diffusa. Associazione puramente casuale?

The radiologic staging of a series of 144 patients (88 males and 56 females) affected with plasma-cell dyscrasias and observed over a 26-month period, revealed both the well-known bone myeloma-related abnormalities and hyperostotic lesions similar to those described in diffuse idiopathic skeletal hyperostosis. The incidence of skeletal hyperostosis was 31.94%, much higher than that reported in literature for the general population (5%). Typically, the axial skeleton is the most common location for abnormalities in multiple myeloma (MM) as well as in DISH: involvement of the dorsal spine was observed in 65% of cases, the cervical spine was involved in 34.8% of patients, and the lumbar spine in 28.3%. Peripheral ossifying enthesopathy, considered as "whiskering" in the pelvis, was found in 12 cases (8.2%), 7 males and 5 females. DISH was indifferently present in both MM (23 cases), with severe osteolysis (stage III) or simple osteoporosis (stage I), and monoclonal gammopathy of undetermined significance (MGUS) (17 cases), usually without any myeloma-related bone lesions, and in Waldenström disease (4 cases). Many hypotheses are discussed as to the possible pathogenesis (e.g.: accidental, dysmetabolic, or degenerative) of hyperostosis in dysgammaglobulinemias, but, to date, they are no more than mere guesses. DISH is a disorder the etiology of which is still unknown: it is likely to be an ossifying diathesis, but its incidence in both illnesses--which are both plasma-cell dyscarsias--is too high for the association to be accidental. Thus, a pathogenetic factor produced by multiple myeloma can be hypothesized, capable of increasing the so-called idiopathic hyperostosis.

[Role of computerized tomography in the diagnosis of bone disease in multiple myeloma]. / Ruolo della tomografia computerizzata nella diagnosi della malattia ossea del mieloma multiplo.

PURPOSE: To assess the role of CT in the diagnosis and management of multiple myeloma (MM) and to investigate if CT findings can influence the clinical approach, prognosis and treatment. STUDY DESIGN AND PATIENTS: We reviewed the findings relative to 273 MM patients submitted to CT June, 1994, to December, 1996. The patients were 143 men and 130 women (mean age: 65 years): 143 were stage I, 38 stage II and 92 stage III according to Durie and Salmon's clinical classification. All patients were submitted to blood tests, spinal radiography and CT, the latter with serial 5-mm scans on several vertebral bodies. The CT unit was a Philips Tomoscan SR 7000. RESULTS: CT showed lysis foci in some vertebral bodies (4 cases) where conventional radiography had shown only aspecific osteopenia. CT also depicted vertebral arch and process involvement in 3 cases with the vertebral pedicle sign. Moreover, CT proved superior to radiography in showing the spread of myelomatous masses into the soft tissues in a case with solitary permeative lesion in the left pubic bone, which facilitated subsequent biopsy. As for extraosseous localizations, CT demonstrated thoracic soft tissue (1 woman) and pelvic (1 man) involvement by myelomatous masses penetrating into surrounding tissues. In our series, only a case of osteosclerotic bone myeloma was observed in the pelvis, associated with lytic abnormalities. DISCUSSION AND CONCLUSIONS: The role of CT in the diagnosis and management of MM has not been assessed, because this technique demonstrates tumor extent more accurately than radiography but CT findings do not seem to improve the clinical approach and therapeutic management of the disease. Nevertheless, we recommend CT for some myelomatous conditions, namely: a) in the patients with focal bone pain but normal skeletal radiographs; b) in the patients with M protein, bone marrow plasmocytosis and back pain, but with an inconclusive MM diagnosis; c) to assess bone spread in the regions which are anatomically complex or difficult to study with radiography and to depict soft tissue involvement; d) for bone biopsy.

Articular cartilage changes mechanically induced "in vivo". An experimental method approach in animals.

A machine designed upon the principles of a crank lever mechanism was built to produce excessive use of the joints of small animals by means of continuous flexion-extension movements. Articular cartilage changes could be consistently produced after 5 to 10 days of exercise. Histochemical studies of the articular cartilage demonstrated a decrease in proteoglycan and an increase in acid phosphatase. These findings suggest that this animal model may be of value for the analysis of the earliest degenerative stages of the articular cartilage.

Chromosome studies of enriched blast cell fractions in myelodysplastic syndromes terminating in acute myeloid leukemia.

For a better understanding of the karyotype evolution of different marrow cell populations in the course of MDS, 6 patients who eventually developed overt leukemia, belonging to a series of 46 MDS referred to our Institution, were studied ad diagnosis and at leukemic progression. In each case the blast cells were separated from the maturing precursors of the erythroid and granulocytic lineage by centrifugation on a Percoll density gradient. Parallel chromosome investigations were performed in each cell fraction. Cytogenetic analysis performed at presentation did not reveal distinctive karyotype features in metaphases arising in the blast enriched cell fraction, as compared with those obtained from the fraction containing erythroblasts and promyelocytes--myelocytes. These findings suggest that in the initial phase of MDS blast cells may lack distinctive cytogenetic features and may thus represent part of a clonal preleukemic proliferation. At the time of leukemia onset, clonal aberrations [trisomy 21 and del(11)(q23)] showing a restricted pattern of distribution within the blast cell enriched fractions were detected in two patients, whereas one patient showed an increase in size of the abnormal clone carrying monosomy 7, an aberration detected in metaphases obtained from both cell fractions. Thus, some evolutive steps in the natural history of these disorders can be heralded by the acquisition of chromosome aberrations more readily detectable in blast enriched cell fractions. In some cases, partial loss of differentiative capability by the abnormal clone may account for the detection, at leukemia onset, of chromosome aberrations involving both the blast cell fraction and the erythroblast-promyelocyte enriched cell fraction.

Detection of numerical aberrations in hematologic neoplasias by fluorescence in situ hybridization.

BACKGROUND AND OBJECTIVE: Over the last 5 years, fluorescence in situ hybridization (FISH) techniques have had an important impact on molecular cytogenetic diagnosis, providing a better understanding of the role of numerical aberrations in hemopoietic neoplasms. The objective of this article is to analyze the clinical applications of FISH in the management of hemopoietic malignancies. EVIDENCE AND INFORMATION SOURCES: The material examined in the present review includes articles and abstracts published in journals covered by the Science Citation Index and Medline, and personal published and unpublished data. STATE OF ART: FISH technology has the advantage of being relatively simple, fast and flexible. Published data and ongoing prospective studies show that, under well-controlled experimental conditions, interphase FISH is more sensitive than conventional metaphase analysis in the detection of numerical abnormalities. Due to the relatively high rate of false positive results, FISH cannot be used for the study of minimal residual disease. However, since molecular strategies for the detection of small-sized aneuploid clones have not been developed yet, FISH represents a useful adjunct to conventional cytogenetics, especially for the quantitation of the size of abnormal clones during the course of the disease and to monitor XX/XY chimerism following sex mis-matched bone marrow transplantation. Different approaches to the study of multiple cell-lineage involvement by chromosome changes have been developed that take advantage of FISH techniques by: a) simultaneous FISH and membrane immunophenotyping of cytologic and histologic preparations; b) two-step analysis based on assessment of the morphology of cells on panoptical stains, with subsequent hybridization and relocation of previously identified cells; c) FISH analysis of enriched cell fractions obtained by cell sorting or by separation of bone marrow cells on a density gradient, and d) study of single hemopoietic colonies grown in semisolid media. PERSPECTIVES: New molecular cytogenetic techniques, such as dual color FISH comparative genomic hybridization, are at hand that will greatly improve the diagnostic power of cytogenetics and make FISH increasingly useful in research laboratories as well as in clinical practice.