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G Castoldi

Publications and source records attributed to G Castoldi.

At least 55 records · Page 3Linked to original sources
PubMed1999

Role of the renal nerves and angiotensin II in the renal function curve.

The relationship between renal perfusion pressure and urinary sodium is involved in arterial pressure regulation. The aim of this study was to investigate the role of renal nerves and angiotensin II in the pressure-natriuresis relationship. Experiments were performed in anaesthetised cats in which one kidney was surgically denervated. Renal perfusion pressure (RPP), renal blood flow (RBF) glomerular filtration rate (GFR, creatinine clearance), urinary volume (V) and sodium excretion (Una + V) were separately measured from both kidneys. RPP was progressively reduced in two consecutive steps by a suprarenal aortic snare. Two groups of animals were studied: the first without any pharmacological treatment (Untreated), the second during treatment with an angiotensin converting enzyme inhibitor (Captopril, 0.4 mg/Kg intravenously followed by an infusion of 0.4 mg/Kg/h). In the Untreated group RPP was reduced from 152.4 +/- 7.3 to 113.6 +/- 5.8 and 83.0 +/- 4.4 mmHg during the first and second step respectively. RBF and GFR were only slightly reduced during the second step of reduced RPP. In control conditions V and UNa + V were greater in the denervated compared to the innervated kidney. The graded decrease in RPP reduced both V and UNa + V in the innervated as well as in the denervated kidney. In the Captopril group V and UNa + V were larger than in the Untreated group in both the innervated and the denervated kidney. A decrease of RPP similar to that observed in the Untreated group, produced similar haemodynamic changes. Also in the Captopril group the graded decrease in RPP reduced both V and UNa + V in the innervated as well as in the denervated kidney. Matching UNa + V against RPP values significant correlations were found in the innervated and denervated kidneys of both groups. Both renal denervation and ACE inhibition were accompanied by an increased gain of the pressure-natriuresis curve, but only renal denervation shifted the crossing of the pressure axis to the left. In the ACE inhibited animals renal denervation only shifted the curve to the left. In conclusion our data suggest that i) at each level of RPP renal nerves and angiotensin II decrease renal sodium excretion, ii) renal nerves and angiotensin II increase the slope of the renal function curve, iii) renal nerves shift to the right the renal function curve.

Angiotensin II↗
PubMed1999

Assessment of distribution of CD34 epitope classes in fresh and cryopreserved peripheral blood progenitor cells and acute myeloid leukemic blasts.

BACKGROUND AND OBJECTIVE: So far several reports have described changes in the expression of surface antigens in progenitor cells and blasts following cryopreservation. However, there are no data on the effects of cryopreservation on the expression of the three CD34 epitope classes, and on their relationship with the clonogenic capacity of PBPC collected by leukapheresis. DESIGN AND METHODS: In order to analyze the effects of freezing/thawing procedures (Eth 80C storage for 3 months) and use of dimethylsulfoxide (DMSO) on the immunophenotype profile and colony production of peripheral blood progenitor cells (PBPC) in apheresis products derived from 20 patients with stage 0-III non-Hodgkin's lymphoma (nHL), a flow cytometry study was undertaken using different CD34 monoclonal antibodies (MoAbs) capable of recognizing the 3 epitope classes of CD34 molecule (class III: HPCA-2/FITC, HPCA-2/PE, 581/FITC, 581/PE; class II: Q-Bend 10/PE; class I: ICH3/PE, BI3C5-PE, Immu-133-PE). CD34 epitope expression was also analyzed in thawed CD34+ blasts obtained from 14 patients with acute myeloid leukemia (AML), who were analyzed using a larger number (#17) of CD34 epitope class I, II, and III reactive MoAbs. RESULTS: Under our experimental conditions it was found that class III and class II CD34 epitopes (differentially resistant to enzymatic cleavage with neuraminidase, chymopapain and glycoprotease) are better preserved than class I epitope Eth sensitive to degradation Eth after cell exposure to cryoprotectant DMSO and the freezing- thawing procedures. Results further showed a concomitant decrease in class I CD34+ counts and in BFU-E colony production. A significant increase in CD34 antigen expression levels (i.e. antibody binding capacity, ABC) by cryopreserved cells stained with CD34 epitope class III, and class II reactive MoAbs was also documented, while no changes after cryopreservation were noted using class I-reactive MoAbs. The slight increase in the percentage of CD34+ cells detected after frozen storage was correlated to a concomitant decrease in the number of more mature myeloid cells (CD15+, CD13+, CD33+). Compared to pre-cryopreservation values, a slight reduction in class I CD34 epitope expression was also found in thawed CD34+ AML blasts. INTERPRETATION AND CONCLUSIONS: As far as the reduction of class I CD34 epitope is concerned, it may be hypothesized that the freezing procedure, use of DMSO, and/or lysis methodology may either damage a CD34 subset, or induce distinct alterations of the CD34 glycoprotein, possibly determining a reduction in their immunoreactivity with some CD34 MoAbs. In conclusion, this study has shown that exposure to the cryoprotectant DMSO and the freezing/thawing procedures modifies the distribution of CD34 epitopes as well as the clonogenic capacity of PBPCs from nHL patients, and CD34+ blasts from AML. These findings need to considered when selecting CD34 MoAbs for enumeration and positive selection of stem/progenitor cells for research and clinical purposes.

Acute Disease↗
PubMed1999

Impact of immunophenotyping on management of acute leukemias.

BACKGROUND AND OBJECTIVE: The diagnosis of acute leukemias (AL) requires a multiparametric approach in order to apply risk-adapted therapeutic protocols and appreciate the potential outcome of any given patient. Blast cells immunophenotyping is a key test in this issue, yet the information provided by immunophenotyping has become staggering, and it may be difficult to identify relevant characteristics clearly. This manuscript provides a critical review of the literature regarding the importance of immunophenotyping in acute leukemia diagnosis and management. DATA SOURCES AND METHODS The information given here is based on the experience of the authors, on their literature files and on additional material retrieved through articles and reviews covered by the Institute for Scientific Information (ISI) and the Medline database. Studies with proper definition of the patients and sufficient information regarding follow-up were considered. RESULTS: Immunophenotyping allows an early confirmation of AL diagnosis and establishes lineage assignment. Adequate and comprehensive panels of monoclonal antibodies also allow detection of aberrant immunophenotypic profiles of prognostic value or of use in detecting minimal residual disease. A number of unusual immunophenotypic features are also associated with prognosis. The development of new antibodies, new insights in the functional properties of differentiation antigens, and the quantimetric approach of immunophenotyping will keep this field changing. Moreover, as therapeutic protocols evolve, some earlier results need to be reconsidered. INTERPRETATION AND CONCLUSIONS: Immunophenotyping, together with cytologic, karyotypic and molecular approaches, retains a crucial place in the diagnosis and management of acute leukemias. It remains a rather specialized approach and should be interpreted in a multidisciplinary perspective, considering for each patient the idiosyncrasies possibly relevant to prognosis.

Acute Disease↗
PubMed1998

The reliability and specificity of c-kit for the diagnosis of acute myeloid leukemias and undifferentiated leukemias. The European Group for the Immunological Classification of Leukemias (EGIL).

We document findings on c-kit (CD117) expression in 1,937 pediatric and adult de novo acute leukemia cases, diagnosed in five single European centers. All cases were well characterized as to the morphologic, cytochemical, and immunologic features, according to the European Group for the Immunological Classification of Leukemias (EGIL). The cases included 1,103 acute myeloid leukemia (AML), 819 acute lymphoblastic leukemia (ALL), 11 biphenotypic acute leukemia (BAL), and 4 undifferentiated (AUL). c-kit was expressed in 741 (67%) AML cases, regardless of the French-American-British (FAB) subtype, one third of BAL, all four AUL, but only in 34 (4%) of ALL cases. The minority of c-kit+ ALL cases were classified as: T-cell lineage (two thirds), mainly pro-T-ALL or T-I, and B lineage (one third); cells from 62% of these ALL cases coexpressed other myeloid markers (CD13, CD33, or both). There were no differences in the frequency of c-kit+ AML or ALL cases according to age being similar in the adult and pediatric groups. Our findings demonstrate that c-kit is a reliable and specific marker to detect leukemia cells committed to the myeloid lineage, and therefore should be included in a routine basis for the diagnosis of acute leukemias to demonstrate myeloid commitment of the blasts. c-kit expression should score higher, at least one point, in the system currently applied to the diagnosis of BAL, as its myeloid specificity is greater than CD13 and CD33. Findings in ALL and AUL suggest that c-kit identifies a subgroup of cases, which may correspond to leukemias either arising from early prothymocytes and/or early hematopoietic cells, both able to differentiate to the lymphoid and myeloid pathways.

Acute Disease↗
PubMed1998

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.

Aged↗
PubMed1998

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.

Adult↗
PubMed1998

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.

Adolescent↗
PubMed1998

Detection and monitoring of trisomy 8 by fluorescence in situ hybridization in acute myeloid leukemia: a multicentric study.

BACKGROUND AND OBJECTIVE: The role of fluorescence in situ hybridization (FISH) in the detection and monitoring of trisomy 8 (+8) in acute myelogenous leukemia (AML) has not been defined exactly. This multicentric study was performed in order to: i) analyze the sensitivity of interphase FISH with respect to conventional chromosome analysis (CCA) in detecting +8; ii) compare the results of FISH and CCA in the quantitation of the frequency of +8-positive cells; iii) analyze the possible role of FISH in the cytogenetic follow-up of patients with +8. DESIGN AND METHODS: One hundred and ninety-eight nonconsecutive patients with a diagnosis of AML seen at five centers over a 3-year period were studied by CCA and FISH with a chromosome 8-specific centromeric probe. Two hundred interphase cells were scored in each test and the cut-off for the recognition of +8 was set at 3%. An irrelevant pericentromeric probe was used as negative control in those cases with an apparently normal karyotype and trisomy 8 in interphase cells. FISH studies were conducted at diagnosis and, in 14 cases with +8, on 1.5 occasions during follow-up. RESULTS: Karyotype aberrations were seen in 121 cases (61.1%), with +8 being present in 38 of them (16 as the sole aberration). Interphase FISH detected +8 in 37/38 cases; in a patient with 1/10 metaphases with +8, 2.3% interphase cells with 3 signals were seen. Fourteen additional cases with occult +8 were detected by FISH, which showed 4-22% interphase cells with three signals; 6 patients had an abnormal karyotype without +8, 3 had a normal karyotype, 5 had no analyzable mitoses. In 24 cases with > 15 analyzable metaphases, percent variations between CCA and FISH in the estimation of the size of the trisomic clone ranged between 0.4% and 51%, median value 22%. Underestimation of the percent of trisomy 8 by FISH occurred in all 10 cases with > 90% +8 metaphases. In 7/14 cases investigated sequentially, FISH detected 5-35% trisomic cells in the BM after induction therapy (4 CR, 3 PR); 4 cases relapsed with +8 at 8-15 months. The absence of +8 in remission marrows was documented in the remaining 7 cases, 4 of which relapsed at 20-32 months. INTERPRETATION AND CONCLUSIONS: It is concluded that FISH was a valuable method in this multicentric study since it showed greater sensitivity than CCA in detecting minor clones with +8, in patients with both normal and abnormal karyotypes. The role of FISH in the cytogenetic follow-up of trisomies in AML patients may be promising.

Acute Disease↗
PubMed1997

Comparative analysis of different permeabilization methods for the flow cytometry measurement of cytoplasmic myeloperoxidase and lysozyme in normal and leukemic cells.

Using a direct one-color (fluorescein isothiocyanate; FITC) staining method with a Facscan flow cytometer, we evaluated the intracellular expression of two granular constituents of myeloid cells [myeloperoxidase (MPO) and lysozyme] on leukemic cells from 21 patients with acute myeloid leukemia (AML), and 6 patients with acute lymphoblastic leukemia (ALL). Three different permeabilization techniques were used [FACS Lysing Solution (FLy), B.Dis; Ortho-PermeaFix (OPF); Fix and Perm (F&P), Caltag] prior to monoclonal antibody (McAb) staining, in order to verify the specificity and the sensitivity of the three labelling methods towards the two model antigens. Peripheral blood cells from 15 healthy subjects and Ortho Absolute Control served as controls. Data were expressed as percentage of positivity, net fluorescence intensity, ratio between mean fluorescence intensity (MFI) of positive cells and that of isotypic controls (P/N ratio; evaluated in both geometric and arithmetic scale), and, in 12 representatives cases (7 AML, 5 normal samples), in the form of both molecules of equivalent soluble fluorochromes (MESF) and antibody binding capacities (ABC). As far as the antigenic expression of MPO and lysozyme in normal samples is concerned, F&P resulted, in our hands, in the most specific and sensitive staining, followed by FLy solution and OPF, which showed positivity for MPO, and, to lesser extent, for lysozyme in a considerable manner of lymphocytes (means 64% and 54%, respectively, for OPF and FLy; range of ABC/cell: 0.9-5.2 x 10(3)) obtained from healthy subjects. With the reference F&P permeabilizing solution, 90% and 80% of FAB M1-M5 cases were found to be positive for MPO and lysozyme, respectively. However, M1, M2, and M3 AML FAB (French-American-British) subvarieties were characterized by a brighter expression for MPO (mean ABC/cell: 89 x 10(3)) than that of lysozyme (mean ABC/cell: 12.5 x 10(3D)), whereas blast cells from patients with M5a FAB subtypes showed higher levels of lysozyme (mean ABC/cell: 65 x 10(3)) than that of MPO (mean ABC/cell: 0.1 x 10(3)). One of five cases of FAB MO AML showed a dull positivity for MPO-7 McAb. Patients with ALL were MPO and lysozyme negative using both F&P and FLy reagents, although a certain degree of positivity was documented in some cases with OPF. Taking these data together, it can be stated that the use of anti-MPO McAbs may be of great value for the diagnosis and monitoring of acute leukemia and, along with lysozyme McAb, can provide useful information in the distinction of myeloid from monocytic leukemias and in the lineage assignment of apparently biphenotypic forms. However, the methodology used for the detection of these myeloid-associated antigens is critical for a correct interpretation of cytofluorimetric data and should be taken into account when evaluating data coming from multicenter trials dealing with leukemias. A standardization of cytofluorimetric analysis of intracellular antigens is needed in order to improve the reproducibility and comparability of results in multicenter studies.

Adult↗
PubMed1997

Cytogenetic and interphase cytogenetic characterization of atypical chronic lymphocytic leukemia carrying BCL1 translocation.

Conventional chromosome analysis (CCA) and fluorescent in situ hybridization (FISH) studies, using a 390-kb yeast artificial chromosome probe spanning the area of multiple breakpoints of the BCL1 locus at 11q13, were performed on 57 patients fulfilling the French-American-British criteria for the diagnosis of atypical B-cell chronic lymphocytic leukemia (CLL). To better define the incidence of 13q deletions and trisomy 12, FISH analysis was also performed using a cosmid probe that recognized a DNA sequence between the Rb gene and the D13S25 locus at band 13q14 and a chromosome 12-specific pericentromeric probe. All patients were characterized by cytoimmunological and hematological studies. Fourteen cases displayed three fluorescent signals in 41-98% interphase cells when hybridized to the BCL1 yeast artificial chromosome probe, documenting the presence of BCL1 translocation (BCL1-positive cases). The presence of t(11;14)(q13;q32) was ascertained in 12 cases using CCA and by dual color interphase FISH using the BCLI probe and a 14q telomere probe in 2 karyotypically normal cases. The remaining 43 cases had two signals in more than 95% interphase cells (BCL1-negative) and did not have the t(11;14) at CCA. Although 13q14 deletions were seen by means of CCA in only 5 of 14 BCL1-positive cases, hemizygous or homozygous deletions at band 13q14 were detected by FISH in 11 of 14 BCL1-positive cases, as compared with 17 of 43 BCL1-negative cases (P = 0.01). A subclone with trisomy 12 in addition to BCL1 translocation and del(13q14) was present in four BCL1-positive cases. We arrived at the following conclusions: (a) FISH with this BCL1 YAC probe is an efficient method for the detection of the t(11;14) and of the corresponding involvement of the BCL1 locus in this lymphoproliferative disorder; (b) the majority of BCL1-positive atypical CLLs by French-American-British criteria may carry 13q14 deletions; (c) the recognition of this cytogenetic subset of atypical CLL, sharing some immunological and cytogenetic features with mantle cell lymphoma, may be important, because these patients usually present isolated peripheral blood and marrow lymphocytosis, with or without mild to moderate spleen involvement, and may require early cytotoxic treatment.

Chromosomes, Artificial, Yeast↗
PubMed1997

Effects of erythropoietin administration on blood pressure and urinary albumin excretion in rats.

The effects of recombinant human erythropoietin (rHuEPO) administration on blood pressure and urinary albumin excretion were studied in normotensive Wistar-Kyoto rats (WKY), in spontaneously hypertensive rats (SHR), and in SHR rats treated with an angiotensin converting enzyme inhibitor (SHR-ACEi). Rats were housed in metabolic cages and treated with rHuEPO (150 U/kg body weight [bw] three times a week) for 6 weeks. Control animals received the vehicle only (0.25 mL of physiological saline). An angiotensin converting enzyme inhibitor was administered in the drinking water for 6 weeks (spirapril 5 mg/kg bw). Systolic blood pressure (SBP), and 24 h urinary albumin excretion (UAE) were measured once a week. No significant differences in SBP were observed between rHuEPO and vehicle-treated normotensive animals at the end of the treatment (171.9 +/- 4.9 v 172.1 +/- 5.6 mm Hg, respectively). After 6 weeks, SBP was significantly higher in SHR and SHR-ACEi groups treated with rHuEPO than in control groups (239.8 +/- 7.3 and 243.0 +/- 7.3 mm Hg v 218.1 +/- 6.0 and 187.9 +/- 4.6 mm Hg, respectively); UAE was significantly higher in groups treated with rHuEPO than in control groups (WKY: 265.9 +/- 19.5 v 127.0 +/- 12.3 microg/100 g bw, SHR: 1668.4 +/- 564.6 v 234.8 +/- 22.9 microg/100 g bw, and SHR-ACEi: 1522.7 +/- 448.3 v 143.0 +/- 18.9 microg/100 g bw, respectively). We concluded that erythropoietin treatment causes an increase in arterial pressure in SHR only, and an increase in UAE in both normotensive and hypertensive rats. The albuminuric effect was not entirely dependent on increased blood pressure. The treatment with an angiotensin converting enzyme inhibitor did not modify either the proteinuric or the pressor effects.

Albuminuria↗
PubMed1997

Flow cytometry measurement of GM-CSF receptors in acute leukemic blasts, and normal hemopoietic cells.

A quantitative analysis of expression levels of GM-CSF receptors was performed by flow cytometry in different disease categories, ie AML (n = 72), ALL (n = 18), and MDS (n = 12), as well as 12 healthy volunteers, using three different unconjugated GM-CSF/R monoclonal antibodies (McAbs) (HGM-CSFR (CD116), M5D12, 4B5F5), and appropriate standards. By using the reference HGM-CSFR McAb, in healthy subjects we found detectable levels of GM-CSF/R on blood monocytes (mean MESF (molecules of equivalent soluble fluorochrome)/cell: 36.1 x 10[3]), neutrophils (mean MESF/cell: 7.4 x 10[3]), bone marrow (BM) myelo-monocytic precursors (MESF range for the myeloid component, ie promyelocytes, myelocytes, metamyelocytes: 11.7-40.5 x 10[3], and for the monocytic lineage: 25.7-69.2 x 10[3]), and in two distinct subsets of BM CD34+ progenitor cells (GM-CSF/R dim: 2.5 x 10[3] MESF/cell, GM-CSF/R bright (10% of the total number of CD34 cells: 22.0 x 10[3] MESF/cell). In these subjects, there was no correlation between the expression levels of GM-CSF/R and CFU (CFU-GM, CFU-GEMM, BFU-E) colony production. Among the AML samples, M5D12 McAb was positive in 33%, 4B5F5 McAb in 90%, and HGM-CSF/R McAb in 78% of the cases examined (range of MESF/cell for the HGM-CSFR McAb: 0.9 x 10[3]-106.7 x 10[3]). The highest MESF values were seen in the M5 FAB subvariety (mean: 39.4 x 10[3]), where all the patients tested (n = 20) showed a strong positivity for the HGM-CSFR McAb. On the contrary, all ALL samples were GM-CSF/R negative except in two patients, who displayed a dim GM-CSF/R positivity (My+ALL: 1.3 x 10[3] MESF/cell; pro-B ALL: 1.0 x 10[3] MESF/cell). In most (>70%) M1 FAB subtypes, GM-CSF/R+ blasts co-expressed CD34low, HLA-DRhigh, CD33, CD38 antigens, and had little or no capacity to form CFU-GM colonies. GM-CSF/R+ blasts from the M5 FAB category were also positive for CD14, CD11c, CD33 and CD87. Furthermore, the number of GM-CSF/R expressed by leukemic cells from five out of 72 (7%) AML patients was above the highest values seen in normal samples (>69.2 x 10[3] MESF/cell), allowing the possibility of using this marker for the monitoring of the minimal residual disease (MRD) in a subset of AML. Cell culture studies aimed at evaluating GM-CSF receptor modulation following AML blast exposure to rhGM-CSF showed two distinct patterns of response; in the first group (6/10 cases) rhGM-CSF down-modulated GM-CSF receptors, whereas in the second group (4/10 cases), rhGM-CSF treatment was associated with either an increase or no change in the number of GM-CSF/R. In conclusion, cellular GM-CSF/R expression was variable and ranged from undetectable (ALL and a minority of AML) to very high intensities in M5 AML, and were also documented in some M0 AML, thus suggesting the concept that GM-CSF/R detection may be of help in lineage assignment of undifferentiated forms. Since the number of GM-CSF/R on AML blasts may be modulated after GM-CSF treatment, it can be postulated that the clinical use of GM-CSF in this disease may be optimized by a dynamic analysis of the number and the affinity status of GM-CSF-R in blasts and normal hemopoietic cells.

Acute Disease↗
PubMed1997

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.

Adult↗