Which metabolic imaging, besides bone scan with 99mTc-phosphonates, for detecting and evaluating bone metastases in prostatic cancer patients? An open discussion.

Prostate cancer bone metastases occur frequently in advanced cancer and this is matter of particular attention, due to the great impact on patient's management and considering that a lot of new emerging therapeutic options have been recently introduced. Imaging bone metastases is essential to localize lesions, to establish their size and number, to study characteristics and changes during therapy. Besides radiological imaging, nuclear medicine modalities can image their features and offer additional information about their metabolic behaviour. They can be classified according to physical characteristics, type of detection, mechanism of uptake, availability for daily use. The physiopathology of metastases formation and the mechanisms of tracer uptake are essential to understand the interpretation of nuclear medicine images. Therefore, radiopharmaceuticals for bone metastases can be classified in agents targeting bone (99mTc-phosphonates, 18F-fluoride) and those targeting prostatic cancer cells (18F-fluoromethylcholine, 11C-choline, 18F-fluorodeoxyglucose). The modalities using the first group of tracers are planar bone scan, SPECT or SPECT/CT with 99mTc-diphosphonates, and 18F-fluoride PET/CT, while the modalities using the second group include 18F/11C-choline derivatives PET/CT, 18F-FDG PET/CT and PET/CT scans with several other radiopharmaceuticals described in the literature, such as 18F/11C-acetate derivatives, 18F-fluoro-5α-dihydrotestosterone (FDHT), 18F-anti-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC), 18F-2'-fluoro-5-methyl-1-ß-D-arabinofuranosyluracil (FMAU) and 68Ga-labeled-prostate specific membrane antigen (PMSA) PET/TC. However, since data on clinical validation for these last novel modalities are not conclusive and/or are not still sufficient in number, at present they can be still considered as promising tools under evaluation. The present paper considers the nuclear modalities today available for the clinical routine. This overview wants to discuss the opportunities and the drawbacks of these current diagnostic tests in a scenario where planar scintigraphy and/or SPECT with phosphonates, is the only metabolic imaging recommended by the most important Guidelines of the Scientific Societies dealing with prostate cancer. Other nuclear medicine modalities are in very few cases just cited, never recommended except in rare situations. Is there space for agents other than 99mTc-phosphonates to image bone lesions from prostate cancer?

Validation of automated whole-body analysis of metabolic and morphological parameters from an integrated FDG-PET/MRI acquisition.

Automated quantification of tissue morphology and tracer uptake in PET/MR images could streamline the analysis compared to traditional manual methods. To validate a single atlas image segmentation approach for automated assessment of tissue volume, fat content (FF) and glucose uptake (GU) from whole-body [18F]FDG-PET/MR images. Twelve subjects underwent whole-body [18F]FDG-PET/MRI during hyperinsulinemic-euglycemic clamp. Automated analysis of tissue volumes, FF and GU were achieved using image registration to a single atlas image with reference segmentations of 18 volume of interests (VOIs). Manual segmentations by an experienced radiologist were used as reference. Quantification accuracy was assessed with Dice scores, group comparisons and correlations. VOI Dice scores ranged from 0.93 to 0.32. Muscles, brain, VAT and liver showed the highest scores. Pancreas, large and small intestines demonstrated lower segmentation accuracy and poor correlations. Estimated tissue volumes differed significantly in 8 cases. Tissue FFs were often slightly but significantly overestimated. Satisfactory agreements were observed in most tissue GUs. Automated tissue identification and characterization using a single atlas segmentation performs well compared to manual segmentation in most tissues and will be valuable in future studies. In certain tissues, alternative quantification methods or improvements to the current approach is needed.

Elevated vascular endothelial growth factor (VEGF) serum levels in idiopathic myelofibrosis.

An increase of angiogenesis has been shown in idiopathic myelofibrosis with myeloid metaplasia (MMM) by microvessel density count method but evaluation of circulating angiogenic factors is still incomplete. In 31 patients affected by MMM and in 12 healthy subjects we evaluated the serum levels of VEGF (vascular endothelial growth factor) and correlated VEGF with clinical and laboratory features of disease. We found that MMM patients had circulating VEGF concentrations much higher than controls (Median 1208 ng/ml vs 138 ng/ml, P < 0.0001). No correlation was found between VEGF and Hb, WBC, PLT, LDH, creatinine, bone marrow cellularity, fibrosis, splenomegaly, hepatomegaly, and therapy. However, in the subgroup of patients with a normal or low VEGF concentration, a direct correlation between VEGF and platelet count (r = 0.90, P = 0.002) was detected. Moreover, patients with a platelet count < 300 x 10(9)/l had VEGF serum levels lower than patients with a higher PLT count (median VEGF 864 vs 1557 pg/ml, P = 0.001). In six patients and in eight controls we also had the opportunity to measure VEGF in the plasma and we calculated that VEGF concentration was much higher in platelet-rich than in platelet-poor plasma and that platetets of MMM patients contained four times more VEGF than those of healthy controls. These results indicate that VEGF is overproduced in MMM, thus confirming an increased angiogenic activity. Platelets are probably a major source of VEGF in MMM but not the only one.

CD34 expression in adult acute lymphoblastic leukemia.

The expression of the pluripotent stem cell antigen CD34 was evaluated at diagnosis in forty-five adult patients with de novo ALL. Comparison of clinical and hematological features between CD34 positive (24/45) and CD34 negative (21/45) patients showed that the former were of older age, had more pronounced lymphoid organ involvement and higher serum LDH levels. Immunophenotypic analysis of marrow blast cells revealed a significant predominance of the 'null' phenotype in the CD34 positive group, together with a strong expression of the VLA-4 and VLA-5 integrins (fibronectin receptors). CD34 positive ALL were also more frequently associated with either aberrant myeloid-related antigens (CD13, CD33) or the P-gp/MDR-1 phenotype. Only 11 out of 24 (45%) CD34 positive patients achieved complete remission after induction chemotherapy, compared to 20/21 (95%) CD34 negative cases. Furthermore, survival was significantly shorter in the CD34 positive group (6.6 mo. vs 13.5 mo.). These results suggest that in ALL, as in AML, CD34 positivity may predict a poor prognosis.

[Use of a particular cellulose acetate supporting agent in the electrophoretic evaluation of human hemoglobin]. / Impiego di un particolare supporto di acetato di cellulosa nella valutazione elettroforetica dell'emoglobina umana.

576 subjects of whom 450 with hereditary anaemia and 116 normal are studied to establish the haemoglobin pattern. The assay is carried out using the standard cellulose acetate and an particular cellulose acetate medium cellogel RS "Wedge". The results show that cellogel RS in comporation with standard medium permits either an better resolution of the hemoglobin bands or a better detection of the pathologic bands.

T lymphocyte subpopulations in the bone marrow and peripheral blood of untreated patients with myeloma.

The quantitative distribution of the two main T lymphocyte subsets, recognizable by the 'high' and "low-affinity' E rosette-forming cell technique of West, was studied in both the bone marrow and peripheral blood from ten untreated multiple myeloma (MM) patients. A reduced total T lymphocyte count, with a relative predominance of 'low-affinity' T lymphocytes (putative suppressor T cells), was found in the peripheral blood. Within a normal total T lymphoid cell count, a predominance of the T lymphocyte subset with 'low-affinity' characteristics was also observed in the bone marrow. An inverse correlation, that was statistically significant, was seen between the monoclonal malignant cellular B component and the 'low-affinity' T cell percentage in all cases. It is concluded, therefore, that such an imbalance between the 'high' and "low-affinity' T subsets, with the latter predominating, could be of importance in the regulation of the growth rate of the monoclonal cellular B component.

[The nitroblue tetrazolium activated test in the study of granulocytic function. Proposed methodology]. / Il test attivato al nitro blu tetrazolio nello studio della funzionalita' granulocitaria. Proposta metodologica.

It was reported a combined methodological proposal to test simultaneously activated-NBT and phagocytic index (PI) assay using zymosan particles. Such a method allowed to evaluate these two steps of the phagocytic process in the same cellular population. Comparable results were obtained performing the two methods separately.

[Fc gamma+ T-lymphocytes and depressed polyclonal immunoglobulin synthesis in multiple myeloma]. / T-linfociti Fc gamma+ e depressa sintesi policlonale immunoglobulinica nel mieloma multiplo.

In the present study the effects on the polyclonal Ig synthesis of peripheral MM T gamma and T non-gamma cell fractions when cocultured with autologous and normal allogenic B-lymphocytes have been reported. Five untreated MM patients (three IgG-kappa, two IgG-lambda) were studied employing a five-day PWM-stimulated co-culture technique, in which the percentage of cells with detectable amounts of cytoplasmic Ig was evaluated by direct immunofluorescence. Our results indicated that depressed polyclonal Ig synthesis in human MM could be ascribed not only to an increased "suppressive" activity of T gamma cells but also to an impaired "inducer" function of T non-gamma lymphocytes and to an intrinsic B-lymphocyte disfunction as well. In addition, it was noteworthy that MM T gamma cells showed on normal Ig synthesis a selective suppressive effect mainly for those Ig chains corresponding to the monoclonal Ig which characterizes the own myeloma type. The significance of this datum, so far not yet reported, remains to be established.

Serum levels of soluble interleukin-2 receptor (sIL-2R) in B-chronic lymphocytic leukemia.

By using an enzyme-linked immunosorbent assay, the levels of the soluble form of the interleukin-2 receptor (sIL-2R) were evaluated in the peripheral blood of 20 patients with cell chronic lymphocytic leukemia in different stages of disease and in supernatants obtained from enriched B cell suspensions. In either all serum samples or in one out of three supernatants, elevated levels of sIL-2R were found. This could indicate that the B leukemic cells release sIL-2R which in turn, for its potential capacity of binding circulating IL-2, could contribute to the abnormal immunoregulation which characterizes B-CLL. This finding, which needs further investigation, could have prognostic significance.

Multiple myeloma and renal transplant.

Until now, no case of multiple myeloma (MM) had been reported among the B-lymphoproliferative disorders occurring in organ-transplant recipients. The history of a 58-year-old man who developed IgG-kappa MM 31 months after a cadaveric renal transplant is described. A possible relationship between drug-mediated immunosuppression and the development of MM is discussed.

T-subset abnormalities in thalassaemia intermedia: possible evidence for a thymus functional deficiency.

Peripheral blood T-lymphocyte subsets, evaluated by means of a series of monoclonal antibodies, were assessed in 14 patients affected by thalassaemia intermedia, 7 of them previously splenectomized. A significant reduction of T+4 cells ('helper' T cells) was found in almost all patients, whereas T+8 cells ('suppressor/cytotoxic') showed a marked increase only in splenectomized subjects. Together with these quantitative T-subset abnormalities, which seemed to be partly affected by either splenectomy or high serum iron levels, an unusual circulating T-cell subpopulation labelled by T6 monoclonal antibody was detected in all patients. Complete disappearance of T+6 cells ('thymocyte-like' T lymphocytes) and normalization of the T4/T8 ratio was observed after 'in vitro' incubation of patient's lymphocytes with a crude thymus extract (Thymostimulin). This would suggest the presence of a so far unreported thymus-dependent defect of T-lymphocyte phenotypic maturation occurring in thalassaemia intermedia.

Beta-1-integrin expression in adult acute lymphoblastic leukemia: possible relationship with the stem cell antigen CD34.

In the hemopoietic system, interactions between stem cells and components of the bone marrow microenvironment play a pivotal role in blood cell proliferation and differentiation. Among the adhesion molecules, the integrins of the beta 1-subfamily are known to direct cell-cell and cell-matrix interactions and evidence has been provided that CD34-positive stem cells bind either to the bone marrow stroma or to the extracellular matrix proteins through the beta 1-integrins. It seems that changes in their expression pattern or signalling function are likely to reflect disturbances at the hemopoietic bone marrow microenvironmental level. Any alteration of their biological functions makes them attractive candidates for playing decisive roles in the leukemic processes. In this view, beta 1-integrins have been recognized to mediate those cellular interactions and migrations that are important in the biology of leukemia. In this paper we review some aspects of the role played by beta 1-integrins, especially VLA-4 and VLA-5, in adult acute lymphoblastic leukemia in relation with the expression rate of the stem cell antigen CD34.

[Bone marrow T-lymphocyte subpopulations in patients with multiple myeloma]. / Studio delle sottopopolazioni T-linfocitarie nel midollo osseo di soggetti con mieloma multiplo.

The bone marrow quantitative distribution of the two main T-lymphocyte subsets, recognizable by the "high" and "low-affinity" E-rosette forming cell technique, according to West, was evaluated in ten untreated myeloma patients and twelve normal controls. It was observed, within a normal total T-lymphoid cell count, a significant predominance of the T-lymphocyte subset with "low-affinity" characteristics. An inverse correlation, with statistical significance, between the monoclonal malignant B-component and "low-affinity" T-cell percentage was also seen in all cases. It was suggested, therefore, that such an imbalance between "high" and "low-affinity" T-subsets, with the latter predominating, could play a role in the regulation of the monoclonal B-component growth rate.

'Mu' heavy chain type 'non-excretory' myeloma.

An unusual case of 'non-excretory' myeloma is described in which, using immunofluorescence, only 'mu' heavy chains were detected in almost all bone marrow plasma-cell cytoplasm. Cytoplasmic light chains were completely lacking, and neither monoclonal whole immunoglobulin (Ig) nor free heavy nor light chains were detected in serum and urine, although the clinical and morphological features showed the classical pattern of myeloma. The possible mechanism which could play a role in the disturbance of the Ig-chain secretion observed in this case is discussed.

All-trans-retinoic-acid- and growth-factor- mediated induction of alkaline phosphatase activity in freshly isolated chronic myeloid leukemia cells.

Reduced or absent neutrophil alkaline phosphatase (NAP) activity is a common feature of neutrophilic granulocytes from patients with chronic myeloid leukemia (CML). In this study we examined whether NAP activity could be restored in vitro by stimulating CML cells with different promoters such as all-trans-retinoic acid (ATRA), granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF). The results obtained indicated that ATRA and G-CSF, either alone or in combination, were effective in inducing NAP activity in CML cells, whereas GM-CSF was not. Further, NAP restoration in ATRA- and G-CSF-treated cultures was accompanied by increased morphologic differentiation of the CML clone. It might be concluded that the CML clone could be driven in vitro by ATRA and G-CSF both to achieve granulocytic maturation and to correct functional NAP-related defects.

Vitro drug-induced apoptosis in freshly isolated leukemic cells: a flow cytometric analysis.

Fludarabine is considered a useful drug in the management of B-CLL resistant to conventional chemotherapy as it is able to trigger apoptosis in neoplastic B cells. In order to analyze this aspect, we tested by means of a simple and rapid flow cytometric method the in vitro apoptotic response of CD5+ B-CLL lymphocytes to FAMP, in comparison with other cytoreductive agents such as Interferons. Our findings showed that apoptosis occurred significantly in lymphocytes cultured with FAMP, but not with IFNs. In conclusion, flow cytometry allows an easy and rapid detection of in vitro drug-induced apoptosis, possibly representing also a reliable assay for testing tumor cell sensitivity or resistance.

In vitro apoptotic response of freshly isolated chronic myeloid leukemia cells to all-trans retinoic acid and cytosine arabinoside.

Chronic myeloid leukemia (CML) is a hematological malignancy resulting from clonal expansion and massive accumulation of leukemic myeloid cells that retain differentiation and maturation capacity. Since CML cell accumulation has been related to apoptosis inhibition by the product of the BCR-ABL gene, attempts to eradicate leukemic cells would require therapeutic drugs able to overcome this inherent resistance. Here, we investigated in vitro the apoptotic effect of all-trans retinoic acid (ATRA) and cytosine arabinoside (ARA-C), employed alone, in combination or in sequence, on freshly isolated cells from 10 patients with chronic-phase CML. Our cell cultures showed that both ATRA and ARA-C were able to induce apoptosis in CML cells, even if ARA-C resulted more effective than ATRA. The combined use of ATRA and ARA-C seemed to have only an additive effect while the sequential use did not show any advantage. These in vitro observations indicate that ATRA and ARA-C may be effective in reducing CML cells through apoptosis induction, suggesting that it could be worthwhile to examine ATRA and ARA-C combinations in the therapy of CML.

Radioisotopic microassay of adenosine deaminase in human lymphocytes.

A radioisotopic method for a rapid assay of adenosine deaminase in human lymphocytes is proposed here. [2-3H] adenosine, as substrate, has been employed for the enzymatic assay. The products of reaction have been resolved by thin layer chromatography on PEI cellulose. The plates were developed with distilled water and inosine spots absorbing in the U.V. were eluted with 0.1 N HCl. The eluates obtained from the inosine spots were employed for radioactive measurements.