Circulating angiopoietin-1 to angiopoietin-2 ratio is an independent prognostic factor for survival in newly diagnosed patients with multiple myeloma who received therapy with novel antimyeloma agents

The circulating levels of several angiogenic cytokines [angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), vascular endothelial growth factor (VEGF), angiogenin and basic fibroblast growth factor (bFGF)] were evaluated in 174 consecutive patients with newly diagnosed, symptomatic, multiple myeloma (MM). Circulating levels of Ang-1/Ang-2 were reduced in myeloma patients compared to controls, whereas VEGF and angiogenin levels were increased. Reduced angiopoietin-1/angiopoietin-2 ratio correlated with advanced disease features including international staging system (ISS)-3 stage, renal impairment and extensive bone disease. Based on immunohistochemical results in 20 patients (10 with the higher and 10 with the lower values of circulating angiopoietin-2) we found that angiopoietin-2 is expressed by myeloma cells and correlates with increased microvessel density in subsets of patients. Furthermore, Ang-1/Ang-2 ratio correlated with survival. Patients with circulating Ang-1/Ang-2 below or equal to the median value (6.03) had a median survival of 26.3 months compared to 53 months of all others (p = 0.002). Interestingly, this was mainly observed in patients who received first-line therapy with novel agent-based regimens (65% of our patients). Furthermore, a subset of ISS-3 patients with serum Ang-1/Ang-2 above the median value had favourable prognosis (median survival: 45 months versus 17 months of all others; p = 0.0001). The multivariate analysis revealed that low Ang-1/Ang-2 ratio could independently predict for inferior survival in our cohort of patients (relative risk (RR) 2.07, 95% CI 1.50-2.42; p < 0.001). These results highlight the role of angiopoietins pathway in the biology of MM and reveal novel targets for the development of antimyeloma agents.     

Bone marrow plasma macrophage inflammatory protein protein-1 alpha(MIP-1 alpha) and sclerostin in multiple myeloma: Relationship with bone disease and clinical characteristics

The aim of the study was to investigate the expression of MIP-1 alpha and sclerostin in bone marrow of patients with multiple myeloma (MM), the possible association of the sclerostin and MIP-1 alpha with MBD and the clinical characteristics. 53 patients (29 M, 24 F), median age 64 years was studied. MIP-1 alpha, sclerostin and bone-specific alkaline phosphatase (bALP) levels were quantified using an enzyme-linked immunosorbent assay (ELISA). Sclerostin and MIP-1 alpha mRNA expression was determined by RT-PCR. PTH and 1,25(OH) 2D3 levels were measured with an electrochemiluminescence immunoassay. The sclerostin and MIP-1 alpha concentrations in patients with MM were higher than those in the controls. RT-PCR analysis verified that the bone marrow mononuclear cells (BMMNCs) of most patients showed sclerostin and MIP-1 alpha mRNA expression. The sclerostin and MIP-1 alpha levels in patients with ISS stage III disease were significantly higher than those in patients with ISS stage II disease (p = 0.01 and 0.06). The sclerostin and MIP-1 alpha levels in patients with BMD in group C were significantly higher than those in group A + B. There was positive correlation between sclerostin levels and MIP-1 alpha, beta2-microglobulin and aCa levels. A negative association was seen between sclerostin levels and bALP, HB and ALB levels. The MM patients with high sclerostin levels (>0.72 ng/ml) had significantly shorter median survival than those with low sclerostin levels (≤0.72 ng/ml) (χ² = 7.574, p = 0.006). Our findings support the positive relationship between sclerostin levels and MIP-1alpha levels deserve further detailed research.     

The Value of the Bone Marrow Plasma Cell Cytoplasmic Light Chain Ratio in Differentiating Between Multiple Myeloma and Monoclonal Gammopathy of Undetermined Significance

We compared the plasma cell light chain ratios in the bone marrows of 13 patients with multiple myeloma (MM), with those of 13 patients with monoclonal gammopathy of undetermined significance (MGUS). The mean light chain ratio in favour of the paraprotein isotype in the myeloma group was 51.83 (95% confidence limits (CL) 29.52-74.14) while in the MGUS group it was 5.30 (CL 2.07-8.52). The difference between the MGUS and MM groups was significant (p = 0.0005). Neither the bone marrow plasma cell count nor the paraprotein level were significantly correlated with the light chain ratio in either of these two groups. We found a cut-off ratio of 8 to be the most useful in differentiating between myeloma and MGUS. Only one patient with myeloma had a ratio below 8, and one MGUS patient had a ratio above this cut-off point. We conclude that determination of the bone marrow plasma cell light chain ratio is a simple and useful test in differentiating between myeloma and MGUS in difficult cases.     

Serum Levels of Total-RANKL in Multiple Myeloma

BackgroundReceptor activator of nuclear factor-κB ligand (RANKL) plays a key role in osteoclast activation in myeloma bone disease. The increased expression of RANKL in the bone marrow microenvironment was demonstrated in several studies, but there are only rare data on circulating RANKL levels in patients with multiple myeloma (MM).Patients and MethodsIn the current study, we investigated the clinical significance of serum RANKL levels, using an enzyme-linked immunosorbent assay test that detects both free and osteoprotegerin (OPG)-bound RANKL (total-RANKL, tRANKL) in patients with newly diagnosed MM (n = 93) and monoclonal gammopathy of undetermined significance (MGUS; n = 20) compared with healthy controls (n = 20).ResultsCirculating serum tRANKL was significantly elevated in patients with MM compared with controls (P < .001) or MGUS (P < .001). Furthermore, tRANKL levels were higher in smoldering MM versus MGUS (P = .031) and in symptomatic versus smoldering MM (P < .001). Serum tRANKL increased parallel to International Staging System stages I to III (P = .004) and correlated with the presence of lytic bone lesions (P < .001). Total-RANKL was a prognostic factor for overall survival in symptomatic MM (P = .043). A significantly longer progression-free survival was observed in patients with a > 50% decrease in tRANKL levels after 3 months of combined chemotherapy and bisphosphonate treatment.ConclusionOur study demonstrates for the first time that serum tRANKL reflects advanced disease, lytic bone destruction, and poor prognosis in MM.     

Serum concentrations of Dickkopf-1 protein are increased in patients with multiple myeloma and reduced after autologous stem cell transplantation

Dickkopf-1 (DKK-1) protein, a soluble inhibitor of Wnt signalling, has been implicated in the pathogenesis of myeloma bone disease through the suppression of osteoblast differentiation. In this study, serum concentrations of DKK-1 were measured in 50 myeloma patients (32 at diagnosis and 18 before and after autologous stem cell transplantation (ASCT), 18 patients with monoclonal gammopathy of undetermined significance (MGUS), and 22 healthy controls. Serum DKK-1 levels were increased in MM at diagnosis compared with MGUS (mean +/- SD: 67 +/- 54 ng/mL vs. 38 +/- 13 ng/mL; p = 0.006) and controls (31 +/- 11 ng/mL; p = 0.02), while there was no difference between MGUS patients and controls. Although patients with stage 2 and 3 myeloma had higher DKK-1 values than stage 1 patients (79 +/- 63 vs. 40 +/- 13; p = 0.005), no significant correlation between serum DKK-1 and myeloma bone disease was observed. Myeloma patients before ASCT also had increased levels of DKK-1 (63 +/- 77 ng/mL; p = 0.03) compared with controls, supporting the notion that DKK-1 may be responsible for the suppressed osteoblast activity even in patients with low tumor burden. After ASCT, there was a sustained decrease in DKK-1 levels over time, while bone formation markers elevated, suggesting that the reduction of DKK-1 levels after ASCT may correlate with the normalization of osteoblast function. These results could provide the basis for developing agents that block DKK-1, thus restoring osteoblast function and counteracting the increased osteoclastogenesis observed in myeloma.     

Bone marrow angiogenesis in 400 patients with monoclonal gammopathy of undetermined significance, multiple myeloma, and primary amyloidosis.

PURPOSE: To determine whether bone marrow (BM) angiogenesis progressively increases along the spectrum of plasma cell disorders ranging from monoclonal gammopathy of undetermined significance (MGUS) to advanced myeloma. EXPERIMENTAL DESIGN: Four hundred patients with the following disorders were studied: MGUS (76 patients); smoldering (indolent; early-stage) multiple myeloma (SMM; 112 patients); newly diagnosed, active multiple myeloma (MM; 99 patients); relapsed (advanced) multiple myeloma (RMM; 26 patients); and primary amyloidosis (AL; 87 patients). Forty-two normal control BM samples were studied for comparison. BM angiogenesis was studied in a blinded manner by immunohistochemical staining for CD34 to identify microvessels. RESULTS: The median (range) microvessel density (MVD) per x400 high power field was 1.3 (0-11) in the controls, 1.7 (0-10) in AL, 3 (0-23) in MGUS, 4 (1-30) in SMM, 11 (1-48) in newly diagnosed MM, and 20 (6-47) in RMM; P < 0.001. MVD was significantly higher in MGUS, SMM, newly diagnosed MM, and RMM compared with controls and AL; P < 0.001. MVD was not significantly different between controls and AL. By grading, high-grade angiogenesis was present in 0% of controls and AL, 1% of MGUS, 3% of SMM, 29% of newly diagnosed MM, and 42% of RMM; P < 0.001. MVD correlated with the BM plasma cell labeling index (rho = 0.46, P < 0.001) and BM plasma cell percentage (rho 0.5, P < 0.001). Survival was 28 months in SMM and newly diagnosed MM with high-grade angiogenesis, compared with 53 months for those with low- and intermediate-grade angiogenesis; P = 0.02. CONCLUSIONS: BM angiogenesis progressively increases along the spectrum of plasma cell disorders, from the more benign MGUS stage to advanced myeloma, indicating that angiogenesis may be related to disease progression.     

CD45 expression by bone marrow plasma cells in multiple myeloma: clinical and biological correlations.

Multiple myeloma (MM) is characterized by accumulation of clonal plasma cells (PCs). CD45, a key regulator of antigen-mediated signaling and activation in lymphocytes, is present in early stages of PCs development. We studied CD45 expression on MM PCs by flow cytometry, correlating it to important biological disease characteristics. Additionally, we examined the expression of various adhesion molecules on PCs. A total of 75 patients with untreated MM (29), relapsed MM (17), smoldering MM (12), and monoclonal gammopathy of undetermined significance (MGUS) (17) were studied. The proportion of PCs expressing CD45 was higher among those with early disease (MGUS or smoldering MM) compared to those with advanced disease (new or relapsed MM) (43 vs 22%; P=0.005). Among those with advanced disease, patients with bone lesions had a lower percentage of CD45-positive (CD45+) PCs; 14 vs 34% (P=0.02). Patients with high-grade angiogenesis had a lower percentage of CD45+ PCs; 13 vs 31% (P=0.03). The median overall survival for the CD45+ group (>20% PCs positive) was 39 vs 18 months for the CD45-negative (CD45-) group (P=0.07). The expression of CD138, CD56 and CD54 were higher among the CD45- PCs. This study demonstrates important biological correlates of CD45 expression on myeloma cells.     

Serum thymidine kinase in monoclonal gammopathies. A prospective study. The Cooperative Group for Study and Treatment of Multiple Myeloma.

Between January 1986 and March 1990, the serum levels of thymidine kinase (TK) were evaluated at diagnosis in 97 patients with monoclonal gammopathy of undetermined significance (MGUS) and 149 patients with multiple myeloma (MM) enrolled in a prospective protocol for treatment of MM. At presentation, patients with MGUS had lower TK levels than those with Stage I MM (P less than 0.05) and the overall population of those with MM (P less than 0.0005). TK levels were increased in advanced stages in comparison with earlier ones (P less than 0.01). The TK level was related to survival. With a median follow-up of 29 months, patients with TK levels greater than 7.0 U/microliters had shorter survival times than those with lower levels (medians, 23 and 42 months; P less than 0.0001). In a multivariate analysis, TK explained most of the variability of survival (P less than 0.0001), the remaining being accounted for by serum creatinine and beta-2 microglobulin. No changes in TK levels occurred during follow-up of patients with stable MGUS, whereas TK levels increased in two patients at time of progression to overt MM. In patients with MM, TK levels decreased (P less than 0.01) in those who responded to treatment but increased in those having relapses (P less than 0.03) and those with progressive disease (P less than 0.03). These results indicate that TK has clinical and prognostic relevance in monoclonal gammopathies, and additional investigations are warranted to determine whether it is a useful tool for the clinical evaluation, staging, and follow-up of patients with MM.     

Serum bone sialoprotein as a marker of tumour burden and neoplastic bone involvement and as a prognostic factor in multiple myeloma

To test the potential of immunoreactive BSP, a non-collagenous bone matrix component, as a clinical guide in patients with plasma cell dyscrasias, serum BSP concentrations were measured in 62 patients with newly diagnosed multiple myeloma (MM) followed over a period of 4 years, in 46 patients with monoclonal gammopathy of undetermined significance (MGUS), in 71 patients with untreated benign vertebral osteoporosis (OPO), and in 139 healthy adults. Results were compared with clinical and laboratory data, including serum osteocalcin (OC), and urinary pyridinoline (PYD) and deoxypyridinoline (DPD) as markers of bone turnover. In MM, serum BSP, and urinary PYD and DPD were higher than in healthy controls and in MGUS or OPO (P< 0.001). BSP levels correlated with the bone marrow plasma cell content (r = 0.40, P< 0.001), and serum beta2-microglobulin (r = 0.31, P < 0.01). The differentiation of MM from healthy controls and from MGUS or OPO was highest for BSP. After chemotherapy, BSP reflected the response to treatment and correlated with the change in monoclonal protein (r = 0.55, P< 0.001). MM patients with normal baseline BSP levels survived longer than patients with initially elevated BSP values (P< 0.001, log rank test). Only serum monoclonal protein and BSP were independent predictors of survival. We conclude that in MM, BSP levels are associated with skeletal involvement and tumour cell burden. The quantification of serum BSP may be a non-invasive method for the diagnosis and follow-up, and may improve the prognostic value of conventional staging in MM.     

Importance of quantitative histology of bone changes in monoclonal gammopathy

Quantitative histology of bone changes, using undecalcified transiliac bone biopsies (UTBB), was performed blindly in 46 individuals with monoclonal gammopathy (MG), including 17 with MG of undetermined significance (MGUS) and 29 with overt multiple myeloma (MM). Three MGUS presented an excess of osteoclastic resorption (OR) in the vicinity of clusters of tumour cells and developed overt B cell malignancies, chronic lymphocytic leukaemia, Waldenström''s disease and MM respectively. On the other hand, MGUS with normal OR remained stable (median follow-up = 28 months), with one exception who developed a systemic amyloidosis. In MM, excessive OR was only observed in areas invaded by myeloma cells. OR was frequently normal in active MM lacking myeloma cells in UTBB. Active MM without lesions on radiography had excessive OR. IgA and pure Bence Jones MM appeared more osteoclastic than IgG cases (P less than 0.05). Of major interest was the finding that one third of MM presented histological bone changes similar to osteoporosis, osteosclerosis or osteoblastic metastasis. Two major findings must be emphasized from the current data: UTBB could be of major interest for the early detection of a B cell malignancy; heterogeneity of myeloma bone condition is unexpected. If some changes appear directly related to the tumour (i.e. excessive OR or osteoblastic dysfunction), some others are probably accidentally associated with it (i.e. osteoporosis), both needing treatment other than chemotherapy.     

Ras oncogene expression and DNA content in plasma cell dyscrasias: a flow cytofluorimetric study

Using bivariate flow cytofluorometry, we have determined the nuclear DNA distribution and the expression of the p21 protein (coded by the Ha-ras oncogene) in the bone marrow (BM) cells of five solid tumour patients having histologically normal BM and in those of 57 patients with plasma cell dyscrasia (28 with monoclonal gammopathies of undertermined significance, MGUS, and 29 with multiple myeloma, MM). All normal and MGUS and 21/29 (72.4%) MM BM had diploid modal DNA content and 8/29 (27.6%) MM BM had both diploid and hyperdiploid cell populations. In normal and MGUS BM, the level of the p21 oncoprotein was low and uniform in all G0/G1, S and G2 cells (median fluorescence values in arbitrary units were 6.1 and 7.5, respectively). The level of p21 was increased both in different aliquots of G0/G1 cells and in the S and G2 cells in diploid MM (median value for G0/G1 cells was 20), and especially in MM with hyperdiploid clones (median value for hyperdiploid cells was 40.5, P less than 0.005 with respect to normal and MGUS BM and less than 0.005 with respect to diploid MM BM). The p21 expression was greater in patients with advanced (stage III) than in earlier MM (stages I + II) (P less than 0.005), and it was directly related to the BMPC infiltration (r = 0.7; P less than 0.005). Since p21 expression is greater in MM than in both normal and MGUS BM, Ha-ras could be involved in the malignant plasma cell transformation that distinguishes MM from MGUS.     

The International Scoring System (ISS) for multiple myeloma remains a robust prognostic tool independently of patients’ renal function

BackgroundThe International Staging System (ISS) is the most widely used staging system for patients with multiple myeloma (MM). However, serum β2-microglobulin increases in renal impairment (RI) and there have been concerns that ISS-3 stage may include ‘up-staged’ MM patients in whom elevated β2-microglobulin reflects the degree of renal dysfunction rather than tumor load.Patients and methodsIn order to assess the impact of RI on the prognostic value of ISS, we analyzed 1516 patients with symptomatic MM and the degree of RI was classified according to the Kidney Disease Outcomes Quality Initiative-Chronic Kidney Disease (CKD) criteria.ResultsForty-eight percent patients had stages 3–5 CKD while 29% of patients had ISS-1, 38% had ISS-2 and 33% ISS-3. The frequency and severity of RI were more common in ISS-3 patients. RI was associated with inferior survival in univariate but not in multivariate analysis. When analyzed separately, ISS-1 and ISS-2 patients with RI had inferior survival in univariate but not in multivariate analysis. In ISS-3 MM patients, RI had no prognostic impact either in univariate or multivariate analysis. Results were similar, when we analyzed only patients with Bence-Jones >200 mg/day.ConclusionsISS remains unaffected by the degree of RI, even in patients with ISS-3, which includes most patients with renal dysfunction.     

Coexistence of Myeloproliferative Neoplasm and Plasma-Cell Dyscrasia

IntroductionPhiladelphia chromosome-negative myeloproliferative neoplasms (MPNs) include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), and are characterized by clonal proliferation of hematopoietic cells in the bone marrow. There are numerous case reports and reviews reporting patients with coexisting MPN and plasma-cell disease such as multiple myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS).MethodsWe report 15 patients treated at our institution over a 5-year period (January 2008 to December 2012) with a diagnosis of both an MPN and MGUS or MM. We also reviewed and summarized published case reports and studies describing the coexistence of these two disease entities.ResultsMost patients (12/15) had an MPN diagnosis made before or at the same time as the MGUS/MM diagnosis. Eventually, 2 patients developed a lymphoid leukemia, 1 patient developed lymphoma, and 1 patient developed acute myeloid leukemia, raising the question of whether patients with coexistence of myeloid- and lymphoid-derived neoplasms are more prone to leukemic or lymphomatous transformation. We did not find any treatment-related effect that could have contributed to the development of coexisting MGUS or MM and MPN. Of the 7 patients with an abnormal karyotype, 3 patients had trisomy 8.ConclusionAt present, management strategies are aimed at treating the MPN and regularly monitoring the MGUS for transformation to an overt plasma-cell malignancy. However, for patients who develop overt MM, management is focused more on treating the myeloma and monitoring the MPN. It has not yet been definitively shown that these 2 entities arise from a common-ancestor hematopoietic stem cell.     

Potential usefulness of serum p53 for laboratory management of plasma cell dyscrasias

We measured the serum levels of p53 mutant protein (p53M-ELISA) in 65 patients with plasma cell dyscrasia (PCD) and compared them with some conventional laboratory variables. Our aim was to assess, for the first time, the potential of this parameter as a new marker for laboratory management of PCD. Twenthy-tree out of 65 patients had monoclonal gammapathy of undetermined significance (MGUS) and 42 suffered from multiple myeloma (MM). MM patients, with no prior chemotherapy consecutively entered this study. They were treated with standard regimens of Melphalan and Prednisone (MP) and were analyzed for serum p53M level from the time of diagnosis to response to therapy or death. A subgroup of nine patients was regularly monitored for changes occurring in p53M levels during MP therapy. Serum levels of p53M were elevated in MM patients compared with MGUS and healthy controls (p = 0.002). Significantly higher p53M levels were shown by MM patients refractory to chemotherapy than by responding patients (0.38 ng/ml vs 0.22 ng/ml, p = 0.05). The measurement of serum p53M in the nine patients during the course of chemotherapy correlated with disease progression or response to therapy. If confirmed on a larger series of patients, these results suggest a potential role of serum p53 mutant levels in laboratory management of PCD patients.     

14q32 translocations and monosomy 13 observed in monoclonal gammopathy of undetermined significance delineate a multistep process for the oncogenesis of multiple myeloma. Intergroupe Francophone du Myélome.

Clonal plasma cells in monoclonal gammopathy of undetermined significance (MGUS) have been shown to bear copy number chromosome changes. To extend our knowledge of MGUS to structural chromosomal abnormalities, we have performed fluorescence in situ hybridization experiments with probes directed to the 14q32 and 13q14 chromosomal regions in 100 patients with either MGUS or smoldering multiple myeloma (SMM). 14q32 abnormalities were observed in at least 46% of patients with MGUS/SMM, with these abnormalities being present in the majority of clonal plasma cells. Whereas t(11;14)(q13;q32) occurs in 15% of MGUS/SMM patients, an incidence similar to that of overt multiple myeloma (MM) patients, translocation t(4;14)(p16;q32) is observed in only 2% of these cases [P = 0.002 for difference with t(11;14)], as compared with 12% in MM patients (P = 0.013). Monoallelic deletions of the 13q14 region were found in 21% of patients, with two types of situations. In half of the evaluable patients, and especially in patients with SMM, the deletion is present in the majority of clonal plasma cells, as in MM, whereas in the other half of the evaluable patients (essentially in MGUS patients), it is observed in subclones only. These data enable us to elaborate a plasma cell oncogenesis model from MGUS to MM.     

Staging and therapy monitoring of multiple myeloma by 99mTc-sestamibi scintigraphy: a five year single center experience

The aim of the present study was the evaluation of the diagnostic value of 99mTc-sestamibi (MIBI) in the detection of bone marrow involvement in patients suffering from multiple myeloma (MM) and its possible role in the follow-up. Between 1998 and 2003, 68 patients with MM and 42 pts with monoclonal gammopathy of undetermined significance (MGUS) were consecutively enrolled in this study. 51/68 MM patients had active disease (AD), 11/62 were in complete remission (CR) and 6/68 in partial remission (PR) after chemotherapy. 18 patients with MM repeated a 99mTc-MIBI scintigraphic study at least 2 months after high-dose chemotherapy. All the scans were scored semi quantitatively according to extension and intensity of tracer uptake. All MGUS pts had a negative 99mTc-MIBI. As far as the MM pts are concerned, 54/68 (49%) pts (48 with AD, 5 with PR and 1 with CR) had a positive 99mTc-MIBI scan, while the 99mTc-MIBI scan was negative in 14/68 pts (10 with CR, 1 with PR and 3 with AD). The overall sensitivity of the 99mTc-MIBI scintigraphy was 92%; specificity was 96%. In the follow up of the pts treated with chemotherapy 99mTc-MIBI closely paralleled the activity of myeloma bone disease. In conclusion, these results indicate that 99mTc-MIBI scintigraphy closely reflects myeloma disease activity in the bone marrow, and that a negative 99mTc-MIBI scan in patients with suspected MM clearly, though not absolutely, indicates absence of disease or clinical remission. The results of this study suggest a clear diagnostic value of 99mTc-MIBI scintigraphy in patients with MM and its potential role during the follow-up for the monitoring of MM bone disease.     

Elevated level of plasma basic fibroblast growth factor in multiple myeloma correlates with increased disease activity.

Recent reports that bone marrow angiogenesis is increased in multiple myeloma prompted us to examine plasma concentrations of angiogenic growth factors and to elucidate their clinical and biological significance. In 45 cases including 36 cases of multiple myeloma and 9 cases of monoclonal gammopathies of undetermined significance (MGUS), plasma concentrations of basic fibroblast growth factor (FGF-2) and vascular endothelial growth factor (VEGF) were evaluated. FGF-2 was significantly elevated in 25 out of 45 (56%) of the patients with multiple myeloma compared with control subjects (median 9.01 pg ml vs. 1.58 pg/ml, P < 0.0001). The 25 cases were all active multiple myeloma, and none of the non-active myeloma and MGUS patients showed a high FGF-2 level. VEGF level was also elevated in 26 out of 45 patients (58%) compared with control subjects (median 42.0 pg/ml vs. 15.8 pg/ml, P < 0.0001 for VEGF). VEGF concentration was high in 20 active myelomas, but also in one non-active myeloma and five MGUS. Elevation of FGF-2 level was associated with beta2-microglobulin level, anemia and bone marrow plasma cell percentage, which represent disease activity. Interestingly, none of five Bence-Jones type myelomas, including four clinically active cases, revealed a high plasma FGF-2 level, while all of them showed a high VEGF level. In all five responders, the plasma FGF-2 levels were significantly decreased after chemotherapy. FGF-2 was immunohistochemically detected in the bone marrow myeloma cells of the patients with high plasma FGF-2 level. We conclude that plasma concentration of FGF-2 can be a useful indicator of disease activity.     

CD117 (c-kit) is aberrantly expressed in a subset of MGUS and multiple myeloma with unexpectedly good prognosis

CD117 (c-kit) was evaluated on normal plasma cells (PC) (n=10), PC of individuals with monoclonal gammopathy of undetermined significance (MGUS, n=12), malignant PC from patients with multiple myeloma (MM) either at diagnosis (n=83) or relapse (n=38) and on 23 human myeloma cell lines (HMCL). Whereas CD117 is never expressed in normal PC, it is expressed in 50% of MGUS (p=0.015). Furthermore, 33% of MM at diagnosis do express CD117, as opposed to 8% of those in relapse (p=0.003). Finally, CD117 was never found in HMCL. CD117 expression was associated with a better prognosis: overall survival was 93% at 4 years in CD117+ MM versus 64% in CD117- MM (p=0.05). Conversely, lack of CD117, but also high beta-2 microglobulin, t(4;14) and CD221 (IGF-1R) expression were associated with a poorer prognosis. Multivariate analysis revealed that CD117- patients were those with CD221 and t(4;14) and had the poorest prognosis. In conclusion, CD117 (c-kit) is aberrantly expressed on a subset of MGUS and MM with a more indolent presentation and is functionally antinomic to CD221 (IGF-1R). CD117 expression could be related to a specific oncogenic pathway in MM.     

Gain of 1q21 and distinct adverse cytogenetic abnormalities correlate with increased microcirculation in multiple myeloma

To identify genetic mechanisms controlling bone marrow microcirculation and angiogenesis in patients with plasma cell disease we simultaneously performed bone marrow dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and cytogenetics (iFISH) on CD138 purified plasma cells of MGUS (n=31) and untreated multiple myeloma (MM) (n = 87) patients. The adverse cytogenetic abnormalities gain of 1q21, deletion 17p13 and deletion 13q14 significantly correlated with at least one DCE-MRI finding (aberrant "focal" microcirculation pattern, increase in median microcirculation parameter Amplitude A or exchange rate constant kep). We conclude that gain of 1q21, deletion 13q14 and deletion 17p13 trigger the angiogenic cascade in MM. Our findings will have important implications for the design, analysis and stratification for clinical studies of patients with MM in particular if compounds with antiangiogenic activity are used.