The clinical and prognostic significance of erythrocyte sedimentation rate (ESR), serum interleukin‐6 (IL‐6) and acute phase protein levels in multiple myeloma

Summary Interleukin‐6 (IL‐6) and acute phase proteins are commonly increased in patients with multiple myeloma. Several of these acute phase proteins are believed to predict prognosis and influence survival. We measured interleukin‐6 (IL‐6), C‐reactive protein (CRP), alpha‐1‐antitrypsin (a₁AT), acid alpha‐1‐glycoprotein (a₁AG), haptoglobin (HAP), transferrin (TRF), hemoglobin (Hb), beta‐2‐microglobulin (β₂M) and erythrocyte sedimentation rate (ESR) in 42 newly diagnosed multiple myeloma patients and 25 normal controls. At the time of blood collection, nine patients were at stage I of disease, 14 at stage II, and 19 at stage III according to the Durie and Salmon myeloma staging system. Mean ± SD values of IL‐6, CRP, a₁AT, a₁AG, HAP, β₂M, and ESR were significantly higher and Hb significantly lower than those found in the controls. Univariate analysis, using the log‐rank test, showed that among the acute phase proteins, serum CRP (P < 0.002), a₁AT (P < 0.008) and ESR (P < 0.008) were significantly correlated with survival. However, when a multivariate Cox proportional hazard model was performed, ESR, CRP, a₁AT, a₁AG and β₂M were identified as independent prognostic factors, while the others were not. We conclude that ESR, a simple and easily performed marker, was found to be an independent prognostic factor for survival in patients with multiple myeloma.     

Relationship between circulating serum soluble interleukin-6 receptor and the angiogenic cytokines basic fibroblast growth factor and vascular endothelial growth factor in multiple myeloma

Angiogenesis plays an important role in multiple myeloma (MM) progression. Various mitogens such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF-2) have been implicated in the angiogenic process of various malignancies. Interleukin-6 (IL-6) is a growth factor of myeloma cells and its signaling is mediated via a cell surface receptor complex (IL-6r). IL-6 and tumor necrosis factor-alpha (TNF-alpha) are involved in the secretion of VEGF by IL-6r expressing myeloma cells. In this study, serum FGF-2, VEGF, IL-6r, and TNF-alpha were measured in 46 untreated MM patients and were studied in relation to disease stage (by Salmon-Durie criteria) and severity [assessed by serum beta(2)-microglobulin (beta(2)M), C-reactive protein (CRP), alpha(1)-antitrypsin (alpha(1)AT), and lactic dehydrogenase (LDH) levels]. The results showed that FGF-2, VEGF, IL-6r, and TNF-alpha were significantly elevated in MM patients in comparison to controls ( p<0.008) and were significantly higher in stage III disease in comparison to stages I and II ( p<0.03). The mean concentrations of IL-6r were 877+/-374, 1220+/-308, 1431+/-878, and 453+/-180 pg/ml for stages I, II, and III and controls, respectively. Levels of beta(2)M, alpha(1)AT, CRP, and LDH were all significantly higher in MM patients than controls and increased with advancing stage of disease. There were positive correlations of both VEGF and FGF-2 with IL-6r, TNF-alpha, beta(2)M, alpha(1)AT, CRP, and LDH. We conclude that IL-6r and TNF-alpha increase in parallel to VEGF and FGF-2 with increasing stage of MM disease. These molecules correlate with biochemical markers of disease activity and may play a role in the progression of multiple myeloma.     

Immunoreactive interleukin-6 and acute phase proteins as prognostic factors in multiple myeloma. Finnish Leukemia Group

High serum level of bioactive interleukin-6 (IL-6) is regarded as a predictor of poor prognosis in multiple myeloma (MM). On the other hand, the reported levels of immunoreactive IL-6 have been highly variable, and the prognostic value of immunoreactive IL-6 in MM is not clear. We have analyzed the prognostic significance of serum immunoreactive IL-6, as measured by a sensitive immunosorbent assay, in 210 patients with newly diagnosed MM subsequently treated with intermittent melphalan and prednisone. The serum levels of acute phase proteins C-reactive protein (CRP), alpha 1-antitrypsin (alpha 1AT), and acid alpha 1-glycoprotein (orosomucoid; OM) were evaluated as surrogates for IL-6. Serum IL-6, CRP, alpha 1AT, and OM levels were raised in 42%, 40%, 41%, and 24% of the patients, respectively. There was a significant correlation between the clinical stage of the patients and serum IL-6 (P = .006), alpha 1AT (P = .001), and OM (P = .004) levels at diagnosis. At 3 years, 52% of the patients were alive. Univariate logistic regression analysis showed that high levels of IL-6 (P = .002), CRP (P = .02), alpha 1AT (P < .001), OM (P = .007), beta 2- microglobulin (beta 2M; P < .001), and thymidine kinase (P < .05) were all associated with 3-year mortality. In multivariate regression analysis, beta 2M (P < .0001) and alpha 1AT (P = .01) had independent prognostic significance. The patients with high levels of both beta 2M and alpha 1AT or IL-6 were at very high risk of dying within 3 years from diagnosis (16% and 21% of the patients in these groups were alive, respectively). When the patients were stratified according to the clinical stage, the prognostic significance of serum IL-6 and alpha 1AT was especially evident in stage II patients. When the patients were divided into two groups according to normal or raised serum IL-6 levels, the patients with high IL-6 levels had more frequent osteolytic bone lesions (P = .03) and a more aggressive disease. We conclude that serum immunoreactive IL-6 is a significant prognostic marker in MM.     

Accumulation of 5-methyltetrahydrofolic acid and folylpolyglutamate synthetase expression by mitogen stimulated human lymphocytes

Serum IL-6 levels have been shown to correlate with disease severity and prognosis in patients with plasma cell dyscrasias. Among its pleiotropic actions, IL-6 is also the major regulator of the acute phase response in humans. The possible impact on survival of the major serum acute phase proteins (s.APP) [C-reactive protein (s.CRP), alpha-1-anti-trypsin (s.AAT), haptoglobin, acid alpha-1-glycoprotein and alpha-2-macroglobulin (used as control)] was assessed on a population of 103 consecutive, previously untreated myeloma patients. Univariate analysis showed that among the acute phase proteins only s.AAT ( P = 0.015) and s.CRP ( P = 0.027) were significantly correlated with survival. The multivariate Cox proportional hazard model applied to s.APP and other common parameters showed that s.β-2-microglobulin (s.b2M), s.calcium, s.creatinine, BM plasma cell percentage, age and s.AAT correlated significantly with survival. Combining s.b2M and s.AAT allowed stratification of myeloma patients: those with low levels of s.b2M (3 mg/l) and of s.AAT ( 3 g/l) presented an excellent prognosis (median survival exceeding 10 years) while those presenting higher values of the two parameters presented a median survival of 2.5 years ( P = 0.002).     

Serum level of interleukin-16 in multiple myeloma patients and its relationship to disease activity

Interleukin-16 (IL-16) is a chemoattractant of CD4+ lymphocytes, and it has been implicated in the pathogenesis of various inflammatory diseases. There is evidence that it may have a role in multiple myeloma (MM). In the present study, we determined the serum level of IL-16 both before and after treatment of MM and related it to inflammatory markers and survival. Forty-eight newly diagnosed MM patients were included in the study. Disease stage was defined using the Durie-Salmon classification system (10 patients were in stage I, 19 in stage II, and 19 in stage III). After standard treatment, 22 patients reached the plateau phase and were re-evaluated. The following serum parameters were measured: IL-16, IL-6, alpha-1 antitrypsin (alpha1AT), and C-reactive protein (CRP). Survival was determined as the number of months elapsed since original diagnosis. The mean +/- SD of serum IL-16 was 343 +/- 195 pg/ml in the pre-treatment MM group and 101 +/- 30 pg/ml in the control group. All measured parameters were higher in the patient group compared to healthy controls. Furthermore, IL-16, IL-6, alpha1AT, and CRP were significantly increased with increasing stage of disease, from stage I to stage III (P<0.01). All parameters decreased significantly following effective chemotherapy (P<0.002). Patients with a high level of IL-16 (>430 pg/ml) displayed an inferior survival time in comparison to those with lower levels of IL-16. In the pre-treatment group, IL-16 correlated with alpha1AT and IL-6 (r=0.374, P<0.01 and r=0.454, P<0.002, respectively). IL-16 may play a role in multiple myeloma; however, further functional studies are required.     

C-reactive protein and beta-2 microglobulin produce a simple and powerful myeloma staging system.

Multiple myeloma (MM) staging procedures are still inadequate for detection of the optimal therapeutic procedure for an individual patient. The Durie & Salmon staging system and serum beta 2-microglobulin (beta 2M) are used worldwide because of their easy clinical application. Other prognostic parameters, such as myeloma cell proliferative activity, are of exceeding importance, but are not as simple as standard methods. Recently, interleukin-6 (IL-6) has been shown to be a major growth factor for MM. IL-6 is a pleiotropic cytokine acting on several cell lineages, and, at the hepatocyte level, stimulates the synthesis of acute phase proteins, such as the well known C-Reactive Protein (CRP). Serum CRP concentration actually reflects the IL-6 activity. A survival analysis carried out in 162 MM patients at diagnosis showed that serum CRP level is a highly significant prognostic factor. Moreover, serum CRP was independent of serum beta 2M. This feature allowed stratification of MM patients into 3 groups according to CRP and beta 2M serum levels: (1) low risk group, CRP and beta 2M less than 6 mg/L (50% of patients); (2) intermediate risk group, CRP or beta 2M greater than or equal to 6 mg/L (35% of patients); (3) high risk group, CRP and beta 2M greater than or equal to 6 mg/L (15% of patients). Survival was 54, 27, and 6 months, respectively (P less than .0001). We thus propose a new and powerful myeloma staging system based on simple and reliable laboratory evaluations.     

Clinical significance of interleukin-6 measurement in early rheumatoid arthritis: relation with laboratory and clinical variables and radiological progression in a three year prospective study.

OBJECTIVE--To evaluate the clinical significance of interleukin-6 (IL-6) measurements in relation to laboratory and clinical measures of disease activity and radiological progression in early rheumatoid arthritis (RA). METHODS--A prospective study was performed in 51 patients with early RA during the first three years of the disease, with monthly clinical and laboratory assessments and biannual radiographs of the hands and feet. IL-6 was measured by enzyme linked immunosorbent assay (ELISA). Cross sectional (n = 51) and longitudinal (n = 20) correlations between plasma IL-6 concentrations and values of C reactive protein (CRP), serum amyloid A protein (SAA), erythrocyte sedimentation rate (ESR), haemoglobin (Hb), platelets, and joint scores were calculated, and correlations made between time integrated values of IL-6, CRP and ESR, and radiological progression over three years (n = 20). RESULTS--Significant correlations were found between IL-6 and the acute phase response and platelets, but variable results were obtained for the correlation between IL-6 and Hb. In contrast to a significant correlation between time integrated values of CRP or ESR and radiological progression, time integrated values of IL-6 did not correlate with radiological progression over three years follow up. CONCLUSION--The course of disease activity and the radiological progression of joint damage are better reflected by CRP, SAA, and ESR values than by plasma IL-6 concentrations, particularly in stages of low disease activity.     

Acute phase proteins and interleukins in steady state sickle cell disease

Abstract: To identify a possible acute phase response during the steady state of sickle cell disease, we estimated the serum alterations of acute phase proteins, β2-microglobulin (β2M), κ and λ light chains, interleukins (ILs) and tumor necrosis factor-α (TNFα) in 21 patients. Increased concentrations of C-reactive protein (CRP) were found in 5 patients, alpha-1-acid-glycoprotein (AGP) in 3, alpha-1-antitrypsin (AAT) in 8, ceruloplasmin (CER) in 2, alpha-2-macrogiobulin (AMG) in 14 and decreased haptoglobin (HPT) and transferrin (TFR) in 11 and 9, respectively. Increased β2M was found in 10 patients and κ and λ light chains in 11. IL-1β, IL-2, IL-4, IL-10 and TNFα were not detected in any of the patients. However, significantly increased values of IL-6 and sIL-2r were found. This study has demonstrated increased serum levels of some of the acute phase proteins in patients during the steady state of sickle cell disease. This may be a result of a subclinical vaso-occlusion which in turn leads to a covert inflammatory response. Cytokines, and in particular IL-6, produced after this response, seem to be responsible for the high levels of acute phase proteins in the steady state of this disease.     

Hemoglobin levels correlate with interleukin-6 levels in patients with advanced untreated epithelial ovarian cancer: role of inflammation in cancer-related anemia

Anemia occurs in more than 30% of patients with epithelial ovarian cancer before any surgery. High levels of proinflammatory cytokines and increased oxidative stress may contribute to the development of cancer-related anemia. We assessed a population of previously untreated patients with advanced epithelial ovarian cancer to evaluate whether there was a correlation between hemoglobin (Hb) and parameters of inflammation and oxidative stress, stage of disease, and performance status (PS). In 91 patients with epithelial ovarian cancer and 95 healthy women matched for age, weight, and height, levels of Hb, C-reactive protein (CRP), fibrinogen (Fbg), proinflammatory cytokines, leptin, reactive oxygen species (ROS), and antioxidant enzymes were assessed at diagnosis before treatment. The correlations between Hb, parameters of inflammation and oxidative stress, stage, and PS were evaluated. Hb levels were lower in patients with advanced epithelial ovarian cancer than in control subjects and inversely related to stage and PS. Hb negatively correlated with CRP, Fbg, interleukin 1beta (IL-1beta), IL-6, tumor necrosis factor alpha (TNFalpha), and ROS, and positively correlated with leptin and glutathione peroxidase (GPx). Multivariate regression analysis showed that stage and IL-6 were independent factors determining Hb values. This evidence suggests that anemia in epithelial ovarian cancer is common and its presence is related to stage of disease and markers of inflammation.     

Elevated serum concentration of hepatocyte growth factor in patients with multiple myeloma: correlation with markers of disease activity

Hepatocyte growth factor (HGF) has been shown to be involved in angiogenesis, epithelial cell proliferation, and osteoclast activation. HGF and its receptor are expressed on myeloma cell lines and could be involved in the pathogenesis of bone destruction in multiple myeloma (MM). The aim of this study was to examine serum levels of HGF in untreated MM patients and its correlation with bone turnover indices and markers of disease activity. Forty-seven newly diagnosed MM patients and 25 controls were included: 12 patients were of stage I, 13 of stage II, and 22 of stage III (Durie-Salmon classification). Bone lesions were scored from 0 to 3, according to X-ray findings. Serum osteocalcin (OC), interleukin-6 (IL-6), TNF-alpha, beta(2)-microglobulin (beta(2)M), CRP, calcium, and 24-hr urine N-telopeptide cross-links of collagen breakdown (NTx) were determined. HGF levels were significantly higher at stage III compared to stages II and I (medians: 1,990.4 vs. 1,743.8 and 1,432.4 pg/mL, respectively, P < 0.05). Similarly, NTx, IL-6, TNF-alpha, CRP, beta(2)M, and calcium increased significantly with advancing stage (P < 0.01). OC was higher at stage I in comparison to stages II and III (P < 0.01). All parameters were significantly higher in patients than controls. HGF showed a strong correlation with IL-6 and TNF-alpha and less with beta(2)M, CRP, NTx, and OC. We conclude that serum HGF levels are increased in advanced stages of MM disease and extended bone lesions. HGF correlates with IL-6 and TNF-alpha, which are cytokines involved in osteoclast stimulation in MM. However, an independent association of HGF with bone turnover markers was not shown in this study, thus its role in MM bone disease needs to be further clarified.     

Different monocyte reaction patterns in newly diagnosed,untreated rheumatoid arthritis and lupus patients probably confer disparate C-reactive protein levels

OBJECTIVES: To investigate the different capacities of monocytes to produce cytokines in newly diagnosed, untreated patients with rheumatoid arthritis (RA) or systemic lupus and to examine the possible correlation among serum C-reactive protein (CRP), cytokines, swollen joint counts, and erythrocyte sedimentation rates (ESR) in untreated RA patients. METHODS: Monocytes from untreated RA or lupus patients were cultured in vitro with lipopolysaccharide (LPS, as bacterial infection) or immune complexes (as endogenous immune deviation) and supernatants were collected for cytokine determination. Sera from RA patients were assayed for interleukin-6 (IL-6), IL-1 beta, IL-10, tumor necrosis factor-alpha (TNF-alpha) and IL-1 receptor antagonist (IL-1ra). These cytokines were related to serum CRP, swollen joint counts, and ESR. RESULTS: RA monocytes uniformly produced IL-6, IL-1 beta, TNF-alpha, or IL-10 in vitro. In contrast, lupus monocytes could be divided into two subsets: (i) monocytes which produce cytokines on LPS stimulation but not on challenging with immune complexes; and (ii) monocytes which, interestingly, generate cytokines on stimulation by immune complexes but not LPS. These cytokines in turn stimulate the liver to synthesize CRP differently in the SLE subsets and RA patients. Moreover, serum IL-1ra levels correlated significantly with serum IL-6, IL-1 beta, and TNF-alpha concentrations (p = 0.005, 0.008, or 0.040, respectively), but not with IL-10 (p = 0.582) in RA patients. CONCLUSIONS: Two lupus subsets exist that react either to LPS or immune complexes to produce CRP-inducing cytokines, in contrast to homogeneous RA monocytes. This is the first report that different reaction patterns of CRP-inducing cytokine production in RA and lupus monocytes probably underlie the high CRP levels in RA versus low heterogeneity in lupus. The correlation of serum IL-1ra levels with serum IL-6, IL-1 beta, or TNF-alpha concentrations, and the borderline correlation of the former with CRP levels, demonstrate that IL-1ra is an acute phase reactant in RA as well as in SLE patients.     

Serum immunoreactive interleukin-6 and C-reactive protein levels in patients with multiple myeloma at diagnosis

Summary Serum bioactive but not immunoreactive interleukin-6 (IL-6), and serum C-reactive protein (CRP), have been reported to be of prognostic significance in multiple myeloma (MM). We measured serum immunoreactive IL-6 by a sensitive enzyme-linked immunosorbent assay in 30 MM patients at diagnosis. In 30% of the patients serum immuno-reactive IL-6 exceeded the upper reference limit. The concentrations of CRP and IL-6 showed a linear association. Logarithmically transformed IL-6, CRP and β₂-microglobulin were significant variables by univariate survival analysis: by multivariate analysis CRP was a slightly stronger prognostic factor than IL-6 and the only one of independent prognostic significance.     

Plasma cell labeling index and beta 2-microglobulin predict survival independent of thymidine kinase and C-reactive protein in multiple myeloma [see comments]

The plasma cell labeling index (PCLI) and serum beta 2-microglobulin (beta 2M) are independent prognostic factors in multiple myeloma (MM). Recently, levels of thymidine kinase (TK) and C-reactive protein (CRP) have been shown to have prognostic value. We studied 107 patients with newly diagnosed myeloma to determine whether TK and CRP values added prognostic information not already available using the PCLI and beta 2M. Univariate survival analysis showed prognostic significance for the PCLI, TK, beta 2M, age, serum albumin, and CRP. Multivariate analysis showed that only PCLI and beta 2M have independent prognostic significance. The survival curves were better separated using the PCLI and beta 2M than with other combinations of variables. Among nine patients under age 65 with low PCLI and low beta 2M, eight were alive almost 6 years after starting chemotherapy. These good-risk patients could not be identified by standard clinical features. Although creatinine and calcium were normal, other features such as bone lesions, osteoporosis, fracture, and anemia were present and stage distribution was similar to other patients in the study. In conclusion, PCLI and beta 2M measured at diagnosis are independent prognostic factors. They must be considered when interpreting the results of clinical trials and should be helpful in counseling patients and in designing new trials. When the PCLI and beta 2M values are known, the TK and CRP values do not add useful additional prognostic information.     

Elevated levels of interleukin-1 beta (IL-1 beta) and IL-6 in serum and increased production of IL-1 beta mRNA in lymph nodes of patients with polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome

To evaluate a possible implication of cytokines in the pathogenesis of polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome, we studied five consecutive patients with this condition, of which four had sclerotic bone lesions and four had multicentric Castleman's disease. Interleukin-1 beta (IL-1 beta) and IL- 6 serum levels were determined in these patients (13 serum samples) and in patients with multiple myeloma (5) and Waldenstrom's macroglobulinemia (5). In situ hybridization of the relevant mRNAs was performed on lymph node specimens of two patients with POEMS syndrome who had Castleman's disease. Elevated serum levels of IL-1 beta (13/13 samples), and IL-6 (7/13 samples) were found in patients with POEMS syndrome. In the other patients, serum IL-1 beta was undetectable or slightly increased and IL-6 was elevated in a single patient with Waldenstrom's macroglobulinemia. Abundant IL-1 beta mRNA-producing cells were present in interfollicular spaces in the two tested patients, while IL-6 mRNA-producing cells were rare. We conclude that IL-1 beta and IL-6 serum levels may be chronically elevated in patients with POEMS syndrome, and that lymph node may be one site of IL-1 beta overproduction. These results are in keeping with the hypothesis that cytokines mediate systemic manifestations of POEMS syndrome.     

Effect of pamidronate administration on markers of bone turnover and disease activity in multiple myeloma

AIM: Bisphosphonates are potent inhibitors of osteoclastic activity and are used in the treatment of multiple myeloma (MM) in combination with chemotherapy. The effect of pamidronate on markers of bone resorption [cross-linked N-telopeptides of type I collagen (NTx)], markers of bone formation [serum alkaline phosphatase (BAP) and osteocalcin (OSC)], interleukin-6 (IL-6), beta2-microglobulin, CRP, paraprotein and disease-related pain and skeletal events has been evaluated in 62 newly diagnosed patients with MM. PATIENTS AND METHODS: The patients were randomly assigned to two groups: the first included 32 patients under chemotherapy and pamidronate (group I) and the second 30 patients on chemotherapy only (group II). Pamidronate was administered at a monthly dose of 90 mg iv, and the above parameters were evaluated at the beginning of this study and after 1, 3, 6, 9, 12 and 14 months of treatment. RESULTS: The addition of pamidronate to chemotherapy resulted in a significant reduction of NTx, IL-6 and paraprotein from the 3rd month and of beta2-microglobulin, CRP and pain from the 6th month of treatment. No changes of NTx, IL-6, beta2-microglobulin, CRP or skeletal events were observed in patients of group II, while paraprotein was significantly reduced after 6 months of treatment. The differences in NTx, IL-6, paraprotein and beta2-microglobulin were statistically significant between the two groups. Multivariate analysis revealed a significant correlation between changes of NTx, changes of IL-6 in both groups and reduction of pain and paraprotein in group I. CONCLUSIONS: These results suggest that pamidronate may have a synergistic action with chemotherapy in decreasing osteoclastic activity, in reducing markers of myeloma activity and myeloma related pain and in improving the quality of life in patients with MM.     

Pituitary-gonadal hormones and interleukin patterns in leprosy

The functional status of pituitary-gonadal hormones and their relationship to the pattern of inflammatory cytokines in the lepromatous (LL/BL) and tuberculoid (TT/BT) poles of leprosy were investigated. Gonadotropins [luteinizing hormone (LH) and follicle-stimulating hormone (FSH)], interleukin (IL)-1beta, IL-6, tumour necrosis factor (TNF)-alpha and C-reactive protein (CRP) concentrations and erythrocyte sedimentation rate (ESR) were significantly higher in LL/BL leprosy patients than in controls and were not different from controls in TT/BT patients. LH and FSH were positively correlated with IL-1beta, IL-6 and TNF-alpha, and CRP concentrations and ESR. Testosterone plasma levels were significantly decreased in LL/BL patients and not different in TT/BT patients compared with controls. In addition, testosterone levels were inversely correlated with IL-6 and TNF-alpha. Prolactin plasma levels of both LL/BL and TT/BT patients were not different when compared with those of controls. There was a significant positive correlation between IL-6 and TNF-alpha plasma levels and ESR and CRP concentrations. IL-1beta was positively correlated with ESR but not with CRP. The significant correlations between gonadotropins and testosterone and cytokines in leprosy patients suggest that cytokines may have a direct influence at testicular level and may be of pathogenetic significance in leprosy and in other inflammatory states involving reproductive dysfunction.     

C-Reactive Protein as a Prognostic Variable That Reflects Uncontrolled Up-Regulation of the IL-1-IL-6 Network System in Colorectal Carcinoma

Up-regulation of the IL-1-IL-6 network stimulates systemic expression of C-reactive protein (CRP). This cytokine network system plays a pivotal role in inducing angiogenic growth factors in intestinal mucosa. Serum CRP level and tissue concentrations of cytokines in colorectal cancer patients were determined and an in vitro model was employed to determine the time course of induction of IL-6 in Caco-2 cells. Increased serum CRP was associated with recurrent disease and shorter survival time. Intense surgical stress and the presence of an acute phase reactant were independently associated with overexpression of IL-6 in the tumor. Enhanced IL-6 protein expression in Caco-2 cells induced by the initial treatment with IL-1beta or lipopolysaccharide could be abrogated by additional presupplementation of IL-1ra. The presence of an acute phase reactant reflects uncontrolled up-regulation of the local IL-1-IL-6 network system in the tumor, which may enhance the survival and proliferation of remnant cancer cells after tumor resection.     

ADAM-9 (MDC-9/meltrin-gamma), a member of the a disintegrin and metalloproteinase family, regulates myeloma-cell-induced interleukin-6 production in osteoblasts by direct interaction with the alpha(v)beta5 integrin

ADAM-9, a member of the a disintegrin and metalloproteinase family, contains both metalloproteinase and disintegrin domains. Myeloma cell lines express ADAM-9; however, its function and role in the pathophysiology of multiple myeloma is unknown. The aim of this study was to establish whether primary myeloma cells express ADAM-9, whether ADAM-9 regulates IL-6 production in human osteoblasts (hOBs), whether ADAM-9 interacts with specific integrin heterodimers, and the identity of downstream signaling pathways. Primary myeloma cells demonstrated increased expression of ADAM-9 (P < .01). ADAM-9 promoted a 5-fold increase in IL-6, but not IL-1beta mRNA, and a dose- and time-dependent increase in IL-6 production by hOBs (P < .01). IL-6 induction was inhibited by an antibody to the alpha(v)beta5 integrin (P < .01) but not by antibodies to other integrin heterodimers. ADAM-9 was shown to bind directly to the alpha(v)beta5 integrin on hOBs. Antibodies to ADAM-9 and alpha(v)beta5 integrin inhibited myeloma cell-induced IL-6 production by hOBs (P < .01). Furthermore, inhibitors of p38 MAPK and cPLA2, but not NF-kappaB and JAK2, signaling pathways inhibited ADAM-9-induced IL-6 production by hOBs (P < .01). These data demonstrate that ADAM-9, expressed by myeloma cells, stimulates IL-6 production in hOBs by binding the alpha(v)beta5 integrin. This may have important consequences for the growth and survival of myeloma cells in bone.     

Overproduction of proinflammatory cytokines imbalanced by their antagonists in POEMS syndrome

The polyneuropathy, organomegaly, endocrinopathy, M protein, skin changes (POEMS) syndrome is a rare multisystem disorder of obscure pathogenesis associated with osteosclerotic myeloma. Circulating levels of proinflammatory cytokines (tumor necrosis factor-alpha (TNF-alpha) interleukin-1 beta [IL-1 beta], IL-2, IL-6, and interferon-gamma [IFN- gamma]), anti-inflammatory cytokines (transforming growth factor beta 1 [TGF beta 1], IL-4, IL-10, and IL-13), the cytokine carrier protein alpha 2 macroglobulin, IL-1 receptor antagonist (IL-1ra), soluble TNF receptors (sTNFr) p55 and p75, and soluble IL-6 receptor (sIL-6r) were determined in 15 patients with POEMS syndrome and 15 with multiple myeloma. Patients with POEMS syndrome had higher serum levels of IL-1 beta, TNF-alpha, and IL-6 and lower serum levels of TGF beta 1 than did patients with multiple myeloma. Serum levels of IL-2, IL-4, IL-10, IL- 13, IFN-gamma, alpha 2 macroglobulin, and sIL-6r were similar in both groups. IL-1ra and sTNFrs were increased in POEMS syndrome, but out of proportion to the increase of IL-1 beta and TNF-alpha. Serial evaluations in 1 patient showed that proinflammatory cytokine serum levels paralleled disease activity assessed by platelet count and neurologic involvement. Our results suggest that the manifestations of POEMS syndrome might be regarded as the result of a marked activation of the proinflammatory cytokine network (IL-1 beta, IL-6, and TNF- alpha) associated with a weak or even decreased (TGF beta 1) antagonistic reaction insufficient to counteract the noxious effects of cytokines.     

Paracrine rather than autocrine regulation of myeloma-cell growth and differentiation by interleukin-6

To explore the mechanisms involved in the pathogenesis of human multiple myeloma (MM), we investigated the potential role of interleukin-6 (IL-6), a B-cell differentiation factor in humans, and a growth factor for rat/mouse heterohybridomas and murine plasmacytomas. Using a heterohybridoma assay, we found that two well-documented human myeloma cell lines, RPMI 8226 and U266, did not secrete IL-6 and did not express RNA messengers for IL-6. Neutralizing antibodies to IL-6 did not inhibit their proliferation, and recombinant IL-6 did not stimulate it. Taken together, these data show that IL-6 is not the autocrine growth factor of these human myeloma cell lines. A high production of IL-6 was found in the bone marrows of patients with fulminating MM, compared with patients with inactive or slightly active MM, or to healthy donors. This IL-6 production was assigned to adherent cells of the bone-marrow environment but not to myeloma cells. A spontaneous proliferation of myeloma cells freshly isolated from patients was observed in short-term cultures. Recombinant IL-6 was able to amplify it two- to threefold. The spontaneous proliferation of the myeloma cells was inhibited by anti-IL-6 antibodies and reinduced by recombinant IL-6. After 2 to 3 weeks of culture, the myeloma-cell proliferation progressively declined and no IL-6-dependent myeloma cell lines could be obtained despite repeated additions of fresh IL-6 and costimulation with other cytokines such as tumor necrosis factor (TNF)beta, or IL-1 beta. These data demonstrated a paracrine but not autocrine regulation of the growth and differentiation of myeloma cells by IL-6.