The Key Role of Hepcidin-25 in Anemia in Multiple Myeloma Patients with Renal Impairment.

Background and objectives: Anemia is common in multiple myeloma (MM) and is caused by a complex pathomechanism, including impaired iron homeostasis. Our aim is to evaluate the biomarkers of iron turnover: serum soluble transferrin receptor (sTfR) and hepcidin-25 in patients at various stages of MM in relation with markers of anemia, iron status, inflammation, renal impairment and burden of the disease and as predictors of mortality. Materials and methods: Seventy-three MM patients (six with smoldering and 67 with symptomatic disease) were recruited and observed for up to 27 months. Control group included 21 healthy individuals. Serum sTfR and hepcidin were measured with immunoenzymatic assays. Results: MM patients with and without anemia had higher sTFR compared to controls, while only anemic patients had higher hepcidin-25. Both hepcidin-25 and sTfR were higher in anemic than non-anemic patients. Higher hepcidin-25 (but not sTfR) was associated with increasing MM advancement (from smoldering to International Staging System stage III disease) and with poor response to MM treatment, which was accompanied by lower blood hemoglobin and increased anisocytosis. Neither serum hepcidin-25 nor sTfR were correlated with markers of renal impairment. Hepcidin-25 predicted blood hemoglobin in MM patients independently of other predictors, including markers of renal impairment, inflammation and MM burden. Moreover, both blood hemoglobin and serum hepcidin-25 were independently associated with patients' 2-year survival. Conclusions: Our results suggest that hepcidin-25 is involved in anemia in MM and its concentrations are not affected by kidney impairment. Moreover, serum hepcidin-25 may be an early predictor of survival in this disease, independent of hemoglobin concentration. It should be further evaluated whether including hepcidin improves the early diagnosis of anemia in MM.

Renal Impairment Detectors: IGFBP-7 and NGAL as Tubular Injury Markers in Multiple Myeloma Patients.

Background and Objectives: Urine insulin-like growth factor-binding protein 7 (IGFBP-7), tissue inhibitor of matrix metalloproteinase 2 (TIMP-2), and neutrophil gelatinase-associated lipocalin (NGAL) monomer are novel tubular kidney injury biomarkers. In multiple myeloma (MM), immunoglobulin free light chains (FLCs) play an integral role in renal impairment. This study aimed to investigate the correlation between new biomarkers and acclaimed parameters of renal failure, MM stage, and prognosis. Materials and Methods: The examined parameters included: urinary and serum cystatin-C, IGFBP-7, and TIMP-2, and urinary NGAL monomer in 124 enrolled patients. Results: Urinary and serum IGFBP-7 and urinary NGAL were higher among patients with an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2, and positively correlated with urine light chains. Serum and urine IGFBP-7 and urine NGAL were greater among patients with a higher disease stage. In the whole study group, urinary concentrations of the studied markers were positively correlated with each other. In multiple linear regression, urinary IGFBP-7 and NGAL were associated with lower eGFR, independently of other urinary markers. Conclusions: Urinary IGFBP-7 and NGAL monomer may be useful markers of tubular renal damage in patients with MM. Biomarker-based diagnostics may contribute to earlier treatment that may improve renal outcomes and life expectancy in MM.

Transgelin-2 in Multiple Myeloma: A New Marker of Renal Impairment?

Transgelin is a 22-kDa protein involved in cytoskeletal organization and expressed in smooth muscle tissue. According to animal studies, it is a potential mediator of kidney injury and fibrosis, and moreover, its role in tumorigenesis is emerging in a variety of cancers. The study included 126 ambulatory patients with multiple myeloma (MM). Serum transgelin-2 concentrations were measured by enzyme-linked immunoassay. We evaluated associations between baseline transgelin and kidney function (serum creatinine, estimated glomerular filtration rate-eGFR, urinary markers of tubular injury: cystatin-C, neutrophil gelatinase associated lipocalin-NGAL monomer, cell cycle arrest biomarkers IGFBP-7 and TIMP-2) and markers of MM burden. Baseline serum transgelin was also evaluated as a predictor of kidney function after a follow-up of 27 months from the start of the study. Significant correlations were detected between serum transgelin-2 and serum creatinine (R = 0.29; p = 0.001) and eGFR (R = -0.25; p = 0.007). Transgelin significantly correlated with serum free light chains lambda (R = 0.18; p = 0.047) and serum periostin (R = -0.22; p = 0.013), after exclusion of smoldering MM patients. Patients with decreasing eGFR had higher transgelin levels (median 106.6 versus 83.9 ng/mL), although the difference was marginally significant (p = 0.05). However, baseline transgelin positively correlated with serum creatinine after the follow-up period (R = 0.37; p < 0.001) and negatively correlated with eGFR after the follow-up period (R = -0.33; p < 0.001). Moreover, higher baseline serum transgelin (beta = -0.11 ± 0.05; p = 0.032) significantly predicted lower eGFR values after the follow-up period, irrespective of baseline eGFR and follow-up duration. Our study shows for the first time that elevated serum transgelin is negatively associated with glomerular filtration in MM and predicts a decline in renal function over long-term follow-up.

Evaluating the Relationship of GDF-15 with Clinical Characteristics, Cardinal Features, and Survival in Multiple Myeloma.

Growth differentiation factor 15 (GDF-15), a member of the transforming growth factor-ß superfamily, participates in processes associated with myeloma development and its end-organ complications. It plays a significant role in both physiological and abnormal erythropoiesis and regulates iron homeostasis through modulation of hepcidin. It is abnormally secreted in marrow stromal cells of patients with multiple myeloma (MM), which may reflect the tumor microenvironment. We analyzed the associations of serum GDF-15 with clinical characteristics of 73 MM patients (including asymptomatic MM) and the laboratory indices of renal function, anemia, and inflammation. Baseline serum GDF-15 was studied as the predictor of two-year survival. We defined five clinically relevant subgroups of patients (symptomatic MM only, patients with and without remission, patients on chemotherapy, and without treatment). Increased GDF-15 concentrations were associated with more advanced MM stage, anemia, renal impairment (lower glomerular filtration and higher markers of tubular injury), and inflammation. Most of the results were confirmed in the subgroup analysis. Serum cystatin C and urine neutrophil gelatinase-associated lipocalin were associated with GDF-15 independently of other variables. In the studied MM patients, GDF-15 did not significantly predict survival (p = 0.06). Our results suggest that serum GDF-15 reflects myeloma burden and shares a relationship with several markers of prognostic significance, as well as major manifestations.

New Markers of Renal Failure in Multiple Myeloma and Monoclonal Gammopathies.

* Correspondence: kasiajanda@op [...].

Interplay of nitric oxide metabolites and markers of endothelial injury, inflammation, and vascular disease in the spectrum of advanced chronic kidney disease.

BACKGROUND: Chronic kidney disease is linked to cardiovascular morbidity; therefore, relevant biomarkers are widely investigated. AIMS: We aimed to assess the relationship between nitric oxide (as measured by its metabolites, NOx), a key endothelial molecule, with markers of endothelial dysfunction, inflammation, antioxidant status, and mineral disorders as well as histologically assessed vascular calcification in uremic and hemodialysis patients with chronic kidney disease. METHODS: Plasma and serum samples were obtained from 62 patients with renal failure. NOx was assessed by the Griess method, while the other biomarkers were measured by the immunoenzymatic assay. Morphological analysis of arterial calcification was performed in a blinded, semiquantitative manner. Common carotid intima­media thickness and atherosclerotic plaques were assessed by ultrasonography. RESULTS: In the simple analysis, NOx levels correlated positively with the parameters of renal function, mineral metabolism, endothelial injury, and inflammation. NOx predicted carotid intima­media thickness in simple (P = 0.014) and multiple analysis (P = 0.036) adjusted for the Framingham risk score, C­reactive protein, serum creatinine, and parathormone. The occurrence of atherosclerotic plaques in the common carotid artery was correlated with higher NOx concentrations (P = 0.021). CONCLUSIONS: In chronic renal failure, NOx is associated with surrogate markers of atherosclerosis, even after adjustment for traditional cardiovascular risk factors, inflammation, and renal function, but not with the presence or grade of medial arterial calcification. Endothelial injury, inflammation, and mineral metabolism markers are associated with NOx levels, though a causal link requires further study.

New Biomarkers of Ferric Management in Multiple Myeloma and Kidney Disease-Associated Anemia.

Multiple myeloma (MM) is a malignancy of clonal plasma cells accounting for approximately 10% of haematological malignancies. MM mainly affects older patients, more often males and is more frequently seen in African Americans. The most frequent manifestations of MM are anaemia, osteolytic bone lesions, kidney failure and hypercalcemia. The anaemia develops secondary to suppression of erythropoiesis by cytokine networks, similarly to the mechanism of anaemia of chronic disease. The concomitant presence of kidney failure, especially chronic kidney disease (CKD) and MM per se, leading to anaemia of chronic disease (ACD) in combination, provoked us to pose the question about their reciprocal dependence and relationship with specific biomarkers; namely, soluble transferrin receptor (sTfR), growth differentiation factor 15 (GDF15), hepcidin 25 and zonulin. One or more of these are new biomarkers of ferric management may be utilized in the near future as prognostic predictors for patients with MM and kidney failure.

Proteoglycan/glycosaminoglycan and collagen content in the arterial wall of patients with end-stage renal disease: new indicators of vascular disease.

INTRODUCTION: The prevalence of cardiovascular (CV) comorbidity in patients with chronic kidney disease (CKD) is high, particularly in end­stage renal disease (ESRD). There is an ongoing search for novel biomarkers of CV disease in this population. OBJECTIVES: We aimed to investigate the associations of matrix proteoglycans (PGs) and glycosaminoglycans (GAGs), collagen, and arterial calcifications with selected serum and plasma markers of endothelial dysfunction, inflammation, oxidative stress, and bone turnover in patients with ESRD. PATIENTS AND METHODS: We enrolled 47 adult patients (32 men) with stage 5 CKD. The following parameters were investigated: fibrinogen, soluble thrombomodulin (sTM), plasminogen activator inhibitor 1 (PAI­1), stromal cell­derived factor 1α (SDF­1α), calcium (Ca), phosphate (Pi), intact parathormone, interleukin 6, high­sensitivity C­reactive protein (hs­CRP), ferric reducing ability of plasma, 2,2­diphenyl­1­picrylhydrazyl scavenging, ferric reducing ability of ascorbate in plasma, fetuin­A, fibroblast growth factor 23, osteopontin, osteoprotegerin, osteocalcin, transforming growth factor ß (TGF­ß), hepatocyte growth factor, secreted protein acidic and rich in cysteine, as well as matrix metalloproteinase 2. Radial artery specimens were stained with alizarin red for calcifications, alcian blue for PGs and GAGs, and sirius red for collagen. RESULTS: We observed positive correlations between PG and GAG, collagen, and calcification staining. The most intense (grade 3) alcian blue staining was significantly correlated with diabetes as well as higher levels of Ca × Pi product, hs­CRP, fibrinogen, SDF­1α, PAI­1, and sTM. However, PAI­1 was the only significant predictor of grade 3 alcian blue staining in a multiple logistic regression model adjusted for hemodialysis, Ca× Pi product, and hs­CRP levels. CONCLUSIONS: Coagulation disorders and endothelial dysfunction are the hallmarks of ESRD. The levels of SDF­1α, PAI­1, sTM, and fibrinogen may be novel predictors of early vascular wall alterations and may serve as CV risk markers.

Endothelial injury is closely related to osteopontin and TNF receptor-mediated inflammation in end-stage renal disease.

BACKGROUND: Endothelial dysfunction, inflammation and active mineralization are key processes involved in cardiovascular burden in end stage renal disease (ESRD). Serum (soluble) thrombomodulin (sTM) is an established marker of endothelial injury. PATIENTS: 80 patients in ESRD were recruited consecutively. Baseline distribution of sex, age, main comorbidities and Framingham score was similar. A biochemical panel including sTM, intact PTH (iPTH), interleukin-6 (IL-6), pentraxin 3 (PTX3), fibroblast growth factor 23 (FGF-23), osteopontin (OPN), osteoprotegerin (OPG), osteocalcin (OC), osteonectin (ON), soluble tumor necrosis factor receptor type 2 (TNFR2), transforming growth factor-ß (TGF-ß), hepatocyte growth factor (HGF), vascular endothelial growth factor receptor type 2 (sVEGFR2) and stromal cell-derived factor 1α (SDF1α) was investigated in each patient. Samples obtained while establishing haemodialysis (HD) access were stained for radial artery calcifications (RACs) with Alizarin red and examined histologically. RESULTS: After adjustment for HD status, sTM showed a significant positive correlation with serum creatinine, TNFR2, OPN, HGF, SDF1α, sVEGFR2, Pi, iPTH, FGF-23, OPG, OC and ON. In forward stepwise multiple regression, serum creatinine, TNFR2, and OPN were identified as significant, independent predictors of sTM. Grades 1-3 of RACs correlated with sTM (R = 0.50, p = 0.017), while grade 3 RACs were significantly associated with higher sTM (p = 0.02) than less advanced lesions. CONCLUSION: Among novel renal and cardiovascular biomarkers, OPN and TNFR2 are closely related to sTM. This may link endothelial damage, vascular remodeling and inflammation. Progression of RAC parallels a presumed compensatory rise in sTM, reflecting endothelial injury. sTM has an intricate role in endothelial function and potential clinical and prognostic applications.

Neutrophil-to-lymphocyte ratio predicts long-term all-cause mortality in patients with chronic kidney disease stage 5.

INTRODUCTION: A high neutrophil-to-lymphocyte ratio (NLR) has been reported to be a strong biomarker of inflammation. AIM: We sought to evaluate the impact of NLR on long-term all-cause and cardio-vascular (CV) mortality in hemodialysis (HD) patients. MATERIAL AND METHODS: total of 84 chronic kidney disease (CKD) stage 5 patients with 54 of them on HD, with a median age of 61.5 (51.3-74.8) years were enrolled. e association between NLR and clinical biomarkers was investigated. Multivariable Cox regression analysis was used to find significant predictors of all-cause and CV mortality at follow-up. RESULTS: the median NLR (interquartile range) was 3.0 (2.1-4.1). Patients with NLR ≥3.9 (the highest tertile) had higher five-year all-cause mortality then remaining patients (53.6% vs. 30.4%; p = 0.039). On the contrary, only a trend towards increased CV mortality was observed (25.0% vs. 42.9%; p = 0.10). NLR ≥3.9 was a significant predictor of all-cause mortality at five years [hazard ratio (95%CI): 2.23 (1.10-4.50); p = 0.025] in Cox regression model adjusted for age, gender, and diabetes status. Similarly, while using NLR as continuous variable a significant association between NLR and all-cause mortality was confirmed even a er adjustment for covariates [hazard ratio per 1 unit increase (95%CI): 1.26 (1.06-1.51); p = 0.009] with the area under the receiver operating characteristic (ROC) curve of 0.64. Correlations between NLR and WBC, concentration of fibrinogen, albumin were observed. CONCLUSIONS: Asymptomatic inflammation measured by NLR showed an association with long-term all-cause mortality in stage 5 CKD patients, even while white blood cell count was in the normal range.

Elevated Circulating Osteoprotegerin Levels in the Plasma of Hemodialyzed Patients With Severe Artery Calcification.

We studied the correlations between circulating osteoprotegerin (OPG) level and radial artery calcification (RAC) assessed histologically and carotid artery intima-media thickness (CCA-IMT). Moreover, we studied the relationship between OPG levels and all-cause and cardiovascular (CV) mortality during a 5-year observation period. The study comprised 59 CKD patients (36 hemodialyzed (HD), 23 predialysis). The biochemical parameters included: creatinine, calcium, phosphate, intact parathormone, C-reactive protein, interleukin-6, tumor necrosis factor receptor II (TNFRII), transforming growth factor-ß, hepatocyte growth factor, fibroblast growth factor 23, osteonectin (ON), osteopontin, osteoprotegerin, and osteocalcin. CCA-IMT and the presence of atherosclerotic plaques was assessed by ultrasound. Fragments of radial artery obtained during creation of HD access were prepared for microscopy and stained for calcifications with alizarin red. RAC was detected in 34 patients (58%). In multiple regression adjusted for dialysis status, TNFRII, ON and Framingham risk score (FRS) were identified as the independent predictors of OPG. Serum OPG above the median value of 7.55 pmol/L significantly predicted the presence of RAC in simple logistic regression (OR 5.33; 95%CI 1.39-20.4; P = 0.012) and in multiple logistic regression adjusted for FRS, dialysis status and CCA-IMT values (OR 6.56; 95%CI 1.06-40.6; P = 0.036). OPG levels above the median were associated with higher CCA-IMT values (1.02 ± 0.10 vs. 0.86 ± 0.13; P < 0.001) and predicted the presence of atherosclerotic plaques in carotid artery (OR 14.4; 95%CI 2.84-72.9; P < 0.001), independently of FRS, dialysis status and RAC. In this study, elevated serum OPG levels correlated with higher CCA-IMT, the presence of atherosclerotic plaques and the severity of the RAC independently of each other. During follow-up, 25 patients (42%) died, including 21 due to CV causes. In multiple Cox regression, OPG above the median predicted overall survival independently of dialysis status, Framingham risk score, CCA-IMT above the median value, and the presence of atherosclerotic plaques in CCA, but not independently of RAC. We postulate that circulating OPG may play a dual role as a marker for both medial arterial calcification and atherosclerosis, hence it seems to be a valuable tool for assessing CV risk in patients with CKD. OPG might be an early indicator of all-cause mortality in CKD patients with advanced medial arterial calcification.

Asymmetric dimethylarginine as a useful risk marker of radial artery calcification in patients with advanced kidney disease.

INTRODUCTION    Medial arterial calcification is common in patients with chronic kidney disease (CKD) and is considered a risk factor for morbidity and mortality. OBJECTIVES    We aimed to evaluate the correlation between asymmetric dimethylarginine (ADMA) levels, radial artery calcification, and common carotid artery intima-media thickness (CCA­IMT). PATIENTS AND METHODS    The study included 51 patients with CKD, in whom an arteriovenous fistula for hemodialysis access was created to collect radial artery samples for a histological examination, and 33 healthy volunteers, in whom the reference concentrations of ADMA were assessed. The concentrations of creatinine, albumin, calcium, phosphate, fibroblast growth factor 23, osteoprotegerin (OPG), osteopontin (OPN), osteocalcin, secreted protein acidic and rich in cysteine, interleukin 6, interleukin 18, pentraxin 3, stromal cell­derived factor 1α (SDF1α), thrombomodulin, soluble tumor necrosis factor receptor II (sTNFRII), and matrix metalloproteinase 2 (MMP­2) were determined. Radial artery fragments were stained for calcifications using alizarin red. The CCA­IMT was assessed by ultrasonography. RESULTS    Patients with CKD had higher ADMA levels than controls. Patients with ADMA levels above the median were older, had higher levels of phosphate, fibroblast growth factor 23, OPG, OPN, PTX3, sTNFRII, MMP­2, thrombomodulin, and they had more atherosclerotic plaques in the carotid artery. In multiple regression, log­transformed (log)sTNFRII, MMP­2, and SDF1α levels were independent predictors of log(ADMA). Patients with calcifications had higher ADMA levels. A similar correlation was observed between SDF1α and alizarin red staining grades 1 to 3. In logistic regression, ADMA levels positively predicted the presence of calcifications independently of age, hemodialysis status, Framingham risk score, and PTX3. CONCLUSIONS    Circulating ADMA levels indicate medial arterial calcification in patients with CKD.

Pentraxin 3 as a new indicator of cardiovascular­related death in patients with advanced chronic kidney disease.

INTRODUCTION    Pentraxin3 (PTX3) play an important role in the inflammatory response, taking part in recognizing pathogens and damaged tissues. OBJECTIVES    The aim of the study was to assess the relationship between PTX3 levels and all-cause and cardiovascular (CV) mortality in chronic kidney disease (CKD) patients during five-year observation period.  PATIENTS AND METHODS    The study comprised 78 patients (51 hemodialyzed, 27 predialysis). The examined parameters included PTX3, calcium, phosphate, iPTH, interleukin-6 (IL-6), fibroblast growth factor 23 (FGF-23), osteopontin (OPN), osteoprotegerin (OPG), osteocalcin (OC), osteopontin (OPN), osteoprotegerin (OPG), osteocalcin, tumor necrosis factor receptor II (TNF-R II), transforming growth factor-ß (TGF-ß), hepatocyte growth factor (HGF), stromal cell-derived factor α (SDF1α), and thrombomodulin (TM). In a subgroup of 45 patients, fragments of radial artery obtained during creation of hemodialysis access were stained for calcifications. In 51 patients, ultrasonography was performed to assess intima-media thickness (CCA-IMT).  RESULTS    Median serum concentration of PTX3 was 1.43 (0.74-2.50) ng/ml. Higher concentrations of fibrinogen, CRP, IL-6, TNF-R II, TGFß1, HGF, OPN, OPG, FGF-23, TM, SDF1α, lower albumin and uric acid levels were observed in patients with PTX3 above the median. During follow-up, 27 patients (35%) died, including 25 due to CV causes. In contrast to CRP, baseline PTX3 predicted CV mortality independently of classical CV risk factors. Also, PTX3 concentrations significantly predicted mortality after adjustment for age, baseline dialysis status, serum OPG and CRP, radial artery calcifications, and CCA-IMT. CONCLUSIONS    We postulate that PTX3 might be an early marker of CV mortality in patients with advanced CKD yet before the increase of specific marker for systemic inflammation like hsCRP.